X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Ffeatures.rs;h=641c1ffb6f6230fcd0ec6b8f294a78a15c66be1b;hb=7728d3b6a86db7a12d591c8947fbe88a94fdffdd;hp=c334074871eb486a924da2eabdde30865dc55e22;hpb=09d2a71352f738de1f4f36248a735e6383ee0d8d;p=rust-lightning

diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs
index c3340748..641c1ffb 100644
--- a/lightning/src/ln/features.rs
+++ b/lightning/src/ln/features.rs
@@ -29,6 +29,18 @@ mod sealed { // You should just use the type aliases instead.
 	pub trait UpfrontShutdownScript: Context {}
 	impl UpfrontShutdownScript for InitContext {}
 	impl UpfrontShutdownScript for NodeContext {}
+
+	pub trait VariableLengthOnion: Context {}
+	impl VariableLengthOnion for InitContext {}
+	impl VariableLengthOnion for NodeContext {}
+
+	pub trait PaymentSecret: Context {}
+	impl PaymentSecret for InitContext {}
+	impl PaymentSecret for NodeContext {}
+
+	pub trait BasicMPP: Context {}
+	impl BasicMPP for InitContext {}
+	impl BasicMPP for NodeContext {}
 }
 
 /// Tracks the set of features which a node implements, templated by the context in which it
@@ -69,7 +81,7 @@ impl InitFeatures {
 	/// Create a Features with the features we support
 	pub fn supported() -> InitFeatures {
 		InitFeatures {
-			flags: vec![2 | 1 << 5],
+			flags: vec![2 | 1 << 5, 1 << (9-8) | 1 << (15 - 8), 1 << (17 - 8*2)],
 			mark: PhantomData,
 		}
 	}
@@ -118,6 +130,13 @@ impl ChannelFeatures {
 			mark: PhantomData,
 		}
 	}
+
+	/// Takes the flags that we know how to interpret in an init-context features that are also
+	/// relevant in a channel-context features and creates a channel-context features from them.
+	pub(crate) fn with_known_relevant_init_flags(_init_ctx: &InitFeatures) -> Self {
+		// There are currently no channel flags defined that we understand.
+		Self { flags: Vec::new(), mark: PhantomData, }
+	}
 }
 
 impl NodeFeatures {
@@ -125,17 +144,28 @@ impl NodeFeatures {
 	#[cfg(not(feature = "fuzztarget"))]
 	pub(crate) fn supported() -> NodeFeatures {
 		NodeFeatures {
-			flags: vec![2 | 1 << 5],
+			flags: vec![2 | 1 << 5, 1 << (9-8) | 1 << (15 - 8), 1 << (17 - 8*2)],
 			mark: PhantomData,
 		}
 	}
 	#[cfg(feature = "fuzztarget")]
 	pub fn supported() -> NodeFeatures {
 		NodeFeatures {
-			flags: vec![2 | 1 << 5],
+			flags: vec![2 | 1 << 5, 1 << (9-8) | 1 << (15 - 8), 1 << (17 - 8*2)],
 			mark: PhantomData,
 		}
 	}
+
+	/// 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.
+	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);
+		}
+		Self { flags, mark: PhantomData, }
+	}
 }
 
 impl<T: sealed::Context> Features<T> {
@@ -164,13 +194,23 @@ impl<T: sealed::Context> Features<T> {
 
 	pub(crate) fn requires_unknown_bits(&self) -> bool {
 		self.flags.iter().enumerate().any(|(idx, &byte)| {
-			( idx != 0 && (byte & 0x55) != 0 ) || ( idx == 0 && (byte & 0x14) != 0 )
+			(match idx {
+				0 => (byte & 0b01000100),
+				1 => (byte & 0b00010100),
+				2 => (byte & 0b01010100),
+				_ => (byte & 0b01010101),
+			}) != 0
 		})
 	}
 
 	pub(crate) fn supports_unknown_bits(&self) -> bool {
 		self.flags.iter().enumerate().any(|(idx, &byte)| {
-			( idx != 0 && byte != 0 ) || ( idx == 0 && (byte & 0xc4) != 0 )
+			(match idx {
+				0 => (byte & 0b11000100),
+				1 => (byte & 0b00111100),
+				2 => (byte & 0b11111100),
+				_ => byte,
+			}) != 0
 		})
 	}
 
@@ -182,16 +222,19 @@ impl<T: sealed::Context> Features<T> {
 
 	#[cfg(test)]
 	pub(crate) fn set_require_unknown_bits(&mut self) {
-		let newlen = cmp::max(2, self.flags.len());
+		let newlen = cmp::max(3, self.flags.len());
 		self.flags.resize(newlen, 0u8);
-		self.flags[1] |= 0x40;
+		self.flags[2] |= 0x40;
 	}
 
 	#[cfg(test)]
 	pub(crate) fn clear_require_unknown_bits(&mut self) {
-		let newlen = cmp::max(2, self.flags.len());
+		let newlen = cmp::max(3, self.flags.len());
 		self.flags.resize(newlen, 0u8);
-		self.flags[1] &= !0x40;
+		self.flags[2] &= !0x40;
+		if self.flags.len() == 3 && self.flags[2] == 0 {
+			self.flags.resize(2, 0u8);
+		}
 		if self.flags.len() == 2 && self.flags[1] == 0 {
 			self.flags.resize(1, 0u8);
 		}
@@ -214,6 +257,12 @@ impl<T: sealed::UpfrontShutdownScript> Features<T> {
 	}
 }
 
+impl<T: sealed::VariableLengthOnion> Features<T> {
+	pub(crate) fn supports_variable_length_onion(&self) -> bool {
+		self.flags.len() > 1 && (self.flags[1] & 3) != 0
+	}
+}
+
 impl<T: sealed::InitialRoutingSync> Features<T> {
 	pub(crate) fn initial_routing_sync(&self) -> bool {
 		self.flags.len() > 0 && (self.flags[0] & (1 << 3)) != 0
@@ -227,6 +276,23 @@ impl<T: sealed::InitialRoutingSync> Features<T> {
 	}
 }
 
+impl<T: sealed::PaymentSecret> Features<T> {
+	#[allow(dead_code)]
+	// Note that we never need to test this since what really matters is the invoice - iff the
+	// invoice provides a payment_secret, we assume all the way through that we can do MPP.
+	pub(crate) fn payment_secret(&self) -> bool {
+		self.flags.len() > 1 && (self.flags[1] & (3 << (12-8))) != 0
+	}
+}
+
+impl<T: sealed::BasicMPP> Features<T> {
+	// We currently never test for this since we don't actually *generate* multipath routes.
+	#[allow(dead_code)]
+	pub(crate) fn basic_mpp(&self) -> bool {
+		self.flags.len() > 2 && (self.flags[2] & (3 << (16-8*2))) != 0
+	}
+}
+
 impl<T: sealed::Context> Writeable for Features<T> {
 	fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 		w.size_hint(self.flags.len() + 2);
@@ -248,3 +314,38 @@ impl<R: ::std::io::Read, T: sealed::Context> Readable<R> for Features<T> {
 		})
 	}
 }
+
+#[cfg(test)]
+mod tests {
+	use super::{ChannelFeatures, InitFeatures, NodeFeatures};
+
+	#[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());
+
+		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());
+	}
+}