Merge pull request #2696 from TheBlueMatt/2023-10-no-chan-feerate-upper-bound
[rust-lightning] / lightning / src / ln / channel.rs
index 3606b04e6c0874155bc79a15ef3fa909f9d02363..f499127bc36116d52a853fd9039d046aa904f34f 100644 (file)
@@ -39,7 +39,7 @@ use crate::chain::transaction::{OutPoint, TransactionData};
 use crate::sign::{EcdsaChannelSigner, WriteableEcdsaChannelSigner, EntropySource, ChannelSigner, SignerProvider, NodeSigner, Recipient};
 use crate::events::ClosureReason;
 use crate::routing::gossip::NodeId;
-use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer, VecWriter};
+use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer};
 use crate::util::logger::Logger;
 use crate::util::errors::APIError;
 use crate::util::config::{UserConfig, ChannelConfig, LegacyChannelConfig, ChannelHandshakeConfig, ChannelHandshakeLimits, MaxDustHTLCExposure};
@@ -48,6 +48,7 @@ use crate::util::scid_utils::scid_from_parts;
 use crate::io;
 use crate::prelude::*;
 use core::{cmp,mem,fmt};
+use core::convert::TryInto;
 use core::ops::Deref;
 #[cfg(any(test, fuzzing, debug_assertions))]
 use crate::sync::Mutex;
@@ -533,6 +534,15 @@ pub(super) struct MonitorRestoreUpdates {
        pub announcement_sigs: Option<msgs::AnnouncementSignatures>,
 }
 
+/// The return value of `signer_maybe_unblocked`
+#[allow(unused)]
+pub(super) struct SignerResumeUpdates {
+       pub commitment_update: Option<msgs::CommitmentUpdate>,
+       pub funding_signed: Option<msgs::FundingSigned>,
+       pub funding_created: Option<msgs::FundingCreated>,
+       pub channel_ready: Option<msgs::ChannelReady>,
+}
+
 /// The return value of `channel_reestablish`
 pub(super) struct ReestablishResponses {
        pub channel_ready: Option<msgs::ChannelReady>,
@@ -749,6 +759,18 @@ pub(super) struct ChannelContext<SP: Deref> where SP::Target: SignerProvider {
        monitor_pending_failures: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
        monitor_pending_finalized_fulfills: Vec<HTLCSource>,
 
+       /// If we went to send a commitment update (ie some messages then [`msgs::CommitmentSigned`])
+       /// but our signer (initially) refused to give us a signature, we should retry at some point in
+       /// the future when the signer indicates it may have a signature for us.
+       ///
+       /// This flag is set in such a case. Note that we don't need to persist this as we'll end up
+       /// setting it again as a side-effect of [`Channel::channel_reestablish`].
+       signer_pending_commitment_update: bool,
+       /// Similar to [`Self::signer_pending_commitment_update`] but we're waiting to send either a
+       /// [`msgs::FundingCreated`] or [`msgs::FundingSigned`] depending on if this channel is
+       /// outbound or inbound.
+       signer_pending_funding: bool,
+
        // pending_update_fee is filled when sending and receiving update_fee.
        //
        // Because it follows the same commitment flow as HTLCs, `FeeUpdateState` is either `Outbound`
@@ -794,6 +816,19 @@ pub(super) struct ChannelContext<SP: Deref> where SP::Target: SignerProvider {
        #[cfg(not(test))]
        closing_fee_limits: Option<(u64, u64)>,
 
+       /// If we remove an HTLC (or fee update), commit, and receive our counterparty's
+       /// `revoke_and_ack`, we remove all knowledge of said HTLC (or fee update). However, the latest
+       /// local commitment transaction that we can broadcast still contains the HTLC (or old fee)
+       /// until we receive a further `commitment_signed`. Thus we are not eligible for initiating the
+       /// `closing_signed` negotiation if we're expecting a counterparty `commitment_signed`.
+       ///
+       /// To ensure we don't send a `closing_signed` too early, we track this state here, waiting
+       /// until we see a `commitment_signed` before doing so.
+       ///
+       /// We don't bother to persist this - we anticipate this state won't last longer than a few
+       /// milliseconds, so any accidental force-closes here should be exceedingly rare.
+       expecting_peer_commitment_signed: bool,
+
        /// The hash of the block in which the funding transaction was included.
        funding_tx_confirmed_in: Option<BlockHash>,
        funding_tx_confirmation_height: u32,
@@ -1056,6 +1091,12 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                self.outbound_scid_alias
        }
 
+       /// Returns the holder signer for this channel.
+       #[cfg(test)]
+       pub fn get_signer(&self) -> &ChannelSignerType<<SP::Target as SignerProvider>::Signer> {
+               return &self.holder_signer
+       }
+
        /// Only allowed immediately after deserialization if get_outbound_scid_alias returns 0,
        /// indicating we were written by LDK prior to 0.0.106 which did not set outbound SCID aliases
        /// or prior to any channel actions during `Channel` initialization.
@@ -1168,8 +1209,8 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                match self.config.options.max_dust_htlc_exposure {
                        MaxDustHTLCExposure::FeeRateMultiplier(multiplier) => {
                                let feerate_per_kw = fee_estimator.bounded_sat_per_1000_weight(
-                                       ConfirmationTarget::OnChainSweep);
-                               feerate_per_kw as u64 * multiplier
+                                       ConfirmationTarget::OnChainSweep) as u64;
+                               feerate_per_kw.saturating_mul(multiplier)
                        },
                        MaxDustHTLCExposure::FixedLimitMsat(limit) => limit,
                }
@@ -1753,14 +1794,14 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                         context.holder_dust_limit_satoshis       + dust_buffer_feerate * htlc_timeout_tx_weight(context.get_channel_type()) / 1000)
                };
                let on_counterparty_dust_htlc_exposure_msat = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat;
-               if on_counterparty_dust_htlc_exposure_msat as i64 + htlc_success_dust_limit as i64 * 1000 - 1 > max_dust_htlc_exposure_msat as i64 {
+               if on_counterparty_dust_htlc_exposure_msat as i64 + htlc_success_dust_limit as i64 * 1000 - 1 > max_dust_htlc_exposure_msat.try_into().unwrap_or(i64::max_value()) {
                        remaining_msat_below_dust_exposure_limit =
                                Some(max_dust_htlc_exposure_msat.saturating_sub(on_counterparty_dust_htlc_exposure_msat));
                        dust_exposure_dust_limit_msat = cmp::max(dust_exposure_dust_limit_msat, htlc_success_dust_limit * 1000);
                }
 
