ChannelManager initialization docs with example
[rust-lightning] / lightning / src / ln / channel.rs
index 7171608c75e5220aed5cad21ea1a5c11281942b6..33df5303814da439f5f83fd33a2acf53963b115f 100644 (file)
@@ -1161,6 +1161,10 @@ impl_writeable_tlv_based!(PendingChannelMonitorUpdate, {
 pub(super) enum ChannelPhase<SP: Deref> where SP::Target: SignerProvider {
        UnfundedOutboundV1(OutboundV1Channel<SP>),
        UnfundedInboundV1(InboundV1Channel<SP>),
+       #[cfg(dual_funding)]
+       UnfundedOutboundV2(OutboundV2Channel<SP>),
+       #[cfg(dual_funding)]
+       UnfundedInboundV2(InboundV2Channel<SP>),
        Funded(Channel<SP>),
 }
 
@@ -1173,6 +1177,10 @@ impl<'a, SP: Deref> ChannelPhase<SP> where
                        ChannelPhase::Funded(chan) => &chan.context,
                        ChannelPhase::UnfundedOutboundV1(chan) => &chan.context,
                        ChannelPhase::UnfundedInboundV1(chan) => &chan.context,
+                       #[cfg(dual_funding)]
+                       ChannelPhase::UnfundedOutboundV2(chan) => &chan.context,
+                       #[cfg(dual_funding)]
+                       ChannelPhase::UnfundedInboundV2(chan) => &chan.context,
                }
        }
 
@@ -1181,6 +1189,10 @@ impl<'a, SP: Deref> ChannelPhase<SP> where
                        ChannelPhase::Funded(ref mut chan) => &mut chan.context,
                        ChannelPhase::UnfundedOutboundV1(ref mut chan) => &mut chan.context,
                        ChannelPhase::UnfundedInboundV1(ref mut chan) => &mut chan.context,
+                       #[cfg(dual_funding)]
+                       ChannelPhase::UnfundedOutboundV2(ref mut chan) => &mut chan.context,
+                       #[cfg(dual_funding)]
+                       ChannelPhase::UnfundedInboundV2(ref mut chan) => &mut chan.context,
                }
        }
 }
@@ -3364,6 +3376,49 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                        _ => todo!()
                }
        }
+
+       /// If we receive an error message when attempting to open a channel, it may only be a rejection
+       /// of the channel type we tried, not of our ability to open any channel at all. We can see if a
+       /// downgrade of channel features would be possible so that we can still open the channel.
+       pub(crate) fn maybe_downgrade_channel_features<F: Deref>(
+               &mut self, fee_estimator: &LowerBoundedFeeEstimator<F>
+       ) -> Result<(), ()>
+       where
+               F::Target: FeeEstimator
+       {
+               if !self.is_outbound() ||
+                       !matches!(
+                               self.channel_state, ChannelState::NegotiatingFunding(flags)
+                               if flags == NegotiatingFundingFlags::OUR_INIT_SENT
+                       )
+               {
+                       return Err(());
+               }
+               if self.channel_type == ChannelTypeFeatures::only_static_remote_key() {
+                       // We've exhausted our options
+                       return Err(());
+               }
+               // We support opening a few different types of channels. Try removing our additional
+               // features one by one until we've either arrived at our default or the counterparty has
+               // accepted one.
+               //
+               // Due to the order below, we may not negotiate `option_anchors_zero_fee_htlc_tx` if the
+               // counterparty doesn't support `option_scid_privacy`. Since `get_initial_channel_type`
+               // checks whether the counterparty supports every feature, this would only happen if the
+               // counterparty is advertising the feature, but rejecting channels proposing the feature for
+               // whatever reason.
+               if self.channel_type.supports_anchors_zero_fee_htlc_tx() {
+                       self.channel_type.clear_anchors_zero_fee_htlc_tx();
+                       self.feerate_per_kw = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::NonAnchorChannelFee);
+                       assert!(!self.channel_transaction_parameters.channel_type_features.supports_anchors_nonzero_fee_htlc_tx());
+               } else if self.channel_type.supports_scid_privacy() {
+                       self.channel_type.clear_scid_privacy();
+               } else {
+                       self.channel_type = ChannelTypeFeatures::only_static_remote_key();
+               }
+               self.channel_transaction_parameters.channel_type_features = self.channel_type.clone();
+               Ok(())
+       }
 }
 
