+// 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
//! 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.
+//! defined internally by a trait specifying the corresponding flags (i.e., even and odd bits).
//!
//! 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
+//! The following features are currently required in the LDK:
+//! - `VariableLengthOnion` - requires/supports variable-length routing onion payloads
+//! (see [BOLT-4](https://github.com/lightning/bolts/blob/master/04-onion-routing.md) for more information).
+//! - `StaticRemoteKey` - requires/supports static key for remote output
+//! (see [BOLT-3](https://github.com/lightning/bolts/blob/master/03-transactions.md) for more information).
+//!
+//! The following features are currently supported in the LDK:
+//! - `DataLossProtect` - requires/supports that a node which has somehow fallen behind, e.g., has been restored from an old backup,
+//! can detect that it has fallen behind
+//! (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
+//! - `InitialRoutingSync` - requires/supports that the sending node needs a complete routing information dump
+//! (see [BOLT-7](https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#initial-sync) for more information).
+//! - `UpfrontShutdownScript` - commits to a shutdown scriptpubkey when opening a channel
+//! (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-open_channel-message) for more information).
+//! - `GossipQueries` - requires/supports more sophisticated gossip control
+//! (see [BOLT-7](https://github.com/lightning/bolts/blob/master/07-routing-gossip.md) for more information).
+//! - `PaymentSecret` - requires/supports that a node supports payment_secret field
+//! (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
+//! (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
+//! - `PaymentMetadata` - include additional data in invoices which is passed to recipients in the
+//! onion.
+//! (see [BOLT-11](https://github.com/lightning/bolts/blob/master/11-payment-encoding.md) for
+//! more).
+//! - `ZeroConf` - supports accepting HTLCs and using channels prior to funding confirmation
+//! (see
+//! [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-channel_ready-message)
+//! for more info).
+//! - `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).
+//!
+//! LDK knows about the following features, but does not support them:
+//! - `AnchorsNonzeroFeeHtlcTx` - the initial version of anchor outputs, which was later found to be
+//! vulnerable (see this
+//! [mailing list post](https://lists.linuxfoundation.org/pipermail/lightning-dev/2020-September/002796.html)
+//! for more information).
+//!
+//! [BOLT #9]: https://github.com/lightning/bolts/blob/master/09-features.md
+//! [messages]: crate::ln::msgs
-use std::{cmp, fmt};
-use std::result::Result;
-use std::marker::PhantomData;
+use crate::{io, io_extras};
+use crate::prelude::*;
+use core::{cmp, fmt};
+use core::borrow::Borrow;
+use core::hash::{Hash, Hasher};
+use core::marker::PhantomData;
-use ln::msgs::DecodeError;
-use util::ser::{Readable, Writeable, Writer};
+use bitcoin::bech32;
+use bitcoin::bech32::{Base32Len, FromBase32, ToBase32, u5, WriteBase32};
+use crate::ln::msgs::DecodeError;
+use crate::util::ser::{Readable, WithoutLength, Writeable, Writer};
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];
+ use crate::prelude::*;
+ use crate::ln::features::Features;
- /// Bitmask for selecting features that are known to the implementation, regardless of
- /// whether each feature is required or optional.
+ /// 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 {
+ /// Bitmask for selecting features that are known to the implementation.
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 {
- ($context: ident {
- required_features: [$( $( $required_feature: ident )|*, )*],
- optional_features: [$( $( $optional_feature: ident )|*, )*],
- }) => {
+ ($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` | ...,
- // ...,
- // ]
+ const KNOWN_FEATURE_MASK: &'static [u8] = &[
$(
0b00_00_00_00 $(|
- <Self as $required_feature>::REQUIRED_MASK)*
- $(|
- <Self as $optional_feature>::OPTIONAL_MASK)*,
+ <Self as $known_feature>::REQUIRED_MASK |
+ <Self as $known_feature>::OPTIONAL_MASK)*,
)*
];
+ }
- const KNOWN_FEATURE_MASK: &'static [u8] = &[
- // Similar as above, but set both flags for each feature regardless of whether
- // the feature is required or optional.