                let on_holder_dust_htlc_exposure_msat = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat;
-               if on_holder_dust_htlc_exposure_msat as i64 + htlc_timeout_dust_limit as i64 * 1000 - 1 > max_dust_htlc_exposure_msat as i64 {
+               if on_holder_dust_htlc_exposure_msat as i64 + htlc_timeout_dust_limit as i64 * 1000 - 1 > max_dust_htlc_exposure_msat.try_into().unwrap_or(i64::max_value()) {
                        remaining_msat_below_dust_exposure_limit = Some(cmp::min(
                                remaining_msat_below_dust_exposure_limit.unwrap_or(u64::max_value()),
                                max_dust_htlc_exposure_msat.saturating_sub(on_holder_dust_htlc_exposure_msat)));
@@ -2079,6 +2120,71 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                        unbroadcasted_batch_funding_txid,
                }
        }
+
+       /// Only allowed after [`Self::channel_transaction_parameters`] is set.
+       fn get_funding_created_msg<L: Deref>(&mut self, logger: &L) -> Option<msgs::FundingCreated> where L::Target: Logger {
+               let counterparty_keys = self.build_remote_transaction_keys();
+               let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
+               let signature = match &self.holder_signer {
+                       // TODO (taproot|arik): move match into calling method for Taproot
+                       ChannelSignerType::Ecdsa(ecdsa) => {
+                               ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.secp_ctx)
+                                       .map(|(sig, _)| sig).ok()?
+                       }
+               };
+
+               if self.signer_pending_funding {
+                       log_trace!(logger, "Counterparty commitment signature ready for funding_created message: clearing signer_pending_funding");
+                       self.signer_pending_funding = false;
+               }
+
+               Some(msgs::FundingCreated {
+                       temporary_channel_id: self.temporary_channel_id.unwrap(),
+                       funding_txid: self.channel_transaction_parameters.funding_outpoint.as_ref().unwrap().txid,
+                       funding_output_index: self.channel_transaction_parameters.funding_outpoint.as_ref().unwrap().index,
+                       signature,
+                       #[cfg(taproot)]
+                       partial_signature_with_nonce: None,
+                       #[cfg(taproot)]
+                       next_local_nonce: None,
+               })
+       }
+
+       /// Only allowed after [`Self::channel_transaction_parameters`] is set.
+       fn get_funding_signed_msg<L: Deref>(&mut self, logger: &L) -> (CommitmentTransaction, Option<msgs::FundingSigned>) where L::Target: Logger {
+               let counterparty_keys = self.build_remote_transaction_keys();
+               let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number + 1, &counterparty_keys, false, false, logger).tx;
+
+               let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
+               let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
+               log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}",
+                       &self.channel_id(), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));
+
+               match &self.holder_signer {
+                       // TODO (arik): move match into calling method for Taproot
+                       ChannelSignerType::Ecdsa(ecdsa) => {
+                               let funding_signed = ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.secp_ctx)
+                                       .map(|(signature, _)| msgs::FundingSigned {
+                                               channel_id: self.channel_id(),
+                                               signature,
+                                               #[cfg(taproot)]
+                                               partial_signature_with_nonce: None,
+                                       })
+                                       .ok();
+
+                               if funding_signed.is_none() {
+                                       log_trace!(logger, "Counterparty commitment signature not available for funding_signed message; setting signer_pending_funding");
+                                       self.signer_pending_funding = true;
+                               } else if self.signer_pending_funding {
+                                       log_trace!(logger, "Counterparty commitment signature available for funding_signed message; clearing signer_pending_funding");
+                                       self.signer_pending_funding = false;
+                               }
+
+                               // We sign "counterparty" commitment transaction, allowing them to broadcast the tx if they wish.
+                               (counterparty_initial_commitment_tx, funding_signed)
+                       }
+               }
+       }
 }
 
 // Internal utility functions for channels
@@ -3142,6 +3248,7 @@ impl<SP: Deref> Channel<SP> where
                };
 
                self.context.cur_holder_commitment_transaction_number -= 1;
+               self.context.expecting_peer_commitment_signed = false;
                // Note that if we need_commitment & !AwaitingRemoteRevoke we'll call
                // build_commitment_no_status_check() next which will reset this to RAAFirst.
                self.context.resend_order = RAACommitmentOrder::CommitmentFirst;
@@ -3152,8 +3259,8 @@ impl<SP: Deref> Channel<SP> where
                        self.context.monitor_pending_revoke_and_ack = true;
                        if need_commitment && (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 {
                                // If we were going to send a commitment_signed after the RAA, go ahead and do all
-                               // the corresponding HTLC status updates so that get_last_commitment_update
-                               // includes the right HTLCs.
+                               // the corresponding HTLC status updates so that
+                               // get_last_commitment_update_for_send includes the right HTLCs.
                                self.context.monitor_pending_commitment_signed = true;
                                let mut additional_update = self.build_commitment_no_status_check(logger);
                                // build_commitment_no_status_check may bump latest_monitor_id but we want them to be
@@ -3407,6 +3514,7 @@ impl<SP: Deref> Channel<SP> where
                        // Take references explicitly so that we can hold multiple references to self.context.
                        let pending_inbound_htlcs: &mut Vec<_> = &mut self.context.pending_inbound_htlcs;
                        let pending_outbound_htlcs: &mut Vec<_> = &mut self.context.pending_outbound_htlcs;
+                       let expecting_peer_commitment_signed = &mut self.context.expecting_peer_commitment_signed;
 
