//! (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
//! - `Keysend` - send funds to a node without an invoice
//! (see the [`Keysend` feature assignment proposal](https://github.com/lightning/bolts/issues/605#issuecomment-606679798) for more information).
+//! - `AnchorsZeroFeeHtlcTx` - requires/supports that commitment transactions include anchor outputs
+//! and HTLC transactions are pre-signed with zero fee (see
+//! [BOLT-3](https://github.com/lightning/bolts/blob/master/03-transactions.md) for more
+//! information).
//!
//! [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, WithoutLength, 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 known to the
/// implementation, though specification of them as required or optional is up to the code
// Byte 1
VariableLengthOnion | StaticRemoteKey | PaymentSecret,
// Byte 2
- BasicMPP | Wumbo,
+ BasicMPP | Wumbo | AnchorsZeroFeeHtlcTx,
// Byte 3
ShutdownAnySegwit,
// Byte 4
// Byte 1
VariableLengthOnion | StaticRemoteKey | PaymentSecret,
// Byte 2
- BasicMPP | Wumbo,
+ BasicMPP | Wumbo | AnchorsZeroFeeHtlcTx,
// Byte 3
ShutdownAnySegwit,
// Byte 4
// Byte 2
BasicMPP,
]);
+ define_context!(OfferContext, []);
+ define_context!(InvoiceRequestContext, []);
+ define_context!(Bolt12InvoiceContext, [
+ // Byte 0
+ ,
+ // Byte 1
+ ,
+ // Byte 2
+ BasicMPP,
+ ]);
+ define_context!(BlindedHopContext, []);
// This isn't a "real" feature context, and is only used in the channel_type field in an
// `OpenChannel` message.
define_context!(ChannelTypeContext, [
// Byte 1
StaticRemoteKey,
// Byte 2
- ,
+ AnchorsZeroFeeHtlcTx,
// Byte 3
,
// Byte 4
/// [`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!(15, PaymentSecret, [InitContext, NodeContext, InvoiceContext],
"Feature flags for `payment_secret`.", set_payment_secret_optional, set_payment_secret_required,
supports_payment_secret, requires_payment_secret);
- define_feature!(17, BasicMPP, [InitContext, NodeContext, InvoiceContext],
+ define_feature!(17, BasicMPP, [InitContext, NodeContext, InvoiceContext, Bolt12InvoiceContext],
"Feature flags for `basic_mpp`.", set_basic_mpp_optional, set_basic_mpp_required,
supports_basic_mpp, requires_basic_mpp);
define_feature!(19, Wumbo, [InitContext, NodeContext],
"Feature flags for `option_support_large_channel` (aka wumbo channels).", set_wumbo_optional, set_wumbo_required,
supports_wumbo, requires_wumbo);
+ define_feature!(23, AnchorsZeroFeeHtlcTx, [InitContext, NodeContext, ChannelTypeContext],
+ "Feature flags for `option_anchors_zero_fee_htlc_tx`.", set_anchors_zero_fee_htlc_tx_optional,
+ set_anchors_zero_fee_htlc_tx_required, supports_anchors_zero_fee_htlc_tx, requires_anchors_zero_fee_htlc_tx);
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);
supports_keysend, requires_keysend);
#[cfg(test)]
- define_feature!(123456789, UnknownFeature, [NodeContext, ChannelContext, InvoiceContext],
+ define_feature!(123456789, UnknownFeature,
+ [NodeContext, ChannelContext, InvoiceContext, OfferContext, InvoiceRequestContext, Bolt12InvoiceContext, BlindedHopContext],
"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);
}
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 an `invoice`.
+pub type Bolt12InvoiceFeatures = Features<sealed::Bolt12InvoiceContext>;
+/// Features used within BOLT 4 encrypted_data_tlv and BOLT 12 blinded_payinfo
+pub type BlindedHopFeatures = Features<sealed::BlindedHopContext>;
/// Features used within the channel_type field in an OpenChannel message.
///
}
impl ChannelTypeFeatures {
- /// Constructs the implicit channel type based on the common supported types between us and our
- /// counterparty
- pub(crate) fn from_counterparty_init(counterparty_init: &InitFeatures) -> Self {
- let mut ret = counterparty_init.to_context_internal();
+ // Maps the relevant `InitFeatures` to `ChannelTypeFeatures`. Any unknown features to
+ // `ChannelTypeFeatures` are not included in the result.
+ pub(crate) fn from_init(init: &InitFeatures) -> Self {
+ let mut ret = init.to_context_internal();
// ChannelTypeFeatures must only contain required bits, so we OR the required forms of all
// optional bits and then AND out the optional ones.
for byte in ret.flags.iter_mut() {
(byte & unknown_features) != 0
})
}
+
+ // Returns true if the features within `self` are a subset of the features within `other`.