+ impl alloc::fmt::Display for Features<$context> {
+ fn fmt(&self, fmt: &mut alloc::fmt::Formatter) -> Result<(), alloc::fmt::Error> {
$(
- 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)*,
+ $(
+ fmt.write_fmt(format_args!("{}: {}, ", stringify!($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" }
+ else if self.supports_unknown_bits() { "supported" } else { "none" }))
+ }
}
};
}
- 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: [],
- });
+ define_context!(InitContext, [
+ // Byte 0
+ DataLossProtect | InitialRoutingSync | UpfrontShutdownScript | GossipQueries,
+ // Byte 1
+ VariableLengthOnion | StaticRemoteKey | PaymentSecret,
+ // Byte 2
+ BasicMPP | Wumbo | AnchorsNonzeroFeeHtlcTx | AnchorsZeroFeeHtlcTx,
+ // 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 | AnchorsNonzeroFeeHtlcTx | AnchorsZeroFeeHtlcTx,
+ // 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,
+ // Byte 3
+ ,
+ // Byte 4
+ ,
+ // Byte 5
+ ,
+ // Byte 6
+ PaymentMetadata,
+ ]);
+ 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 0
+ ,
+ // Byte 1
+ StaticRemoteKey,
+ // Byte 2
+ AnchorsNonzeroFeeHtlcTx | AnchorsZeroFeeHtlcTx,
+ // 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.
- ///
- /// [`Context`]: trait.Context.html
macro_rules! define_feature {
- ($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr) => {
+ ($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr, $optional_setter: ident,
+ $required_setter: ident, $supported_getter: ident) => {
#[doc = $doc]
///
/// See [BOLT #9] for details.
///
- /// [BOLT #9]: https://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md
+ /// [BOLT #9]: https://github.com/lightning/bolts/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;
/// [`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;
/// [`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;
+ flags[Self::BYTE_OFFSET] &= !Self::OPTIONAL_MASK;
}
/// Sets the feature's optional (odd) bit in the given flags.
}
}
+ impl <T: $feature> Features<T> {
+ /// Set this feature as optional.
+ pub fn $optional_setter(&mut self) {
+ <T as $feature>::set_optional_bit(&mut self.flags);
+ }
+
+ /// Set this feature as required.
+ pub fn $required_setter(&mut self) {
+ <T as $feature>::set_required_bit(&mut self.flags);
+ }
+
+ /// Checks if this feature is supported.
+ pub fn $supported_getter(&self) -> bool {
+ <T as $feature>::supports_feature(&self.flags)
+ }
+ }
+
$(
impl $feature for $context {
// EVEN_BIT % 2 == 0
// 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 $feature>::EVEN_BIT % 8)) - 3;
}
)*
+ };
+ ($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr, $optional_setter: ident,
+ $required_setter: ident, $supported_getter: ident, $required_getter: ident) => {
+ define_feature!($odd_bit, $feature, [$($context),+], $doc, $optional_setter, $required_setter, $supported_getter);
+ impl <T: $feature> Features<T> {
+ /// Checks if this feature is required.
+ pub fn $required_getter(&self) -> bool {
+ <T as $feature>::requires_feature(&self.flags)
+ }
+ }
}
}
define_feature!(1, DataLossProtect, [InitContext, NodeContext],
- "Feature flags for `option_data_loss_protect`.");
+ "Feature flags for `option_data_loss_protect`.", set_data_loss_protect_optional,
+ set_data_loss_protect_required, supports_data_loss_protect, requires_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!(3, InitialRoutingSync, [InitContext], "Feature flags for `initial_routing_sync`.",
+ set_initial_routing_sync_optional, set_initial_routing_sync_required,
+ 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`.");
-
- #[cfg(test)]
- define_context!(TestingContext {
- required_features: [
- // Byte 0
- ,
- // Byte 1
- ,
- // Byte 2
- UnknownFeature,
- ],
- optional_features: [
- // Byte 0
- ,
- // Byte 1
- ,
- // Byte 2
- ,
- ],
- });
+ "Feature flags for `option_upfront_shutdown_script`.", set_upfront_shutdown_script_optional,
+ set_upfront_shutdown_script_required, supports_upfront_shutdown_script,
+ requires_upfront_shutdown_script);
+ define_feature!(7, GossipQueries, [InitContext, NodeContext],
+ "Feature flags for `gossip_queries`.", set_gossip_queries_optional, set_gossip_queries_required,
+ supports_gossip_queries, requires_gossip_queries);
+ define_feature!(9, VariableLengthOnion, [InitContext, NodeContext, InvoiceContext],
+ "Feature flags for `var_onion_optin`.", set_variable_length_onion_optional,
+ set_variable_length_onion_required, supports_variable_length_onion,