                        // We really shouldnt have two passes here, but retain gives a non-mutable ref (Rust bug)
                        pending_inbound_htlcs.retain(|htlc| {
@@ -3415,6 +3523,7 @@ impl<SP: Deref> Channel<SP> where
                                        if let &InboundHTLCRemovalReason::Fulfill(_) = reason {
                                                value_to_self_msat_diff += htlc.amount_msat as i64;
                                        }
+                                       *expecting_peer_commitment_signed = true;
                                        false
                                } else { true }
                        });
@@ -3474,6 +3583,7 @@ impl<SP: Deref> Channel<SP> where
                                if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
                                        log_trace!(logger, " ...promoting outbound LocalAnnounced {} to Committed", &htlc.payment_hash);
                                        htlc.state = OutboundHTLCState::Committed;
+                                       *expecting_peer_commitment_signed = true;
                                }
                                if let &mut OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref mut outcome) = &mut htlc.state {
                                        log_trace!(logger, " ...promoting outbound AwaitingRemoteRevokeToRemove {} to AwaitingRemovedRemoteRevoke", &htlc.payment_hash);
@@ -3494,6 +3604,7 @@ impl<SP: Deref> Channel<SP> where
                                        log_trace!(logger, " ...promoting outbound fee update {} to Committed", feerate);
                                        self.context.feerate_per_kw = feerate;
                                        self.context.pending_update_fee = None;
+                                       self.context.expecting_peer_commitment_signed = true;
                                },
                                FeeUpdateState::RemoteAnnounced => { debug_assert!(!self.context.is_outbound()); },
                                FeeUpdateState::AwaitingRemoteRevokeToAnnounce => {
@@ -3527,9 +3638,10 @@ impl<SP: Deref> Channel<SP> where
                        // cells) while we can't update the monitor, so we just return what we have.
                        if require_commitment {
                                self.context.monitor_pending_commitment_signed = true;
-                               // When the monitor updating is restored we'll call get_last_commitment_update(),
-                               // which does not update state, but we're definitely now awaiting a remote revoke
-                               // before we can step forward any more, so set it here.
+                               // When the monitor updating is restored we'll call
+                               // get_last_commitment_update_for_send(), which does not update state, but we're
+                               // definitely now awaiting a remote revoke before we can step forward any more, so
+                               // set it here.
                                let mut additional_update = self.build_commitment_no_status_check(logger);
                                // build_commitment_no_status_check may bump latest_monitor_id but we want them to be
                                // strictly increasing by one, so decrement it here.
@@ -3832,9 +3944,11 @@ impl<SP: Deref> Channel<SP> where
                        Some(self.get_last_revoke_and_ack())
                } else { None };
                let commitment_update = if self.context.monitor_pending_commitment_signed {
-                       self.mark_awaiting_response();
-                       Some(self.get_last_commitment_update(logger))
+                       self.get_last_commitment_update_for_send(logger).ok()
                } else { None };
+               if commitment_update.is_some() {
+                       self.mark_awaiting_response();
+               }
 
                self.context.monitor_pending_revoke_and_ack = false;
                self.context.monitor_pending_commitment_signed = false;
@@ -3880,6 +3994,37 @@ impl<SP: Deref> Channel<SP> where
                Ok(())
        }
 
+       /// Indicates that the signer may have some signatures for us, so we should retry if we're
+       /// blocked.
+       #[allow(unused)]
+       pub fn signer_maybe_unblocked<L: Deref>(&mut self, logger: &L) -> SignerResumeUpdates where L::Target: Logger {
+               let commitment_update = if self.context.signer_pending_commitment_update {
+                       self.get_last_commitment_update_for_send(logger).ok()
+               } else { None };
+               let funding_signed = if self.context.signer_pending_funding && !self.context.is_outbound() {
+                       self.context.get_funding_signed_msg(logger).1
+               } else { None };
+               let channel_ready = if funding_signed.is_some() {
+                       self.check_get_channel_ready(0)
+               } else { None };
+               let funding_created = if self.context.signer_pending_funding && self.context.is_outbound() {
+                       self.context.get_funding_created_msg(logger)
+               } else { None };
+
+               log_trace!(logger, "Signer unblocked with {} commitment_update, {} funding_signed, {} funding_created, and {} channel_ready",
+                       if commitment_update.is_some() { "a" } else { "no" },
+                       if funding_signed.is_some() { "a" } else { "no" },
+                       if funding_created.is_some() { "a" } else { "no" },
+                       if channel_ready.is_some() { "a" } else { "no" });
+
+               SignerResumeUpdates {
+                       commitment_update,
+                       funding_signed,
+                       funding_created,
+                       channel_ready,
+               }
+       }
+
        fn get_last_revoke_and_ack(&self) -> msgs::RevokeAndACK {
                let next_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 per_commitment_secret = self.context.holder_signer.as_ref().release_commitment_secret(self.context.cur_holder_commitment_transaction_number + 2);
@@ -3892,7 +4037,8 @@ impl<SP: Deref> Channel<SP> where
                }
        }
 
-       fn get_last_commitment_update<L: Deref>(&self, logger: &L) -> msgs::CommitmentUpdate where L::Target: Logger {
+       /// Gets the last commitment update for immediate sending to our peer.
+       fn get_last_commitment_update_for_send<L: Deref>(&mut self, logger: &L) -> Result<msgs::CommitmentUpdate, ()> where L::Target: Logger {
                let mut update_add_htlcs = Vec::new();
                let mut update_fulfill_htlcs = Vec::new();
                let mut update_fail_htlcs = Vec::new();
@@ -3948,13 +4094,26 @@ impl<SP: Deref> Channel<SP> where
                        })
                } else { None };
 
