+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
//! Feature flag definitions for the Lightning protocol according to [BOLT #9].
//!
//! Lightning nodes advertise a supported set of operation through feature flags. Features are
// Byte 0
,
// Byte 1
- ,
+ StaticRemoteKey,
// Byte 2
,
],
// Byte 0
,
// Byte 1
- ,
+ StaticRemoteKey,
// Byte 2
,
],
/// [`BYTE_OFFSET`]: #associatedconstant.BYTE_OFFSET
const OPTIONAL_MASK: u8 = 1 << (Self::ODD_BIT - 8 * Self::BYTE_OFFSET);
+ /// Returns whether the feature is required by the given flags.
+ #[inline]
+ fn requires_feature(flags: &Vec<u8>) -> bool {
+ flags.len() > Self::BYTE_OFFSET &&
+ (flags[Self::BYTE_OFFSET] & Self::REQUIRED_MASK) != 0
+ }
+
/// Returns whether the feature is supported by the given flags.
#[inline]
fn supports_feature(flags: &Vec<u8>) -> bool {
(flags[Self::BYTE_OFFSET] & (Self::REQUIRED_MASK | Self::OPTIONAL_MASK)) != 0
}
+ /// Sets the feature's required (even) bit in the given flags.
+ #[inline]
+ fn set_required_bit(flags: &mut Vec<u8>) {
+ if flags.len() <= Self::BYTE_OFFSET {
+ flags.resize(Self::BYTE_OFFSET + 1, 0u8);
+ }
+
+ flags[Self::BYTE_OFFSET] |= Self::REQUIRED_MASK;
+ }
+
/// Sets the feature's optional (odd) bit in the given flags.
#[inline]
fn set_optional_bit(flags: &mut Vec<u8>) {
flags[Self::BYTE_OFFSET] &= !Self::REQUIRED_MASK;
flags[Self::BYTE_OFFSET] &= !Self::OPTIONAL_MASK;
}
+
+ let last_non_zero_byte = flags.iter().rposition(|&byte| byte != 0);
+ let size = if let Some(offset) = last_non_zero_byte { offset + 1 } else { 0 };
+ flags.resize(size, 0u8);
}
}
"Feature flags for `option_upfront_shutdown_script`.");
define_feature!(9, VariableLengthOnion, [InitContext, NodeContext],
"Feature flags for `var_onion_optin`.");
+ 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`.");
+
+ #[cfg(test)]
+ define_context!(TestingContext {
+ required_features: [
+ // Byte 0
+ ,
+ // Byte 1
+ ,
+ // Byte 2
+ UnknownFeature,
+ ],
+ optional_features: [
+ // Byte 0
+ ,
+ // Byte 1
+ ,
+ // Byte 2
+ ,
+ ],
+ });
+
+ #[cfg(test)]
+ define_feature!(23, UnknownFeature, [TestingContext],
+ "Feature flags for an unknown feature used in testing.");
}
/// Tracks the set of features which a node implements, templated by the context in which it
}
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<T: sealed::Context> Features<T> {
}
}
- /// Takes the flags that we know how to interpret in an init-context features that are also
- /// relevant in a node-context features and creates a node-context features from them.
- /// Be sure to blank out features that are unknown to us.
- pub(crate) fn with_known_relevant_init_flags(init_ctx: &InitFeatures) -> Self {
- let byte_count = T::KNOWN_FEATURE_MASK.len();
+ /// 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, feature_byte) in init_ctx.flags.iter().enumerate() {
+ for (i, byte) in self.flags.iter().enumerate() {
if i < byte_count {
- flags.push(feature_byte & T::KNOWN_FEATURE_MASK[i]);
+ 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);
}
}
- Self { flags, mark: PhantomData, }
+ Features::<C> { flags, mark: PhantomData, }
}
#[cfg(test)]
}
#[cfg(test)]
- pub(crate) fn set_require_unknown_bits(&mut self) {
- let newlen = cmp::max(3, self.flags.len());
- self.flags.resize(newlen, 0u8);
- self.flags[2] |= 0x40;
+ pub(crate) fn set_required_unknown_bits(&mut self) {
+ <sealed::TestingContext as sealed::UnknownFeature>::set_required_bit(&mut self.flags);
}
#[cfg(test)]
- pub(crate) fn clear_require_unknown_bits(&mut self) {
- let newlen = cmp::max(3, self.flags.len());
- self.flags.resize(newlen, 0u8);
- 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);
- }
+ pub(crate) fn set_optional_unknown_bits(&mut self) {
+ <sealed::TestingContext as sealed::UnknownFeature>::set_optional_bit(&mut self.flags);
+ }
+
+ #[cfg(test)]
+ pub(crate) fn clear_unknown_bits(&mut self) {
+ <sealed::TestingContext as sealed::UnknownFeature>::clear_bits(&mut self.flags);
}
}
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)
+ }
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 unset_upfront_shutdown_script(&mut self) {
- <T as sealed::UpfrontShutdownScript>::clear_bits(&mut self.flags)
+ pub(crate) fn clear_upfront_shutdown_script(mut self) -> Self {
+ <T as sealed::UpfrontShutdownScript>::clear_bits(&mut self.flags);
+ self
}
}
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)
}
impl<T: sealed::PaymentSecret> Features<T> {
- #[allow(dead_code)]
+ #[cfg(test)]
+ pub(crate) fn requires_payment_secret(&self) -> bool {
+ <T as sealed::PaymentSecret>::requires_feature(&self.flags)
+ }
// 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).