+ pub(crate) fn is_subset(&self, other: &Self) -> bool {
+ for (idx, byte) in self.flags.iter().enumerate() {
+ if let Some(other_byte) = other.flags.get(idx) {
+ if byte & other_byte != *byte {
+ // `self` has bits set that `other` doesn't.
+ return false;
+ }
+ } else {
+ if *byte > 0 {
+ // `self` has a non-zero byte that `other` doesn't.
+ return false;
+ }
+ }
+ }
+ true
+ }
}
impl<T: sealed::UpfrontShutdownScript> Features<T> {
}
}
+impl<T: sealed::SCIDPrivacy> Features<T> {
+ pub(crate) fn clear_scid_privacy(&mut self) {
+ <T as sealed::SCIDPrivacy>::clear_bits(&mut self.flags);
+ }
+}
+
+impl<T: sealed::AnchorsZeroFeeHtlcTx> Features<T> {
+ pub(crate) fn clear_anchors_zero_fee_htlc_tx(&mut self) {
+ <T as sealed::AnchorsZeroFeeHtlcTx>::clear_bits(&mut self.flags);
+ }
+}
+
+#[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 $features {
impl_feature_len_prefixed_write!(ChannelFeatures);
impl_feature_len_prefixed_write!(NodeFeatures);
impl_feature_len_prefixed_write!(InvoiceFeatures);
+impl_feature_len_prefixed_write!(BlindedHopFeatures);
+
+// Some features only appear inside of TLVs, so they don't have a length prefix when serialized.
+macro_rules! impl_feature_tlv_write {
+ ($features: ident) => {
+ impl Writeable for $features {
+ fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+ WithoutLength(self).write(w)
+ }
+ }
+ impl Readable for $features {
+ fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
+ Ok(WithoutLength::<Self>::read(r)?.0)
+ }
+ }
+ }
+}
+
+impl_feature_tlv_write!(ChannelTypeFeatures);
+
+// Some features may appear both in a TLV record and as part of a TLV subtype sequence. The latter
+// requires a length but the former does not.
-// 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 {
+impl<T: sealed::Context> Writeable for WithoutLength<&Features<T>> {
fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
- self.write_be(w)
+ self.0.write_be(w)
}
}
-impl Readable for ChannelTypeFeatures {
+
+impl<T: sealed::Context> Readable for WithoutLength<Features<T>> {
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))
+ Ok(WithoutLength(Features::<T>::from_be_bytes(v)))
}
}
#[cfg(test)]
mod tests {
- use super::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, InvoiceFeatures, NodeFeatures, sealed};
+ use super::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, InvoiceFeatures, NodeFeatures, OfferFeatures, sealed};
use bitcoin::bech32::{Base32Len, FromBase32, ToBase32, u5};
+ use crate::util::ser::{Readable, WithoutLength, Writeable};
#[test]
fn sanity_test_unknown_bits() {
init_features.set_channel_type_optional();
init_features.set_scid_privacy_optional();
init_features.set_zero_conf_optional();
+ init_features.set_anchors_zero_fee_htlc_tx_optional();
assert!(init_features.initial_routing_sync());
assert!(!init_features.supports_upfront_shutdown_script());
assert_eq!(node_features.flags.len(), 7);
assert_eq!(node_features.flags[0], 0b00000010);
assert_eq!(node_features.flags[1], 0b01010001);
- assert_eq!(node_features.flags[2], 0b00001010);
+ assert_eq!(node_features.flags[2], 0b10001010);
assert_eq!(node_features.flags[3], 0b00001000);
assert_eq!(node_features.flags[4], 0b10000000);
assert_eq!(node_features.flags[5], 0b10100000);
assert!(features.supports_payment_secret());
}
+ #[test]
+ fn encodes_features_without_length() {
+ let features = OfferFeatures::from_le_bytes(vec![1, 2, 3, 4, 5, 42, 100, 101]);
+ assert_eq!(features.flags.len(), 8);
+
+ let mut serialized_features = Vec::new();
+ WithoutLength(&features).write(&mut serialized_features).unwrap();
+ assert_eq!(serialized_features.len(), 8);
+
+ let deserialized_features =
+ WithoutLength::<OfferFeatures>::read(&mut &serialized_features[..]).unwrap().0;
+ assert_eq!(features, deserialized_features);
+ }
+
#[test]
fn invoice_features_encoding() {
let features_as_u5s = vec![
// required-StaticRemoteKey ChannelTypeFeatures.
let mut init_features = InitFeatures::empty();
init_features.set_static_remote_key_optional();
- let converted_features = ChannelTypeFeatures::from_counterparty_init(&init_features);
+ let converted_features = ChannelTypeFeatures::from_init(&init_features);
assert_eq!(converted_features, ChannelTypeFeatures::only_static_remote_key());
assert!(!converted_features.supports_any_optional_bits());
assert!(converted_features.requires_static_remote_key());