diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs index 7171608c75e..2d720824324 100644 --- a/lightning/src/ln/channel.rs +++ b/lightning/src/ln/channel.rs @@ -3364,6 +3364,49 @@ impl ChannelContext 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( + &mut self, fee_estimator: &LowerBoundedFeeEstimator + ) -> 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 @@ -7302,37 +7345,7 @@ impl OutboundV1Channel 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 +7979,19 @@ impl OutboundV2Channel 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( + &mut self, chain_hash: ChainHash, fee_estimator: &LowerBoundedFeeEstimator + ) -> Result + 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");