Update pay_for_offer docs about unsupported chains
[rust-lightning] / lightning / src / ln / channelmanager.rs
index 4d8fbdbbf76fde791498f204632dff5ed7554fe5..02aa5efcd8153359a36e42382c8f1a2e9c165106 100644 (file)
@@ -58,10 +58,11 @@ use crate::ln::msgs::{ChannelMessageHandler, DecodeError, LightningError};
 use crate::ln::outbound_payment;
 use crate::ln::outbound_payment::{Bolt12PaymentError, OutboundPayments, PaymentAttempts, PendingOutboundPayment, SendAlongPathArgs, StaleExpiration};
 use crate::ln::wire::Encode;
-use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, DerivedSigningPubkey, InvoiceBuilder};
+use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder, UnsignedBolt12Invoice};
 use crate::offers::invoice_error::InvoiceError;
+use crate::offers::invoice_request::{DerivedPayerId, InvoiceRequestBuilder};
 use crate::offers::merkle::SignError;
-use crate::offers::offer::{DerivedMetadata, Offer, OfferBuilder};
+use crate::offers::offer::{Offer, OfferBuilder};
 use crate::offers::parse::Bolt12SemanticError;
 use crate::offers::refund::{Refund, RefundBuilder};
 use crate::onion_message::messenger::{Destination, MessageRouter, PendingOnionMessage, new_pending_onion_message};
@@ -77,11 +78,17 @@ use crate::util::logger::{Level, Logger, WithContext};
 use crate::util::errors::APIError;
 #[cfg(not(c_bindings))]
 use {
+       crate::offers::offer::DerivedMetadata,
        crate::routing::router::DefaultRouter,
        crate::routing::gossip::NetworkGraph,
        crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters},
        crate::sign::KeysManager,
 };
+#[cfg(c_bindings)]
+use {
+       crate::offers::offer::OfferWithDerivedMetadataBuilder,
+       crate::offers::refund::RefundMaybeWithDerivedMetadataBuilder,
+};
 
 use alloc::collections::{btree_map, BTreeMap};
 
@@ -905,7 +912,14 @@ impl <SP: Deref> PeerState<SP> where SP::Target: SignerProvider {
                        return false
                }
                !self.channel_by_id.iter().any(|(_, phase)|
-                       matches!(phase, ChannelPhase::Funded(_) | ChannelPhase::UnfundedOutboundV1(_))
+                       match phase {
+                               ChannelPhase::Funded(_) | ChannelPhase::UnfundedOutboundV1(_) => true,
+                               ChannelPhase::UnfundedInboundV1(_) => false,
+                               #[cfg(dual_funding)]
+                               ChannelPhase::UnfundedOutboundV2(_) => true,
+                               #[cfg(dual_funding)]
+                               ChannelPhase::UnfundedInboundV2(_) => false,
+                       }
                )
                        && self.monitor_update_blocked_actions.is_empty()
                        && self.in_flight_monitor_updates.is_empty()
@@ -2092,6 +2106,14 @@ macro_rules! convert_chan_phase_err {
                        ChannelPhase::UnfundedInboundV1(channel) => {
                                convert_chan_phase_err!($self, $err, channel, $channel_id, UNFUNDED_CHANNEL)
                        },
+                       #[cfg(dual_funding)]
+                       ChannelPhase::UnfundedOutboundV2(channel) => {
+                               convert_chan_phase_err!($self, $err, channel, $channel_id, UNFUNDED_CHANNEL)
+                       },
+                       #[cfg(dual_funding)]
+                       ChannelPhase::UnfundedInboundV2(channel) => {
+                               convert_chan_phase_err!($self, $err, channel, $channel_id, UNFUNDED_CHANNEL)
+                       },
                }
        };
 }
@@ -2194,7 +2216,7 @@ macro_rules! handle_monitor_update_completion {
                let logger = WithChannelContext::from(&$self.logger, &$chan.context);
                let mut updates = $chan.monitor_updating_restored(&&logger,
                        &$self.node_signer, $self.chain_hash, &$self.default_configuration,
-                       $self.best_block.read().unwrap().height());
+                       $self.best_block.read().unwrap().height);
                let counterparty_node_id = $chan.context.get_counterparty_node_id();
                let channel_update = if updates.channel_ready.is_some() && $chan.context.is_usable() {
                        // We only send a channel_update in the case where we are just now sending a
@@ -2494,7 +2516,7 @@ where
        }
 
