X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Ffeatures.rs;h=18ea7bffbb8a5840ec7441e6171572630ea9573e;hb=1da1ffa04b7e7b5bb7c19fb9109bfd6c62f5a612;hp=dd0b7fa1a82aba540a259bd18ede2b5156c9eef1;hpb=c906f2843234ba9164e562a19bccaabde0243d95;p=rust-lightning

diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs
index dd0b7fa1..18ea7bff 100644
--- a/lightning/src/ln/features.rs
+++ b/lightning/src/ln/features.rs
@@ -150,11 +150,18 @@ impl NodeFeatures {
 
 	/// Takes the flags that we know how to interpret in an init-context features that are also
 	/// relevant in a node-context features and creates a node-context features from them.
+	/// Be sure to blank out features that are unknown to us.
 	pub(crate) fn with_known_relevant_init_flags(init_ctx: &InitFeatures) -> Self {
 		let mut flags = Vec::new();
-		if init_ctx.flags.len() > 0 {
-			// Pull out data_loss_protect and upfront_shutdown_script (bits 0, 1, 4, and 5)
-			flags.push(init_ctx.flags.last().unwrap() & 0b00110011);
+		for (i, feature_byte)in init_ctx.flags.iter().enumerate() {
+			match i {
+				// Blank out initial_routing_sync (feature bits 2/3), gossip_queries (6/7),
+				// gossip_queries_ex (10/11), option_static_remotekey (12/13), and
+				// payment_secret (14/15)
+				0 => flags.push(feature_byte & 0b00110011),
+				1 => flags.push(feature_byte & 0b00000011),
+				_ => (),
+			}
 		}
 		Self { flags, mark: PhantomData, }
 	}
@@ -187,8 +194,14 @@ impl<T: sealed::Context> Features<T> {
 	pub(crate) fn requires_unknown_bits(&self) -> bool {
 		self.flags.iter().enumerate().any(|(idx, &byte)| {
 			(match idx {
-				0 => (byte & 0b00010100),
+				// Unknown bits are even bits which we don't understand, we list ones which we do
+				// here:
+				// unknown, upfront_shutdown_script, unknown (actually initial_routing_sync, but it
+				// is only valid as an optional feature), and data_loss_protect:
+				0 => (byte & 0b01000100),
+				// unknown, unknown, unknown, var_onion_optin:
 				1 => (byte & 0b01010100),
+				// fallback, all even bits set:
 				_ => (byte & 0b01010101),
 			}) != 0
 		})
@@ -197,7 +210,10 @@ impl<T: sealed::Context> Features<T> {
 	pub(crate) fn supports_unknown_bits(&self) -> bool {
 		self.flags.iter().enumerate().any(|(idx, &byte)| {
 			(match idx {
+				// unknown, upfront_shutdown_script, initial_routing_sync (is only valid as an
+				// optional feature), and data_loss_protect:
 				0 => (byte & 0b11000100),
+				// unknown, unknown, unknown, var_onion_optin:
 				1 => (byte & 0b11111100),
 				_ => byte,
 			}) != 0
@@ -274,8 +290,8 @@ impl<T: sealed::Context> Writeable for Features<T> {
 	}
 }
 
-impl<R: ::std::io::Read, T: sealed::Context> Readable<R> for Features<T> {
-	fn read(r: &mut R) -> Result<Self, DecodeError> {
+impl<T: sealed::Context> Readable for Features<T> {
+	fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
 		let mut flags: Vec<u8> = Readable::read(r)?;
 		flags.reverse(); // Swap to little-endian
 		Ok(Self {
@@ -284,3 +300,63 @@ impl<R: ::std::io::Read, T: sealed::Context> Readable<R> for Features<T> {
 		})
 	}
 }
+
+#[cfg(test)]
+mod tests {
+	use super::{ChannelFeatures, InitFeatures, NodeFeatures, Features};
+
+	#[test]
+	fn sanity_test_our_features() {
+		assert!(!ChannelFeatures::supported().requires_unknown_bits());
+		assert!(!ChannelFeatures::supported().supports_unknown_bits());
+		assert!(!InitFeatures::supported().requires_unknown_bits());
+		assert!(!InitFeatures::supported().supports_unknown_bits());
+		assert!(!NodeFeatures::supported().requires_unknown_bits());
+		assert!(!NodeFeatures::supported().supports_unknown_bits());
+
+		assert!(InitFeatures::supported().supports_upfront_shutdown_script());
+		assert!(NodeFeatures::supported().supports_upfront_shutdown_script());
+
+		assert!(InitFeatures::supported().supports_data_loss_protect());
+		assert!(NodeFeatures::supported().supports_data_loss_protect());
+
+		assert!(InitFeatures::supported().supports_variable_length_onion());
+		assert!(NodeFeatures::supported().supports_variable_length_onion());
+
+		let mut init_features = InitFeatures::supported();
+		init_features.set_initial_routing_sync();
+		assert!(!init_features.requires_unknown_bits());
+		assert!(!init_features.supports_unknown_bits());
+	}
+
+	#[test]
+	fn sanity_test_unkown_bits_testing() {
+		let mut features = ChannelFeatures::supported();
+		features.set_require_unknown_bits();
+		assert!(features.requires_unknown_bits());
+		features.clear_require_unknown_bits();
+		assert!(!features.requires_unknown_bits());
+	}
+
+	#[test]
+	fn test_node_with_known_relevant_init_flags() {
+		// Create an InitFeatures with initial_routing_sync supported.
+		let mut init_features = InitFeatures::supported();
+		init_features.set_initial_routing_sync();
+
+		// Attempt to pull out non-node-context feature flags from these InitFeatures.
+		let res = NodeFeatures::with_known_relevant_init_flags(&init_features);
+
+		{
+			// Check that the flags are as expected: optional_data_loss_protect,
+			// option_upfront_shutdown_script, and var_onion_optin set.
+			assert_eq!(res.flags[0], 0b00100010);
+			assert_eq!(res.flags[1], 0b00000010);
+			assert_eq!(res.flags.len(), 2);
+		}
+
+		// Check that the initial_routing_sync feature was correctly blanked out.
+		let new_features: InitFeatures = Features::from_le_bytes(res.flags);
+		assert!(!new_features.initial_routing_sync());
+	}
+}