X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Ffeatures.rs;h=77d0fa4529fb2ea526682079229b81fa9165ddf6;hb=384c4dc7753e4b7ac53ea380e52809babd8f0f9b;hp=91922f1a45f26748f9fdaf8c7ba009a068f6d6b9;hpb=3fb3218b6c311eaa4d932b3eea9e50e04bda4f9b;p=rust-lightning diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs index 91922f1a..77d0fa45 100644 --- a/lightning/src/ln/features.rs +++ b/lightning/src/ln/features.rs @@ -39,8 +39,13 @@ //! (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 @@ -51,30 +56,26 @@ //! [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]; } @@ -82,41 +83,16 @@ mod sealed { /// 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 $(| - ::REQUIRED_MASK)* - $(| - ::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 $(| - ::REQUIRED_MASK | - ::OPTIONAL_MASK)* - $(| - ::REQUIRED_MASK | - ::OPTIONAL_MASK)*, + ::REQUIRED_MASK | + ::OPTIONAL_MASK)*, )* ]; } @@ -125,17 +101,12 @@ mod sealed { 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" } @@ -145,134 +116,66 @@ mod sealed { }; } - define_context!(InitContext { - required_features: [ - // Byte 0 - , - // Byte 1 - VariableLengthOnion | StaticRemoteKey | PaymentSecret, - // Byte 2 - , - // Byte 3 - , - // Byte 4 - , - // Byte 5 - , - // Byte 6 - , - ], - optional_features: [ - // Note that if new "non-channel-related" flags are added here they should be - // explicitly cleared in InitFeatures::known_channel_features. - // 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, []); // 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. @@ -301,6 +204,12 @@ mod sealed { /// [`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; @@ -387,6 +296,12 @@ mod sealed { // ODD_BIT % 2 == 1 const ASSERT_ODD_BIT_PARITY: usize = (::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[::BYTE_OFFSET] & (::REQUIRED_MASK | ::OPTIONAL_MASK)) + >> (::EVEN_BIT % 8)) - 3; } )* }; @@ -435,8 +350,6 @@ mod sealed { 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); @@ -454,7 +367,7 @@ mod sealed { supports_keysend, requires_keysend); #[cfg(test)] - define_feature!(123456789, UnknownFeature, [NodeContext, ChannelContext, InvoiceContext], + define_feature!(123456789, UnknownFeature, [NodeContext, ChannelContext, InvoiceContext, OfferContext], "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); } @@ -470,6 +383,17 @@ pub struct Features { mark: PhantomData, } +impl Features { + 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 Clone for Features { fn clone(&self) -> Self { Self { @@ -502,6 +426,8 @@ pub type NodeFeatures = Features; pub type ChannelFeatures = Features; /// Features used within an invoice. pub type InvoiceFeatures = Features; +/// Features used within an offer. +pub type OfferFeatures = Features; /// Features used within the channel_type field in an OpenChannel message. /// @@ -532,29 +458,11 @@ impl InitFeatures { 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`. Only known `InitFeatures` relevant to context `C` /// are included in the result. pub(crate) fn to_context(&self) -> Features { self.to_context_internal() } - - /// Returns the set of known init features that are related to channels. At least some of - /// these features are likely required for peers to talk to us. - pub fn known_channel_features() -> InitFeatures { - Self::known() - .clear_initial_routing_sync() - .clear_gossip_queries() - } } impl InvoiceFeatures { @@ -672,14 +580,6 @@ impl Features { } } - /// 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` to `Features`. Only known `T` features relevant to context `C` are /// included in the result. fn to_context_internal(&self) -> Features { @@ -771,22 +671,6 @@ impl Features { } } - -impl Features { - pub(crate) fn clear_gossip_queries(mut self) -> Self { - ::clear_bits(&mut self.flags); - self - } -} - -impl Features { - // Note that initial_routing_sync is ignored if gossip_queries is set. - pub(crate) fn clear_initial_routing_sync(mut self) -> Self { - ::clear_bits(&mut self.flags); - self - } -} - impl Features { #[cfg(test)] pub(crate) fn clear_shutdown_anysegwit(mut self) -> Self { @@ -803,6 +687,15 @@ impl Features { } } +#[cfg(test)] +impl Features { + 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 $features { @@ -823,109 +716,31 @@ impl_feature_len_prefixed_write!(ChannelFeatures); impl_feature_len_prefixed_write!(NodeFeatures); impl_feature_len_prefixed_write!(InvoiceFeatures); -// Because ChannelTypeFeatures only appears inside of TLVs, it doesn't have a length prefix when -// serialized. Thus, we can't use `impl_feature_len_prefixed_write`, above, and have to write our -// own serialization. -impl Writeable for ChannelTypeFeatures { - fn write(&self, w: &mut W) -> Result<(), io::Error> { - self.write_be(w) - } -} -impl Readable for ChannelTypeFeatures { - fn read(r: &mut R) -> Result { - let v = io_extras::read_to_end(r)?; - Ok(Self::from_be_bytes(v)) +// Some features only appear inside of TLVs, so they don't have a length prefix when serialized. +macro_rules! impl_feature_tlv_write { + ($features: ident) => { + impl Writeable for $features { + fn write(&self, w: &mut W) -> Result<(), io::Error> { + self.write_be(w) + } + } + impl Readable for $features { + fn read(r: &mut R) -> Result { + let v = io_extras::read_to_end(r)?; + Ok(Self::from_be_bytes(v)) + } + } } } +impl_feature_tlv_write!(ChannelTypeFeatures); +impl_feature_tlv_write!(OfferFeatures); + #[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 = init_features.clear_initial_routing_sync(); - assert!(!init_features.initial_routing_sync()); - } - #[test] fn sanity_test_unknown_bits() { let features = ChannelFeatures::empty(); @@ -945,7 +760,22 @@ mod tests { #[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()); @@ -957,7 +787,7 @@ mod tests { // - 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); @@ -965,7 +795,7 @@ mod tests { 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); } @@ -983,8 +813,9 @@ mod tests { #[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!(::KNOWN_FEATURE_MASK.len() < + ::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();