        fn create_and_insert_outbound_scid_alias(&self) -> u64 {
-               let height = self.best_block.read().unwrap().height();
+               let height = self.best_block.read().unwrap().height;
                let mut outbound_scid_alias = 0;
                let mut i = 0;
                loop {
@@ -2572,7 +2594,7 @@ where
                        let config = if override_config.is_some() { override_config.as_ref().unwrap() } else { &self.default_configuration };
                        match OutboundV1Channel::new(&self.fee_estimator, &self.entropy_source, &self.signer_provider, their_network_key,
                                their_features, channel_value_satoshis, push_msat, user_channel_id, config,
-                               self.best_block.read().unwrap().height(), outbound_scid_alias, temporary_channel_id)
+                               self.best_block.read().unwrap().height, outbound_scid_alias, temporary_channel_id)
                        {
                                Ok(res) => res,
                                Err(e) => {
@@ -2611,7 +2633,7 @@ where
                // the same channel.
                let mut res = Vec::with_capacity(self.short_to_chan_info.read().unwrap().len());
                {
-                       let best_block_height = self.best_block.read().unwrap().height();
+                       let best_block_height = self.best_block.read().unwrap().height;
                        let per_peer_state = self.per_peer_state.read().unwrap();
                        for (_cp_id, peer_state_mutex) in per_peer_state.iter() {
                                let mut peer_state_lock = peer_state_mutex.lock().unwrap();
@@ -2644,7 +2666,7 @@ where
                // the same channel.
                let mut res = Vec::with_capacity(self.short_to_chan_info.read().unwrap().len());
                {
-                       let best_block_height = self.best_block.read().unwrap().height();
+                       let best_block_height = self.best_block.read().unwrap().height;
                        let per_peer_state = self.per_peer_state.read().unwrap();
                        for (_cp_id, peer_state_mutex) in per_peer_state.iter() {
                                let mut peer_state_lock = peer_state_mutex.lock().unwrap();
@@ -2674,7 +2696,7 @@ where
 
        /// Gets the list of channels we have with a given counterparty, in random order.
        pub fn list_channels_with_counterparty(&self, counterparty_node_id: &PublicKey) -> Vec<ChannelDetails> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let per_peer_state = self.per_peer_state.read().unwrap();
 
                if let Some(peer_state_mutex) = per_peer_state.get(counterparty_node_id) {
@@ -2958,6 +2980,13 @@ where
                                                // Unfunded channel has no update
                                                (None, chan_phase.context().get_counterparty_node_id())
                                        },
+                                       // TODO(dual_funding): Combine this match arm with above once #[cfg(dual_funding)] is removed.
+                                       #[cfg(dual_funding)]
+                                       ChannelPhase::UnfundedOutboundV2(_) | ChannelPhase::UnfundedInboundV2(_) => {
+                                               self.finish_close_channel(chan_phase.context_mut().force_shutdown(false, closure_reason));
+                                               // Unfunded channel has no update
+                                               (None, chan_phase.context().get_counterparty_node_id())
+                                       },
                                }
                        } else if peer_state.inbound_channel_request_by_id.remove(channel_id).is_some() {
                                log_error!(logger, "Force-closing channel {}", &channel_id);
@@ -3177,7 +3206,7 @@ where
                                None
                        };
 
-                       let cur_height = self.best_block.read().unwrap().height() + 1;
+                       let cur_height = self.best_block.read().unwrap().height + 1;
 
                        if let Err((err_msg, code)) = check_incoming_htlc_cltv(
                                cur_height, outgoing_cltv_value, msg.cltv_expiry
@@ -3254,7 +3283,7 @@ where
                match decoded_hop {
                        onion_utils::Hop::Receive(next_hop_data) => {
                                // OUR PAYMENT!
-                               let current_height: u32 = self.best_block.read().unwrap().height();
+                               let current_height: u32 = self.best_block.read().unwrap().height;
                                match create_recv_pending_htlc_info(next_hop_data, shared_secret, msg.payment_hash,
                                        msg.amount_msat, msg.cltv_expiry, None, allow_underpay, msg.skimmed_fee_msat,
                                        current_height, self.default_configuration.accept_mpp_keysend)
@@ -3514,7 +3543,7 @@ where
        /// [`PeerManager::process_events`]: crate::ln::peer_handler::PeerManager::process_events
        /// [`ChannelMonitorUpdateStatus::InProgress`]: crate::chain::ChannelMonitorUpdateStatus::InProgress
        pub fn send_payment_with_route(&self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId) -> Result<(), PaymentSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments
                        .send_payment_with_route(route, payment_hash, recipient_onion, payment_id,
@@ -3525,7 +3554,7 @@ where
        /// Similar to [`ChannelManager::send_payment_with_route`], but will automatically find a route based on
        /// `route_params` and retry failed payment paths based on `retry_strategy`.
        pub fn send_payment(&self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry) -> Result<(), RetryableSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments
                        .send_payment(payment_hash, recipient_onion, payment_id, retry_strategy, route_params,
@@ -3536,7 +3565,7 @@ where
 
        #[cfg(test)]
        pub(super) fn test_send_payment_internal(&self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>, onion_session_privs: Vec<[u8; 32]>) -> Result<(), PaymentSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments.test_send_payment_internal(route, payment_hash, recipient_onion,
                        keysend_preimage, payment_id, recv_value_msat, onion_session_privs, &self.node_signer,
@@ -3545,7 +3574,7 @@ where
 
        #[cfg(test)]
        pub(crate) fn test_add_new_pending_payment(&self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId, route: &Route) -> Result<Vec<[u8; 32]>, PaymentSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                self.pending_outbound_payments.test_add_new_pending_payment(payment_hash, recipient_onion, payment_id, route, None, &self.entropy_source, best_block_height)
        }
 
