-//! Lightning exposes sets of supported operations through "feature flags". This module includes
-//! types to store those feature flags and query for specific flags.
+//! Feature flag definitions for the Lightning protocol according to [BOLT #9].
+//!
+//! 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.
+//!
+//! 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
+//! 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
+//! [messages]: ../msgs/index.html
+//! [`Features`]: struct.Features.html
+//! [`Context`]: sealed/trait.Context.html
use std::{cmp, fmt};
use std::result::Result;
use ln::msgs::DecodeError;
use util::ser::{Readable, Writeable, Writer};
-/// The context in which a Feature object appears determines which bits of features the node
-/// supports will be set. We use this when creating our own Feature objects to select which bits to
-/// set and when passing around Feature objects to ensure the bits we're checking for are
-/// available.
-///
-/// This Context represents when the Feature appears in the init message, sent between peers and not
-/// rumored around the P2P network.
-pub struct FeatureContextInit {}
-/// The context in which a Feature object appears determines which bits of features the node
-/// supports will be set. We use this when creating our own Feature objects to select which bits to
-/// set and when passing around Feature objects to ensure the bits we're checking for are
-/// available.
-///
-/// This Context represents when the Feature appears in the node_announcement message, as it is
-/// rumored around the P2P network.
-pub struct FeatureContextNode {}
-/// The context in which a Feature object appears determines which bits of features the node
-/// supports will be set. We use this when creating our own Feature objects to select which bits to
-/// set and when passing around Feature objects to ensure the bits we're checking for are
-/// available.
-///
-/// This Context represents when the Feature appears in the ChannelAnnouncement message, as it is
-/// rumored around the P2P network.
-pub struct FeatureContextChannel {}
-/// The context in which a Feature object appears determines which bits of features the node
-/// supports will be set. We use this when creating our own Feature objects to select which bits to
-/// set and when passing around Feature objects to ensure the bits we're checking for are
-/// available.
-///
-/// This Context represents when the Feature appears in an invoice, used to determine the different
-/// options available for routing a payment.
-///
-/// Note that this is currently unused as invoices come to us via a different crate and are not
-/// native to rust-lightning directly.
-pub struct FeatureContextInvoice {}
-
-/// An internal trait capturing the various future context types
-pub trait FeatureContext {}
-impl FeatureContext for FeatureContextInit {}
-impl FeatureContext for FeatureContextNode {}
-impl FeatureContext for FeatureContextChannel {}
-impl FeatureContext for FeatureContextInvoice {}
-
-/// An internal trait capturing FeatureContextInit and FeatureContextNode
-pub trait FeatureContextInitNode : FeatureContext {}
-impl FeatureContextInitNode for FeatureContextInit {}
-impl FeatureContextInitNode for FeatureContextNode {}
+mod sealed {
+ /// 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.
+ const KNOWN_FEATURE_FLAGS: &'static [u8];
+
+ /// Bitmask for selecting features that are known to the implementation, regardless of
+ /// whether each feature is required or optional.
+ const KNOWN_FEATURE_MASK: &'static [u8];
+ }
+
+ /// 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 {
+ ($context: ident {
+ required_features: [$( $( $required_feature: ident )|*, )*],
+ optional_features: [$( $( $optional_feature: ident )|*, )*],
+ }) => {
+ pub struct $context {}
+
+ impl Context for $context {
+ const KNOWN_FEATURE_FLAGS: &'static [u8] = &[
+ // For each byte, use bitwise-OR to compute the applicable flags for known
+ // required features `r_i` and optional features `o_j` for all `i` and `j` such
+ // that the following slice is formed:
+ //
+ // [
+ // `r_0` | `r_1` | ... | `o_0` | `o_1` | ...,
+ // ...,
+ // ]
+ $(
+ 0b00_00_00_00 $(|
+ <Self as $required_feature>::REQUIRED_MASK)*
+ $(|
+ <Self as $optional_feature>::OPTIONAL_MASK)*,
+ )*
+ ];
+
+ const KNOWN_FEATURE_MASK: &'static [u8] = &[
+ // Similar as above, but set both flags for each feature regardless of whether
+ // the feature is required or optional.
