//! Lightning nodes advertise a supported set of operation through feature flags. Features are
//! applicable for a specific context as indicated in some [messages]. [`Features`] encapsulates
//! behavior for specifying and checking feature flags for a particular context. Each feature is
-//! defined internally by a trait specifying the corresponding flags (i.e., even and odd bits). A
-//! [`Context`] is used to parameterize [`Features`] and defines which features it can support.
+//! defined internally by a trait specifying the corresponding flags (i.e., even and odd bits).
//!
//! Whether a feature is considered "known" or "unknown" is relative to the implementation, whereas
//! the term "supports" is used in reference to a particular set of [`Features`]. That is, a node
//! 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
-//! [messages]: ../msgs/index.html
-//! [`Features`]: struct.Features.html
-//! [`Context`]: sealed/trait.Context.html
+//! [messages]: crate::ln::msgs
use std::{cmp, fmt};
use std::marker::PhantomData;
use util::ser::{Readable, Writeable, Writer};
mod sealed {
+ use ln::features::Features;
+
/// The context in which [`Features`] are applicable. Defines which features are required and
/// which are optional for the context.
- ///
- /// [`Features`]: ../struct.Features.html
pub trait Context {
/// Features that are known to the implementation, where a required feature is indicated by
/// its even bit and an optional feature is indicated by its odd bit.
/// Defines a [`Context`] by stating which features it requires and which are optional. Features
/// are specified as a comma-separated list of bytes where each byte is a pipe-delimited list of
/// feature identifiers.
- ///
- /// [`Context`]: trait.Context.html
macro_rules! define_context {
($context: ident {
required_features: [$( $( $required_feature: ident )|*, )*],
required_features: [],
optional_features: [],
});
+ define_context!(InvoiceContext {
+ required_features: [,,,],
+ optional_features: [
+ // Byte 0
+ ,
+ // Byte 1
+ VariableLengthOnion | PaymentSecret,
+ // Byte 2
+ BasicMPP,
+ ],
+ });
/// Defines a feature with the given bits for the specified [`Context`]s. The generated trait is
/// useful for manipulating feature flags.
- ///
- /// [`Context`]: trait.Context.html
macro_rules! define_feature {
- ($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr) => {
+ ($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr, $optional_setter: ident,
+ $required_setter: ident) => {
#[doc = $doc]
///
/// See [BOLT #9] for details.
}
}
+ impl <T: $feature> Features<T> {
+ /// Set this feature as optional.
+ pub fn $optional_setter(mut self) -> Self {
+ <T as $feature>::set_optional_bit(&mut self.flags);
+ self
+ }
+
+ /// Set this feature as required.
+ pub fn $required_setter(mut self) -> Self {
+ <T as $feature>::set_required_bit(&mut self.flags);
+ self
+ }
+ }
+
$(
impl $feature for $context {
// EVEN_BIT % 2 == 0
const ASSERT_ODD_BIT_PARITY: usize = (<Self as $feature>::ODD_BIT % 2) - 1;
}
)*
+
}
}
define_feature!(1, DataLossProtect, [InitContext, NodeContext],
- "Feature flags for `option_data_loss_protect`.");
+ "Feature flags for `option_data_loss_protect`.", set_data_loss_protect_optional,
+ set_data_loss_protect_required);
// NOTE: Per Bolt #9, initial_routing_sync has no even bit.
