1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! Feature flag definitions for the Lightning protocol according to [BOLT #9].
12 //! Lightning nodes advertise a supported set of operation through feature flags. Features are
13 //! applicable for a specific context as indicated in some [messages]. [`Features`] encapsulates
14 //! behavior for specifying and checking feature flags for a particular context. Each feature is
15 //! defined internally by a trait specifying the corresponding flags (i.e., even and odd bits).
17 //! Whether a feature is considered "known" or "unknown" is relative to the implementation, whereas
18 //! the term "supports" is used in reference to a particular set of [`Features`]. That is, a node
19 //! supports a feature if it advertises the feature (as either required or optional) to its peers.
20 //! And the implementation can interpret a feature if the feature is known to it.
22 //! [BOLT #9]: https://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md
23 //! [messages]: crate::ln::msgs
26 use std::marker::PhantomData;
28 use ln::msgs::DecodeError;
29 use util::ser::{Readable, Writeable, Writer};
32 use ln::features::Features;
34 /// The context in which [`Features`] are applicable. Defines which features are required and
35 /// which are optional for the context.
37 /// Features that are known to the implementation, where a required feature is indicated by
38 /// its even bit and an optional feature is indicated by its odd bit.
39 const KNOWN_FEATURE_FLAGS: &'static [u8];
41 /// Bitmask for selecting features that are known to the implementation, regardless of
42 /// whether each feature is required or optional.
43 const KNOWN_FEATURE_MASK: &'static [u8];
46 /// Defines a [`Context`] by stating which features it requires and which are optional. Features
47 /// are specified as a comma-separated list of bytes where each byte is a pipe-delimited list of
48 /// feature identifiers.
49 macro_rules! define_context {
51 required_features: [$( $( $required_feature: ident )|*, )*],
52 optional_features: [$( $( $optional_feature: ident )|*, )*],
54 pub struct $context {}
56 impl Context for $context {
57 const KNOWN_FEATURE_FLAGS: &'static [u8] = &[
58 // For each byte, use bitwise-OR to compute the applicable flags for known
59 // required features `r_i` and optional features `o_j` for all `i` and `j` such
60 // that the following slice is formed:
63 // `r_0` | `r_1` | ... | `o_0` | `o_1` | ...,
68 <Self as $required_feature>::REQUIRED_MASK)*
70 <Self as $optional_feature>::OPTIONAL_MASK)*,
74 const KNOWN_FEATURE_MASK: &'static [u8] = &[
75 // Similar as above, but set both flags for each feature regardless of whether
76 // the feature is required or optional.
79 <Self as $required_feature>::REQUIRED_MASK |
80 <Self as $required_feature>::OPTIONAL_MASK)*
82 <Self as $optional_feature>::REQUIRED_MASK |
83 <Self as $optional_feature>::OPTIONAL_MASK)*,
90 define_context!(InitContext {
103 DataLossProtect | InitialRoutingSync | UpfrontShutdownScript | GossipQueries,
105 VariableLengthOnion | PaymentSecret,
112 define_context!(NodeContext {
125 DataLossProtect | UpfrontShutdownScript | GossipQueries,
127 VariableLengthOnion | PaymentSecret,
134 define_context!(ChannelContext {
135 required_features: [],
136 optional_features: [],
138 define_context!(InvoiceContext {
139 required_features: [,,,],
144 VariableLengthOnion | PaymentSecret,
150 /// Defines a feature with the given bits for the specified [`Context`]s. The generated trait is
151 /// useful for manipulating feature flags.
152 macro_rules! define_feature {
153 ($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr, $optional_setter: ident,
154 $required_setter: ident) => {
157 /// See [BOLT #9] for details.
159 /// [BOLT #9]: https://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md
160 pub trait $feature: Context {
161 /// The bit used to signify that the feature is required.
162 const EVEN_BIT: usize = $odd_bit - 1;
164 /// The bit used to signify that the feature is optional.
165 const ODD_BIT: usize = $odd_bit;
167 /// Assertion that [`EVEN_BIT`] is actually even.
169 /// [`EVEN_BIT`]: #associatedconstant.EVEN_BIT
170 const ASSERT_EVEN_BIT_PARITY: usize;
172 /// Assertion that [`ODD_BIT`] is actually odd.