+ $(
+ 0b00_00_00_00 $(|
+ <Self as $required_feature>::REQUIRED_MASK |
+ <Self as $required_feature>::OPTIONAL_MASK)*
+ $(|
+ <Self as $optional_feature>::REQUIRED_MASK |
+ <Self as $optional_feature>::OPTIONAL_MASK)*,
+ )*
+ ];
+ }
+ };
+ }
+
+ define_context!(InitContext {
+ required_features: [
+ // Byte 0
+ ,
+ // Byte 1
+ ,
+ // Byte 2
+ ,
+ ],
+ optional_features: [
+ // Byte 0
+ DataLossProtect | InitialRoutingSync | UpfrontShutdownScript,
+ // Byte 1
+ VariableLengthOnion | PaymentSecret,
+ // Byte 2
+ BasicMPP,
+ ],
+ });
+ define_context!(NodeContext {
+ required_features: [
+ // Byte 0
+ ,
+ // Byte 1
+ ,
+ // Byte 2
+ ,
+ ],
+ optional_features: [
+ // Byte 0
+ DataLossProtect | UpfrontShutdownScript,
+ // Byte 1
+ VariableLengthOnion | PaymentSecret,
+ // Byte 2
+ BasicMPP,
+ ],
+ });
+ define_context!(ChannelContext {
+ required_features: [],
+ optional_features: [],
+ });
+
+ /// Defines a feature with the given bits for the specified [`Context`]s. The generated trait is
+ /// useful for manipulating feature flags.
+ ///
+ /// [`Context`]: trait.Context.html
+ macro_rules! define_feature {
+ ($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr) => {
+ #[doc = $doc]
+ ///
+ /// See [BOLT #9] for details.
+ ///
+ /// [BOLT #9]: https://github.com/lightningnetwork/lightning-rfc/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;
+
+ /// The bit used to signify that the feature is optional.
+ const ODD_BIT: usize = $odd_bit;
+
+ /// Assertion that [`EVEN_BIT`] is actually even.
+ ///
+ /// [`EVEN_BIT`]: #associatedconstant.EVEN_BIT
+ const ASSERT_EVEN_BIT_PARITY: usize;
+
+ /// Assertion that [`ODD_BIT`] is actually odd.
+ ///
+ /// [`ODD_BIT`]: #associatedconstant.ODD_BIT
+ const ASSERT_ODD_BIT_PARITY: usize;
+
+ /// The byte where the feature is set.
+ const BYTE_OFFSET: usize = Self::EVEN_BIT / 8;
+
+ /// The bitmask for the feature's required flag relative to the [`BYTE_OFFSET`].
+ ///
+ /// [`BYTE_OFFSET`]: #associatedconstant.BYTE_OFFSET
+ const REQUIRED_MASK: u8 = 1 << (Self::EVEN_BIT - 8 * Self::BYTE_OFFSET);
+
+ /// The bitmask for the feature's optional flag relative to the [`BYTE_OFFSET`].
+ ///
+ /// [`BYTE_OFFSET`]: #associatedconstant.BYTE_OFFSET
+ const OPTIONAL_MASK: u8 = 1 << (Self::ODD_BIT - 8 * Self::BYTE_OFFSET);
+
+ /// Returns whether the feature is supported by the given flags.
+ #[inline]
+ fn supports_feature(flags: &Vec<u8>) -> bool {
+ flags.len() > Self::BYTE_OFFSET &&
+ (flags[Self::BYTE_OFFSET] & (Self::REQUIRED_MASK | Self::OPTIONAL_MASK)) != 0
+ }
+
+ /// Sets the feature's optional (odd) bit in the given flags.
