X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Ffeatures.rs;h=77d0fa4529fb2ea526682079229b81fa9165ddf6;hb=7527e4b7df674fc2f5442514bb7b1d2294e59ce8;hp=4425a78e03f9ad406fe885e9f65d91a00d866115;hpb=b83e93c799b26fe1cb37e6a43a693e6ed66cdb59;p=rust-lightning

diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs
index 4425a78e..77d0fa45 100644
--- a/lightning/src/ln/features.rs
+++ b/lightning/src/ln/features.rs
@@ -56,20 +56,20 @@
 //! [BOLT #9]: https://github.com/lightning/bolts/blob/master/09-features.md
 //! [messages]: crate::ln::msgs
 
-use {io, io_extras};
-use prelude::*;
+use crate::{io, io_extras};
+use crate::prelude::*;
 use core::{cmp, fmt};
 use core::hash::{Hash, Hasher};
 use core::marker::PhantomData;
 
 use bitcoin::bech32;
 use bitcoin::bech32::{Base32Len, FromBase32, ToBase32, u5, WriteBase32};
-use ln::msgs::DecodeError;
-use util::ser::{Readable, Writeable, Writer};
+use crate::ln::msgs::DecodeError;
+use crate::util::ser::{Readable, Writeable, Writer};
 
 mod sealed {
-	use prelude::*;
-	use ln::features::Features;
+	use crate::prelude::*;
+	use crate::ln::features::Features;
 
 	/// The context in which [`Features`] are applicable. Defines which features are known to the
 	/// implementation, though specification of them as required or optional is up to the code
@@ -157,6 +157,7 @@ mod sealed {
 		// Byte 2
 		BasicMPP,
 	]);
+	define_context!(OfferContext, []);
 	// This isn't a "real" feature context, and is only used in the channel_type field in an
 	// `OpenChannel` message.
 	define_context!(ChannelTypeContext, [
@@ -203,6 +204,12 @@ mod sealed {
 				/// [`ODD_BIT`]: #associatedconstant.ODD_BIT
 				const ASSERT_ODD_BIT_PARITY: usize;
 
+				/// Assertion that the bits are set in the context's [`KNOWN_FEATURE_MASK`].
+				///
+				/// [`KNOWN_FEATURE_MASK`]: Context::KNOWN_FEATURE_MASK
+				#[cfg(not(test))] // We violate this constraint with `UnknownFeature`
+				const ASSERT_BITS_IN_MASK: u8;
+
 				/// The byte where the feature is set.
 				const BYTE_OFFSET: usize = Self::EVEN_BIT / 8;
 
@@ -289,6 +296,12 @@ mod sealed {
 
 					// ODD_BIT % 2 == 1
 					const ASSERT_ODD_BIT_PARITY: usize = (<Self as $feature>::ODD_BIT % 2) - 1;
+
+					// (byte & (REQUIRED_MASK | OPTIONAL_MASK)) >> (EVEN_BIT % 8) == 3
+					#[cfg(not(test))] // We violate this constraint with `UnknownFeature`
+					const ASSERT_BITS_IN_MASK: u8 =
+						((<$context>::KNOWN_FEATURE_MASK[<Self as $feature>::BYTE_OFFSET] & (<Self as $feature>::REQUIRED_MASK | <Self as $feature>::OPTIONAL_MASK))
+						 >> (<Self as $feature>::EVEN_BIT % 8)) - 3;
 				}
 			)*
 		};
@@ -354,7 +367,7 @@ mod sealed {
 		supports_keysend, requires_keysend);
 
 	#[cfg(test)]
-	define_feature!(123456789, UnknownFeature, [NodeContext, ChannelContext, InvoiceContext],
+	define_feature!(123456789, UnknownFeature, [NodeContext, ChannelContext, InvoiceContext, OfferContext],
 		"Feature flags for an unknown feature used in testing.", set_unknown_feature_optional,
 		set_unknown_feature_required, supports_unknown_test_feature, requires_unknown_test_feature);
 }
@@ -413,6 +426,8 @@ pub type NodeFeatures = Features<sealed::NodeContext>;
 pub type ChannelFeatures = Features<sealed::ChannelContext>;
 /// Features used within an invoice.
 pub type InvoiceFeatures = Features<sealed::InvoiceContext>;
+/// Features used within an offer.
+pub type OfferFeatures = Features<sealed::OfferContext>;
 
 /// Features used within the channel_type field in an OpenChannel message.
 ///
@@ -672,6 +687,15 @@ impl<T: sealed::Wumbo> Features<T> {
 	}
 }
 
+#[cfg(test)]
+impl<T: sealed::UnknownFeature> Features<T> {
+	pub(crate) fn unknown() -> Self {
+		let mut features = Self::empty();
+		features.set_unknown_feature_required();
+		features
+	}
+}
+
 macro_rules! impl_feature_len_prefixed_write {
 	($features: ident) => {
 		impl Writeable for $features {
@@ -692,21 +716,26 @@ impl_feature_len_prefixed_write!(ChannelFeatures);
 impl_feature_len_prefixed_write!(NodeFeatures);
 impl_feature_len_prefixed_write!(InvoiceFeatures);
 
-// Because ChannelTypeFeatures only appears inside of TLVs, it doesn't have a length prefix when
-// serialized. Thus, we can't use `impl_feature_len_prefixed_write`, above, and have to write our
-// own serialization.
-impl Writeable for ChannelTypeFeatures {
-	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
-		self.write_be(w)
-	}
-}
-impl Readable for ChannelTypeFeatures {
-	fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
-		let v = io_extras::read_to_end(r)?;
-		Ok(Self::from_be_bytes(v))
+// Some features only appear inside of TLVs, so they don't have a length prefix when serialized.
+macro_rules! impl_feature_tlv_write {
+	($features: ident) => {
+		impl Writeable for $features {
+			fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+				self.write_be(w)
+			}
+		}
+		impl Readable for $features {
+			fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
+				let v = io_extras::read_to_end(r)?;
+				Ok(Self::from_be_bytes(v))
+			}
+		}
 	}
 }
 
+impl_feature_tlv_write!(ChannelTypeFeatures);
+impl_feature_tlv_write!(OfferFeatures);
+
 #[cfg(test)]
 mod tests {
 	use super::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, InvoiceFeatures, NodeFeatures, sealed};