Merge pull request #1657 from TheBlueMatt/2022-08-async-man-update
[rust-lightning] / lightning / src / ln / features.rs
index dab841327802fc8ae3ee0c869395a7ce378c4148..c978c61a3a563428e38f3368e557e544a6c623b9 100644 (file)
 //! supports a feature if it advertises the feature (as either required or optional) to its peers.
 //! And the implementation can interpret a feature if the feature is known to it.
 //!
-//! [BOLT #9]: https://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md
+//! The following features are currently required in the LDK:
+//! - `VariableLengthOnion` - requires/supports variable-length routing onion payloads
+//!     (see [BOLT-4](https://github.com/lightning/bolts/blob/master/04-onion-routing.md) for more information).
+//! - `StaticRemoteKey` - requires/supports static key for remote output
+//!     (see [BOLT-3](https://github.com/lightning/bolts/blob/master/03-transactions.md) for more information).
+//!
+//! The following features are currently supported in the LDK:
+//! - `DataLossProtect` - requires/supports that a node which has somehow fallen behind, e.g., has been restored from an old backup,
+//!     can detect that it has fallen behind
+//!     (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
+//! - `InitialRoutingSync` - requires/supports that the sending node needs a complete routing information dump
+//!     (see [BOLT-7](https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#initial-sync) for more information).
+//! - `UpfrontShutdownScript` - commits to a shutdown scriptpubkey when opening a channel
+//!     (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-open_channel-message) for more information).
+//! - `GossipQueries` - requires/supports more sophisticated gossip control
+//!     (see [BOLT-7](https://github.com/lightning/bolts/blob/master/07-routing-gossip.md) for more information).
+//! - `PaymentSecret` - requires/supports that a node supports payment_secret field
+//!     (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).
+//! - `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).
+//! - `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
+//!     (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
+//! - `Keysend` - send funds to a node without an invoice
+//!     (see the [`Keysend` feature assignment proposal](https://github.com/lightning/bolts/issues/605#issuecomment-606679798) for more information).
+//!
+//! [BOLT #9]: https://github.com/lightning/bolts/blob/master/09-features.md
 //! [messages]: crate::ln::msgs
 
 use {io, io_extras};
@@ -130,6 +159,8 @@ mod sealed {
                        ,
                        // Byte 5
                        ,
+                       // Byte 6
+                       ,
                ],
                optional_features: [
                        // Byte 0
@@ -137,13 +168,15 @@ mod sealed {
                        // Byte 1
                        ,
                        // Byte 2
-                       BasicMPP,
+                       BasicMPP | Wumbo,
                        // Byte 3
                        ShutdownAnySegwit,
                        // Byte 4
                        ,
                        // Byte 5
-                       ChannelType,
+                       ChannelType | SCIDPrivacy,
+                       // Byte 6
+                       ZeroConf,
                ],
        });
        define_context!(NodeContext {
@@ -169,15 +202,15 @@ mod sealed {
                        // Byte 1
                        ,
                        // Byte 2
-                       BasicMPP,
+                       BasicMPP | Wumbo,
                        // Byte 3
                        ShutdownAnySegwit,
                        // Byte 4
                        ,
                        // Byte 5
-                       ChannelType,
+                       ChannelType | SCIDPrivacy,
                        // Byte 6
-                       Keysend,
+                       ZeroConf | Keysend,
                ],
        });
        define_context!(ChannelContext {
@@ -214,6 +247,12 @@ mod sealed {
                        ,
                        // Byte 3
                        ,
+                       // Byte 4
+                       ,
+                       // Byte 5
+                       SCIDPrivacy,
+                       // Byte 6
+                       ZeroConf,
                ],
                optional_features: [
                        // Byte 0
@@ -224,6 +263,12 @@ mod sealed {
                        ,
                        // Byte 3
                        ,
+                       // Byte 4
+                       ,
+                       // Byte 5
+                       ,
+                       // Byte 6
+                       ,
                ],
        });
 
@@ -236,7 +281,7 @@ mod sealed {
                        ///
                        /// See [BOLT #9] for details.
                        ///
-                       /// [BOLT #9]: https://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md
+                       /// [BOLT #9]: https://github.com/lightning/bolts/blob/master/09-features.md
                        pub trait $feature: Context {
                                /// The bit used to signify that the feature is required.
                                const EVEN_BIT: usize = $odd_bit - 1;
@@ -318,15 +363,13 @@ mod sealed {
 