-               log_trace!(logger, "Regenerated latest commitment update in channel {} with{} {} update_adds, {} update_fulfills, {} update_fails, and {} update_fail_malformeds",
+               log_trace!(logger, "Regenerating latest commitment update in channel {} with{} {} update_adds, {} update_fulfills, {} update_fails, and {} update_fail_malformeds",
                                &self.context.channel_id(), if update_fee.is_some() { " update_fee," } else { "" },
                                update_add_htlcs.len(), update_fulfill_htlcs.len(), update_fail_htlcs.len(), update_fail_malformed_htlcs.len());
-               msgs::CommitmentUpdate {
+               let commitment_signed = if let Ok(update) = self.send_commitment_no_state_update(logger).map(|(cu, _)| cu) {
+                       if self.context.signer_pending_commitment_update {
+                               log_trace!(logger, "Commitment update generated: clearing signer_pending_commitment_update");
+                               self.context.signer_pending_commitment_update = false;
+                       }
+                       update
+               } else {
+                       if !self.context.signer_pending_commitment_update {
+                               log_trace!(logger, "Commitment update awaiting signer: setting signer_pending_commitment_update");
+                               self.context.signer_pending_commitment_update = true;
+                       }
+                       return Err(());
+               };
+               Ok(msgs::CommitmentUpdate {
                        update_add_htlcs, update_fulfill_htlcs, update_fail_htlcs, update_fail_malformed_htlcs, update_fee,
-                       commitment_signed: self.send_commitment_no_state_update(logger).expect("It looks like we failed to re-generate a commitment_signed we had previously sent?").0,
-               }
+                       commitment_signed,
+               })
        }
 
        /// Gets the `Shutdown` message we should send our peer on reconnect, if any.
@@ -4134,7 +4293,7 @@ impl<SP: Deref> Channel<SP> where
                                Ok(ReestablishResponses {
                                        channel_ready, shutdown_msg, announcement_sigs,
                                        raa: required_revoke,
-                                       commitment_update: Some(self.get_last_commitment_update(logger)),
+                                       commitment_update: self.get_last_commitment_update_for_send(logger).ok(),
                                        order: self.context.resend_order.clone(),
                                })
                        }
@@ -4223,6 +4382,10 @@ impl<SP: Deref> Channel<SP> where
                -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>, Option<ShutdownResult>), ChannelError>
                where F::Target: FeeEstimator, L::Target: Logger
        {
+               // If we're waiting on a monitor persistence, that implies we're also waiting to send some
+               // message to our counterparty (probably a `revoke_and_ack`). In such a case, we shouldn't
+               // initiate `closing_signed` negotiation until we're clear of all pending messages. Note
+               // that closing_negotiation_ready checks this case (as well as a few others).
                if self.context.last_sent_closing_fee.is_some() || !self.closing_negotiation_ready() {
                        return Ok((None, None, None));
                }
@@ -4234,6 +4397,12 @@ impl<SP: Deref> Channel<SP> where
                        return Ok((None, None, None));
                }
 
+               // If we're waiting on a counterparty `commitment_signed` to clear some updates from our
+               // local commitment transaction, we can't yet initiate `closing_signed` negotiation.
+               if self.context.expecting_peer_commitment_signed {
+                       return Ok((None, None, None));
+               }
+
                let (our_min_fee, our_max_fee) = self.calculate_closing_fee_limits(fee_estimator);
 
                assert!(self.context.shutdown_scriptpubkey.is_some());
@@ -4775,6 +4944,12 @@ impl<SP: Deref> Channel<SP> where
                        return None;
                }
 
+               // If we're still pending the signature on a funding transaction, then we're not ready to send a
+               // channel_ready yet.
+               if self.context.signer_pending_funding {
+                       return None;
+               }
+
                // Note that we don't include ChannelState::WaitingForBatch as we don't want to send
                // channel_ready until the entire batch is ready.
                let non_shutdown_state = self.context.channel_state & (!MULTI_STATE_FLAGS);
@@ -5508,7 +5683,7 @@ impl<SP: Deref> Channel<SP> where
                                        }
 
                                        let res = ecdsa.sign_counterparty_commitment(&commitment_stats.tx, commitment_stats.preimages, &self.context.secp_ctx)
-                                               .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?;
+                                               .map_err(|_| ChannelError::Ignore("Failed to get signatures for new commitment_signed".to_owned()))?;
                                        signature = res.0;
                                        htlc_signatures = res.1;
 
@@ -5713,7 +5888,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
        pub fn new<ES: Deref, F: Deref>(
                fee_estimator: &LowerBoundedFeeEstimator<F>, entropy_source: &ES, signer_provider: &SP, counterparty_node_id: PublicKey, their_features: &InitFeatures,
                channel_value_satoshis: u64, push_msat: u64, user_id: u128, config: &UserConfig, current_chain_height: u32,
-               outbound_scid_alias: u64
+               outbound_scid_alias: u64, temporary_channel_id: Option<ChannelId>
        ) -> Result<OutboundV1Channel<SP>, APIError>
        where ES::Target: EntropySource,
              F::Target: FeeEstimator
@@ -5780,7 +5955,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                        Err(_) => return Err(APIError::ChannelUnavailable { err: "Failed to get destination script".to_owned()}),
                };
 
-               let temporary_channel_id = ChannelId::temporary_from_entropy_source(entropy_source);
+               let temporary_channel_id = temporary_channel_id.unwrap_or_else(|| ChannelId::temporary_from_entropy_source(entropy_source));
 
                Ok(Self {
                        context: ChannelContext {
@@ -5831,6 +6006,9 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                                monitor_pending_failures: Vec::new(),
                                monitor_pending_finalized_fulfills: Vec::new(),
 
+                               signer_pending_commitment_update: false,
+                               signer_pending_funding: false,
+
                                #[cfg(debug_assertions)]
                                holder_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)),
                                #[cfg(debug_assertions)]
@@ -5838,6 +6016,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 
                                last_sent_closing_fee: None,
                                pending_counterparty_closing_signed: None,
+                               expecting_peer_commitment_signed: false,
                                closing_fee_limits: None,
                                target_closing_feerate_sats_per_kw: None,
 
@@ -5911,19 +6090,6 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                })
        }
 