174 /// [`ODD_BIT`]: #associatedconstant.ODD_BIT
175 const ASSERT_ODD_BIT_PARITY: usize;
177 /// The byte where the feature is set.
178 const BYTE_OFFSET: usize = Self::EVEN_BIT / 8;
180 /// The bitmask for the feature's required flag relative to the [`BYTE_OFFSET`].
182 /// [`BYTE_OFFSET`]: #associatedconstant.BYTE_OFFSET
183 const REQUIRED_MASK: u8 = 1 << (Self::EVEN_BIT - 8 * Self::BYTE_OFFSET);
185 /// The bitmask for the feature's optional flag relative to the [`BYTE_OFFSET`].
187 /// [`BYTE_OFFSET`]: #associatedconstant.BYTE_OFFSET
188 const OPTIONAL_MASK: u8 = 1 << (Self::ODD_BIT - 8 * Self::BYTE_OFFSET);
190 /// Returns whether the feature is required by the given flags.
192 fn requires_feature(flags: &Vec<u8>) -> bool {
193 flags.len() > Self::BYTE_OFFSET &&
194 (flags[Self::BYTE_OFFSET] & Self::REQUIRED_MASK) != 0
197 /// Returns whether the feature is supported by the given flags.
199 fn supports_feature(flags: &Vec<u8>) -> bool {
200 flags.len() > Self::BYTE_OFFSET &&
201 (flags[Self::BYTE_OFFSET] & (Self::REQUIRED_MASK | Self::OPTIONAL_MASK)) != 0
204 /// Sets the feature's required (even) bit in the given flags.
206 fn set_required_bit(flags: &mut Vec<u8>) {
207 if flags.len() <= Self::BYTE_OFFSET {
208 flags.resize(Self::BYTE_OFFSET + 1, 0u8);
211 flags[Self::BYTE_OFFSET] |= Self::REQUIRED_MASK;
214 /// Sets the feature's optional (odd) bit in the given flags.
216 fn set_optional_bit(flags: &mut Vec<u8>) {
217 if flags.len() <= Self::BYTE_OFFSET {
218 flags.resize(Self::BYTE_OFFSET + 1, 0u8);
221 flags[Self::BYTE_OFFSET] |= Self::OPTIONAL_MASK;
224 /// Clears the feature's required (even) and optional (odd) bits from the given
227 fn clear_bits(flags: &mut Vec<u8>) {
228 if flags.len() > Self::BYTE_OFFSET {
229 flags[Self::BYTE_OFFSET] &= !Self::REQUIRED_MASK;
230 flags[Self::BYTE_OFFSET] &= !Self::OPTIONAL_MASK;
233 let last_non_zero_byte = flags.iter().rposition(|&byte| byte != 0);
234 let size = if let Some(offset) = last_non_zero_byte { offset + 1 } else { 0 };
235 flags.resize(size, 0u8);
239 impl <T: $feature> Features<T> {
240 /// Set this feature as optional.
241 pub fn $optional_setter(mut self) -> Self {
242 <T as $feature>::set_optional_bit(&mut self.flags);
246 /// Set this feature as required.
247 pub fn $required_setter(mut self) -> Self {
248 <T as $feature>::set_required_bit(&mut self.flags);
254 impl $feature for $context {
256 const ASSERT_EVEN_BIT_PARITY: usize = 0 - (<Self as $feature>::EVEN_BIT % 2);
259 const ASSERT_ODD_BIT_PARITY: usize = (<Self as $feature>::ODD_BIT % 2) - 1;
266 define_feature!(1, DataLossProtect, [InitContext, NodeContext],
267 "Feature flags for `option_data_loss_protect`.", set_data_loss_protect_optional,
268 set_data_loss_protect_required);
269 // NOTE: Per Bolt #9, initial_routing_sync has no even bit.