+ requires_variable_length_onion);
+ define_feature!(13, StaticRemoteKey, [InitContext, NodeContext, ChannelTypeContext],
+ "Feature flags for `option_static_remotekey`.", set_static_remote_key_optional,
+ set_static_remote_key_required, supports_static_remote_key, requires_static_remote_key);
+ 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, 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!(21, AnchorsNonzeroFeeHtlcTx, [InitContext, NodeContext, ChannelTypeContext],
+ "Feature flags for `option_anchors_nonzero_fee_htlc_tx`.", set_anchors_nonzero_fee_htlc_tx_optional,
+ set_anchors_nonzero_fee_htlc_tx_required, supports_anchors_nonzero_fee_htlc_tx, requires_anchors_nonzero_fee_htlc_tx);
+ 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);
+ 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);
+ define_feature!(45, ChannelType, [InitContext, NodeContext],
+ "Feature flags for `option_channel_type`.", set_channel_type_optional,
+ set_channel_type_required, supports_channel_type, requires_channel_type);
+ define_feature!(47, SCIDPrivacy, [InitContext, NodeContext, ChannelTypeContext],
+ "Feature flags for only forwarding with SCID aliasing. Called `option_scid_alias` in the BOLTs",
+ set_scid_privacy_optional, set_scid_privacy_required, supports_scid_privacy, requires_scid_privacy);
+ define_feature!(49, PaymentMetadata, [InvoiceContext],
+ "Feature flags for payment metadata in invoices.", set_payment_metadata_optional,
+ set_payment_metadata_required, supports_payment_metadata, requires_payment_metadata);
+ define_feature!(51, ZeroConf, [InitContext, NodeContext, ChannelTypeContext],
+ "Feature flags for accepting channels with zero confirmations. Called `option_zeroconf` in the BOLTs",
+ set_zero_conf_optional, set_zero_conf_required, supports_zero_conf, requires_zero_conf);
+ define_feature!(55, Keysend, [NodeContext],
+ "Feature flags for keysend payments.", set_keysend_optional, set_keysend_required,
+ supports_keysend, requires_keysend);
+ // Note: update the module-level docs when a new feature bit is added!
#[cfg(test)]
- define_feature!(23, UnknownFeature, [TestingContext],
- "Feature flags for an unknown feature used in testing.");
+ 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);
}
/// Tracks the set of features which a node implements, templated by the context in which it
/// appears.
+///
+/// This is not exported to bindings users as we map the concrete feature types below directly instead
+#[derive(Eq)]
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: sealed::Context, Rhs: Borrow<Self>> core::ops::BitOrAssign<Rhs> for Features<T> {
+ fn bitor_assign(&mut self, rhs: Rhs) {
+ let total_feature_len = cmp::max(self.flags.len(), rhs.borrow().flags.len());
+ self.flags.resize(total_feature_len, 0u8);
+ for (byte, rhs_byte) in self.flags.iter_mut().zip(rhs.borrow().flags.iter()) {
+ *byte |= *rhs_byte;
+ }
+ }
+}
+
+impl<T: sealed::Context> core::ops::BitOr for Features<T> {
+ type Output = Self;
+
+ fn bitor(mut self, o: Self) -> Self {
+ self |= o;
+ self
+ }
+}
+
impl<T: sealed::Context> Clone for Features<T> {
fn clone(&self) -> Self {
Self {
}
}
}
+impl<T: sealed::Context> Hash for Features<T> {
+ fn hash<H: Hasher>(&self, hasher: &mut H) {
+ self.flags.hash(hasher);
+ }
+}
impl<T: sealed::Context> PartialEq for Features<T> {
fn eq(&self, o: &Self) -> bool {
self.flags.eq(&o.flags)
}
}
+impl<T: sealed::Context> PartialOrd for Features<T> {
+ fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
+ self.flags.partial_cmp(&other.flags)
+ }
+}
+impl<T: sealed::Context + Eq> Ord for Features<T> {
+ fn cmp(&self, other: &Self) -> cmp::Ordering {
+ self.flags.cmp(&other.flags)
+ }
+}
impl<T: sealed::Context> fmt::Debug for Features<T> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
self.flags.fmt(fmt)
pub type NodeFeatures = Features<sealed::NodeContext>;
/// Features used within a `channel_announcement` message.
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.
+///
+/// A channel is always of some known "type", describing the transaction formats used and the exact
+/// semantics of our interaction with our peer.
+///
+/// Note that because a channel is a specific type which is proposed by the opener and accepted by
+/// the counterparty, only required features are allowed here.
+///
+/// This is serialized differently from other feature types - it is not prefixed by a length, and
+/// thus must only appear inside a TLV where its length is known in advance.
