//! (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).
+//! - `Wumbo` - requires/supports that a node create large channels. Called `option_support_large_channel` in the spec.
+//! (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-open_channel-message) 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).
+//! - `OnionMessages` - requires/supports forwarding onion messages
+//! (see [BOLT-7](https://github.com/lightning/bolts/pull/759/files) for more information).
+//! TODO: update link
//! - `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
//! [BOLT #9]: https://github.com/lightning/bolts/blob/master/09-features.md
//! [messages]: crate::ln::msgs
-use {io, io_extras};
-use prelude::*;
+use crate::{io, io_extras};
+use crate::prelude::*;
use core::{cmp, fmt};
use core::hash::{Hash, Hasher};
use core::marker::PhantomData;
use bitcoin::bech32;
use bitcoin::bech32::{Base32Len, FromBase32, ToBase32, u5, WriteBase32};
-use ln::msgs::DecodeError;
-use util::ser::{Readable, Writeable, Writer};
+use crate::ln::msgs::DecodeError;
+use crate::util::ser::{Readable, Writeable, Writer};
mod sealed {
- use prelude::*;
- use ln::features::Features;
+ use crate::prelude::*;
+ use crate::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: [
- // Byte 0
- DataLossProtect | InitialRoutingSync | UpfrontShutdownScript | GossipQueries,
- // Byte 1
- ,
- // Byte 2
- BasicMPP | Wumbo,
- // Byte 3
- ShutdownAnySegwit,
- // Byte 4
- ,
- // 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
- ,
- // 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,
+ ]);
+ define_context!(OfferContext, []);
+ define_context!(InvoiceRequestContext, []);
// 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;
}
)*
};
define_feature!(27, ShutdownAnySegwit, [InitContext, NodeContext],
"Feature flags for `opt_shutdown_anysegwit`.", set_shutdown_any_segwit_optional,
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);
supports_keysend, requires_keysend);
#[cfg(test)]
- define_feature!(123456789, UnknownFeature, [NodeContext, ChannelContext, InvoiceContext],
+ define_feature!(123456789, UnknownFeature,
+ [NodeContext, ChannelContext, InvoiceContext, OfferContext, InvoiceRequestContext],
"Feature flags for an unknown feature used in testing.", set_unknown_feature_optional,
set_unknown_feature_required, supports_unknown_test_feature, requires_unknown_test_feature);
}
mark: PhantomData<T>,
}
+impl <T: sealed::Context> Features<T> {
+ pub(crate) fn or(mut self, o: Self) -> Self {
+ 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
+ }
+}
+
impl<T: sealed::Context> Clone for Features<T> {
fn clone(&self) -> Self {
Self {
pub type ChannelFeatures = Features<sealed::ChannelContext>;
/// Features used within an invoice.
pub type InvoiceFeatures = Features<sealed::InvoiceContext>;
+/// Features used within an `offer`.
+pub type OfferFeatures = Features<sealed::OfferContext>;
+/// Features used within an `invoice_request`.
+pub type InvoiceRequestFeatures = Features<sealed::InvoiceRequestContext>;
/// Features used within the channel_type field in an OpenChannel message.
///
Ok(())
}
- /// 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> {
}
}
- /// 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> {
- #[cfg(test)]
- 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> {
- // 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
- // been negotiated.
- #[cfg(test)]
- pub(crate) fn clear_initial_routing_sync(&mut self) {
- <T as sealed::InitialRoutingSync>::clear_bits(&mut self.flags)
- }
-}
-
impl<T: sealed::ShutdownAnySegwit> Features<T> {
#[cfg(test)]
pub(crate) fn clear_shutdown_anysegwit(mut self) -> Self {
}
}
+#[cfg(test)]
+impl<T: sealed::UnknownFeature> Features<T> {
+ pub(crate) fn unknown() -> Self {
+ let mut features = Self::empty();
+ features.set_unknown_feature_required();
+ features
+ }
+}
+
macro_rules! impl_feature_len_prefixed_write {
($features: ident) => {
impl Writeable for $features {
impl_feature_len_prefixed_write!(NodeFeatures);
impl_feature_len_prefixed_write!(InvoiceFeatures);
-// Because ChannelTypeFeatures only appears inside of TLVs, it doesn't have a length prefix when
-// serialized. Thus, we can't use `impl_feature_len_prefixed_write`, above, and have to write our
-// own serialization.
-impl Writeable for ChannelTypeFeatures {
- fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
- self.write_be(w)
- }
-}
-impl Readable for ChannelTypeFeatures {
- fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
- let v = io_extras::read_to_end(r)?;
- Ok(Self::from_be_bytes(v))
+// Some features only appear inside of TLVs, so they don't have a length prefix when serialized.
+macro_rules! impl_feature_tlv_write {
+ ($features: ident) => {
+ impl Writeable for $features {
+ fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+ self.write_be(w)
+ }
+ }
+ impl Readable for $features {
+ fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
+ let v = io_extras::read_to_end(r)?;
+ Ok(Self::from_be_bytes(v))
+ }
+ }
}
}
+impl_feature_tlv_write!(ChannelTypeFeatures);
+impl_feature_tlv_write!(OfferFeatures);
+impl_feature_tlv_write!(InvoiceRequestFeatures);
+
#[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_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!(!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());
// - var_onion_optin (req) | static_remote_key (req) | payment_secret(req)
// - basic_mpp | wumbo
// - opt_shutdown_anysegwit
- // -
+ // - onion_messages
// - option_channel_type | option_scid_alias
// - option_zeroconf
assert_eq!(node_features.flags.len(), 7);
assert_eq!(node_features.flags[1], 0b01010001);
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[4], 0b10000000);
assert_eq!(node_features.flags[5], 0b10100000);
assert_eq!(node_features.flags[6], 0b00001000);
}
#[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();