+ #[inline]
+ fn set_optional_bit(flags: &mut Vec<u8>) {
+ if flags.len() <= Self::BYTE_OFFSET {
+ flags.resize(Self::BYTE_OFFSET + 1, 0u8);
+ }
+
+ flags[Self::BYTE_OFFSET] |= Self::OPTIONAL_MASK;
+ }
+
+ /// Clears the feature's required (even) and optional (odd) bits from the given
+ /// flags.
+ #[inline]
+ fn clear_bits(flags: &mut Vec<u8>) {
+ if flags.len() > Self::BYTE_OFFSET {
+ flags[Self::BYTE_OFFSET] &= !Self::REQUIRED_MASK;
+ flags[Self::BYTE_OFFSET] &= !Self::OPTIONAL_MASK;
+ }
+ }
+ }
+
+ $(
+ impl $feature for $context {
+ // EVEN_BIT % 2 == 0
+ const ASSERT_EVEN_BIT_PARITY: usize = 0 - (<Self as $feature>::EVEN_BIT % 2);
+
+ // ODD_BIT % 2 == 1
+ 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`.");
+ // NOTE: Per Bolt #9, initial_routing_sync has no even bit.
+ define_feature!(3, InitialRoutingSync, [InitContext],
+ "Feature flags for `initial_routing_sync`.");
+ define_feature!(5, UpfrontShutdownScript, [InitContext, NodeContext],
+ "Feature flags for `option_upfront_shutdown_script`.");
+ define_feature!(9, VariableLengthOnion, [InitContext, NodeContext],
+ "Feature flags for `var_onion_optin`.");
+ define_feature!(15, PaymentSecret, [InitContext, NodeContext],
+ "Feature flags for `payment_secret`.");
+ define_feature!(17, BasicMPP, [InitContext, NodeContext],
+ "Feature flags for `basic_mpp`.");
+}
/// Tracks the set of features which a node implements, templated by the context in which it
/// appears.
-pub struct Features<T: FeatureContext> {
- /// Note that, for convinience, flags is LITTLE endian (despite being big-endian on the wire)
+pub struct Features<T: sealed::Context> {
+ /// Note that, for convenience, flags is LITTLE endian (despite being big-endian on the wire)
flags: Vec<u8>,
mark: PhantomData<T>,
}
-impl<T: FeatureContext> Clone for Features<T> {
+impl<T: sealed::Context> Clone for Features<T> {
fn clone(&self) -> Self {
Self {
flags: self.flags.clone(),
}
}
}
-impl<T: FeatureContext> PartialEq for Features<T> {
+impl<T: sealed::Context> PartialEq for Features<T> {
fn eq(&self, o: &Self) -> bool {
self.flags.eq(&o.flags)
}
}
-impl<T: FeatureContext> fmt::Debug for Features<T> {
+impl<T: sealed::Context> fmt::Debug for Features<T> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
self.flags.fmt(fmt)
}
}
-/// A feature message as it appears in an init message
-pub type InitFeatures = Features<FeatureContextInit>;
-/// A feature message as it appears in a node_announcement message
-pub type NodeFeatures = Features<FeatureContextNode>;
-/// A feature message as it appears in a channel_announcement message
-pub type ChannelFeatures = Features<FeatureContextChannel>;
-
-impl<T: FeatureContextInitNode> Features<T> {
- /// Create a Features with the features we support
- #[cfg(not(feature = "fuzztarget"))]
- pub(crate) fn supported() -> Features<T> {
- Features {
- flags: vec![2 | 1 << 5],
- mark: PhantomData,
+/// Features used within an `init` message.
+pub type InitFeatures = Features<sealed::InitContext>;
+/// Features used within a `node_announcement` message.
+pub type NodeFeatures = Features<sealed::NodeContext>;
+/// Features used within a `channel_announcement` message.
+pub type ChannelFeatures = Features<sealed::ChannelContext>;
+
+impl InitFeatures {
+ /// Writes all features present up to, and including, 13.