-       /// If an Err is returned, it is a ChannelError::Close (for get_funding_created)
-       fn get_funding_created_signature<L: Deref>(&mut self, logger: &L) -> Result<Signature, ChannelError> where L::Target: Logger {
-               let counterparty_keys = self.context.build_remote_transaction_keys();
-               let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
-               match &self.context.holder_signer {
-                       // TODO (taproot|arik): move match into calling method for Taproot
-                       ChannelSignerType::Ecdsa(ecdsa) => {
-                               Ok(ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.context.secp_ctx)
-                                       .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0)
-                       }
-               }
-       }
-
        /// Updates channel state with knowledge of the funding transaction's txid/index, and generates
        /// a funding_created message for the remote peer.
        /// Panics if called at some time other than immediately after initial handshake, if called twice,
@@ -5932,7 +6098,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
        /// Do NOT broadcast the funding transaction until after a successful funding_signed call!
        /// If an Err is returned, it is a ChannelError::Close.
        pub fn get_funding_created<L: Deref>(mut self, funding_transaction: Transaction, funding_txo: OutPoint, is_batch_funding: bool, logger: &L)
-       -> Result<(Channel<SP>, msgs::FundingCreated), (Self, ChannelError)> where L::Target: Logger {
+       -> Result<(Channel<SP>, Option<msgs::FundingCreated>), (Self, ChannelError)> where L::Target: Logger {
                if !self.context.is_outbound() {
                        panic!("Tried to create outbound funding_created message on an inbound channel!");
                }
@@ -5948,17 +6114,6 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                self.context.channel_transaction_parameters.funding_outpoint = Some(funding_txo);
                self.context.holder_signer.as_mut().provide_channel_parameters(&self.context.channel_transaction_parameters);
 
-               let signature = match self.get_funding_created_signature(logger) {
-                       Ok(res) => res,
-                       Err(e) => {
-                               log_error!(logger, "Got bad signatures: {:?}!", e);
-                               self.context.channel_transaction_parameters.funding_outpoint = None;
-                               return Err((self, e));
-                       }
-               };
-
-               let temporary_channel_id = self.context.channel_id;
-
                // Now that we're past error-generating stuff, update our local state:
 
                self.context.channel_state = ChannelState::FundingCreated as u32;
@@ -5975,20 +6130,19 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                self.context.funding_transaction = Some(funding_transaction);
                self.context.is_batch_funding = Some(()).filter(|_| is_batch_funding);
 
+               let funding_created = self.context.get_funding_created_msg(logger);
+               if funding_created.is_none() {
+                       if !self.context.signer_pending_funding {
+                               log_trace!(logger, "funding_created awaiting signer; setting signer_pending_funding");
+                               self.context.signer_pending_funding = true;
+                       }
+               }
+
                let channel = Channel {
                        context: self.context,
                };
 
-               Ok((channel, msgs::FundingCreated {
-                       temporary_channel_id,
-                       funding_txid: funding_txo.txid,
-                       funding_output_index: funding_txo.index,
-                       signature,
-                       #[cfg(taproot)]
-                       partial_signature_with_nonce: None,
-                       #[cfg(taproot)]
-                       next_local_nonce: None,
-               }))
+               Ok((channel, funding_created))
        }
 
        fn get_initial_channel_type(config: &UserConfig, their_features: &InitFeatures) -> ChannelTypeFeatures {
@@ -6485,6 +6639,9 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                                monitor_pending_failures: Vec::new(),
                                monitor_pending_finalized_fulfills: Vec::new(),
 
+                               signer_pending_commitment_update: false,
+                               signer_pending_funding: false,
+
                                #[cfg(debug_assertions)]
                                holder_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)),
                                #[cfg(debug_assertions)]
@@ -6492,6 +6649,7 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 
                                last_sent_closing_fee: None,
                                pending_counterparty_closing_signed: None,
+                               expecting_peer_commitment_signed: false,
                                closing_fee_limits: None,
                                target_closing_feerate_sats_per_kw: None,
 
@@ -6632,46 +6790,27 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                self.generate_accept_channel_message()
        }
 
-       fn funding_created_signature<L: Deref>(&mut self, sig: &Signature, logger: &L) -> Result<(CommitmentTransaction, CommitmentTransaction, Signature), ChannelError> where L::Target: Logger {
+       fn check_funding_created_signature<L: Deref>(&mut self, sig: &Signature, logger: &L) -> Result<CommitmentTransaction, ChannelError> where L::Target: Logger {
                let funding_script = self.context.get_funding_redeemscript();
 
                let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number);
                let initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, false, logger).tx;
-               {
-                       let trusted_tx = initial_commitment_tx.trust();
-                       let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
-                       let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis);
-                       // They sign the holder commitment transaction...
-                       log_trace!(logger, "Checking funding_created tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} for channel {}.",
-                               log_bytes!(sig.serialize_compact()[..]), log_bytes!(self.context.counterparty_funding_pubkey().serialize()),
-                               encode::serialize_hex(&initial_commitment_bitcoin_tx.transaction), log_bytes!(sighash[..]),
-                               encode::serialize_hex(&funding_script), &self.context.channel_id());
-                       secp_check!(self.context.secp_ctx.verify_ecdsa(&sighash, &sig, self.context.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
-               }
-
-               let counterparty_keys = self.context.build_remote_transaction_keys();
-               let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
+               let trusted_tx = initial_commitment_tx.trust();
+               let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
+               let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis);
+               // They sign the holder commitment transaction...
+               log_trace!(logger, "Checking funding_created tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} for channel {}.",
+                       log_bytes!(sig.serialize_compact()[..]), log_bytes!(self.context.counterparty_funding_pubkey().serialize()),
+                       encode::serialize_hex(&initial_commitment_bitcoin_tx.transaction), log_bytes!(sighash[..]),
+                       encode::serialize_hex(&funding_script), &self.context.channel_id());
+               secp_check!(self.context.secp_ctx.verify_ecdsa(&sighash, &sig, self.context.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
 
-               let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
-               let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
-               log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}",
-                       &self.context.channel_id(), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));
-
-               match &self.context.holder_signer {
-                       // TODO (arik): move match into calling method for Taproot
-                       ChannelSignerType::Ecdsa(ecdsa) => {
-                               let counterparty_signature = ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.context.secp_ctx)
-                                       .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0;
-
-                               // We sign "counterparty" commitment transaction, allowing them to broadcast the tx if they wish.
-                               Ok((counterparty_initial_commitment_tx, initial_commitment_tx, counterparty_signature))
-                       }
-               }
+               Ok(initial_commitment_tx)
        }
 
        pub fn funding_created<L: Deref>(
                mut self, msg: &msgs::FundingCreated, best_block: BestBlock, signer_provider: &SP, logger: &L
-       ) -> Result<(Channel<SP>, msgs::FundingSigned, ChannelMonitor<<SP::Target as SignerProvider>::Signer>), (Self, ChannelError)>
+       ) -> Result<(Channel<SP>, Option<msgs::FundingSigned>, ChannelMonitor<<SP::Target as SignerProvider>::Signer>), (Self, ChannelError)>
        where
                L::Target: Logger
        {
@@ -6693,10 +6832,10 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                let funding_txo = OutPoint { txid: msg.funding_txid, index: msg.funding_output_index };
                self.context.channel_transaction_parameters.funding_outpoint = Some(funding_txo);
                // This is an externally observable change before we finish all our checks.  In particular
-               // funding_created_signature may fail.
+               // check_funding_created_signature may fail.
                self.context.holder_signer.as_mut().provide_channel_parameters(&self.context.channel_transaction_parameters);
 