@@ -3555,7 +3584,7 @@ where
        }
 
        pub(super) fn send_payment_for_bolt12_invoice(&self, invoice: &Bolt12Invoice, payment_id: PaymentId) -> Result<(), Bolt12PaymentError> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments
                        .send_payment_for_bolt12_invoice(
@@ -3612,7 +3641,7 @@ where
        ///
        /// [`send_payment`]: Self::send_payment
        pub fn send_spontaneous_payment(&self, route: &Route, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields, payment_id: PaymentId) -> Result<PaymentHash, PaymentSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments.send_spontaneous_payment_with_route(
                        route, payment_preimage, recipient_onion, payment_id, &self.entropy_source,
@@ -3627,7 +3656,7 @@ where
        ///
        /// [`PaymentParameters::for_keysend`]: crate::routing::router::PaymentParameters::for_keysend
        pub fn send_spontaneous_payment_with_retry(&self, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields, payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry) -> Result<PaymentHash, RetryableSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments.send_spontaneous_payment(payment_preimage, recipient_onion,
                        payment_id, retry_strategy, route_params, &self.router, self.list_usable_channels(),
@@ -3639,7 +3668,7 @@ where
        /// [`PaymentHash`] of probes based on a static secret and a random [`PaymentId`], which allows
        /// us to easily discern them from real payments.
        pub fn send_probe(&self, path: Path) -> Result<(PaymentHash, PaymentId), PaymentSendFailure> {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
                self.pending_outbound_payments.send_probe(path, self.probing_cookie_secret,
                        &self.entropy_source, &self.node_signer, best_block_height,
@@ -3917,7 +3946,7 @@ where
                        }));
                }
                {
-                       let height = self.best_block.read().unwrap().height();
+                       let height = self.best_block.read().unwrap().height;
                        // Transactions are evaluated as final by network mempools if their locktime is strictly
                        // lower than the next block height. However, the modules constituting our Lightning
                        // node might not have perfect sync about their blockchain views. Thus, if the wallet
@@ -4341,7 +4370,7 @@ where
                                                                                                };
                                                                                                match next_hop {
                                                                                                        onion_utils::Hop::Receive(hop_data) => {
-                                                                                                               let current_height: u32 = self.best_block.read().unwrap().height();
+                                                                                                               let current_height: u32 = self.best_block.read().unwrap().height;
                                                                                                                match create_recv_pending_htlc_info(hop_data,
                                                                                                                        incoming_shared_secret, payment_hash, outgoing_amt_msat,
                                                                                                                        outgoing_cltv_value, Some(phantom_shared_secret), false, None,
@@ -4538,7 +4567,7 @@ where
                                                                                debug_assert!(!committed_to_claimable);
                                                                                let mut htlc_msat_height_data = $htlc.value.to_be_bytes().to_vec();
                                                                                htlc_msat_height_data.extend_from_slice(
-                                                                                       &self.best_block.read().unwrap().height().to_be_bytes(),
+                                                                                       &self.best_block.read().unwrap().height.to_be_bytes(),
                                                                                );
                                                                                failed_forwards.push((HTLCSource::PreviousHopData(HTLCPreviousHopData {
                                                                                                short_channel_id: $htlc.prev_hop.short_channel_id,
@@ -4676,7 +4705,7 @@ where
                                                                                                        }
                                                                                                };
                                                                                                if let Some(min_final_cltv_expiry_delta) = min_final_cltv_expiry_delta {
-                                                                                                       let expected_min_expiry_height = (self.current_best_block().height() + min_final_cltv_expiry_delta as u32) as u64;
+                                                                                                       let expected_min_expiry_height = (self.current_best_block().height + min_final_cltv_expiry_delta as u32) as u64;
                                                                                                        if (cltv_expiry as u64) < expected_min_expiry_height {
                                                                                                                log_trace!(self.logger, "Failing new HTLC with payment_hash {} as its CLTV expiry was too soon (had {}, earliest expected {})",
                                                                                                                        &payment_hash, cltv_expiry, expected_min_expiry_height);
@@ -4730,7 +4759,7 @@ where
                        }
                }
 
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                self.pending_outbound_payments.check_retry_payments(&self.router, || self.list_usable_channels(),
                        || self.compute_inflight_htlcs(), &self.entropy_source, &self.node_signer, best_block_height,
                        &self.pending_events, &self.logger, |args| self.send_payment_along_path(args));
@@ -5031,6 +5060,16 @@ where
                                                                process_unfunded_channel_tick(chan_id, &mut chan.context, &mut chan.unfunded_context,
                                                                        pending_msg_events, counterparty_node_id)
                                                        },
+                                                       #[cfg(dual_funding)]
+                                                       ChannelPhase::UnfundedInboundV2(chan) => {
+                                                               process_unfunded_channel_tick(chan_id, &mut chan.context, &mut chan.unfunded_context,
+                                                                       pending_msg_events, counterparty_node_id)
+                                                       },
+                                                       #[cfg(dual_funding)]
+                                                       ChannelPhase::UnfundedOutboundV2(chan) => {
+                                                               process_unfunded_channel_tick(chan_id, &mut chan.context, &mut chan.unfunded_context,
+                                                                       pending_msg_events, counterparty_node_id)
+                                                       },
                                                }
                                        });
 
