Enable wumbo channels to be created

Author: valentinewallace

lightning/src/ln/channel.rs

@@ -854,8 +854,11 @@ impl<Signer: Sign> Channel<Signer> {
 		let holder_signer = keys_provider.get_channel_signer(false, channel_value_satoshis);
 		let pubkeys = holder_signer.pubkeys().clone();
 
-		if channel_value_satoshis >= MAX_FUNDING_SATOSHIS_NO_WUMBO {
-			return Err(APIError::APIMisuseError{err: format!("funding_value must be smaller than {}, it was {}", MAX_FUNDING_SATOSHIS_NO_WUMBO, channel_value_satoshis)});
+		if !their_features.supports_wumbo() && channel_value_satoshis >= MAX_FUNDING_SATOSHIS_NO_WUMBO {
+			return Err(APIError::APIMisuseError{err: format!("funding_value must be smaller than {}, it was {}", MAX_FUNDING_SATOSHIS_NO_WUMBO, channel_value_satoshis) });
+		}
+		if channel_value_satoshis >= TOTAL_BITCOIN_SUPPLY_SATOSHIS {
+			return Err(APIError::APIMisuseError { err: format!("funding_value must be smaller than the total bitcoin supply, it was {}", channel_value_satoshis) });
 		}
 		let channel_value_msat = channel_value_satoshis * 1000;
 		if push_msat > channel_value_msat {
@@ -1080,9 +1083,15 @@ impl<Signer: Sign> Channel<Signer> {
 		}
 
 		// Check sanity of message fields:
-		if msg.funding_satoshis >= MAX_FUNDING_SATOSHIS_NO_WUMBO {
+		if !their_features.supports_wumbo() && msg.funding_satoshis >= MAX_FUNDING_SATOSHIS_NO_WUMBO {
 			return Err(ChannelError::Close(format!("Funding must be smaller than {}. It was {}", MAX_FUNDING_SATOSHIS_NO_WUMBO, msg.funding_satoshis)));
 		}
+		if msg.funding_satoshis >= config.peer_channel_config_limits.max_funding_satoshis {
+			return Err(ChannelError::Close(format!("Per our config, funding must be smaller than {}. It was {}", config.peer_channel_config_limits.max_funding_satoshis, msg.funding_satoshis)));
+		}
+		if msg.funding_satoshis > TOTAL_BITCOIN_SUPPLY_SATOSHIS {
+			return Err(ChannelError::Close(format!("Funding must be smaller than the total bitcoin supply. It was {}", msg.funding_satoshis)));
+		}
 		if msg.channel_reserve_satoshis > msg.funding_satoshis {
 			return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must be not greater than funding_satoshis: {}", msg.channel_reserve_satoshis, msg.funding_satoshis)));
 		}
@@ -4114,7 +4123,7 @@ impl<Signer: Sign> Channel<Signer> {
 		if !self.pending_inbound_htlcs.is_empty() || !self.pending_outbound_htlcs.is_empty() {
 			return Err(ChannelError::Close("Remote end sent us a closing_signed while there were still pending HTLCs".to_owned()));
 		}
-		if msg.fee_satoshis > TOTAL_BITCOIN_SUPPLY_SATOSHIS { //this is required to stop potential overflow in build_closing_transaction
+		if msg.fee_satoshis > TOTAL_BITCOIN_SUPPLY_SATOSHIS { // this is required to stop potential overflow in build_closing_transaction
 			return Err(ChannelError::Close("Remote tried to send us a closing tx with > 21 million BTC fee".to_owned()));
 		}
 

lightning/src/ln/features.rs

@@ -743,6 +743,15 @@ impl<T: sealed::ShutdownAnySegwit> Features<T> {
 		self
 	}
 }
+
+impl<T: sealed::Wumbo> Features<T> {
+	#[cfg(test)]
+	pub(crate) fn clear_wumbo(mut self) -> Self {
+		<T as sealed::Wumbo>::clear_bits(&mut self.flags);
+		self
+	}
+}
+
 macro_rules! impl_feature_len_prefixed_write {
 	($features: ident) => {
 		impl Writeable for $features {

lightning/src/ln/functional_tests.rs

@@ -97,7 +97,12 @@ fn test_insane_channel_opens() {
 	use ln::channelmanager::MAX_LOCAL_BREAKDOWN_TIMEOUT;
 
 	// Test all mutations that would make the channel open message insane
-	insane_open_helper(format!("Funding must be smaller than {}. It was {}", MAX_FUNDING_SATOSHIS_NO_WUMBO, MAX_FUNDING_SATOSHIS_NO_WUMBO).as_str(), |mut msg| { msg.funding_satoshis = MAX_FUNDING_SATOSHIS_NO_WUMBO; msg }, |f| f);
+	insane_open_helper(
+		format!("Funding must be smaller than {}. It was {}", MAX_FUNDING_SATOSHIS_NO_WUMBO, MAX_FUNDING_SATOSHIS_NO_WUMBO).as_str(),
+		|mut msg| { msg.funding_satoshis = MAX_FUNDING_SATOSHIS_NO_WUMBO; msg },
+		|features| features.clear_wumbo());
+
+	insane_open_helper(format!("Per our config, funding must be smaller than {}. It was {}", MAX_FUNDING_SATOSHIS_NO_WUMBO, MAX_FUNDING_SATOSHIS_NO_WUMBO).as_str(), |mut msg| { msg.funding_satoshis = MAX_FUNDING_SATOSHIS_NO_WUMBO; msg }, |f| f);
 
 	insane_open_helper("Bogus channel_reserve_satoshis", |mut msg| { msg.channel_reserve_satoshis = msg.funding_satoshis + 1; msg }, |f| f);