270 define_feature!(3, InitialRoutingSync, [InitContext], "Feature flags for `initial_routing_sync`.",
271 set_initial_routing_sync_optional, set_initial_routing_sync_required);
272 define_feature!(5, UpfrontShutdownScript, [InitContext, NodeContext],
273 "Feature flags for `option_upfront_shutdown_script`.", set_upfront_shutdown_script_optional,
274 set_upfront_shutdown_script_required);
275 define_feature!(7, GossipQueries, [InitContext, NodeContext],
276 "Feature flags for `gossip_queries`.", set_gossip_queries_optional, set_gossip_queries_required);
277 define_feature!(9, VariableLengthOnion, [InitContext, NodeContext, InvoiceContext],
278 "Feature flags for `var_onion_optin`.", set_variable_length_onion_optional,
279 set_variable_length_onion_required);
280 define_feature!(13, StaticRemoteKey, [InitContext, NodeContext],
281 "Feature flags for `option_static_remotekey`.", set_static_remote_key_optional,
282 set_static_remote_key_required);
283 define_feature!(15, PaymentSecret, [InitContext, NodeContext, InvoiceContext],
284 "Feature flags for `payment_secret`.", set_payment_secret_optional, set_payment_secret_required);
285 define_feature!(17, BasicMPP, [InitContext, NodeContext, InvoiceContext],
286 "Feature flags for `basic_mpp`.", set_basic_mpp_optional, set_basic_mpp_required);
287 define_feature!(27, ShutdownAnySegwit, [InitContext, NodeContext],
288 "Feature flags for `opt_shutdown_anysegwit`.", set_shutdown_any_segwit_optional,
289 set_shutdown_any_segwit_required);
292 define_context!(TestingContext {
312 define_feature!(23, UnknownFeature, [TestingContext],
313 "Feature flags for an unknown feature used in testing.", set_unknown_feature_optional,
314 set_unknown_feature_required);
317 /// Tracks the set of features which a node implements, templated by the context in which it
320 /// (C-not exported) as we map the concrete feature types below directly instead
321 pub struct Features<T: sealed::Context> {
322 /// Note that, for convenience, flags is LITTLE endian (despite being big-endian on the wire)
324 mark: PhantomData<T>,
327 impl<T: sealed::Context> Clone for Features<T> {
328 fn clone(&self) -> Self {
330 flags: self.flags.clone(),
335 impl<T: sealed::Context> PartialEq for Features<T> {
336 fn eq(&self, o: &Self) -> bool {
337 self.flags.eq(&o.flags)
340 impl<T: sealed::Context> fmt::Debug for Features<T> {
341 fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
346 /// Features used within an `init` message.
347 pub type InitFeatures = Features<sealed::InitContext>;
348 /// Features used within a `node_announcement` message.
349 pub type NodeFeatures = Features<sealed::NodeContext>;
350 /// Features used within a `channel_announcement` message.
351 pub type ChannelFeatures = Features<sealed::ChannelContext>;
352 /// Features used within an invoice.
353 pub type InvoiceFeatures = Features<sealed::InvoiceContext>;
356 /// Writes all features present up to, and including, 13.
357 pub(crate) fn write_up_to_13<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
358 let len = cmp::min(2, self.flags.len());
359 w.size_hint(len + 2);
360 (len as u16).write(w)?;
361 for i in (0..len).rev() {
363 self.flags[i].write(w)?;
365 // On byte 1, we want up-to-and-including-bit-13, 0-indexed, which is
366 // up-to-and-including-bit-5, 0-indexed, on this byte:
367 (self.flags[i] & 0b00_11_11_11).write(w)?;
373 /// or's another InitFeatures into this one.
374 pub(crate) fn or(mut self, o: InitFeatures) -> InitFeatures {
375 let total_feature_len = cmp::max(self.flags.len(), o.flags.len());
376 self.flags.resize(total_feature_len, 0u8);
377 for (byte, o_byte) in self.flags.iter_mut().zip(o.flags.iter()) {
383 /// Converts `InitFeatures` to `Features<C>`. Only known `InitFeatures` relevant to context `C`
384 /// are included in the result.
385 pub(crate) fn to_context<C: sealed::Context>(&self) -> Features<C> {
386 self.to_context_internal()
390 impl InvoiceFeatures {
391 /// Converts `InvoiceFeatures` to `Features<C>`. Only known `InvoiceFeatures` relevant to
392 /// context `C` are included in the result.