- define_feature!(3, InitialRoutingSync, [InitContext],
- "Feature flags for `initial_routing_sync`.");
+ define_feature!(3, InitialRoutingSync, [InitContext], "Feature flags for `initial_routing_sync`.",
+ set_initial_routing_sync_optional, set_initial_routing_sync_required);
define_feature!(5, UpfrontShutdownScript, [InitContext, NodeContext],
- "Feature flags for `option_upfront_shutdown_script`.");
+ "Feature flags for `option_upfront_shutdown_script`.", set_upfront_shutdown_script_optional,
+ set_upfront_shutdown_script_required);
define_feature!(7, GossipQueries, [InitContext, NodeContext],
- "Feature flags for `gossip_queries`.");
- define_feature!(9, VariableLengthOnion, [InitContext, NodeContext],
- "Feature flags for `var_onion_optin`.");
+ "Feature flags for `gossip_queries`.", set_gossip_queries_optional, set_gossip_queries_required);
+ define_feature!(9, VariableLengthOnion, [InitContext, NodeContext, InvoiceContext],
+ "Feature flags for `var_onion_optin`.", set_variable_length_onion_optional,
+ set_variable_length_onion_required);
define_feature!(13, StaticRemoteKey, [InitContext, NodeContext],
- "Feature flags for `option_static_remotekey`.");
- define_feature!(15, PaymentSecret, [InitContext, NodeContext],
- "Feature flags for `payment_secret`.");
- define_feature!(17, BasicMPP, [InitContext, NodeContext],
- "Feature flags for `basic_mpp`.");
+ "Feature flags for `option_static_remotekey`.", set_static_remote_key_optional,
+ set_static_remote_key_required);
+ define_feature!(15, PaymentSecret, [InitContext, NodeContext, InvoiceContext],
+ "Feature flags for `payment_secret`.", set_payment_secret_optional, set_payment_secret_required);
+ define_feature!(17, BasicMPP, [InitContext, NodeContext, InvoiceContext],
+ "Feature flags for `basic_mpp`.", set_basic_mpp_optional, set_basic_mpp_required);
define_feature!(27, ShutdownAnySegwit, [InitContext, NodeContext],
- "Feature flags for `opt_shutdown_anysegwit`.");
+ "Feature flags for `opt_shutdown_anysegwit`.", set_shutdown_any_segwit_optional,
+ set_shutdown_any_segwit_required);
#[cfg(test)]
define_context!(TestingContext {
#[cfg(test)]
define_feature!(23, UnknownFeature, [TestingContext],
- "Feature flags for an unknown feature used in testing.");
+ "Feature flags for an unknown feature used in testing.", set_unknown_feature_optional,
+ set_unknown_feature_required);
}
/// Tracks the set of features which a node implements, templated by the context in which it
pub type NodeFeatures = Features<sealed::NodeContext>;
/// Features used within a `channel_announcement` message.
pub type ChannelFeatures = Features<sealed::ChannelContext>;
+/// Features used within an invoice.
+pub type InvoiceFeatures = Features<sealed::InvoiceContext>;
impl InitFeatures {
/// Writes all features present up to, and including, 13.
}
}
+impl InvoiceFeatures {
+ /// Converts `InvoiceFeatures` to `Features<C>`. Only known `InvoiceFeatures` relevant to
+ /// context `C` are included in the result.
+ pub(crate) fn to_context<C: sealed::Context>(&self) -> Features<C> {
+ self.to_context_internal()
+ }
+}
+
impl<T: sealed::Context> Features<T> {
/// Create a blank Features with no features set
pub fn empty() -> Self {
}
}
- /// Creates features known by the implementation as defined by [`T::KNOWN_FEATURE_FLAGS`].
- ///
- /// [`T::KNOWN_FEATURE_FLAGS`]: sealed/trait.Context.html#associatedconstant.KNOWN_FEATURE_FLAGS
+ /// Creates a Features with the bits set which are known by the implementation
pub fn known() -> Self {
Self {
flags: T::KNOWN_FEATURE_FLAGS.to_vec(),
Features::<C> { flags, mark: PhantomData, }
}
- #[cfg(test)]
/// Create a Features given a set of flags, in LE.
pub fn from_le_bytes(flags: Vec<u8>) -> Features<T> {
Features {
<T as sealed::BasicMPP>::requires_feature(&self.flags)
}
// We currently never test for this since we don't actually *generate* multipath routes.
- #[allow(dead_code)]
pub(crate) fn supports_basic_mpp(&self) -> bool {
<T as sealed::BasicMPP>::supports_feature(&self.flags)
}
#[cfg(test)]
mod tests {
- use super::{ChannelFeatures, InitFeatures, NodeFeatures};
+ use super::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
#[test]
fn sanity_test_known_features() {
assert!(!features.supports_upfront_shutdown_script());
assert!(!init_features.supports_gossip_queries());
}
+
+ #[test]
+ fn set_feature_bits() {
+ let features = InvoiceFeatures::empty()
+ .set_basic_mpp_optional()
+ .set_payment_secret_required();
+ assert!(features.supports_basic_mpp());
+ assert!(!features.requires_basic_mpp());
+ assert!(features.requires_payment_secret());
+ assert!(features.supports_payment_secret());
+ }
}
projects / rust-lightning / blobdiff