-               let (counterparty_initial_commitment_tx, initial_commitment_tx, signature) = match self.funding_created_signature(&msg.signature, logger) {
+               let initial_commitment_tx = match self.check_funding_created_signature(&msg.signature, logger) {
                        Ok(res) => res,
                        Err(ChannelError::Close(e)) => {
                                self.context.channel_transaction_parameters.funding_outpoint = None;
@@ -6705,7 +6844,7 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                        Err(e) => {
                                // The only error we know how to handle is ChannelError::Close, so we fall over here
                                // to make sure we don't continue with an inconsistent state.
-                               panic!("unexpected error type from funding_created_signature {:?}", e);
+                               panic!("unexpected error type from check_funding_created_signature {:?}", e);
                        }
                };
 
@@ -6723,6 +6862,13 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 
                // Now that we're past error-generating stuff, update our local state:
 
+               self.context.channel_state = ChannelState::FundingSent as u32;
+               self.context.channel_id = funding_txo.to_channel_id();
+               self.context.cur_counterparty_commitment_transaction_number -= 1;
+               self.context.cur_holder_commitment_transaction_number -= 1;
+
+               let (counterparty_initial_commitment_tx, funding_signed) = self.context.get_funding_signed_msg(logger);
+
                let funding_redeemscript = self.context.get_funding_redeemscript();
                let funding_txo_script = funding_redeemscript.to_v0_p2wsh();
                let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.context.get_holder_pubkeys().payment_point, &self.context.get_counterparty_pubkeys().payment_point, self.context.is_outbound());
@@ -6739,38 +6885,28 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 
                channel_monitor.provide_initial_counterparty_commitment_tx(
                        counterparty_initial_commitment_tx.trust().txid(), Vec::new(),
-                       self.context.cur_counterparty_commitment_transaction_number,
+                       self.context.cur_counterparty_commitment_transaction_number + 1,
                        self.context.counterparty_cur_commitment_point.unwrap(), self.context.feerate_per_kw,
                        counterparty_initial_commitment_tx.to_broadcaster_value_sat(),
                        counterparty_initial_commitment_tx.to_countersignatory_value_sat(), logger);
 
-               self.context.channel_state = ChannelState::FundingSent as u32;
-               self.context.channel_id = funding_txo.to_channel_id();
-               self.context.cur_counterparty_commitment_transaction_number -= 1;
-               self.context.cur_holder_commitment_transaction_number -= 1;
-
-               log_info!(logger, "Generated funding_signed for peer for channel {}", &self.context.channel_id());
+               log_info!(logger, "{} funding_signed for peer for channel {}",
+                       if funding_signed.is_some() { "Generated" } else { "Waiting for signature on" }, &self.context.channel_id());
 
                // Promote the channel to a full-fledged one now that we have updated the state and have a
                // `ChannelMonitor`.
                let mut channel = Channel {
                        context: self.context,
                };
-               let channel_id = channel.context.channel_id.clone();
                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());
 
-               Ok((channel, msgs::FundingSigned {
-                       channel_id,
-                       signature,
-                       #[cfg(taproot)]
-                       partial_signature_with_nonce: None,
-               }, channel_monitor))
+               Ok((channel, funding_signed, channel_monitor))
        }
 }
 
 const SERIALIZATION_VERSION: u8 = 3;
-const MIN_SERIALIZATION_VERSION: u8 = 2;
+const MIN_SERIALIZATION_VERSION: u8 = 3;
 
 impl_writeable_tlv_based_enum!(InboundHTLCRemovalReason,;
        (0, FailRelay),
@@ -6850,14 +6986,6 @@ impl<SP: Deref> Writeable for Channel<SP> where SP::Target: SignerProvider {
 
                self.context.latest_monitor_update_id.write(writer)?;
 
-               let mut key_data = VecWriter(Vec::new());
-               // TODO (taproot|arik): Introduce serialization distinction for non-ECDSA signers.
-               self.context.holder_signer.as_ecdsa().expect("Only ECDSA signers may be serialized").write(&mut key_data)?;
-               assert!(key_data.0.len() < core::usize::MAX);
-               assert!(key_data.0.len() < core::u32::MAX as usize);
-               (key_data.0.len() as u32).write(writer)?;
-               writer.write_all(&key_data.0[..])?;
-
                // Write out the old serialization for shutdown_pubkey for backwards compatibility, if
                // deserialized from that format.
                match self.context.shutdown_scriptpubkey.as_ref().and_then(|script| script.as_legacy_pubkey()) {
@@ -7576,6 +7704,9 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
                                monitor_pending_failures,
                                monitor_pending_finalized_fulfills: monitor_pending_finalized_fulfills.unwrap(),
 
+                               signer_pending_commitment_update: false,
+                               signer_pending_funding: false,
+
                                pending_update_fee,
                                holding_cell_update_fee,
                                next_holder_htlc_id,
@@ -7590,6 +7721,7 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
 
                                last_sent_closing_fee: None,
                                pending_counterparty_closing_signed: None,
+                               expecting_peer_commitment_signed: false,
                                closing_fee_limits: None,
                                target_closing_feerate_sats_per_kw,
 