393 pub(crate) fn to_context<C: sealed::Context>(&self) -> Features<C> {
394 self.to_context_internal()
398 impl<T: sealed::Context> Features<T> {
399 /// Create a blank Features with no features set
400 pub fn empty() -> Self {
407 /// Creates a Features with the bits set which are known by the implementation
408 pub fn known() -> Self {
410 flags: T::KNOWN_FEATURE_FLAGS.to_vec(),
415 /// Converts `Features<T>` to `Features<C>`. Only known `T` features relevant to context `C` are
416 /// included in the result.
417 fn to_context_internal<C: sealed::Context>(&self) -> Features<C> {
418 let byte_count = C::KNOWN_FEATURE_MASK.len();
419 let mut flags = Vec::new();
420 for (i, byte) in self.flags.iter().enumerate() {
422 let known_source_features = T::KNOWN_FEATURE_MASK[i];
423 let known_target_features = C::KNOWN_FEATURE_MASK[i];
424 flags.push(byte & known_source_features & known_target_features);
427 Features::<C> { flags, mark: PhantomData, }
430 /// Create a Features given a set of flags, in LE.
431 pub fn from_le_bytes(flags: Vec<u8>) -> Features<T> {
439 /// Gets the underlying flags set, in LE.
440 pub fn le_flags(&self) -> &Vec<u8> {
444 pub(crate) fn requires_unknown_bits(&self) -> bool {
445 // Bitwise AND-ing with all even bits set except for known features will select required
447 let byte_count = T::KNOWN_FEATURE_MASK.len();
448 self.flags.iter().enumerate().any(|(i, &byte)| {
449 let required_features = 0b01_01_01_01;
450 let unknown_features = if i < byte_count {
451 !T::KNOWN_FEATURE_MASK[i]
455 (byte & (required_features & unknown_features)) != 0
459 pub(crate) fn supports_unknown_bits(&self) -> bool {
460 // Bitwise AND-ing with all even and odd bits set except for known features will select
461 // both required and optional unknown features.
462 let byte_count = T::KNOWN_FEATURE_MASK.len();
463 self.flags.iter().enumerate().any(|(i, &byte)| {
464 let unknown_features = if i < byte_count {
465 !T::KNOWN_FEATURE_MASK[i]
469 (byte & unknown_features) != 0
473 /// The number of bytes required to represent the feature flags present. This does not include
474 /// the length bytes which are included in the serialized form.
475 pub(crate) fn byte_count(&self) -> usize {
480 pub(crate) fn set_required_unknown_bits(&mut self) {
481 <sealed::TestingContext as sealed::UnknownFeature>::set_required_bit(&mut self.flags);
485 pub(crate) fn set_optional_unknown_bits(&mut self) {
486 <sealed::TestingContext as sealed::UnknownFeature>::set_optional_bit(&mut self.flags);
490 pub(crate) fn clear_unknown_bits(&mut self) {
491 <sealed::TestingContext as sealed::UnknownFeature>::clear_bits(&mut self.flags);
495 impl<T: sealed::DataLossProtect> Features<T> {
497 pub(crate) fn requires_data_loss_protect(&self) -> bool {
498 <T as sealed::DataLossProtect>::requires_feature(&self.flags)
500 pub(crate) fn supports_data_loss_protect(&self) -> bool {
501 <T as sealed::DataLossProtect>::supports_feature(&self.flags)
505 impl<T: sealed::UpfrontShutdownScript> Features<T> {
507 pub(crate) fn requires_upfront_shutdown_script(&self) -> bool {
508 <T as sealed::UpfrontShutdownScript>::requires_feature(&self.flags)
510 pub(crate) fn supports_upfront_shutdown_script(&self) -> bool {
511 <T as sealed::UpfrontShutdownScript>::supports_feature(&self.flags)
514 pub(crate) fn clear_upfront_shutdown_script(mut self) -> Self {
515 <T as sealed::UpfrontShutdownScript>::clear_bits(&mut self.flags);
521 impl<T: sealed::GossipQueries> Features<T> {
523 pub(crate) fn requires_gossip_queries(&self) -> bool {
524 <T as sealed::GossipQueries>::requires_feature(&self.flags)
526 pub(crate) fn supports_gossip_queries(&self) -> bool {
527 <T as sealed::GossipQueries>::supports_feature(&self.flags)
530 pub(crate) fn clear_gossip_queries(mut self) -> Self {