                        impl <T: $feature> Features<T> {
                                /// Set this feature as optional.
-                               pub fn $optional_setter(mut self) -> Self {
+                               pub fn $optional_setter(&mut self) {
                                        <T as $feature>::set_optional_bit(&mut self.flags);
-                                       self
                                }
 
                                /// Set this feature as required.
-                               pub fn $required_setter(mut self) -> Self {
+                               pub fn $required_setter(&mut self) {
                                        <T as $feature>::set_required_bit(&mut self.flags);
-                                       self
                                }
 
                                /// Checks if this feature is supported.
@@ -384,12 +427,26 @@ mod sealed {
        define_feature!(17, BasicMPP, [InitContext, NodeContext, InvoiceContext],
                "Feature flags for `basic_mpp`.", set_basic_mpp_optional, set_basic_mpp_required,
                supports_basic_mpp, requires_basic_mpp);
+       define_feature!(19, Wumbo, [InitContext, NodeContext],
+               "Feature flags for `option_support_large_channel` (aka wumbo channels).", set_wumbo_optional, set_wumbo_required,
+               supports_wumbo, requires_wumbo);
        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);
        define_feature!(45, ChannelType, [InitContext, NodeContext],
                "Feature flags for `option_channel_type`.", set_channel_type_optional,
                set_channel_type_required, supports_channel_type, requires_channel_type);
+       define_feature!(47, SCIDPrivacy, [InitContext, NodeContext, ChannelTypeContext],
+               "Feature flags for only forwarding with SCID aliasing. Called `option_scid_alias` in the BOLTs",
+               set_scid_privacy_optional, set_scid_privacy_required, supports_scid_privacy, requires_scid_privacy);
+       define_feature!(51, ZeroConf, [InitContext, NodeContext, ChannelTypeContext],
+               "Feature flags for accepting channels with zero confirmations. Called `option_zeroconf` in the BOLTs",
+               set_zero_conf_optional, set_zero_conf_required, supports_zero_conf, requires_zero_conf);
        define_feature!(55, Keysend, [NodeContext],
                "Feature flags for keysend payments.", set_keysend_optional, set_keysend_required,
                supports_keysend, requires_keysend);
@@ -500,13 +557,15 @@ impl InvoiceFeatures {
        /// Getting a route for a keysend payment to a private node requires providing the payee's
        /// features (since they were not announced in a node announcement). However, keysend payments
        /// don't have an invoice to pull the payee's features from, so this method is provided for use in
-       /// [`Payee::for_keysend`], thus omitting the need for payers to manually construct an
+       /// [`PaymentParameters::for_keysend`], thus omitting the need for payers to manually construct an
        /// `InvoiceFeatures` for [`find_route`].
        ///
-       /// [`Payee::for_keysend`]: crate::routing::router::Payee::for_keysend
+       /// [`PaymentParameters::for_keysend`]: crate::routing::router::PaymentParameters::for_keysend
        /// [`find_route`]: crate::routing::router::find_route
        pub(crate) fn for_keysend() -> InvoiceFeatures {
-               InvoiceFeatures::empty().set_variable_length_onion_optional()
+               let mut res = InvoiceFeatures::empty();
+               res.set_variable_length_onion_optional();
+               res
        }
 }
 
@@ -713,7 +772,7 @@ impl<T: sealed::GossipQueries> Features<T> {
 
 impl<T: sealed::InitialRoutingSync> Features<T> {
        // We are no longer setting initial_routing_sync now that gossip_queries
-       // is enabled. This feature is ignored by a peer when gossip_queries has 
+       // is enabled. This feature is ignored by a peer when gossip_queries has
        // been negotiated.
        #[cfg(test)]
        pub(crate) fn clear_initial_routing_sync(&mut self) {
@@ -728,6 +787,15 @@ impl<T: sealed::ShutdownAnySegwit> Features<T> {
                self
        }
 }
+
+impl<T: sealed::Wumbo> Features<T> {
+       #[cfg(test)]
+       pub(crate) fn clear_wumbo(mut self) -> Self {
+               <T as sealed::Wumbo>::clear_bits(&mut self.flags);
+               self
+       }
+}
+
 macro_rules! impl_feature_len_prefixed_write {
        ($features: ident) => {
                impl Writeable for $features {
@@ -826,6 +894,25 @@ mod tests {
                assert!(InitFeatures::known().supports_shutdown_anysegwit());
                assert!(NodeFeatures::known().supports_shutdown_anysegwit());
 