@@ -7765,7 +7897,7 @@ mod tests {
                let secp_ctx = Secp256k1::new();
                let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
-               match OutboundV1Channel::<&TestKeysInterface>::new(&LowerBoundedFeeEstimator::new(&TestFeeEstimator { fee_est: 253 }), &&keys_provider, &&keys_provider, node_id, &features, 10000000, 100000, 42, &config, 0, 42) {
+               match OutboundV1Channel::<&TestKeysInterface>::new(&LowerBoundedFeeEstimator::new(&TestFeeEstimator { fee_est: 253 }), &&keys_provider, &&keys_provider, node_id, &features, 10000000, 100000, 42, &config, 0, 42, None) {
                        Err(APIError::IncompatibleShutdownScript { script }) => {
                                assert_eq!(script.into_inner(), non_v0_segwit_shutdown_script.into_inner());
                        },
@@ -7788,7 +7920,7 @@ mod tests {
 
                let node_a_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
-               let node_a_chan = OutboundV1Channel::<&TestKeysInterface>::new(&bounded_fee_estimator, &&keys_provider, &&keys_provider, node_a_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let node_a_chan = OutboundV1Channel::<&TestKeysInterface>::new(&bounded_fee_estimator, &&keys_provider, &&keys_provider, node_a_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).unwrap();
 
                // Now change the fee so we can check that the fee in the open_channel message is the
                // same as the old fee.
@@ -7815,7 +7947,7 @@ mod tests {
                // Create Node A's channel pointing to Node B's pubkey
                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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut node_a_chan = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).unwrap();
 
                // Create Node B's channel by receiving Node A's open_channel message
                // Make sure A's dust limit is as we expect.
@@ -7836,10 +7968,10 @@ mod tests {
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let (mut node_a_chan, funding_created_msg) = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, false, &&logger).map_err(|_| ()).unwrap();
-               let (_, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
+               let (_, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg.unwrap(), best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
 
                // Node B --> Node A: funding signed
-               let _ = node_a_chan.funding_signed(&funding_signed_msg, best_block, &&keys_provider, &&logger).unwrap();
+               let _ = node_a_chan.funding_signed(&funding_signed_msg.unwrap(), best_block, &&keys_provider, &&logger).unwrap();
 
                // Put some inbound and outbound HTLCs in A's channel.
                let htlc_amount_msat = 11_092_000; // put an amount below A's effective dust limit but above B's.
@@ -7896,7 +8028,7 @@ mod tests {
 
                let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
-               let mut chan = OutboundV1Channel::<&TestKeysInterface>::new(&fee_est, &&keys_provider, &&keys_provider, node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut chan = OutboundV1Channel::<&TestKeysInterface>::new(&fee_est, &&keys_provider, &&keys_provider, node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).unwrap();
 
                let commitment_tx_fee_0_htlcs = commit_tx_fee_msat(chan.context.feerate_per_kw, 0, chan.context.get_channel_type());
                let commitment_tx_fee_1_htlc = commit_tx_fee_msat(chan.context.feerate_per_kw, 1, chan.context.get_channel_type());
@@ -7945,7 +8077,7 @@ mod tests {
                // Create Node A's channel pointing to Node B's pubkey
                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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut node_a_chan = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).unwrap();
 
                // Create Node B's channel by receiving Node A's open_channel message
                let open_channel_msg = node_a_chan.get_open_channel(chain_hash);
@@ -7963,10 +8095,10 @@ mod tests {
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let (mut node_a_chan, funding_created_msg) = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, false, &&logger).map_err(|_| ()).unwrap();
-               let (mut node_b_chan, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
+               let (mut node_b_chan, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg.unwrap(), best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
 
                // Node B --> Node A: funding signed
-               let _ = node_a_chan.funding_signed(&funding_signed_msg, best_block, &&keys_provider, &&logger).unwrap();
+               let _ = node_a_chan.funding_signed(&funding_signed_msg.unwrap(), best_block, &&keys_provider, &&logger).unwrap();
 
                // Now disconnect the two nodes and check that the commitment point in
                // Node B's channel_reestablish message is sane.
@@ -8008,12 +8140,12 @@ mod tests {
                // Test that `OutboundV1Channel::new` creates a channel with the correct value for
                // `holder_max_htlc_value_in_flight_msat`, when configured with a valid percentage value,
                // which is set to the lower bound + 1 (2%) of the `channel_value`.
-               let chan_1 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_2_percent), 10000000, 100000, 42, &config_2_percent, 0, 42).unwrap();
+               let chan_1 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_2_percent), 10000000, 100000, 42, &config_2_percent, 0, 42, None).unwrap();
                let chan_1_value_msat = chan_1.context.channel_value_satoshis * 1000;
                assert_eq!(chan_1.context.holder_max_htlc_value_in_flight_msat, (chan_1_value_msat as f64 * 0.02) as u64);
 
                // Test with the upper bound - 1 of valid values (99%).
-               let chan_2 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_99_percent), 10000000, 100000, 42, &config_99_percent, 0, 42).unwrap();
+               let chan_2 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_99_percent), 10000000, 100000, 42, &config_99_percent, 0, 42, None).unwrap();
                let chan_2_value_msat = chan_2.context.channel_value_satoshis * 1000;
                assert_eq!(chan_2.context.holder_max_htlc_value_in_flight_msat, (chan_2_value_msat as f64 * 0.99) as u64);
 
@@ -8033,14 +8165,14 @@ mod tests {
 
                // Test that `OutboundV1Channel::new` uses the lower bound of the configurable percentage values (1%)
                // if `max_inbound_htlc_value_in_flight_percent_of_channel` is set to a value less than 1.
-               let chan_5 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_0_percent), 10000000, 100000, 42, &config_0_percent, 0, 42).unwrap();
+               let chan_5 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_0_percent), 10000000, 100000, 42, &config_0_percent, 0, 42, None).unwrap();
                let chan_5_value_msat = chan_5.context.channel_value_satoshis * 1000;
                assert_eq!(chan_5.context.holder_max_htlc_value_in_flight_msat, (chan_5_value_msat as f64 * 0.01) as u64);
 
                // Test that `OutboundV1Channel::new` uses the upper bound of the configurable percentage values
                // (100%) if `max_inbound_htlc_value_in_flight_percent_of_channel` is set to a larger value
                // than 100.
-               let chan_6 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_101_percent), 10000000, 100000, 42, &config_101_percent, 0, 42).unwrap();
+               let chan_6 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_101_percent), 10000000, 100000, 42, &config_101_percent, 0, 42, None).unwrap();
                let chan_6_value_msat = chan_6.context.channel_value_satoshis * 1000;
                assert_eq!(chan_6.context.holder_max_htlc_value_in_flight_msat, chan_6_value_msat);
 
