//! 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};
,
// Byte 3
,
+ // Byte 4
+ ,
+ // Byte 5
+ ,
+ // Byte 6
+ ,
],
optional_features: [
// Byte 0
// Byte 1
,
// Byte 2
- BasicMPP,
+ BasicMPP | Wumbo,
// Byte 3
ShutdownAnySegwit,
+ // Byte 4
+ ,
+ // Byte 5
+ ChannelType | SCIDPrivacy,
+ // Byte 6
+ ZeroConf,
],
});
define_context!(NodeContext {
// Byte 1
,
// Byte 2
- BasicMPP,
+ BasicMPP | Wumbo,
// Byte 3
ShutdownAnySegwit,
// Byte 4
,
// Byte 5
- ,
+ ChannelType | SCIDPrivacy,
// Byte 6
- Keysend,
+ ZeroConf | Keysend,
],
});
define_context!(ChannelContext {
,
// Byte 3
,
+ // Byte 4
+ ,
+ // Byte 5
+ SCIDPrivacy,
+ // Byte 6
+ ZeroConf,
],
optional_features: [
// Byte 0
,
// Byte 3
,
+ // Byte 4
+ ,
+ // Byte 5
+ ,
+ // Byte 6
+ ,
],
});
/// useful for manipulating feature flags.
macro_rules! define_feature {
($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr, $optional_setter: ident,
- $required_setter: ident) => {
+ $required_setter: ident, $supported_getter: ident) => {
#[doc = $doc]
///
/// 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;
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.
+ pub fn $supported_getter(&self) -> bool {
+ <T as $feature>::supports_feature(&self.flags)
}
}
const ASSERT_ODD_BIT_PARITY: usize = (<Self as $feature>::ODD_BIT % 2) - 1;
}
)*
-
+ };
+ ($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr, $optional_setter: ident,
+ $required_setter: ident, $supported_getter: ident, $required_getter: ident) => {
+ define_feature!($odd_bit, $feature, [$($context),+], $doc, $optional_setter, $required_setter, $supported_getter);
+ impl <T: $feature> Features<T> {
+ /// Checks if this feature is required.
+ pub fn $required_getter(&self) -> bool {
+ <T as $feature>::requires_feature(&self.flags)
+ }
+ }
}
}
define_feature!(1, DataLossProtect, [InitContext, NodeContext],
"Feature flags for `option_data_loss_protect`.", set_data_loss_protect_optional,
- set_data_loss_protect_required);
+ set_data_loss_protect_required, supports_data_loss_protect, requires_data_loss_protect);
// NOTE: Per Bolt #9, initial_routing_sync has no even bit.
define_feature!(3, InitialRoutingSync, [InitContext], "Feature flags for `initial_routing_sync`.",
- set_initial_routing_sync_optional, set_initial_routing_sync_required);
+ set_initial_routing_sync_optional, set_initial_routing_sync_required,
+ initial_routing_sync);
define_feature!(5, UpfrontShutdownScript, [InitContext, NodeContext],
"Feature flags for `option_upfront_shutdown_script`.", set_upfront_shutdown_script_optional,
- set_upfront_shutdown_script_required);
+ set_upfront_shutdown_script_required, supports_upfront_shutdown_script,
+ requires_upfront_shutdown_script);
define_feature!(7, GossipQueries, [InitContext, NodeContext],
- "Feature flags for `gossip_queries`.", set_gossip_queries_optional, set_gossip_queries_required);
+ "Feature flags for `gossip_queries`.", set_gossip_queries_optional, set_gossip_queries_required,
+ supports_gossip_queries, requires_gossip_queries);
define_feature!(9, VariableLengthOnion, [InitContext, NodeContext, InvoiceContext],
"Feature flags for `var_onion_optin`.", set_variable_length_onion_optional,
- set_variable_length_onion_required);
+ set_variable_length_onion_required, supports_variable_length_onion,
+ requires_variable_length_onion);
define_feature!(13, StaticRemoteKey, [InitContext, NodeContext, ChannelTypeContext],
"Feature flags for `option_static_remotekey`.", set_static_remote_key_optional,
- set_static_remote_key_required);
+ set_static_remote_key_required, supports_static_remote_key, requires_static_remote_key);
define_feature!(15, PaymentSecret, [InitContext, NodeContext, InvoiceContext],
- "Feature flags for `payment_secret`.", set_payment_secret_optional, set_payment_secret_required);
+ "Feature flags for `payment_secret`.", set_payment_secret_optional, set_payment_secret_required,
+ supports_payment_secret, requires_payment_secret);
define_feature!(17, BasicMPP, [InitContext, NodeContext, InvoiceContext],
- "Feature flags for `basic_mpp`.", set_basic_mpp_optional, set_basic_mpp_required);
+ "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);
+ 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);
+ "Feature flags for keysend payments.", set_keysend_optional, set_keysend_required,
+ supports_keysend, requires_keysend);
#[cfg(test)]
define_feature!(123456789, UnknownFeature, [NodeContext, ChannelContext, InvoiceContext],
"Feature flags for an unknown feature used in testing.", set_unknown_feature_optional,
- set_unknown_feature_required);
+ set_unknown_feature_required, supports_unknown_test_feature, requires_unknown_test_feature);
}
/// Tracks the set of features which a node implements, templated by the context in which it
/// 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
- /// [`get_keysend_route`], thus omitting the need for payers to manually construct an
- /// `InvoiceFeatures` for [`get_route`].