+pub type ChannelTypeFeatures = Features<sealed::ChannelTypeContext>;
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> {
+ pub(crate) fn write_up_to_13<W: Writer>(&self, w: &mut W) -> Result<(), 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 {
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;
+ /// 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 InvoiceFeatures {
+ /// Converts `InvoiceFeatures` to `Features<C>`. Only known `InvoiceFeatures` relevant to
+ /// context `C` are included in the result.
+ pub(crate) fn to_context<C: sealed::Context>(&self) -> Features<C> {
+ self.to_context_internal()
+ }
+
+ /// Getting a route for a keysend payment to a private node requires providing the payee's
+ /// features (since they were not announced in a node announcement). However, keysend payments
+ /// don't have an invoice to pull the payee's features from, so this method is provided for use in
+ /// [`PaymentParameters::for_keysend`], thus omitting the need for payers to manually construct an
+ /// `InvoiceFeatures` for [`find_route`].
+ ///
+ /// MPP keysend is not widely supported yet, so we parameterize support to allow the user to
+ /// choose whether their router should find multi-part routes.
+ ///
+ /// [`PaymentParameters::for_keysend`]: crate::routing::router::PaymentParameters::for_keysend
+ /// [`find_route`]: crate::routing::router::find_route
+ pub(crate) fn for_keysend(allow_mpp: bool) -> InvoiceFeatures {
+ let mut res = InvoiceFeatures::empty();
+ res.set_variable_length_onion_optional();
+ if allow_mpp {
+ res.set_basic_mpp_optional();
}
- self
+ res
}
+}
- /// Converts `InitFeatures` to `Features<C>`. Only known `InitFeatures` relevant to context `C`
- /// are included in the result.
+impl Bolt12InvoiceFeatures {
+ /// Converts `Bolt12InvoiceFeatures` to `Features<C>`. Only known `Bolt12InvoiceFeatures` 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 ChannelTypeFeatures {
+ // 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 |= (*byte & 0b10_10_10_10) >> 1;
+ *byte &= 0b01_01_01_01;
+ }
+ ret
+ }
+
+ /// Constructs a ChannelTypeFeatures with only static_remotekey set
+ pub(crate) fn only_static_remote_key() -> Self {
+ let mut ret = Self::empty();
+ <sealed::ChannelTypeContext as sealed::StaticRemoteKey>::set_required_bit(&mut ret.flags);
+ ret
+ }
+
+ /// Constructs a ChannelTypeFeatures with anchors support
+ pub(crate) fn anchors_zero_htlc_fee_and_dependencies() -> Self {
+ let mut ret = Self::empty();
+ <sealed::ChannelTypeContext as sealed::StaticRemoteKey>::set_required_bit(&mut ret.flags);
+ <sealed::ChannelTypeContext as sealed::AnchorsZeroFeeHtlcTx>::set_required_bit(&mut ret.flags);
+ ret
+ }
+}
+
+impl ToBase32 for InvoiceFeatures {
+ fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
+ // Explanation for the "4": the normal way to round up when dividing is to add the divisor
+ // minus one before dividing
+ let length_u5s = (self.flags.len() * 8 + 4) / 5 as usize;
+ let mut res_u5s: Vec<u5> = vec![u5::try_from_u8(0).unwrap(); length_u5s];
+ for (byte_idx, byte) in self.flags.iter().enumerate() {
+ let bit_pos_from_left_0_indexed = byte_idx * 8;
+ let new_u5_idx = length_u5s - (bit_pos_from_left_0_indexed / 5) as usize - 1;
+ let new_bit_pos = bit_pos_from_left_0_indexed % 5;
+ let shifted_chunk_u16 = (*byte as u16) << new_bit_pos;
+ let curr_u5_as_u8 = res_u5s[new_u5_idx].to_u8();
+ res_u5s[new_u5_idx] = u5::try_from_u8(curr_u5_as_u8 | ((shifted_chunk_u16 & 0x001f) as u8)).unwrap();
+ if new_u5_idx > 0 {
+ let curr_u5_as_u8 = res_u5s[new_u5_idx - 1].to_u8();
+ res_u5s[new_u5_idx - 1] = u5::try_from_u8(curr_u5_as_u8 | (((shifted_chunk_u16 >> 5) & 0x001f) as u8)).unwrap();
+ }
+ if new_u5_idx > 1 {
+ let curr_u5_as_u8 = res_u5s[new_u5_idx - 2].to_u8();
+ res_u5s[new_u5_idx - 2] = u5::try_from_u8(curr_u5_as_u8 | (((shifted_chunk_u16 >> 10) & 0x001f) as u8)).unwrap();
+ }
+ }
+ // Trim the highest feature bits.
