use prelude::*;
use ln::features::Features;
- /// The context in which [`Features`] are applicable. Defines which features are required and
- /// which are optional for the context.
+ /// The context in which [`Features`] are applicable. Defines which features are known to the
+ /// implementation, though specification of them as required or optional is up to the code
+ /// constructing a features object.
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.
+ /// Bitmask for selecting features that are known to the implementation.
const KNOWN_FEATURE_MASK: &'static [u8];
}
/// are specified as a comma-separated list of bytes where each byte is a pipe-delimited list of
/// feature identifiers.
macro_rules! define_context {
- ($context: ident {
- required_features: [$( $( $required_feature: ident )|*, )*],
- optional_features: [$( $( $optional_feature: ident )|*, )*],
- }) => {
+ ($context: ident, [$( $( $known_feature: ident )|*, )*]) => {
#[derive(Eq, PartialEq)]
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)*,
+ <Self as $known_feature>::REQUIRED_MASK |
+ <Self as $known_feature>::OPTIONAL_MASK)*,
)*
];
}
fn fmt(&self, fmt: &mut alloc::fmt::Formatter) -> Result<(), alloc::fmt::Error> {
$(
$(
- fmt.write_fmt(format_args!("{}: {}, ", stringify!($required_feature),
- if <$context as $required_feature>::requires_feature(&self.flags) { "required" }
- else if <$context as $required_feature>::supports_feature(&self.flags) { "supported" }
- else { "not supported" }))?;
- )*
- $(
- fmt.write_fmt(format_args!("{}: {}, ", stringify!($optional_feature),
- if <$context as $optional_feature>::requires_feature(&self.flags) { "required" }
- else if <$context as $optional_feature>::supports_feature(&self.flags) { "supported" }
+ fmt.write_fmt(format_args!("{}: {}, ", stringify!($known_feature),
+ if <$context as $known_feature>::requires_feature(&self.flags) { "required" }
+ else if <$context as $known_feature>::supports_feature(&self.flags) { "supported" }
else { "not supported" }))?;
)*
+ {} // Rust gets mad if we only have a $()* block here, so add a dummy {}
)*
fmt.write_fmt(format_args!("unknown flags: {}",
if self.requires_unknown_bits() { "required" }
};
}
- define_context!(InitContext {
- required_features: [
- // Byte 0
- ,
- // Byte 1
- VariableLengthOnion | StaticRemoteKey | PaymentSecret,
- // Byte 2
- ,
- // Byte 3
- ,
- // Byte 4
- ,
- // Byte 5
- ,
- // Byte 6
- ,
- ],
- optional_features: [
- // Note that if new "non-channel-related" flags are added here they should be
- // explicitly cleared in InitFeatures::known_channel_features and
- // NodeFeatures::known_channel_features.
- // Byte 0
- DataLossProtect | InitialRoutingSync | UpfrontShutdownScript | GossipQueries,
- // Byte 1
- ,
- // Byte 2
- BasicMPP | Wumbo,
- // Byte 3
- ShutdownAnySegwit,
- // Byte 4
- OnionMessages,
- // Byte 5
- ChannelType | SCIDPrivacy,
- // Byte 6
- ZeroConf,
- ],
- });
- define_context!(NodeContext {
- required_features: [
- // Byte 0
- ,
- // Byte 1
- VariableLengthOnion | StaticRemoteKey | PaymentSecret,
- // Byte 2
- ,
- // Byte 3
- ,
- // Byte 4
- ,
- // Byte 5
- ,
- // Byte 6
- ,
- ],
- optional_features: [
- // Byte 0
- DataLossProtect | UpfrontShutdownScript | GossipQueries,
- // Byte 1
- ,
- // Byte 2
- BasicMPP | Wumbo,
- // Byte 3
- ShutdownAnySegwit,
- // Byte 4
- OnionMessages,
- // Byte 5
- ChannelType | SCIDPrivacy,
- // Byte 6
- ZeroConf | Keysend,
- ],