@@ -5191,7 +5230,7 @@ where
                        FailureCode::RequiredNodeFeatureMissing => HTLCFailReason::from_failure_code(failure_code.into()),
                        FailureCode::IncorrectOrUnknownPaymentDetails => {
                                let mut htlc_msat_height_data = htlc.value.to_be_bytes().to_vec();
-                               htlc_msat_height_data.extend_from_slice(&self.best_block.read().unwrap().height().to_be_bytes());
+                               htlc_msat_height_data.extend_from_slice(&self.best_block.read().unwrap().height.to_be_bytes());
                                HTLCFailReason::reason(failure_code.into(), htlc_msat_height_data)
                        },
                        FailureCode::InvalidOnionPayload(data) => {
@@ -5522,7 +5561,7 @@ where
                if !valid_mpp {
                        for htlc in sources.drain(..) {
                                let mut htlc_msat_height_data = htlc.value.to_be_bytes().to_vec();
-                               htlc_msat_height_data.extend_from_slice(&self.best_block.read().unwrap().height().to_be_bytes());
+                               htlc_msat_height_data.extend_from_slice(&self.best_block.read().unwrap().height.to_be_bytes());
                                let source = HTLCSource::PreviousHopData(htlc.prev_hop);
                                let reason = HTLCFailReason::reason(0x4000 | 15, htlc_msat_height_data);
                                let receiver = HTLCDestination::FailedPayment { payment_hash };
@@ -6068,7 +6107,7 @@ where
                // succeed.
                let mut channel = match peer_state.inbound_channel_request_by_id.remove(temporary_channel_id) {
                        Some(unaccepted_channel) => {
-                               let best_block_height = self.best_block.read().unwrap().height();
+                               let best_block_height = self.best_block.read().unwrap().height;
                                InboundV1Channel::new(&self.fee_estimator, &self.entropy_source, &self.signer_provider,
                                        counterparty_node_id.clone(), &self.channel_type_features(), &peer_state.latest_features,
                                        &unaccepted_channel.open_channel_msg, user_channel_id, &self.default_configuration, best_block_height,
@@ -6143,7 +6182,7 @@ where
        fn peers_without_funded_channels<Filter>(&self, maybe_count_peer: Filter) -> usize
        where Filter: Fn(&PeerState<SP>) -> bool {
                let mut peers_without_funded_channels = 0;
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                {
                        let peer_state_lock = self.per_peer_state.read().unwrap();
                        for (_, peer_mtx) in peer_state_lock.iter() {
@@ -6178,9 +6217,25 @@ where
                                                num_unfunded_channels += 1;
                                        }
                                },
+                               // TODO(dual_funding): Combine this match arm with above once #[cfg(dual_funding)] is removed.
+                               #[cfg(dual_funding)]
+                               ChannelPhase::UnfundedInboundV2(chan) => {
+                                       // Only inbound V2 channels that are not 0conf and that we do not contribute to will be
+                                       // included in the unfunded count.
+                                       if chan.context.minimum_depth().unwrap_or(1) != 0 &&
+                                               chan.dual_funding_context.our_funding_satoshis == 0 {
+                                               num_unfunded_channels += 1;
+                                       }
+                               },
                                ChannelPhase::UnfundedOutboundV1(_) => {
                                        // Outbound channels don't contribute to the unfunded count in the DoS context.
                                        continue;
+                               },
+                               // TODO(dual_funding): Combine this match arm with above once #[cfg(dual_funding)] is removed.
+                               #[cfg(dual_funding)]
+                               ChannelPhase::UnfundedOutboundV2(_) => {
+                                       // Outbound channels don't contribute to the unfunded count in the DoS context.
+                                       continue;
                                }
                        }
                }
@@ -6229,7 +6284,7 @@ where
                                msg.common_fields.temporary_channel_id.clone()));
                }
 
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                if Self::unfunded_channel_count(peer_state, best_block_height) >= MAX_UNFUNDED_CHANS_PER_PEER {
                        return Err(MsgHandleErrInternal::send_err_msg_no_close(
                                format!("Refusing more than {} unfunded channels.", MAX_UNFUNDED_CHANS_PER_PEER),
@@ -6603,6 +6658,14 @@ where
                                                let mut chan = remove_channel_phase!(self, chan_phase_entry);
                                                finish_shutdown = Some(chan.context_mut().force_shutdown(false, ClosureReason::CounterpartyCoopClosedUnfundedChannel));
                                        },
+                                       // TODO(dual_funding): Combine this match arm with above.
+                                       #[cfg(dual_funding)]
+                                       ChannelPhase::UnfundedInboundV2(_) | ChannelPhase::UnfundedOutboundV2(_) => {
+                                               let context = phase.context_mut();
+                                               log_error!(self.logger, "Immediately closing unfunded channel {} as peer asked to cooperatively shut it down (which is unnecessary)", &msg.channel_id);
+                                               let mut chan = remove_channel_phase!(self, chan_phase_entry);
+                                               finish_shutdown = Some(chan.context_mut().force_shutdown(false, ClosureReason::CounterpartyCoopClosedUnfundedChannel));
+                                       },
                                }
                        } else {
                                return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got a message for a channel from the wrong node! No such channel for the passed counterparty_node_id {}", counterparty_node_id), msg.channel_id))
@@ -7114,7 +7177,7 @@ where
 