531 <T as sealed::GossipQueries>::clear_bits(&mut self.flags);
536 impl<T: sealed::VariableLengthOnion> Features<T> {
538 pub(crate) fn requires_variable_length_onion(&self) -> bool {
539 <T as sealed::VariableLengthOnion>::requires_feature(&self.flags)
541 pub(crate) fn supports_variable_length_onion(&self) -> bool {
542 <T as sealed::VariableLengthOnion>::supports_feature(&self.flags)
546 impl<T: sealed::StaticRemoteKey> Features<T> {
547 pub(crate) fn supports_static_remote_key(&self) -> bool {
548 <T as sealed::StaticRemoteKey>::supports_feature(&self.flags)
551 pub(crate) fn requires_static_remote_key(&self) -> bool {
552 <T as sealed::StaticRemoteKey>::requires_feature(&self.flags)
556 impl<T: sealed::InitialRoutingSync> Features<T> {
557 pub(crate) fn initial_routing_sync(&self) -> bool {
558 <T as sealed::InitialRoutingSync>::supports_feature(&self.flags)
560 // We are no longer setting initial_routing_sync now that gossip_queries
561 // is enabled. This feature is ignored by a peer when gossip_queries has
564 pub(crate) fn clear_initial_routing_sync(&mut self) {
565 <T as sealed::InitialRoutingSync>::clear_bits(&mut self.flags)
569 impl<T: sealed::PaymentSecret> Features<T> {
571 pub(crate) fn requires_payment_secret(&self) -> bool {
572 <T as sealed::PaymentSecret>::requires_feature(&self.flags)
574 // Note that we never need to test this since what really matters is the invoice - iff the
575 // invoice provides a payment_secret, we assume that we can use it (ie that the recipient
576 // supports payment_secret).
578 pub(crate) fn supports_payment_secret(&self) -> bool {
579 <T as sealed::PaymentSecret>::supports_feature(&self.flags)
583 impl<T: sealed::BasicMPP> Features<T> {
585 pub(crate) fn requires_basic_mpp(&self) -> bool {
586 <T as sealed::BasicMPP>::requires_feature(&self.flags)
588 // We currently never test for this since we don't actually *generate* multipath routes.
589 pub(crate) fn supports_basic_mpp(&self) -> bool {
590 <T as sealed::BasicMPP>::supports_feature(&self.flags)
594 impl<T: sealed::ShutdownAnySegwit> Features<T> {
595 pub(crate) fn supports_shutdown_anysegwit(&self) -> bool {
596 <T as sealed::ShutdownAnySegwit>::supports_feature(&self.flags)
599 pub(crate) fn clear_shutdown_anysegwit(mut self) -> Self {
600 <T as sealed::ShutdownAnySegwit>::clear_bits(&mut self.flags);
605 impl<T: sealed::Context> Writeable for Features<T> {
606 fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
607 w.size_hint(self.flags.len() + 2);
608 (self.flags.len() as u16).write(w)?;
609 for f in self.flags.iter().rev() { // Swap back to big-endian
616 impl<T: sealed::Context> Readable for Features<T> {
617 fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
618 let mut flags: Vec<u8> = Readable::read(r)?;
619 flags.reverse(); // Swap to little-endian
629 use super::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
632 fn sanity_test_known_features() {
633 assert!(!ChannelFeatures::known().requires_unknown_bits());
634 assert!(!ChannelFeatures::known().supports_unknown_bits());
635 assert!(!InitFeatures::known().requires_unknown_bits());
636 assert!(!InitFeatures::known().supports_unknown_bits());
637 assert!(!NodeFeatures::known().requires_unknown_bits());
638 assert!(!NodeFeatures::known().supports_unknown_bits());
640 assert!(InitFeatures::known().supports_upfront_shutdown_script());
641 assert!(NodeFeatures::known().supports_upfront_shutdown_script());
642 assert!(!InitFeatures::known().requires_upfront_shutdown_script());
643 assert!(!NodeFeatures::known().requires_upfront_shutdown_script());
645 assert!(InitFeatures::known().supports_gossip_queries());
646 assert!(NodeFeatures::known().supports_gossip_queries());
647 assert!(!InitFeatures::known().requires_gossip_queries());
648 assert!(!NodeFeatures::known().requires_gossip_queries());