- });
- define_context!(ChannelContext {
- required_features: [],
- optional_features: [],
- });
- define_context!(InvoiceContext {
- required_features: [
- // Byte 0
- ,
- // Byte 1
- VariableLengthOnion | PaymentSecret,
- // Byte 2
- ,
- ],
- optional_features: [
- // Byte 0
- ,
- // Byte 1
- ,
- // Byte 2
- BasicMPP,
- ],
- });
+ define_context!(InitContext, [
+ // Byte 0
+ DataLossProtect | InitialRoutingSync | UpfrontShutdownScript | GossipQueries,
+ // Byte 1
+ VariableLengthOnion | StaticRemoteKey | PaymentSecret,
+ // Byte 2
+ BasicMPP | Wumbo,
+ // Byte 3
+ ShutdownAnySegwit,
+ // Byte 4
+ OnionMessages,
+ // Byte 5
+ ChannelType | SCIDPrivacy,
+ // Byte 6
+ ZeroConf,
+ ]);
+ define_context!(NodeContext, [
+ // Byte 0
+ DataLossProtect | UpfrontShutdownScript | GossipQueries,
+ // Byte 1
+ VariableLengthOnion | StaticRemoteKey | PaymentSecret,
+ // Byte 2
+ BasicMPP | Wumbo,
+ // Byte 3
+ ShutdownAnySegwit,
+ // Byte 4
+ OnionMessages,
+ // Byte 5
+ ChannelType | SCIDPrivacy,
+ // Byte 6
+ ZeroConf | Keysend,
+ ]);
+ define_context!(ChannelContext, []);
+ define_context!(InvoiceContext, [
+ // Byte 0
+ ,
+ // Byte 1
+ VariableLengthOnion | PaymentSecret,
+ // Byte 2
+ BasicMPP,
+ ]);
// This isn't a "real" feature context, and is only used in the channel_type field in an
// `OpenChannel` message.
- define_context!(ChannelTypeContext {
- required_features: [
- // Byte 0
- ,
- // Byte 1
- StaticRemoteKey,
- // Byte 2
- ,
- // Byte 3
- ,
- // Byte 4
- ,
- // Byte 5
- SCIDPrivacy,
- // Byte 6
- ZeroConf,
- ],
- optional_features: [
- // Byte 0
- ,
- // Byte 1
- ,
- // Byte 2
- ,
- // Byte 3
- ,
- // Byte 4
- ,
- // Byte 5
- ,
- // Byte 6
- ,
- ],
- });
+ define_context!(ChannelTypeContext, [
+ // Byte 0
+ ,
+ // Byte 1
+ StaticRemoteKey,
+ // Byte 2
+ ,
+ // Byte 3
+ ,
+ // Byte 4
+ ,
+ // Byte 5
+ SCIDPrivacy,
+ // Byte 6
+ ZeroConf,
+ ]);
/// Defines a feature with the given bits for the specified [`Context`]s. The generated trait is
/// useful for manipulating feature flags.
/// [`ODD_BIT`]: #associatedconstant.ODD_BIT
const ASSERT_ODD_BIT_PARITY: usize;
+ /// Assertion that the bits are set in the context's [`KNOWN_FEATURE_MASK`].
+ ///
+ /// [`KNOWN_FEATURE_MASK`]: Context::KNOWN_FEATURE_MASK
+ #[cfg(not(test))] // We violate this constraint with `UnknownFeature`
+ const ASSERT_BITS_IN_MASK: u8;
+
/// The byte where the feature is set.
const BYTE_OFFSET: usize = Self::EVEN_BIT / 8;
// ODD_BIT % 2 == 1
const ASSERT_ODD_BIT_PARITY: usize = (<Self as $feature>::ODD_BIT % 2) - 1;
+
+ // (byte & (REQUIRED_MASK | OPTIONAL_MASK)) >> (EVEN_BIT % 8) == 3
+ #[cfg(not(test))] // We violate this constraint with `UnknownFeature`
+ const ASSERT_BITS_IN_MASK: u8 =
+ ((<$context>::KNOWN_FEATURE_MASK[<Self as $feature>::BYTE_OFFSET] & (<Self as $feature>::REQUIRED_MASK | <Self as $feature>::OPTIONAL_MASK))
+ >> (<Self as $feature>::EVEN_BIT % 8)) - 3;
}
)*
};
pub(crate) fn to_context<C: sealed::Context>(&self) -> Features<C> {
self.to_context_internal()
}
-
- /// Returns the set of known init features that are related to channels. At least some of
- /// these features are likely required for peers to talk to us.
- pub fn known_channel_features() -> InitFeatures {
- Self::known()
- .clear_initial_routing_sync()
- .clear_gossip_queries()
- .clear_onion_messages()
- }
-}
-
-impl NodeFeatures {
- /// Returns the set of known node features that are related to channels.