+ while !res_u5s.is_empty() && res_u5s[0] == u5::try_from_u8(0).unwrap() {
+ res_u5s.remove(0);
+ }
+ writer.write(&res_u5s)
+ }
+}
+
+impl Base32Len for InvoiceFeatures {
+ fn base32_len(&self) -> usize {
+ self.to_base32().len()
+ }
+}
+
+impl FromBase32 for InvoiceFeatures {
+ type Err = bech32::Error;
+
+ fn from_base32(field_data: &[u5]) -> Result<InvoiceFeatures, bech32::Error> {
+ // Explanation for the "7": the normal way to round up when dividing is to add the divisor
+ // minus one before dividing
+ let length_bytes = (field_data.len() * 5 + 7) / 8 as usize;
+ let mut res_bytes: Vec<u8> = vec![0; length_bytes];
+ for (u5_idx, chunk) in field_data.iter().enumerate() {
+ let bit_pos_from_right_0_indexed = (field_data.len() - u5_idx - 1) * 5;
+ let new_byte_idx = (bit_pos_from_right_0_indexed / 8) as usize;
+ let new_bit_pos = bit_pos_from_right_0_indexed % 8;
+ let chunk_u16 = chunk.to_u8() as u16;
+ res_bytes[new_byte_idx] |= ((chunk_u16 << new_bit_pos) & 0xff) as u8;
+ if new_byte_idx != length_bytes - 1 {
+ res_bytes[new_byte_idx + 1] |= ((chunk_u16 >> (8-new_bit_pos)) & 0xff) as u8;
+ }
+ }
+ // Trim the highest feature bits.
+ while !res_bytes.is_empty() && res_bytes[res_bytes.len() - 1] == 0 {
+ res_bytes.pop();
+ }
+ Ok(InvoiceFeatures::from_le_bytes(res_bytes))
+ }
+}
+
impl<T: sealed::Context> Features<T> {
/// Create a blank Features with no features set
- pub fn empty() -> Features<T> {
+ pub fn empty() -> Self {
Features {
flags: Vec::new(),
mark: PhantomData,
}
}
- /// 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,
- }
- }
-
/// 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 from_byte_count = T::KNOWN_FEATURE_MASK.len();
+ let to_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);
+ if i < from_byte_count && i < to_byte_count {
+ let from_known_features = T::KNOWN_FEATURE_MASK[i];
+ let to_known_features = C::KNOWN_FEATURE_MASK[i];
+ flags.push(byte & from_known_features & to_known_features);
}
}
Features::<C> { flags, mark: PhantomData, }
}
- #[cfg(test)]
- /// Create a Features given a set of flags, in LE.
+ /// Create a Features given a set of flags, in little-endian. This is in reverse byte order from
+ /// most on-the-wire encodings.
+ ///
+ /// This is not exported to bindings users as we don't support export across multiple T
pub fn from_le_bytes(flags: Vec<u8>) -> Features<T> {
Features {
flags,
&self.flags
}
- pub(crate) fn requires_unknown_bits(&self) -> bool {
+ fn write_be<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+ for f in self.flags.iter().rev() { // Swap back to big-endian
+ f.write(w)?;
+ }
+ Ok(())
+ }
+
+ fn from_be_bytes(mut flags: Vec<u8>) -> Features<T> {
+ flags.reverse(); // Swap to little-endian
+ Self {
+ flags,
+ mark: PhantomData,
+ }
+ }
+
+ pub(crate) fn supports_any_optional_bits(&self) -> bool {
+ self.flags.iter().any(|&byte| (byte & 0b10_10_10_10) != 0)
+ }
+
+ /// Returns true if this `Features` object contains required features unknown by `other`.
+ pub fn requires_unknown_bits_from(&self, other: &Features<T>) -> bool {
+ // Bitwise AND-ing with all even bits set except for known features will select required
+ // unknown features.
+ self.flags.iter().enumerate().any(|(i, &byte)| {
+ const REQUIRED_FEATURES: u8 = 0b01_01_01_01;
+ const OPTIONAL_FEATURES: u8 = 0b10_10_10_10;
+ let unknown_features = if i < other.flags.len() {
+ // Form a mask similar to !T::KNOWN_FEATURE_MASK only for `other`
+ !(other.flags[i]
+ | ((other.flags[i] >> 1) & REQUIRED_FEATURES)
+ | ((other.flags[i] << 1) & OPTIONAL_FEATURES))
+ } else {
+ 0b11_11_11_11
+ };
+ (byte & (REQUIRED_FEATURES & unknown_features)) != 0
+ })
+ }
+
+ /// Returns true if this `Features` object contains unknown feature flags which are set as
+ /// "required".