+ pub(crate) fn write_up_to_13<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
+ let len = cmp::min(2, self.flags.len());
+ w.size_hint(len + 2);
+ (len as u16).write(w)?;
+ for i in (0..len).rev() {
+ if i == 0 {
+ self.flags[i].write(w)?;
+ } else {
+ // On byte 1, we want up-to-and-including-bit-13, 0-indexed, which is
+ // up-to-and-including-bit-5, 0-indexed, on this byte:
+ (self.flags[i] & 0b00_11_11_11).write(w)?;
+ }
}
+ Ok(())
}
- #[cfg(feature = "fuzztarget")]
- pub fn supported() -> Features<T> {
- Features {
- flags: vec![2 | 1 << 5],
- mark: PhantomData,
+
+ /// 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> {
+ self.to_context_internal()
}
}
-impl Features<FeatureContextChannel> {
- /// Create a Features with the features we support
- #[cfg(not(feature = "fuzztarget"))]
- pub(crate) fn supported() -> Features<FeatureContextChannel> {
+impl<T: sealed::Context> Features<T> {
+ /// Create a blank Features with no features set
+ pub fn empty() -> Features<T> {
Features {
flags: Vec::new(),
mark: PhantomData,
}
}
- #[cfg(feature = "fuzztarget")]
- pub fn supported() -> Features<FeatureContextChannel> {
- Features {
- flags: Vec::new(),
+
+ /// 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
+ pub fn known() -> Features<T> {
+ Self {
+ flags: T::KNOWN_FEATURE_FLAGS.to_vec(),
mark: PhantomData,
}
}
-}
-impl<T: FeatureContext> Features<T> {
- /// Create a blank Features with no features set
- pub fn empty() -> Features<T> {
- Features {
- flags: Vec::new(),
- mark: PhantomData,
+ /// Converts `Features<T>` to `Features<C>`. Only known `T` features relevant to context `C` are
+ /// included in the result.
+ fn to_context_internal<C: sealed::Context>(&self) -> Features<C> {
+ let byte_count = C::KNOWN_FEATURE_MASK.len();
+ let mut flags = Vec::new();
+ for (i, byte) in self.flags.iter().enumerate() {
+ if i < byte_count {
+ let known_source_features = T::KNOWN_FEATURE_MASK[i];
+ let known_target_features = C::KNOWN_FEATURE_MASK[i];
+ flags.push(byte & known_source_features & known_target_features);
+ }
}
+ Features::<C> { flags, mark: PhantomData, }
}
#[cfg(test)]
}
pub(crate) fn requires_unknown_bits(&self) -> bool {
- self.flags.iter().enumerate().any(|(idx, &byte)| {
- ( idx != 0 && (byte & 0x55) != 0 ) || ( idx == 0 && (byte & 0x14) != 0 )
+ // Bitwise AND-ing with all even bits set except for known features will select required
+ // unknown features.
+ let byte_count = T::KNOWN_FEATURE_MASK.len();
+ self.flags.iter().enumerate().any(|(i, &byte)| {
+ let required_features = 0b01_01_01_01;
+ let unknown_features = if i < byte_count {
+ !T::KNOWN_FEATURE_MASK[i]
+ } else {
+ 0b11_11_11_11
+ };
+ (byte & (required_features & unknown_features)) != 0
})
}
pub(crate) fn supports_unknown_bits(&self) -> bool {
- self.flags.iter().enumerate().any(|(idx, &byte)| {
- ( idx != 0 && byte != 0 ) || ( idx == 0 && (byte & 0xc4) != 0 )
+ // Bitwise AND-ing with all even and odd bits set except for known features will select
+ // both required and optional unknown features.
