X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Ffeatures.rs;h=b4a5c5ae52d5282135b6e664819c2b5962ea0b2c;hb=31e78ff258195837abafa045c12c036528696d7f;hp=082890557d3fdbf20af0f22509258628fb6e6771;hpb=31a59629c4d309a8e023632508b11943c74fff33;p=rust-lightning

diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs
index 08289055..b4a5c5ae 100644
--- a/lightning/src/ln/features.rs
+++ b/lightning/src/ln/features.rs
@@ -393,7 +393,7 @@ mod sealed {
 /// Tracks the set of features which a node implements, templated by the context in which it
 /// appears.
 ///
-/// (C-not exported) as we map the concrete feature types below directly instead
+/// This is not exported to bindings users as we map the concrete feature types below directly instead
 #[derive(Eq)]
 pub struct Features<T: sealed::Context> {
 	/// Note that, for convenience, flags is LITTLE endian (despite being big-endian on the wire)
@@ -512,10 +512,10 @@ impl InvoiceFeatures {
 }
 
 impl ChannelTypeFeatures {
-	/// Constructs the implicit channel type based on the common supported types between us and our
-	/// counterparty
-	pub(crate) fn from_counterparty_init(counterparty_init: &InitFeatures) -> Self {
-		let mut ret = counterparty_init.to_context_internal();
+	// Maps the relevant `InitFeatures` to `ChannelTypeFeatures`. Any unknown features to
+	// `ChannelTypeFeatures` are not included in the result.
+	pub(crate) fn from_init(init: &InitFeatures) -> Self {
+		let mut ret = init.to_context_internal();
 		// ChannelTypeFeatures must only contain required bits, so we OR the required forms of all
 		// optional bits and then AND out the optional ones.
 		for byte in ret.flags.iter_mut() {
@@ -622,7 +622,8 @@ impl<T: sealed::Context> Features<T> {
 
 	/// Create a Features given a set of flags, in little-endian. This is in reverse byte order from
 	/// most on-the-wire encodings.
-	/// (C-not exported) as we don't support export across multiple T
+	///
+	/// This is not exported to bindings users as we don't support export across multiple T
 	pub fn from_le_bytes(flags: Vec<u8>) -> Features<T> {
 		Features {
 			flags,
@@ -685,6 +686,24 @@ impl<T: sealed::Context> Features<T> {
 			(byte & unknown_features) != 0
 		})
 	}
+
+	// Returns true if the features within `self` are a subset of the features within `other`.
+	pub(crate) fn is_subset(&self, other: &Self) -> bool {
+		for (idx, byte) in self.flags.iter().enumerate() {
+			if let Some(other_byte) = other.flags.get(idx) {
+				if byte & other_byte != *byte {
+					// `self` has bits set that `other` doesn't.
+					return false;
+				}
+			} else {
+				if *byte > 0 {
+					// `self` has a non-zero byte that `other` doesn't.
+					return false;
+				}
+			}
+		}
+		true
+	}
 }
 
 impl<T: sealed::UpfrontShutdownScript> Features<T> {
@@ -711,6 +730,18 @@ impl<T: sealed::Wumbo> Features<T> {
 	}
 }
 
+impl<T: sealed::SCIDPrivacy> Features<T> {
+	pub(crate) fn clear_scid_privacy(&mut self) {
+		<T as sealed::SCIDPrivacy>::clear_bits(&mut self.flags);
+	}
+}
+
+impl<T: sealed::AnchorsZeroFeeHtlcTx> Features<T> {
+	pub(crate) fn clear_anchors_zero_fee_htlc_tx(&mut self) {
+		<T as sealed::AnchorsZeroFeeHtlcTx>::clear_bits(&mut self.flags);
+	}
+}
+
 #[cfg(test)]
 impl<T: sealed::UnknownFeature> Features<T> {
 	pub(crate) fn unknown() -> Self {
@@ -815,6 +846,7 @@ mod tests {
 		init_features.set_channel_type_optional();
 		init_features.set_scid_privacy_optional();
 		init_features.set_zero_conf_optional();
+		init_features.set_anchors_zero_fee_htlc_tx_optional();
 
 		assert!(init_features.initial_routing_sync());
 		assert!(!init_features.supports_upfront_shutdown_script());
@@ -924,7 +956,7 @@ mod tests {
 		// required-StaticRemoteKey ChannelTypeFeatures.
 		let mut init_features = InitFeatures::empty();
 		init_features.set_static_remote_key_optional();
-		let converted_features = ChannelTypeFeatures::from_counterparty_init(&init_features);
+		let converted_features = ChannelTypeFeatures::from_init(&init_features);
 		assert_eq!(converted_features, ChannelTypeFeatures::only_static_remote_key());
 		assert!(!converted_features.supports_any_optional_bits());
 		assert!(converted_features.requires_static_remote_key());