@@ -8093,7 +8225,7 @@ mod tests {
 
                let mut outbound_node_config = UserConfig::default();
                outbound_node_config.channel_handshake_config.their_channel_reserve_proportional_millionths = (outbound_selected_channel_reserve_perc * 1_000_000.0) as u32;
-               let chan = OutboundV1Channel::<&TestKeysInterface>::new(&&fee_est, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&outbound_node_config), channel_value_satoshis, 100_000, 42, &outbound_node_config, 0, 42).unwrap();
+               let chan = OutboundV1Channel::<&TestKeysInterface>::new(&&fee_est, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&outbound_node_config), channel_value_satoshis, 100_000, 42, &outbound_node_config, 0, 42, None).unwrap();
 
                let expected_outbound_selected_chan_reserve = cmp::max(MIN_THEIR_CHAN_RESERVE_SATOSHIS, (chan.context.channel_value_satoshis as f64 * outbound_selected_channel_reserve_perc) as u64);
                assert_eq!(chan.context.holder_selected_channel_reserve_satoshis, expected_outbound_selected_chan_reserve);
@@ -8130,7 +8262,7 @@ mod tests {
                // Create Node A's channel pointing to Node B's pubkey
                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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut node_a_chan = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).unwrap();
 
                // Create Node B's channel by receiving Node A's open_channel message
                // Make sure A's dust limit is as we expect.
@@ -8151,10 +8283,10 @@ mod tests {
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let (mut node_a_chan, funding_created_msg) = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, false, &&logger).map_err(|_| ()).unwrap();
-               let (_, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
+               let (_, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg.unwrap(), best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
 
                // Node B --> Node A: funding signed
-               let _ = node_a_chan.funding_signed(&funding_signed_msg, best_block, &&keys_provider, &&logger).unwrap();
+               let _ = node_a_chan.funding_signed(&funding_signed_msg.unwrap(), best_block, &&keys_provider, &&logger).unwrap();
 
                // Make sure that receiving a channel update will update the Channel as expected.
                let update = ChannelUpdate {
@@ -8232,7 +8364,7 @@ mod tests {
                let counterparty_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let mut config = UserConfig::default();
                config.channel_handshake_config.announced_channel = false;
-               let mut chan = OutboundV1Channel::<&Keys>::new(&LowerBoundedFeeEstimator::new(&feeest), &&keys_provider, &&keys_provider, counterparty_node_id, &channelmanager::provided_init_features(&config), 10_000_000, 0, 42, &config, 0, 42).unwrap(); // Nothing uses their network key in this test
+               let mut chan = OutboundV1Channel::<&Keys>::new(&LowerBoundedFeeEstimator::new(&feeest), &&keys_provider, &&keys_provider, counterparty_node_id, &channelmanager::provided_init_features(&config), 10_000_000, 0, 42, &config, 0, 42, None).unwrap(); // Nothing uses their network key in this test
                chan.context.holder_dust_limit_satoshis = 546;
                chan.context.counterparty_selected_channel_reserve_satoshis = Some(0); // Filled in in accept_channel
 
@@ -8978,7 +9110,7 @@ mod tests {
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
                let node_a_chan = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider,
-                       node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+                       node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).unwrap();
 
                let mut channel_type_features = ChannelTypeFeatures::only_static_remote_key();
                channel_type_features.set_zero_conf_required();
@@ -9013,7 +9145,7 @@ mod tests {
                let channel_a = OutboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_b,
                        &channelmanager::provided_init_features(&UserConfig::default()), 10000000, 100000, 42,
-                       &config, 0, 42
+                       &config, 0, 42, None
                ).unwrap();
                assert!(!channel_a.context.channel_type.supports_anchors_zero_fee_htlc_tx());
 
@@ -9023,7 +9155,8 @@ mod tests {
 
                let channel_a = OutboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_b,
-                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42
+                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42,
+                       None
                ).unwrap();
 
                let open_channel_msg = channel_a.get_open_channel(ChainHash::using_genesis_block(network));
@@ -9060,7 +9193,8 @@ mod tests {
 
                let channel_a = OutboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_b,
-                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42
+                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42,
+                       None
                ).unwrap();
 
                // Set `channel_type` to `None` to force the implicit feature negotiation.
@@ -9106,7 +9240,8 @@ mod tests {
                // B as it's not supported by LDK.
                let channel_a = OutboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_b,
-                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42
+                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42,
+                       None
                ).unwrap();
 
                let mut open_channel_msg = channel_a.get_open_channel(ChainHash::using_genesis_block(network));
@@ -9125,7 +9260,7 @@ mod tests {
                // LDK.
                let mut channel_a = OutboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_b, &simple_anchors_init,
-                       10000000, 100000, 42, &config, 0, 42
+                       10000000, 100000, 42, &config, 0, 42, None
                ).unwrap();
 
                let open_channel_msg = channel_a.get_open_channel(ChainHash::using_genesis_block(network));
@@ -9175,6 +9310,7 @@ mod tests {
                        &config,
                        0,
                        42,
+                       None
                ).unwrap();
 
                let open_channel_msg = node_a_chan.get_open_channel(ChainHash::using_genesis_block(network));
@@ -9223,7 +9359,7 @@ mod tests {
                        &&logger,
                ).map_err(|_| ()).unwrap();
                let (mut node_b_chan, funding_signed_msg, _) = node_b_chan.funding_created(
-                       &funding_created_msg,
+                       &funding_created_msg.unwrap(),
                        best_block,
                        &&keys_provider,
                        &&logger,
@@ -9239,7 +9375,7 @@ mod tests {
                // Receive funding_signed, but the channel will be configured to hold sending channel_ready and
                // broadcasting the funding transaction until the batch is ready.
                let _ = node_a_chan.funding_signed(
-                       &funding_signed_msg,
+                       &funding_signed_msg.unwrap(),
                        best_block,
                        &&keys_provider,
                        &&logger,