+ let byte_count = T::KNOWN_FEATURE_MASK.len();
+ self.flags.iter().enumerate().any(|(i, &byte)| {
+ let unknown_features = if i < byte_count {
+ !T::KNOWN_FEATURE_MASK[i]
+ } else {
+ 0b11_11_11_11
+ };
+ (byte & unknown_features) != 0
})
}
#[cfg(test)]
pub(crate) fn set_require_unknown_bits(&mut self) {
- let newlen = cmp::max(2, self.flags.len());
+ let newlen = cmp::max(3, self.flags.len());
self.flags.resize(newlen, 0u8);
- self.flags[1] |= 0x40;
+ self.flags[2] |= 0x40;
}
#[cfg(test)]
pub(crate) fn clear_require_unknown_bits(&mut self) {
- let newlen = cmp::max(2, self.flags.len());
+ let newlen = cmp::max(3, self.flags.len());
self.flags.resize(newlen, 0u8);
- self.flags[1] &= !0x40;
+ self.flags[2] &= !0x40;
+ if self.flags.len() == 3 && self.flags[2] == 0 {
+ self.flags.resize(2, 0u8);
+ }
if self.flags.len() == 2 && self.flags[1] == 0 {
self.flags.resize(1, 0u8);
}
}
}
-impl<T: FeatureContextInitNode> Features<T> {
+impl<T: sealed::DataLossProtect> Features<T> {
pub(crate) fn supports_data_loss_protect(&self) -> bool {
- self.flags.len() > 0 && (self.flags[0] & 3) != 0
+ <T as sealed::DataLossProtect>::supports_feature(&self.flags)
}
+}
+impl<T: sealed::UpfrontShutdownScript> Features<T> {
pub(crate) fn supports_upfront_shutdown_script(&self) -> bool {
- self.flags.len() > 0 && (self.flags[0] & (3 << 4)) != 0
+ <T as sealed::UpfrontShutdownScript>::supports_feature(&self.flags)
}
#[cfg(test)]
- pub(crate) fn unset_upfront_shutdown_script(&mut self) {
- self.flags[0] ^= 1 << 5;
+ pub(crate) fn clear_upfront_shutdown_script(mut self) -> Self {
+ <T as sealed::UpfrontShutdownScript>::clear_bits(&mut self.flags);
+ self
}
}
-impl Features<FeatureContextInit> {
+impl<T: sealed::VariableLengthOnion> Features<T> {
+ pub(crate) fn supports_variable_length_onion(&self) -> bool {
+ <T as sealed::VariableLengthOnion>::supports_feature(&self.flags)
+ }
+}
+
+impl<T: sealed::InitialRoutingSync> Features<T> {
pub(crate) fn initial_routing_sync(&self) -> bool {
- self.flags.len() > 0 && (self.flags[0] & (1 << 3)) != 0
+ <T as sealed::InitialRoutingSync>::supports_feature(&self.flags)
}
- pub(crate) fn set_initial_routing_sync(&mut self) {
- if self.flags.len() == 0 {
- self.flags.resize(1, 1 << 3);
- } else {
- self.flags[0] |= 1 << 3;
- }
+ pub(crate) fn clear_initial_routing_sync(&mut self) {
+ <T as sealed::InitialRoutingSync>::clear_bits(&mut self.flags)
}
+}
- /// Writes all features present up to, and including, 13.
- pub(crate) fn write_up_to_13<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
- let len = cmp::min(2, self.flags.len());
- w.size_hint(len + 2);
- (len as u16).write(w)?;
- for i in (0..len).rev() {
- if i == 0 {
- self.flags[i].write(w)?;
- } else {
- (self.flags[i] & ((1 << (14 - 8)) - 1)).write(w)?;
- }
- }
- Ok(())
+impl<T: sealed::PaymentSecret> Features<T> {
+ #[allow(dead_code)]
+ // Note that we never need to test this since what really matters is the invoice - iff the
+ // invoice provides a payment_secret, we assume that we can use it (ie that the recipient
+ // supports payment_secret).
