Merge pull request #1688 from valentinewallace/2022-08-flip-om-feature-bit

[rust-lightning] / lightning / src / ln / features.rs

diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs
index 91922f1a45f26748f9fdaf8c7ba009a068f6d6b9..642298f56ed52265952eb2b4642163a06f5b0474 100644 (file)
--- a/lightning/src/ln/features.rs
+++ b/lightning/src/ln/features.rs
@@ -39,8 +39,13 @@
 //!     (see [BOLT-4](https://github.com/lightning/bolts/blob/master/04-onion-routing.md) for more information).
 //! - `BasicMPP` - requires/supports that a node can receive basic multi-part payments
 //!     (see [BOLT-4](https://github.com/lightning/bolts/blob/master/04-onion-routing.md#basic-multi-part-payments) for more information).
+//! - `Wumbo` - requires/supports that a node create large channels. Called `option_support_large_channel` in the spec.
+//!     (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-open_channel-message) for more information).
 //! - `ShutdownAnySegwit` - requires/supports that future segwit versions are allowed in `shutdown`
 //!     (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
+//! - `OnionMessages` - requires/supports forwarding onion messages
+//!     (see [BOLT-7](https://github.com/lightning/bolts/pull/759/files) for more information).
+//!     TODO: update link
 //! - `ChannelType` - node supports the channel_type field in open/accept
 //!     (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
 //! - `SCIDPrivacy` - supply channel aliases for routing
@@ -164,7 +169,8 @@ mod sealed {
                ],
                optional_features: [
                        // Note that if new "non-channel-related" flags are added here they should be
-                       // explicitly cleared in InitFeatures::known_channel_features.
+                       // explicitly cleared in InitFeatures::known_channel_features and
+                       // NodeFeatures::known_channel_features.
                        // Byte 0
                        DataLossProtect | InitialRoutingSync | UpfrontShutdownScript | GossipQueries,
                        // Byte 1
@@ -174,7 +180,7 @@ mod sealed {
                        // Byte 3
                        ShutdownAnySegwit,
                        // Byte 4
-                       ,
+                       OnionMessages,
                        // Byte 5
                        ChannelType | SCIDPrivacy,
                        // Byte 6
@@ -208,7 +214,7 @@ mod sealed {
                        // Byte 3
                        ShutdownAnySegwit,
                        // Byte 4
-                       ,
+                       OnionMessages,
                        // Byte 5
                        ChannelType | SCIDPrivacy,
                        // Byte 6
@@ -435,8 +441,6 @@ mod sealed {
        define_feature!(27, ShutdownAnySegwit, [InitContext, NodeContext],
                "Feature flags for `opt_shutdown_anysegwit`.", set_shutdown_any_segwit_optional,
                set_shutdown_any_segwit_required, supports_shutdown_anysegwit, requires_shutdown_anysegwit);
-       // We do not yet advertise the onion messages feature bit, but we need to detect when peers
-       // support it.
        define_feature!(39, OnionMessages, [InitContext, NodeContext],
                "Feature flags for `option_onion_messages`.", set_onion_messages_optional,
                set_onion_messages_required, supports_onion_messages, requires_onion_messages);
@@ -470,6 +474,17 @@ pub struct Features<T: sealed::Context> {
        mark: PhantomData<T>,
 }
 
+impl <T: sealed::Context> Features<T> {
+       pub(crate) fn or(mut self, o: Self) -> Self {
+               let total_feature_len = cmp::max(self.flags.len(), o.flags.len());
+               self.flags.resize(total_feature_len, 0u8);
+               for (byte, o_byte) in self.flags.iter_mut().zip(o.flags.iter()) {
+                       *byte |= *o_byte;
+               }
+               self
+       }
+}
+
 impl<T: sealed::Context> Clone for Features<T> {
        fn clone(&self) -> Self {
                Self {
@@ -532,16 +547,6 @@ impl InitFeatures {
                Ok(())
        }
 
-       /// or's another InitFeatures into this one.
-       pub(crate) fn or(mut self, o: InitFeatures) -> InitFeatures {
-               let total_feature_len = cmp::max(self.flags.len(), o.flags.len());
-               self.flags.resize(total_feature_len, 0u8);
-               for (byte, o_byte) in self.flags.iter_mut().zip(o.flags.iter()) {
-                       *byte |= *o_byte;
-               }
-               self
-       }
-
        /// Converts `InitFeatures` to `Features<C>`. Only known `InitFeatures` relevant to context `C`
        /// are included in the result.
        pub(crate) fn to_context<C: sealed::Context>(&self) -> Features<C> {
@@ -554,6 +559,16 @@ impl InitFeatures {
                Self::known()
                        .clear_initial_routing_sync()
                        .clear_gossip_queries()
+                       .clear_onion_messages()
+       }
+}
+
+impl NodeFeatures {
+       /// Returns the set of known node features that are related to channels.
+       pub fn known_channel_features() -> NodeFeatures {
+               Self::known()
+                       .clear_gossip_queries()
+                       .clear_onion_messages()
        }
 }
 
@@ -787,6 +802,13 @@ impl<T: sealed::InitialRoutingSync> Features<T> {
        }
 }
 
+impl<T: sealed::OnionMessages> Features<T> {
+       pub(crate) fn clear_onion_messages(mut self) -> Self {
+               <T as sealed::OnionMessages>::clear_bits(&mut self.flags);
+               self
+       }
+}
+
 impl<T: sealed::ShutdownAnySegwit> Features<T> {
        #[cfg(test)]
        pub(crate) fn clear_shutdown_anysegwit(mut self) -> Self {
@@ -913,6 +935,11 @@ mod tests {
                assert!(!InitFeatures::known().requires_wumbo());
                assert!(!NodeFeatures::known().requires_wumbo());
 
+               assert!(InitFeatures::known().supports_onion_messages());
+               assert!(NodeFeatures::known().supports_onion_messages());
+               assert!(!InitFeatures::known().requires_onion_messages());
+               assert!(!NodeFeatures::known().requires_onion_messages());
+
                assert!(InitFeatures::known().supports_zero_conf());
                assert!(!InitFeatures::known().requires_zero_conf());
                assert!(NodeFeatures::known().supports_zero_conf());
@@ -957,7 +984,7 @@ mod tests {
                        // - var_onion_optin (req) | static_remote_key (req) | payment_secret(req)
                        // - basic_mpp | wumbo
                        // - opt_shutdown_anysegwit
-                       // -
+                       // - onion_messages
                        // - option_channel_type | option_scid_alias
                        // - option_zeroconf
                        assert_eq!(node_features.flags.len(), 7);
@@ -965,7 +992,7 @@ mod tests {
                        assert_eq!(node_features.flags[1], 0b01010001);
                        assert_eq!(node_features.flags[2], 0b00001010);
                        assert_eq!(node_features.flags[3], 0b00001000);
-                       assert_eq!(node_features.flags[4], 0b00000000);
+                       assert_eq!(node_features.flags[4], 0b10000000);
                        assert_eq!(node_features.flags[5], 0b10100000);
                        assert_eq!(node_features.flags[6], 0b00001000);
                }