 // Internal utility functions for channels
@@ -4031,7 +4086,7 @@ impl<SP: Deref> Channel<SP> where
 
                log_info!(logger, "Received channel_ready from peer for channel {}", &self.context.channel_id());
 
-               Ok(self.get_announcement_sigs(node_signer, chain_hash, user_config, best_block.height(), logger))
+               Ok(self.get_announcement_sigs(node_signer, chain_hash, user_config, best_block.height, logger))
        }
 
        pub fn update_add_htlc<F, FE: Deref, L: Deref>(
@@ -5420,7 +5475,7 @@ impl<SP: Deref> Channel<SP> where
 
                let shutdown_msg = self.get_outbound_shutdown();
 
-               let announcement_sigs = self.get_announcement_sigs(node_signer, chain_hash, user_config, best_block.height(), logger);
+               let announcement_sigs = self.get_announcement_sigs(node_signer, chain_hash, user_config, best_block.height, logger);
 
                if matches!(self.context.channel_state, ChannelState::AwaitingChannelReady(_)) {
                        // If we're waiting on a monitor update, we shouldn't re-send any channel_ready's.
@@ -7302,37 +7357,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
        where
                F::Target: FeeEstimator
        {
-               if !self.context.is_outbound() ||
-                       !matches!(
-                               self.context.channel_state, ChannelState::NegotiatingFunding(flags)
-                               if flags == NegotiatingFundingFlags::OUR_INIT_SENT
-                       )
-               {
-                       return Err(());
-               }
-               if self.context.channel_type == ChannelTypeFeatures::only_static_remote_key() {
-                       // We've exhausted our options
-                       return Err(());
-               }
-               // We support opening a few different types of channels. Try removing our additional
-               // features one by one until we've either arrived at our default or the counterparty has
-               // accepted one.
-               //
-               // Due to the order below, we may not negotiate `option_anchors_zero_fee_htlc_tx` if the
-               // counterparty doesn't support `option_scid_privacy`. Since `get_initial_channel_type`
-               // checks whether the counterparty supports every feature, this would only happen if the
-               // counterparty is advertising the feature, but rejecting channels proposing the feature for
-               // whatever reason.
-               if self.context.channel_type.supports_anchors_zero_fee_htlc_tx() {
-                       self.context.channel_type.clear_anchors_zero_fee_htlc_tx();
-                       self.context.feerate_per_kw = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::NonAnchorChannelFee);
-                       assert!(!self.context.channel_transaction_parameters.channel_type_features.supports_anchors_nonzero_fee_htlc_tx());
-               } else if self.context.channel_type.supports_scid_privacy() {
-                       self.context.channel_type.clear_scid_privacy();
-               } else {
-                       self.context.channel_type = ChannelTypeFeatures::only_static_remote_key();
-               }
-               self.context.channel_transaction_parameters.channel_type_features = self.context.channel_type.clone();
+               self.context.maybe_downgrade_channel_features(fee_estimator)?;
                Ok(self.get_open_channel(chain_hash))
        }
 
@@ -7966,6 +7991,19 @@ impl<SP: Deref> OutboundV2Channel<SP> where SP::Target: SignerProvider {
                Ok(chan)
        }
 
+       /// If we receive an error message, it may only be a rejection of the channel type we tried,
+       /// not of our ability to open any channel at all. Thus, on error, we should first call this
+       /// and see if we get a new `OpenChannelV2` message, otherwise the channel is failed.
+       pub(crate) fn maybe_handle_error_without_close<F: Deref>(
+               &mut self, chain_hash: ChainHash, fee_estimator: &LowerBoundedFeeEstimator<F>
+       ) -> Result<msgs::OpenChannelV2, ()>
+       where
+               F::Target: FeeEstimator
+       {
+               self.context.maybe_downgrade_channel_features(fee_estimator)?;
+               Ok(self.get_open_channel_v2(chain_hash))
+       }
+
        pub fn get_open_channel_v2(&self, chain_hash: ChainHash) -> msgs::OpenChannelV2 {
                if self.context.have_received_message() {
                        debug_assert!(false, "Cannot generate an open_channel2 after we've moved forward");