+ pub fn requires_unknown_bits(&self) -> bool {
// 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();
})
}
- /// The number of bytes required to represent the feature flags present. This does not include
- /// the length bytes which are included in the serialized form.
- pub(crate) fn byte_count(&self) -> usize {
- self.flags.len()
+ // 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
}
- #[cfg(test)]
- pub(crate) fn set_required_unknown_bits(&mut self) {
- <sealed::TestingContext as sealed::UnknownFeature>::set_required_bit(&mut self.flags);
+ /// Sets a required custom feature bit. Errors if `bit` is outside the custom range as defined
+ /// by [bLIP 2] or if it is a known `T` feature.
+ ///
+ /// Note: Required bits are even. If an odd bit is given, then the corresponding even bit will
+ /// be set instead (i.e., `bit - 1`).
+ ///
+ /// [bLIP 2]: https://github.com/lightning/blips/blob/master/blip-0002.md#feature-bits
+ pub fn set_required_custom_bit(&mut self, bit: usize) -> Result<(), ()> {
+ self.set_custom_bit(bit - (bit % 2))
}
- #[cfg(test)]
- pub(crate) fn set_optional_unknown_bits(&mut self) {
- <sealed::TestingContext as sealed::UnknownFeature>::set_optional_bit(&mut self.flags);
+ /// Sets an optional custom feature bit. Errors if `bit` is outside the custom range as defined
+ /// by [bLIP 2] or if it is a known `T` feature.
+ ///
+ /// Note: Optional bits are odd. If an even bit is given, then the corresponding odd bit will be
+ /// set instead (i.e., `bit + 1`).
+ ///
+ /// [bLIP 2]: https://github.com/lightning/blips/blob/master/blip-0002.md#feature-bits
+ pub fn set_optional_custom_bit(&mut self, bit: usize) -> Result<(), ()> {
+ self.set_custom_bit(bit + (1 - (bit % 2)))
}
- #[cfg(test)]
- pub(crate) fn clear_unknown_bits(&mut self) {
- <sealed::TestingContext as sealed::UnknownFeature>::clear_bits(&mut self.flags);
- }
-}
+ fn set_custom_bit(&mut self, bit: usize) -> Result<(), ()> {
+ if bit < 256 {
+ return Err(());
+ }
-impl<T: sealed::DataLossProtect> Features<T> {
- pub(crate) fn supports_data_loss_protect(&self) -> bool {
- <T as sealed::DataLossProtect>::supports_feature(&self.flags)
+ let byte_offset = bit / 8;
+ let mask = 1 << (bit - 8 * byte_offset);
+ if byte_offset < T::KNOWN_FEATURE_MASK.len() {
+ if (T::KNOWN_FEATURE_MASK[byte_offset] & mask) != 0 {
+ return Err(());
+ }
+ }
+
+ if self.flags.len() <= byte_offset {
+ self.flags.resize(byte_offset + 1, 0u8);
+ }
+
+ self.flags[byte_offset] |= mask;
+
+ Ok(())
}
}
impl<T: sealed::UpfrontShutdownScript> Features<T> {
- pub(crate) fn supports_upfront_shutdown_script(&self) -> bool {
- <T as sealed::UpfrontShutdownScript>::supports_feature(&self.flags)
- }
#[cfg(test)]
pub(crate) fn clear_upfront_shutdown_script(mut self) -> Self {
<T as sealed::UpfrontShutdownScript>::clear_bits(&mut self.flags);
}
}
-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::ShutdownAnySegwit> Features<T> {
+ #[cfg(test)]
+ pub(crate) fn clear_shutdown_anysegwit(mut self) -> Self {
+ <T as sealed::ShutdownAnySegwit>::clear_bits(&mut self.flags);
+ self
}
}
-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::Wumbo> Features<T> {
+ #[cfg(test)]
+ pub(crate) fn clear_wumbo(mut self) -> Self {
+ <T as sealed::Wumbo>::clear_bits(&mut self.flags);
+ self
}
- pub(crate) fn clear_initial_routing_sync(&mut self) {
- <T as sealed::InitialRoutingSync>::clear_bits(&mut self.flags)
+}
+
+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::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)
+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);
}
}
-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)
+#[cfg(test)]
+impl<T: sealed::UnknownFeature> Features<T> {
+ pub(crate) fn unknown() -> Self {
+ let mut features = Self::empty();
+ features.set_unknown_feature_required();
+ features
}
}
-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)?;
- for f in self.flags.iter().rev() { // Swap back to big-endian
- f.write(w)?;
+macro_rules! impl_feature_len_prefixed_write {
+ ($features: ident) => {
+ impl Writeable for $features {
+ fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+ (self.flags.len() as u16).write(w)?;
+ self.write_be(w)
+ }
+ }
+ impl Readable for $features {
+ fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
+ Ok(Self::from_be_bytes(Vec::<u8>::read(r)?))