                                        peer_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelAnnouncement {
                                                msg: try_chan_phase_entry!(self, chan.announcement_signatures(
-                                                       &self.node_signer, self.chain_hash, self.best_block.read().unwrap().height(),
+                                                       &self.node_signer, self.chain_hash, self.best_block.read().unwrap().height,
                                                        msg, &self.default_configuration
                                                ), chan_phase_entry),
                                                // Note that announcement_signatures fails if the channel cannot be announced,
@@ -7577,7 +7640,9 @@ where
                        self.finish_close_channel(failure);
                }
        }
+}
 
+macro_rules! create_offer_builder { ($self: ident, $builder: ty) => {
        /// Creates an [`OfferBuilder`] such that the [`Offer`] it builds is recognized by the
        /// [`ChannelManager`] when handling [`InvoiceRequest`] messages for the offer. The offer will
        /// not have an expiration unless otherwise set on the builder.
@@ -7606,23 +7671,25 @@ where
        /// [`Offer`]: crate::offers::offer::Offer
        /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
        pub fn create_offer_builder(
-               &self, description: String
-       ) -> Result<OfferBuilder<DerivedMetadata, secp256k1::All>, Bolt12SemanticError> {
-               let node_id = self.get_our_node_id();
-               let expanded_key = &self.inbound_payment_key;
-               let entropy = &*self.entropy_source;
-               let secp_ctx = &self.secp_ctx;
-
-               let path = self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
+               &$self, description: String
+       ) -> Result<$builder, Bolt12SemanticError> {
+               let node_id = $self.get_our_node_id();
+               let expanded_key = &$self.inbound_payment_key;
+               let entropy = &*$self.entropy_source;
+               let secp_ctx = &$self.secp_ctx;
+
+               let path = $self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
                let builder = OfferBuilder::deriving_signing_pubkey(
                        description, node_id, expanded_key, entropy, secp_ctx
                )
-                       .chain_hash(self.chain_hash)
+                       .chain_hash($self.chain_hash)
                        .path(path);
 
-               Ok(builder)
+               Ok(builder.into())
        }
+} }
 
+macro_rules! create_refund_builder { ($self: ident, $builder: ty) => {
        /// Creates a [`RefundBuilder`] such that the [`Refund`] it builds is recognized by the
        /// [`ChannelManager`] when handling [`Bolt12Invoice`] messages for the refund.
        ///
@@ -7672,31 +7739,53 @@ where
        /// [`Bolt12Invoice::payment_paths`]: crate::offers::invoice::Bolt12Invoice::payment_paths
        /// [Avoiding Duplicate Payments]: #avoiding-duplicate-payments
        pub fn create_refund_builder(
-               &self, description: String, amount_msats: u64, absolute_expiry: Duration,
+               &$self, description: String, amount_msats: u64, absolute_expiry: Duration,
                payment_id: PaymentId, retry_strategy: Retry, max_total_routing_fee_msat: Option<u64>
-       ) -> Result<RefundBuilder<secp256k1::All>, Bolt12SemanticError> {
-               let node_id = self.get_our_node_id();
-               let expanded_key = &self.inbound_payment_key;
-               let entropy = &*self.entropy_source;
-               let secp_ctx = &self.secp_ctx;
+       ) -> Result<$builder, Bolt12SemanticError> {
+               let node_id = $self.get_our_node_id();
+               let expanded_key = &$self.inbound_payment_key;
+               let entropy = &*$self.entropy_source;
+               let secp_ctx = &$self.secp_ctx;
 
-               let path = self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
+               let path = $self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
                let builder = RefundBuilder::deriving_payer_id(
                        description, node_id, expanded_key, entropy, secp_ctx, amount_msats, payment_id
                )?
-                       .chain_hash(self.chain_hash)
+                       .chain_hash($self.chain_hash)
                        .absolute_expiry(absolute_expiry)
                        .path(path);
 
                let expiration = StaleExpiration::AbsoluteTimeout(absolute_expiry);
-               self.pending_outbound_payments
+               $self.pending_outbound_payments
                        .add_new_awaiting_invoice(
                                payment_id, expiration, retry_strategy, max_total_routing_fee_msat,
                        )
                        .map_err(|_| Bolt12SemanticError::DuplicatePaymentId)?;
 
-               Ok(builder)
+               Ok(builder.into())
        }
+} }
+
+impl<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref> ChannelManager<M, T, ES, NS, SP, F, R, L>
+where
+       M::Target: chain::Watch<<SP::Target as SignerProvider>::EcdsaSigner>,
+       T::Target: BroadcasterInterface,
+       ES::Target: EntropySource,
+       NS::Target: NodeSigner,
+       SP::Target: SignerProvider,
+       F::Target: FeeEstimator,
+       R::Target: Router,
+       L::Target: Logger,
+{
+       #[cfg(not(c_bindings))]
+       create_offer_builder!(self, OfferBuilder<DerivedMetadata, secp256k1::All>);
+       #[cfg(not(c_bindings))]
+       create_refund_builder!(self, RefundBuilder<secp256k1::All>);
+
+       #[cfg(c_bindings)]
+       create_offer_builder!(self, OfferWithDerivedMetadataBuilder);
+       #[cfg(c_bindings)]
+       create_refund_builder!(self, RefundMaybeWithDerivedMetadataBuilder);
 