+               assert!(InitFeatures::known().supports_scid_privacy());
+               assert!(NodeFeatures::known().supports_scid_privacy());
+               assert!(ChannelTypeFeatures::known().supports_scid_privacy());
+               assert!(!InitFeatures::known().requires_scid_privacy());
+               assert!(!NodeFeatures::known().requires_scid_privacy());
+               assert!(ChannelTypeFeatures::known().requires_scid_privacy());
+
+               assert!(InitFeatures::known().supports_wumbo());
+               assert!(NodeFeatures::known().supports_wumbo());
+               assert!(!InitFeatures::known().requires_wumbo());
+               assert!(!NodeFeatures::known().requires_wumbo());
+
+               assert!(InitFeatures::known().supports_zero_conf());
+               assert!(!InitFeatures::known().requires_zero_conf());
+               assert!(NodeFeatures::known().supports_zero_conf());
+               assert!(!NodeFeatures::known().requires_zero_conf());
+               assert!(ChannelTypeFeatures::known().supports_zero_conf());
+               assert!(ChannelTypeFeatures::known().requires_zero_conf());
+
                let mut init_features = InitFeatures::known();
                assert!(init_features.initial_routing_sync());
                init_features.clear_initial_routing_sync();
@@ -838,11 +925,13 @@ mod tests {
                assert!(!features.requires_unknown_bits());
                assert!(!features.supports_unknown_bits());
 
-               let features = ChannelFeatures::empty().set_unknown_feature_required();
+               let mut features = ChannelFeatures::empty();
+               features.set_unknown_feature_required();
                assert!(features.requires_unknown_bits());
                assert!(features.supports_unknown_bits());
 
-               let features = ChannelFeatures::empty().set_unknown_feature_optional();
+               let mut features = ChannelFeatures::empty();
+               features.set_unknown_feature_optional();
                assert!(!features.requires_unknown_bits());
                assert!(features.supports_unknown_bits());
        }
@@ -859,17 +948,19 @@ mod tests {
                        // Check that the flags are as expected:
                        // - option_data_loss_protect
                        // - var_onion_optin (req) | static_remote_key (req) | payment_secret(req)
-                       // - basic_mpp
+                       // - basic_mpp | wumbo
                        // - opt_shutdown_anysegwit
                        // -
-                       // - option_channel_type
-                       assert_eq!(node_features.flags.len(), 6);
+                       // - option_channel_type | option_scid_alias
+                       // - option_zeroconf
+                       assert_eq!(node_features.flags.len(), 7);
                        assert_eq!(node_features.flags[0], 0b00000010);
                        assert_eq!(node_features.flags[1], 0b01010001);
-                       assert_eq!(node_features.flags[2], 0b00000010);
+                       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[5], 0b00100000);
+                       assert_eq!(node_features.flags[5], 0b10100000);
+                       assert_eq!(node_features.flags[6], 0b00001000);
                }
 
                // Check that cleared flags are kept blank when converting back:
@@ -886,7 +977,8 @@ mod tests {
        fn convert_to_context_with_unknown_flags() {
                // Ensure the `from` context has fewer known feature bytes than the `to` context.
                assert!(InvoiceFeatures::known().flags.len() < NodeFeatures::known().flags.len());
-               let invoice_features = InvoiceFeatures::known().set_unknown_feature_optional();
+               let mut invoice_features = InvoiceFeatures::known();
+               invoice_features.set_unknown_feature_optional();
                assert!(invoice_features.supports_unknown_bits());
                let node_features: NodeFeatures = invoice_features.to_context();
                assert!(!node_features.supports_unknown_bits());
@@ -894,9 +986,9 @@ mod tests {
 
        #[test]
        fn set_feature_bits() {
-               let features = InvoiceFeatures::empty()
-                       .set_basic_mpp_optional()
-                       .set_payment_secret_required();
+               let mut features = InvoiceFeatures::empty();
+               features.set_basic_mpp_optional();
+               features.set_payment_secret_required();
                assert!(features.supports_basic_mpp());
                assert!(!features.requires_basic_mpp());
                assert!(features.requires_payment_secret());
@@ -938,7 +1030,8 @@ mod tests {
        fn test_channel_type_mapping() {
                // If we map an InvoiceFeatures with StaticRemoteKey optional, it should map into a
                // required-StaticRemoteKey ChannelTypeFeatures.
-               let init_features = InitFeatures::empty().set_static_remote_key_optional();
+               let mut init_features = InitFeatures::empty();
+               init_features.set_static_remote_key_optional();
                let converted_features = ChannelTypeFeatures::from_counterparty_init(&init_features);
                assert_eq!(converted_features, ChannelTypeFeatures::only_static_remote_key());
                assert!(!converted_features.supports_any_optional_bits());