- pub fn known_channel_features() -> NodeFeatures {
- Self::known()
- .clear_gossip_queries()
- .clear_onion_messages()
- }
}
impl InvoiceFeatures {
}
}
- /// 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(),
- 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> {
}
}
-
-impl<T: sealed::GossipQueries> Features<T> {
- pub(crate) fn clear_gossip_queries(mut self) -> Self {
- <T as sealed::GossipQueries>::clear_bits(&mut self.flags);
- self
- }
-}
-
-impl<T: sealed::InitialRoutingSync> Features<T> {
- // Note that initial_routing_sync is ignored if gossip_queries is set.
- pub(crate) fn clear_initial_routing_sync(mut self) -> Self {
- <T as sealed::InitialRoutingSync>::clear_bits(&mut self.flags);
- self
- }
-}
-
-impl<T: sealed::OnionMessages> Features<T> {
- pub(crate) fn clear_onion_messages(mut self) -> Self {
- <T as sealed::OnionMessages>::clear_bits(&mut self.flags);
- self
- }
-}
-
impl<T: sealed::ShutdownAnySegwit> Features<T> {
#[cfg(test)]
pub(crate) fn clear_shutdown_anysegwit(mut self) -> Self {
#[cfg(test)]
mod tests {
- use super::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
+ use super::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, InvoiceFeatures, NodeFeatures, sealed};
use bitcoin::bech32::{Base32Len, FromBase32, ToBase32, u5};
- #[test]
- 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_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().requires_upfront_shutdown_script());
- assert!(!NodeFeatures::known().requires_upfront_shutdown_script());
-
- assert!(InitFeatures::known().supports_gossip_queries());
- assert!(NodeFeatures::known().supports_gossip_queries());
- assert!(!InitFeatures::known().requires_gossip_queries());
- assert!(!NodeFeatures::known().requires_gossip_queries());
-
- 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!(InvoiceFeatures::known().supports_variable_length_onion());
- assert!(InitFeatures::known().requires_variable_length_onion());
- assert!(NodeFeatures::known().requires_variable_length_onion());
- assert!(InvoiceFeatures::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!(InvoiceFeatures::known().supports_payment_secret());
- assert!(InitFeatures::known().requires_payment_secret());
- assert!(NodeFeatures::known().requires_payment_secret());
- assert!(InvoiceFeatures::known().requires_payment_secret());
-
- assert!(InitFeatures::known().supports_basic_mpp());
- assert!(NodeFeatures::known().supports_basic_mpp());
- assert!(InvoiceFeatures::known().supports_basic_mpp());
- assert!(!InitFeatures::known().requires_basic_mpp());
- 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_onion_messages());
- assert!(NodeFeatures::known().supports_onion_messages());
- assert!(!InitFeatures::known().requires_onion_messages());
- assert!(!NodeFeatures::known().requires_onion_messages());
-
- 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 = init_features.clear_initial_routing_sync();
- assert!(!init_features.initial_routing_sync());
- }
-
#[test]
fn sanity_test_unknown_bits() {
let features = ChannelFeatures::empty();
#[test]
fn convert_to_context_with_relevant_flags() {
- let init_features = InitFeatures::known().clear_upfront_shutdown_script().clear_gossip_queries();
+ let mut init_features = InitFeatures::empty();
+ // Set a bunch of features we use, plus initial_routing_sync_required (which shouldn't get
+ // converted as it's only relevant in an init context).
+ init_features.set_initial_routing_sync_required();
+ init_features.set_data_loss_protect_optional();
+ init_features.set_variable_length_onion_required();
+ init_features.set_static_remote_key_required();
+ init_features.set_payment_secret_required();
+ init_features.set_basic_mpp_optional();
+ init_features.set_wumbo_optional();
+ init_features.set_shutdown_any_segwit_optional();
+ init_features.set_onion_messages_optional();
+ init_features.set_channel_type_optional();
+ init_features.set_scid_privacy_optional();
+ init_features.set_zero_conf_optional();
+
assert!(init_features.initial_routing_sync());
assert!(!init_features.supports_upfront_shutdown_script());
assert!(!init_features.supports_gossip_queries());
#[test]
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 mut invoice_features = InvoiceFeatures::known();
+ assert!(<sealed::InvoiceContext as sealed::Context>::KNOWN_FEATURE_MASK.len() <
+ <sealed::NodeContext as sealed::Context>::KNOWN_FEATURE_MASK.len());
+ let mut invoice_features = InvoiceFeatures::empty();
invoice_features.set_unknown_feature_optional();
assert!(invoice_features.supports_unknown_bits());
let node_features: NodeFeatures = invoice_features.to_context();
projects / rust-lightning / blobdiff