        /// Pays for an [`Offer`] using the given parameters by creating an [`InvoiceRequest`] and
        /// enqueuing it to be sent via an onion message. [`ChannelManager`] will pay the actual
@@ -7741,6 +7830,7 @@ where
        /// Errors if:
        /// - a duplicate `payment_id` is provided given the caveats in the aforementioned link,
        /// - the provided parameters are invalid for the offer,
+       /// - the offer is for an unsupported chain, or
        /// - the parameterized [`Router`] is unable to create a blinded reply path for the invoice
        ///   request.
        ///
@@ -7760,9 +7850,11 @@ where
                let entropy = &*self.entropy_source;
                let secp_ctx = &self.secp_ctx;
 
-               let builder = offer
+               let builder: InvoiceRequestBuilder<DerivedPayerId, secp256k1::All> = offer
                        .request_invoice_deriving_payer_id(expanded_key, entropy, secp_ctx, payment_id)?
-                       .chain_hash(self.chain_hash)?;
+                       .into();
+               let builder = builder.chain_hash(self.chain_hash)?;
+
                let builder = match quantity {
                        None => builder,
                        Some(quantity) => builder.quantity(quantity)?,
@@ -7856,6 +7948,7 @@ where
                                let builder = refund.respond_using_derived_keys_no_std(
                                        payment_paths, payment_hash, created_at, expanded_key, entropy
                                )?;
+                               let builder: InvoiceBuilder<DerivedSigningPubkey> = builder.into();
                                let invoice = builder.allow_mpp().build_and_sign(secp_ctx)?;
                                let reply_path = self.create_blinded_path()
                                        .map_err(|_| Bolt12SemanticError::MissingPaths)?;
@@ -8012,7 +8105,7 @@ where
 
                let first_hops = self.list_usable_channels();
                let payee_node_id = self.get_our_node_id();
-               let max_cltv_expiry = self.best_block.read().unwrap().height() + CLTV_FAR_FAR_AWAY
+               let max_cltv_expiry = self.best_block.read().unwrap().height + CLTV_FAR_FAR_AWAY
                        + LATENCY_GRACE_PERIOD_BLOCKS;
                let payee_tlvs = ReceiveTlvs {
                        payment_secret,
@@ -8031,7 +8124,7 @@ where
        ///
        /// [phantom node payments]: crate::sign::PhantomKeysManager
        pub fn get_phantom_scid(&self) -> u64 {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let short_to_chan_info = self.short_to_chan_info.read().unwrap();
                loop {
                        let scid_candidate = fake_scid::Namespace::Phantom.get_fake_scid(best_block_height, &self.chain_hash, &self.fake_scid_rand_bytes, &self.entropy_source);
@@ -8061,7 +8154,7 @@ where
        /// Note that this method is not guaranteed to return unique values, you may need to call it a few
        /// times to get a unique scid.
        pub fn get_intercept_scid(&self) -> u64 {
-               let best_block_height = self.best_block.read().unwrap().height();
+               let best_block_height = self.best_block.read().unwrap().height;
                let short_to_chan_info = self.short_to_chan_info.read().unwrap();
                loop {
                        let scid_candidate = fake_scid::Namespace::Intercept.get_fake_scid(best_block_height, &self.chain_hash, &self.fake_scid_rand_bytes, &self.entropy_source);
@@ -8309,9 +8402,9 @@ where
        fn filtered_block_connected(&self, header: &Header, txdata: &TransactionData, height: u32) {
                {
                        let best_block = self.best_block.read().unwrap();
-                       assert_eq!(best_block.block_hash(), header.prev_blockhash,
+                       assert_eq!(best_block.block_hash, header.prev_blockhash,
                                "Blocks must be connected in chain-order - the connected header must build on the last connected header");
-                       assert_eq!(best_block.height(), height - 1,
+                       assert_eq!(best_block.height, height - 1,
                                "Blocks must be connected in chain-order - the connected block height must be one greater than the previous height");
                }
 
@@ -8326,9 +8419,9 @@ where
                let new_height = height - 1;
                {
                        let mut best_block = self.best_block.write().unwrap();
-                       assert_eq!(best_block.block_hash(), header.block_hash(),
+                       assert_eq!(best_block.block_hash, header.block_hash(),
                                "Blocks must be disconnected in chain-order - the disconnected header must be the last connected header");
-                       assert_eq!(best_block.height(), height,
+                       assert_eq!(best_block.height, height,
                                "Blocks must be disconnected in chain-order - the disconnected block must have the correct height");
                        *best_block = BestBlock::new(header.prev_blockhash, new_height)
                }
@@ -8362,7 +8455,7 @@ where
                self.do_chain_event(Some(height), |channel| channel.transactions_confirmed(&block_hash, height, txdata, self.chain_hash, &self.node_signer, &self.default_configuration, &&WithChannelContext::from(&self.logger, &channel.context))
                        .map(|(a, b)| (a, Vec::new(), b)));
 