+ }
}
- Ok(())
}
}
-
-impl<T: sealed::Context> Readable for Features<T> {
- fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
- let mut flags: Vec<u8> = Readable::read(r)?;
- flags.reverse(); // Swap to little-endian
- Ok(Self {
- flags,
- mark: PhantomData,
- })
+impl_feature_len_prefixed_write!(InitFeatures);
+impl_feature_len_prefixed_write!(ChannelFeatures);
+impl_feature_len_prefixed_write!(NodeFeatures);
+impl_feature_len_prefixed_write!(InvoiceFeatures);
+impl_feature_len_prefixed_write!(Bolt12InvoiceFeatures);
+impl_feature_len_prefixed_write!(BlindedHopFeatures);
+
+// Some features only appear inside of TLVs, so they don't have a length prefix when serialized.
+macro_rules! impl_feature_tlv_write {
+ ($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)
+ }
+ }
}
}
-#[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());
+impl_feature_tlv_write!(ChannelTypeFeatures);
- assert!(InitFeatures::known().supports_data_loss_protect());
- assert!(NodeFeatures::known().supports_data_loss_protect());
+// 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.
- 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());
+impl<T: sealed::Context> Writeable for WithoutLength<&Features<T>> {
+ fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+ self.0.write_be(w)
+ }
+}
- let mut init_features = InitFeatures::known();
- assert!(init_features.initial_routing_sync());
- init_features.clear_initial_routing_sync();
- assert!(!init_features.initial_routing_sync());
+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(WithoutLength(Features::<T>::from_be_bytes(v)))
}
+}
+
+#[cfg(test)]
+mod tests {
+ 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() {
- let mut features = ChannelFeatures::empty();
+ let features = ChannelFeatures::empty();
assert!(!features.requires_unknown_bits());
assert!(!features.supports_unknown_bits());
- features.set_required_unknown_bits();
+ let mut features = ChannelFeatures::empty();
+ features.set_unknown_feature_required();
assert!(features.requires_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();
+ let mut features = ChannelFeatures::empty();
+ features.set_unknown_feature_optional();
assert!(!features.requires_unknown_bits());
assert!(features.supports_unknown_bits());
}
+ #[test]
+ fn requires_unknown_bits_from() {
+ let mut features1 = InitFeatures::empty();
+ let mut features2 = InitFeatures::empty();
+ assert!(!features1.requires_unknown_bits_from(&features2));
+ assert!(!features2.requires_unknown_bits_from(&features1));
+
+ features1.set_data_loss_protect_required();
+ assert!(features1.requires_unknown_bits_from(&features2));
+ assert!(!features2.requires_unknown_bits_from(&features1));
+
+ features2.set_data_loss_protect_optional();
+ assert!(!features1.requires_unknown_bits_from(&features2));
+ assert!(!features2.requires_unknown_bits_from(&features1));
+
+ features2.set_gossip_queries_required();
+ assert!(!features1.requires_unknown_bits_from(&features2));
+ assert!(features2.requires_unknown_bits_from(&features1));
+
+ features1.set_gossip_queries_optional();
+ assert!(!features1.requires_unknown_bits_from(&features2));
+ assert!(!features2.requires_unknown_bits_from(&features1));
+
+ features1.set_variable_length_onion_required();
+ assert!(features1.requires_unknown_bits_from(&features2));
+ assert!(!features2.requires_unknown_bits_from(&features1));
+
+ features2.set_variable_length_onion_optional();
+ assert!(!features1.requires_unknown_bits_from(&features2));
+ assert!(!features2.requires_unknown_bits_from(&features1));
+
+ features1.set_basic_mpp_required();
+ features2.set_wumbo_required();
+ assert!(features1.requires_unknown_bits_from(&features2));
+ assert!(features2.requires_unknown_bits_from(&features1));
+ }
+
#[test]
fn convert_to_context_with_relevant_flags() {
- let init_features = InitFeatures::known().clear_upfront_shutdown_script();
+ 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_required();
+ 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_anchors_zero_fee_htlc_tx_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());