650 assert!(InitFeatures::known().supports_data_loss_protect());
651 assert!(NodeFeatures::known().supports_data_loss_protect());
652 assert!(!InitFeatures::known().requires_data_loss_protect());
653 assert!(!NodeFeatures::known().requires_data_loss_protect());
655 assert!(InitFeatures::known().supports_variable_length_onion());
656 assert!(NodeFeatures::known().supports_variable_length_onion());
657 assert!(!InitFeatures::known().requires_variable_length_onion());
658 assert!(!NodeFeatures::known().requires_variable_length_onion());
660 assert!(InitFeatures::known().supports_static_remote_key());
661 assert!(NodeFeatures::known().supports_static_remote_key());
662 assert!(InitFeatures::known().requires_static_remote_key());
663 assert!(NodeFeatures::known().requires_static_remote_key());
665 assert!(InitFeatures::known().supports_payment_secret());
666 assert!(NodeFeatures::known().supports_payment_secret());
667 assert!(!InitFeatures::known().requires_payment_secret());
668 assert!(!NodeFeatures::known().requires_payment_secret());
670 assert!(InitFeatures::known().supports_basic_mpp());
671 assert!(NodeFeatures::known().supports_basic_mpp());
672 assert!(!InitFeatures::known().requires_basic_mpp());
673 assert!(!NodeFeatures::known().requires_basic_mpp());
675 assert!(InitFeatures::known().supports_shutdown_anysegwit());
676 assert!(NodeFeatures::known().supports_shutdown_anysegwit());
678 let mut init_features = InitFeatures::known();
679 assert!(init_features.initial_routing_sync());
680 init_features.clear_initial_routing_sync();
681 assert!(!init_features.initial_routing_sync());
685 fn sanity_test_unknown_bits() {
686 let mut features = ChannelFeatures::empty();
687 assert!(!features.requires_unknown_bits());
688 assert!(!features.supports_unknown_bits());
690 features.set_required_unknown_bits();
691 assert!(features.requires_unknown_bits());
692 assert!(features.supports_unknown_bits());
694 features.clear_unknown_bits();
695 assert!(!features.requires_unknown_bits());
696 assert!(!features.supports_unknown_bits());
698 features.set_optional_unknown_bits();
699 assert!(!features.requires_unknown_bits());
700 assert!(features.supports_unknown_bits());
704 fn convert_to_context_with_relevant_flags() {
705 let init_features = InitFeatures::known().clear_upfront_shutdown_script().clear_gossip_queries();
706 assert!(init_features.initial_routing_sync());
707 assert!(!init_features.supports_upfront_shutdown_script());
708 assert!(!init_features.supports_gossip_queries());
710 let node_features: NodeFeatures = init_features.to_context();
712 // Check that the flags are as expected:
713 // - option_data_loss_protect
714 // - var_onion_optin | static_remote_key (req) | payment_secret
716 // - opt_shutdown_anysegwit
717 assert_eq!(node_features.flags.len(), 4);
718 assert_eq!(node_features.flags[0], 0b00000010);
719 assert_eq!(node_features.flags[1], 0b10010010);
720 assert_eq!(node_features.flags[2], 0b00000010);
721 assert_eq!(node_features.flags[3], 0b00001000);
724 // Check that cleared flags are kept blank when converting back:
725 // - initial_routing_sync was not applicable to NodeContext
726 // - upfront_shutdown_script was cleared before converting
727 // - gossip_queries was cleared before converting
728 let features: InitFeatures = node_features.to_context_internal();
729 assert!(!features.initial_routing_sync());
730 assert!(!features.supports_upfront_shutdown_script());
731 assert!(!init_features.supports_gossip_queries());
735 fn set_feature_bits() {
736 let features = InvoiceFeatures::empty()
737 .set_basic_mpp_optional()
738 .set_payment_secret_required();
739 assert!(features.supports_basic_mpp());
740 assert!(!features.requires_basic_mpp());
741 assert!(features.requires_payment_secret());
742 assert!(features.supports_payment_secret());