+ /// [`PaymentParameters::for_keysend`], thus omitting the need for payers to manually construct an
+ /// `InvoiceFeatures` for [`find_route`].
///
- /// [`get_keysend_route`]: crate::routing::router::get_keysend_route
- /// [`get_route`]: crate::routing::router::get_route
+ /// [`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
}
}
}
}
-impl<T: sealed::DataLossProtect> Features<T> {
- #[cfg(test)]
- pub(crate) fn requires_data_loss_protect(&self) -> bool {
- <T as sealed::DataLossProtect>::requires_feature(&self.flags)
- }
- #[cfg(test)]
- pub(crate) fn supports_data_loss_protect(&self) -> bool {
- <T as sealed::DataLossProtect>::supports_feature(&self.flags)
- }
-}
-
impl<T: sealed::UpfrontShutdownScript> Features<T> {
- #[cfg(test)]
- pub(crate) fn requires_upfront_shutdown_script(&self) -> bool {
- <T as sealed::UpfrontShutdownScript>::requires_feature(&self.flags)
- }
- pub(crate) fn supports_upfront_shutdown_script(&self) -> bool {
- <T as sealed::UpfrontShutdownScript>::supports_feature(&self.flags)
- }
#[cfg(test)]
pub(crate) fn clear_upfront_shutdown_script(mut self) -> Self {
<T as sealed::UpfrontShutdownScript>::clear_bits(&mut self.flags);
impl<T: sealed::GossipQueries> Features<T> {
- #[cfg(test)]
- pub(crate) fn requires_gossip_queries(&self) -> bool {
- <T as sealed::GossipQueries>::requires_feature(&self.flags)
- }
- pub(crate) fn supports_gossip_queries(&self) -> bool {
- <T as sealed::GossipQueries>::supports_feature(&self.flags)
- }
#[cfg(test)]
pub(crate) fn clear_gossip_queries(mut self) -> Self {
<T as sealed::GossipQueries>::clear_bits(&mut self.flags);
}
}
-impl<T: sealed::VariableLengthOnion> Features<T> {
- #[cfg(test)]
- pub(crate) fn requires_variable_length_onion(&self) -> bool {
- <T as sealed::VariableLengthOnion>::requires_feature(&self.flags)
- }
- pub(crate) fn supports_variable_length_onion(&self) -> bool {
- <T as sealed::VariableLengthOnion>::supports_feature(&self.flags)
- }
-}
-
-impl<T: sealed::StaticRemoteKey> Features<T> {
- pub(crate) fn supports_static_remote_key(&self) -> bool {
- <T as sealed::StaticRemoteKey>::supports_feature(&self.flags)
- }
- #[cfg(test)]
- pub(crate) fn requires_static_remote_key(&self) -> bool {
- <T as sealed::StaticRemoteKey>::requires_feature(&self.flags)
- }
-}
-
impl<T: sealed::InitialRoutingSync> Features<T> {
- pub(crate) fn initial_routing_sync(&self) -> bool {
- <T as sealed::InitialRoutingSync>::supports_feature(&self.flags)
- }
// 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) {
}
}
-impl<T: sealed::PaymentSecret> Features<T> {
- #[cfg(test)]
- pub(crate) fn requires_payment_secret(&self) -> bool {
- <T as sealed::PaymentSecret>::requires_feature(&self.flags)
- }
- /// Returns whether the `payment_secret` feature is supported.
- pub fn supports_payment_secret(&self) -> bool {
- <T as sealed::PaymentSecret>::supports_feature(&self.flags)
- }
-}
-
-impl<T: sealed::BasicMPP> Features<T> {
+impl<T: sealed::ShutdownAnySegwit> Features<T> {
#[cfg(test)]
- pub(crate) fn requires_basic_mpp(&self) -> bool {
- <T as sealed::BasicMPP>::requires_feature(&self.flags)
- }
- // We currently never test for this since we don't actually *generate* multipath routes.
- pub(crate) fn supports_basic_mpp(&self) -> bool {
- <T as sealed::BasicMPP>::supports_feature(&self.flags)
+ pub(crate) fn clear_shutdown_anysegwit(mut self) -> Self {
+ <T as sealed::ShutdownAnySegwit>::clear_bits(&mut self.flags);
+ self
}
}
-impl<T: sealed::ShutdownAnySegwit> Features<T> {
- pub(crate) fn supports_shutdown_anysegwit(&self) -> bool {
- <T as sealed::ShutdownAnySegwit>::supports_feature(&self.flags)
- }
+impl<T: sealed::Wumbo> Features<T> {
#[cfg(test)]
- pub(crate) fn clear_shutdown_anysegwit(mut self) -> Self {
- <T as sealed::ShutdownAnySegwit>::clear_bits(&mut self.flags);
+ 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 {
assert!(!NodeFeatures::known().requires_basic_mpp());
assert!(!InvoiceFeatures::known().requires_basic_mpp());
+ assert!(InitFeatures::known().supports_channel_type());
+ assert!(NodeFeatures::known().supports_channel_type());
+ assert!(!InitFeatures::known().requires_channel_type());
+ assert!(!NodeFeatures::known().requires_channel_type());
+
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();
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());
}
// 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
- assert_eq!(node_features.flags.len(), 4);
+ // -
+ // - 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], 0b10100000);
+ assert_eq!(node_features.flags[6], 0b00001000);
}
// Check that cleared flags are kept blank when converting back:
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());
#[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());
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());