+ #[allow(dead_code)]
pub(crate) fn supports_payment_secret(&self) -> bool {
<T as sealed::PaymentSecret>::supports_feature(&self.flags)
}
}
impl<T: sealed::BasicMPP> 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.
#[allow(dead_code)]
pub(crate) fn supports_basic_mpp(&self) -> bool {
#[cfg(test)]
mod tests {
- use super::{ChannelFeatures, InitFeatures, NodeFeatures, Features};
+ use super::{ChannelFeatures, InitFeatures, NodeFeatures};
#[test]
- fn sanity_test_our_features() {
+ fn sanity_test_known_features() {
assert!(!ChannelFeatures::known().requires_unknown_bits());
assert!(!ChannelFeatures::known().supports_unknown_bits());
assert!(!InitFeatures::known().requires_unknown_bits());
assert!(InitFeatures::known().supports_upfront_shutdown_script());
assert!(NodeFeatures::known().supports_upfront_shutdown_script());
+ assert!(!InitFeatures::known().requires_upfront_shutdown_script());
+ assert!(!NodeFeatures::known().requires_upfront_shutdown_script());
assert!(InitFeatures::known().supports_data_loss_protect());
assert!(NodeFeatures::known().supports_data_loss_protect());
+ assert!(!InitFeatures::known().requires_data_loss_protect());
+ assert!(!NodeFeatures::known().requires_data_loss_protect());
assert!(InitFeatures::known().supports_variable_length_onion());
assert!(NodeFeatures::known().supports_variable_length_onion());
+ assert!(!InitFeatures::known().requires_variable_length_onion());
+ assert!(!NodeFeatures::known().requires_variable_length_onion());
+
+ assert!(InitFeatures::known().supports_static_remote_key());
+ assert!(NodeFeatures::known().supports_static_remote_key());
+ assert!(InitFeatures::known().requires_static_remote_key());
+ assert!(NodeFeatures::known().requires_static_remote_key());
assert!(InitFeatures::known().supports_payment_secret());
assert!(NodeFeatures::known().supports_payment_secret());
+ assert!(!InitFeatures::known().requires_payment_secret());
+ assert!(!NodeFeatures::known().requires_payment_secret());
assert!(InitFeatures::known().supports_basic_mpp());
assert!(NodeFeatures::known().supports_basic_mpp());
+ assert!(!InitFeatures::known().requires_basic_mpp());
+ assert!(!NodeFeatures::known().requires_basic_mpp());
let mut init_features = InitFeatures::known();
assert!(init_features.initial_routing_sync());
}
#[test]
- fn sanity_test_unkown_bits_testing() {
- let mut features = ChannelFeatures::known();
- features.set_require_unknown_bits();
+ fn sanity_test_unknown_bits() {
+ let mut features = ChannelFeatures::empty();
+ assert!(!features.requires_unknown_bits());
+ assert!(!features.supports_unknown_bits());
+
+ features.set_required_unknown_bits();
assert!(features.requires_unknown_bits());
- features.clear_require_unknown_bits();
+ assert!(features.supports_unknown_bits());
+
+ features.clear_unknown_bits();
+ assert!(!features.requires_unknown_bits());
+ assert!(!features.supports_unknown_bits());
+
+ features.set_optional_unknown_bits();
assert!(!features.requires_unknown_bits());
+ assert!(features.supports_unknown_bits());
}
#[test]
- fn test_node_with_known_relevant_init_flags() {
- // Create an InitFeatures with initial_routing_sync supported.
- let init_features = InitFeatures::known();
+ 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());
- // Attempt to pull out non-node-context feature flags from these InitFeatures.
- let res = NodeFeatures::with_known_relevant_init_flags(&init_features);
-
+ let node_features: NodeFeatures = init_features.to_context();
{
- // Check that the flags are as expected: optional_data_loss_protect,
- // option_upfront_shutdown_script, var_onion_optin, payment_secret, and
- // basic_mpp.
- assert_eq!(res.flags.len(), 3);
- assert_eq!(res.flags[0], 0b00100010);
- assert_eq!(res.flags[1], 0b10000010);
- assert_eq!(res.flags[2], 0b00000010);
+ // Check that the flags are as expected:
+ // - option_data_loss_protect
+ // - var_onion_optin | static_remote_key (req) | payment_secret
+ // - basic_mpp
+ assert_eq!(node_features.flags.len(), 3);
+ assert_eq!(node_features.flags[0], 0b00000010);
+ assert_eq!(node_features.flags[1], 0b10010010);
+ assert_eq!(node_features.flags[2], 0b00000010);
}
- // Check that the initial_routing_sync feature was correctly blanked out.
- let new_features: InitFeatures = Features::from_le_bytes(res.flags);
- assert!(!new_features.initial_routing_sync());
+ // 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());
}
}