-               let last_best_block_height = self.best_block.read().unwrap().height();
+               let last_best_block_height = self.best_block.read().unwrap().height;
                if height < last_best_block_height {
                        let timestamp = self.highest_seen_timestamp.load(Ordering::Acquire);
                        self.do_chain_event(Some(last_best_block_height), |channel| channel.best_block_updated(last_best_block_height, timestamp as u32, self.chain_hash, &self.node_signer, &self.default_configuration, &&WithChannelContext::from(&self.logger, &channel.context)));
@@ -8470,6 +8563,9 @@ where
                                        match phase {
                                                // Retain unfunded channels.
                                                ChannelPhase::UnfundedOutboundV1(_) | ChannelPhase::UnfundedInboundV1(_) => true,
+                                               // TODO(dual_funding): Combine this match arm with above.
+                                               #[cfg(dual_funding)]
+                                               ChannelPhase::UnfundedOutboundV2(_) | ChannelPhase::UnfundedInboundV2(_) => true,
                                                ChannelPhase::Funded(channel) => {
                                                        let res = f(channel);
                                                        if let Ok((channel_ready_opt, mut timed_out_pending_htlcs, announcement_sigs)) = res {
@@ -8939,6 +9035,14 @@ where
                                                ChannelPhase::UnfundedInboundV1(chan) => {
                                                        &mut chan.context
                                                },
+                                               #[cfg(dual_funding)]
+                                               ChannelPhase::UnfundedOutboundV2(chan) => {
+                                                       &mut chan.context
+                                               },
+                                               #[cfg(dual_funding)]
+                                               ChannelPhase::UnfundedInboundV2(chan) => {
+                                                       &mut chan.context
+                                               },
                                        };
                                        // Clean up for removal.
                                        update_maps_on_chan_removal!(self, &context);
@@ -9051,7 +9155,7 @@ where
                                                let mut peer_state = e.get().lock().unwrap();
                                                peer_state.latest_features = init_msg.features.clone();
 
-                                               let best_block_height = self.best_block.read().unwrap().height();
+                                               let best_block_height = self.best_block.read().unwrap().height;
                                                if inbound_peer_limited &&
                                                        Self::unfunded_channel_count(&*peer_state, best_block_height) ==
                                                        peer_state.channel_by_id.len()
@@ -9091,12 +9195,30 @@ where
                                                        });
                                                }
 
+                                               // TODO(dual_funding): Combine this match arm with above once #[cfg(dual_funding)] is removed.
+                                               #[cfg(dual_funding)]
+                                               ChannelPhase::UnfundedOutboundV2(chan) => {
+                                                       pending_msg_events.push(events::MessageSendEvent::SendOpenChannelV2 {
+                                                               node_id: chan.context.get_counterparty_node_id(),
+                                                               msg: chan.get_open_channel_v2(self.chain_hash),
+                                                       });
+                                               },
+
                                                ChannelPhase::UnfundedInboundV1(_) => {
                                                        // Since unfunded inbound channel maps are cleared upon disconnecting a peer,
                                                        // they are not persisted and won't be recovered after a crash.
                                                        // Therefore, they shouldn't exist at this point.
                                                        debug_assert!(false);
                                                }
+
+                                               // TODO(dual_funding): Combine this match arm with above once #[cfg(dual_funding)] is removed.
+                                               #[cfg(dual_funding)]
+                                               ChannelPhase::UnfundedInboundV2(channel) => {
+                                                       // Since unfunded inbound channel maps are cleared upon disconnecting a peer,
+                                                       // they are not persisted and won't be recovered after a crash.
+                                                       // Therefore, they shouldn't exist at this point.
+                                                       debug_assert!(false);
+                                               },
                                        }
                                }
                        }
@@ -9174,14 +9296,29 @@ where
                                if peer_state_mutex_opt.is_none() { return; }
                                let mut peer_state_lock = peer_state_mutex_opt.unwrap().lock().unwrap();
                                let peer_state = &mut *peer_state_lock;
-                               if let Some(ChannelPhase::UnfundedOutboundV1(chan)) = peer_state.channel_by_id.get_mut(&msg.channel_id) {
-                                       if let Ok(msg) = chan.maybe_handle_error_without_close(self.chain_hash, &self.fee_estimator) {
-                                               peer_state.pending_msg_events.push(events::MessageSendEvent::SendOpenChannel {
-                                                       node_id: *counterparty_node_id,
-                                                       msg,
-                                               });
-                                               return;
-                                       }
+                               match peer_state.channel_by_id.get_mut(&msg.channel_id) {
+                                       Some(ChannelPhase::UnfundedOutboundV1(ref mut chan)) => {
+                                               if let Ok(msg) = chan.maybe_handle_error_without_close(self.chain_hash, &self.fee_estimator) {
+                                                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendOpenChannel {
+                                                               node_id: *counterparty_node_id,
+                                                               msg,
+                                                       });
+                                                       return;
+                                               }
+                                       },
+                                       #[cfg(dual_funding)]
+                                       Some(ChannelPhase::UnfundedOutboundV2(ref mut chan)) => {
+                                               if let Ok(msg) = chan.maybe_handle_error_without_close(self.chain_hash, &self.fee_estimator) {
+                                                       peer_state.pending_msg_events.push(events::MessageSendEvent::SendOpenChannelV2 {
+                                                               node_id: *counterparty_node_id,
+                                                               msg,
+                                                       });
+                                                       return;
+                                               }
+                                       },
+                                       None | Some(ChannelPhase::UnfundedInboundV1(_) | ChannelPhase::Funded(_)) => (),
+                                       #[cfg(dual_funding)]
+                                       Some(ChannelPhase::UnfundedInboundV2(_)) => (),
                                }
                        }
 