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);
+ // - option_data_loss_protect (req)
+ // - var_onion_optin (req) | static_remote_key (req) | payment_secret(req)
+ // - basic_mpp | wumbo | anchors_zero_fee_htlc_tx
+ // - 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[0], 0b00000001);
+ assert_eq!(node_features.flags[1], 0b01010001);
+ 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_eq!(node_features.flags[6], 0b00001000);
}
// 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
+ // - gossip_queries was cleared before converting
let features: InitFeatures = node_features.to_context_internal();
assert!(!features.initial_routing_sync());
assert!(!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!(<sealed::ChannelContext as sealed::Context>::KNOWN_FEATURE_MASK.len() <
+ <sealed::InvoiceContext as sealed::Context>::KNOWN_FEATURE_MASK.len());
+ let mut channel_features = ChannelFeatures::empty();
+ channel_features.set_unknown_feature_optional();
+ assert!(channel_features.supports_unknown_bits());
+ let invoice_features: InvoiceFeatures = channel_features.to_context_internal();
+ assert!(!invoice_features.supports_unknown_bits());
+ }
+
+ #[test]
+ fn set_feature_bits() {
+ let mut features = InvoiceFeatures::empty();
+ features.set_basic_mpp_optional();
+ features.set_payment_secret_required();
+ assert!(features.supports_basic_mpp());
+ assert!(!features.requires_basic_mpp());
+ assert!(features.requires_payment_secret());
+ assert!(features.supports_payment_secret());
+ }
+
+ #[test]
+ fn set_custom_bits() {
+ let mut features = InvoiceFeatures::empty();
+ features.set_variable_length_onion_optional();
+ assert_eq!(features.flags[1], 0b00000010);
+
+ assert!(features.set_optional_custom_bit(255).is_err());
+ assert!(features.set_required_custom_bit(256).is_ok());
+ assert!(features.set_required_custom_bit(258).is_ok());
+ assert_eq!(features.flags[31], 0b00000000);
+ assert_eq!(features.flags[32], 0b00000101);
+
+ let known_bit = <sealed::InvoiceContext as sealed::PaymentSecret>::EVEN_BIT;
+ let byte_offset = <sealed::InvoiceContext as sealed::PaymentSecret>::BYTE_OFFSET;
+ assert_eq!(byte_offset, 1);
+ assert_eq!(features.flags[byte_offset], 0b00000010);
+ assert!(features.set_required_custom_bit(known_bit).is_err());
+ assert_eq!(features.flags[byte_offset], 0b00000010);
+
+ let mut features = InvoiceFeatures::empty();
+ assert!(features.set_optional_custom_bit(256).is_ok());
+ assert!(features.set_optional_custom_bit(259).is_ok());
+ assert_eq!(features.flags[32], 0b00001010);
+
+ let mut features = InvoiceFeatures::empty();
+ assert!(features.set_required_custom_bit(257).is_ok());
+ assert!(features.set_required_custom_bit(258).is_ok());
+ assert_eq!(features.flags[32], 0b00000101);
+ }
+
+ #[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![
+ u5::try_from_u8(6).unwrap(),
+ u5::try_from_u8(10).unwrap(),
+ u5::try_from_u8(25).unwrap(),
+ u5::try_from_u8(1).unwrap(),
+ u5::try_from_u8(10).unwrap(),
+ u5::try_from_u8(0).unwrap(),
+ u5::try_from_u8(20).unwrap(),
+ u5::try_from_u8(2).unwrap(),
+ u5::try_from_u8(0).unwrap(),
+ u5::try_from_u8(6).unwrap(),
+ u5::try_from_u8(0).unwrap(),
+ u5::try_from_u8(16).unwrap(),
+ u5::try_from_u8(1).unwrap(),
+ ];
+ let features = InvoiceFeatures::from_le_bytes(vec![1, 2, 3, 4, 5, 42, 100, 101]);
+
+ // Test length calculation.
+ assert_eq!(features.base32_len(), 13);
+
+ // Test serialization.
+ let features_serialized = features.to_base32();
+ assert_eq!(features_as_u5s, features_serialized);
+
+ // Test deserialization.
+ let features_deserialized = InvoiceFeatures::from_base32(&features_as_u5s).unwrap();
+ assert_eq!(features, features_deserialized);
+ }
+
+ #[test]
+ fn test_channel_type_mapping() {
+ // If we map an InvoiceFeatures with StaticRemoteKey optional, it should map into a
+ // required-StaticRemoteKey ChannelTypeFeatures.
+ let mut init_features = InitFeatures::empty();
+ init_features.set_static_remote_key_optional();
+ 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());
}
}