+ pub(crate) fn supports_payment_secret(&self) -> bool {
+ <T as sealed::PaymentSecret>::supports_feature(&self.flags)
}
+}
- /// 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 (feature, o_feature) in self.flags.iter_mut().zip(o.flags.iter()) {
- *feature |= *o_feature;
- }
- self
+impl<T: sealed::BasicMPP> Features<T> {
+ // 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)
}
}
-impl<T: FeatureContext> Writeable for Features<T> {
+impl<T: sealed::Context> Writeable for Features<T> {
fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
w.size_hint(self.flags.len() + 2);
(self.flags.len() as u16).write(w)?;
}
}
-impl<R: ::std::io::Read, T: FeatureContext> Readable<R> for Features<T> {
- fn read(r: &mut R) -> Result<Self, DecodeError> {
+impl<T: sealed::Context> Readable for Features<T> {
+ fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
let mut flags: Vec<u8> = Readable::read(r)?;
flags.reverse(); // Swap to little-endian
Ok(Self {
})
}
}
+
+#[cfg(test)]
+mod tests {
+ use super::{ChannelFeatures, InitFeatures, NodeFeatures};
+
+ #[test]
+ fn sanity_test_our_features() {
+ assert!(!ChannelFeatures::known().requires_unknown_bits());
+ assert!(!ChannelFeatures::known().supports_unknown_bits());
+ assert!(!InitFeatures::known().requires_unknown_bits());
+ assert!(!InitFeatures::known().supports_unknown_bits());
+ assert!(!NodeFeatures::known().requires_unknown_bits());
+ assert!(!NodeFeatures::known().supports_unknown_bits());
+
+ assert!(InitFeatures::known().supports_upfront_shutdown_script());
+ assert!(NodeFeatures::known().supports_upfront_shutdown_script());
+
+ assert!(InitFeatures::known().supports_data_loss_protect());
+ assert!(NodeFeatures::known().supports_data_loss_protect());
+
+ assert!(InitFeatures::known().supports_variable_length_onion());
+ assert!(NodeFeatures::known().supports_variable_length_onion());
+
+ assert!(InitFeatures::known().supports_payment_secret());
+ assert!(NodeFeatures::known().supports_payment_secret());
+
+ assert!(InitFeatures::known().supports_basic_mpp());
+ assert!(NodeFeatures::known().supports_basic_mpp());
+
+ let mut init_features = InitFeatures::known();
+ assert!(init_features.initial_routing_sync());
+ init_features.clear_initial_routing_sync();
+ assert!(!init_features.initial_routing_sync());
+ }
+
+ #[test]
+ fn sanity_test_unkown_bits_testing() {
+ let mut features = ChannelFeatures::known();
+ features.set_require_unknown_bits();
+ assert!(features.requires_unknown_bits());
+ features.clear_require_unknown_bits();
+ assert!(!features.requires_unknown_bits());
+ }
+
+ #[test]
+ fn convert_to_context_with_relevant_flags() {
+ let init_features = InitFeatures::known().clear_upfront_shutdown_script();
+ assert!(init_features.initial_routing_sync());
+ assert!(!init_features.supports_upfront_shutdown_script());
+
+ let node_features: NodeFeatures = init_features.to_context();
+ {
+ // Check that the flags are as expected:
+ // - option_data_loss_protect
+ // - var_onion_optin | payment_secret
+ // - basic_mpp
+ assert_eq!(node_features.flags.len(), 3);
+ assert_eq!(node_features.flags[0], 0b00000010);
+ assert_eq!(node_features.flags[1], 0b10000010);
+ assert_eq!(node_features.flags[2], 0b00000010);
+ }
+
+ // Check that cleared flags are kept blank when converting back:
+ // - initial_routing_sync was not applicable to NodeContext
+ // - upfront_shutdown_script was cleared before converting
+ let features: InitFeatures = node_features.to_context_internal();
+ assert!(!features.initial_routing_sync());
+ assert!(!features.supports_upfront_shutdown_script());
+ }
+}
projects / rust-lightning / blobdiff