@@ -9324,6 +9461,8 @@ where
                                        let builder = invoice_request.respond_using_derived_keys_no_std(
                                                payment_paths, payment_hash, created_at
                                        );
+                                       let builder: Result<InvoiceBuilder<DerivedSigningPubkey>, _> =
+                                               builder.map(|b| b.into());
                                        match builder.and_then(|b| b.allow_mpp().build_and_sign(secp_ctx)) {
                                                Ok(invoice) => Some(OffersMessage::Invoice(invoice)),
                                                Err(error) => Some(OffersMessage::InvoiceError(error.into())),
@@ -9335,18 +9474,25 @@ where
                                        let builder = invoice_request.respond_with_no_std(
                                                payment_paths, payment_hash, created_at
                                        );
+                                       let builder: Result<InvoiceBuilder<ExplicitSigningPubkey>, _> =
+                                               builder.map(|b| b.into());
                                        let response = builder.and_then(|builder| builder.allow_mpp().build())
                                                .map_err(|e| OffersMessage::InvoiceError(e.into()))
-                                               .and_then(|invoice|
-                                                       match invoice.sign(|invoice| self.node_signer.sign_bolt12_invoice(invoice)) {
+                                               .and_then(|invoice| {
+                                                       #[cfg(c_bindings)]
+                                                       let mut invoice = invoice;
+                                                       match invoice.sign(|invoice: &UnsignedBolt12Invoice|
+                                                               self.node_signer.sign_bolt12_invoice(invoice)
+                                                       ) {
                                                                Ok(invoice) => Ok(OffersMessage::Invoice(invoice)),
-                                                               Err(SignError::Signing(())) => Err(OffersMessage::InvoiceError(
+                                                               Err(SignError::Signing) => Err(OffersMessage::InvoiceError(
                                                                                InvoiceError::from_string("Failed signing invoice".to_string())
                                                                )),
                                                                Err(SignError::Verification(_)) => Err(OffersMessage::InvoiceError(
                                                                                InvoiceError::from_string("Failed invoice signature verification".to_string())
                                                                )),
-                                                       });
+                                                       }
+                                               });
                                        match response {
                                                Ok(invoice) => Some(invoice),
                                                Err(error) => Some(error),
@@ -9960,8 +10106,8 @@ where
                self.chain_hash.write(writer)?;
                {
                        let best_block = self.best_block.read().unwrap();
-                       best_block.height().write(writer)?;
-                       best_block.block_hash().write(writer)?;
+                       best_block.height.write(writer)?;
+                       best_block.block_hash.write(writer)?;
                }
 
                let mut serializable_peer_count: u64 = 0;
@@ -12243,7 +12389,7 @@ mod tests {
                };
                // Check that if the amount we received + the penultimate hop extra fee is less than the sender
                // intended amount, we fail the payment.
-               let current_height: u32 = node[0].node.best_block.read().unwrap().height();
+               let current_height: u32 = node[0].node.best_block.read().unwrap().height;
                if let Err(crate::ln::channelmanager::InboundHTLCErr { err_code, .. }) =
                        create_recv_pending_htlc_info(hop_data, [0; 32], PaymentHash([0; 32]),
                                sender_intended_amt_msat - extra_fee_msat - 1, 42, None, true, Some(extra_fee_msat),
@@ -12263,7 +12409,7 @@ mod tests {
                        }),
                        custom_tlvs: Vec::new(),
                };
-               let current_height: u32 = node[0].node.best_block.read().unwrap().height();
+               let current_height: u32 = node[0].node.best_block.read().unwrap().height;
                assert!(create_recv_pending_htlc_info(hop_data, [0; 32], PaymentHash([0; 32]),
                        sender_intended_amt_msat - extra_fee_msat, 42, None, true, Some(extra_fee_msat),
                        current_height, node[0].node.default_configuration.accept_mpp_keysend).is_ok());
@@ -12276,7 +12422,7 @@ mod tests {
                let node_chanmgr = create_node_chanmgrs(1, &node_cfg, &[None]);
                let node = create_network(1, &node_cfg, &node_chanmgr);
 
-               let current_height: u32 = node[0].node.best_block.read().unwrap().height();
+               let current_height: u32 = node[0].node.best_block.read().unwrap().height;
                let result = create_recv_pending_htlc_info(msgs::InboundOnionPayload::Receive {
                        sender_intended_htlc_amt_msat: 100,
                        cltv_expiry_height: 22,
@@ -12702,7 +12848,7 @@ pub mod bench {
 
                assert_eq!(&tx_broadcaster.txn_broadcasted.lock().unwrap()[..], &[tx.clone()]);
 
-               let block = create_dummy_block(BestBlock::from_network(network).block_hash(), 42, vec![tx]);
+               let block = create_dummy_block(BestBlock::from_network(network).block_hash, 42, vec![tx]);
                Listen::block_connected(&node_a, &block, 1);
                Listen::block_connected(&node_b, &block, 1);