X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Ffeatures.rs;h=613d2db14590b5115b9ae6c18461699141dd0c19;hb=b1c6499e1c50fc41c443883dde8e8248106089c3;hp=fc2526fe55842bf41022cd67d88fba50a34aa672;hpb=9dd2be15e90d9fa7369e7f9757cabce81c293602;p=rust-lightning diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs index fc2526fe..613d2db1 100644 --- a/lightning/src/ln/features.rs +++ b/lightning/src/ln/features.rs @@ -173,6 +173,16 @@ mod sealed { (flags[Self::BYTE_OFFSET] & (Self::REQUIRED_MASK | Self::OPTIONAL_MASK)) != 0 } + /// Sets the feature's required (even) bit in the given flags. + #[inline] + fn set_required_bit(flags: &mut Vec) { + if flags.len() <= Self::BYTE_OFFSET { + flags.resize(Self::BYTE_OFFSET + 1, 0u8); + } + + flags[Self::BYTE_OFFSET] |= Self::REQUIRED_MASK; + } + /// Sets the feature's optional (odd) bit in the given flags. #[inline] fn set_optional_bit(flags: &mut Vec) { @@ -191,6 +201,10 @@ mod sealed { flags[Self::BYTE_OFFSET] &= !Self::REQUIRED_MASK; flags[Self::BYTE_OFFSET] &= !Self::OPTIONAL_MASK; } + + let last_non_zero_byte = flags.iter().rposition(|&byte| byte != 0); + let size = if let Some(offset) = last_non_zero_byte { offset + 1 } else { 0 }; + flags.resize(size, 0u8); } } @@ -219,6 +233,30 @@ mod sealed { "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 + , + ], + }); + + #[cfg(test)] + define_feature!(23, UnknownFeature, [TestingContext], + "Feature flags for an unknown feature used in testing."); } /// Tracks the set of features which a node implements, templated by the context in which it @@ -282,32 +320,11 @@ impl InitFeatures { } self } -} -impl ChannelFeatures { - /// Takes the flags that we know how to interpret in an init-context features that are also - /// relevant in a channel-context features and creates a channel-context features from them. - pub(crate) fn with_known_relevant_init_flags(_init_ctx: &InitFeatures) -> Self { - // There are currently no channel flags defined that we understand. - Self { flags: Vec::new(), mark: PhantomData, } - } -} - -impl NodeFeatures { - /// Takes the flags that we know how to interpret in an init-context features that are also - /// relevant in a node-context features and creates a node-context features from them. - /// Be sure to blank out features that are unknown to us. - pub(crate) fn with_known_relevant_init_flags(init_ctx: &InitFeatures) -> Self { - use ln::features::sealed::Context; - let byte_count = sealed::NodeContext::KNOWN_FEATURE_MASK.len(); - - let mut flags = Vec::new(); - for (i, feature_byte) in init_ctx.flags.iter().enumerate() { - if i < byte_count { - flags.push(feature_byte & sealed::NodeContext::KNOWN_FEATURE_MASK[i]); - } - } - Self { flags, mark: PhantomData, } + /// 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() } } @@ -330,6 +347,21 @@ impl Features { } } + /// Converts `Features` to `Features`. Only known `T` features relevant to context `C` are + /// included in the result. + fn to_context_internal(&self) -> Features { + let 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); + } + } + Features:: { flags, mark: PhantomData, } + } + #[cfg(test)] /// Create a Features given a set of flags, in LE. pub fn from_le_bytes(flags: Vec) -> Features { @@ -346,15 +378,13 @@ impl Features { } pub(crate) fn requires_unknown_bits(&self) -> bool { - use ln::features::sealed::Context; - let byte_count = sealed::InitContext::KNOWN_FEATURE_MASK.len(); - - // Bitwise AND-ing with all even bits set except for known features will select unknown - // required features. + // 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(); self.flags.iter().enumerate().any(|(i, &byte)| { let required_features = 0b01_01_01_01; let unknown_features = if i < byte_count { - !sealed::InitContext::KNOWN_FEATURE_MASK[i] + !T::KNOWN_FEATURE_MASK[i] } else { 0b11_11_11_11 }; @@ -363,14 +393,12 @@ impl Features { } pub(crate) fn supports_unknown_bits(&self) -> bool { - use ln::features::sealed::Context; - let byte_count = sealed::InitContext::KNOWN_FEATURE_MASK.len(); - // Bitwise AND-ing with all even and odd bits set except for known features will select - // unknown features. + // both required and optional unknown features. + let byte_count = T::KNOWN_FEATURE_MASK.len(); self.flags.iter().enumerate().any(|(i, &byte)| { let unknown_features = if i < byte_count { - !sealed::InitContext::KNOWN_FEATURE_MASK[i] + !T::KNOWN_FEATURE_MASK[i] } else { 0b11_11_11_11 }; @@ -385,23 +413,18 @@ impl Features { } #[cfg(test)] - pub(crate) fn set_require_unknown_bits(&mut self) { - let newlen = cmp::max(3, self.flags.len()); - self.flags.resize(newlen, 0u8); - self.flags[2] |= 0x40; + pub(crate) fn set_required_unknown_bits(&mut self) { + ::set_required_bit(&mut self.flags); } #[cfg(test)] - pub(crate) fn clear_require_unknown_bits(&mut self) { - let newlen = cmp::max(3, self.flags.len()); - self.flags.resize(newlen, 0u8); - self.flags[2] &= !0x40; - if self.flags.len() == 3 && self.flags[2] == 0 { - self.flags.resize(2, 0u8); - } - if self.flags.len() == 2 && self.flags[1] == 0 { - self.flags.resize(1, 0u8); - } + pub(crate) fn set_optional_unknown_bits(&mut self) { + ::set_optional_bit(&mut self.flags); + } + + #[cfg(test)] + pub(crate) fn clear_unknown_bits(&mut self) { + ::clear_bits(&mut self.flags); } } @@ -416,8 +439,9 @@ impl Features { ::supports_feature(&self.flags) } #[cfg(test)] - pub(crate) fn unset_upfront_shutdown_script(&mut self) { - ::clear_bits(&mut self.flags) + pub(crate) fn clear_upfront_shutdown_script(mut self) -> Self { + ::clear_bits(&mut self.flags); + self } } @@ -478,7 +502,7 @@ impl Readable for Features { #[cfg(test)] mod tests { - use super::{ChannelFeatures, InitFeatures, NodeFeatures, Features}; + use super::{ChannelFeatures, InitFeatures, NodeFeatures}; #[test] fn sanity_test_our_features() { @@ -511,35 +535,47 @@ mod tests { } #[test] - fn sanity_test_unkown_bits_testing() { - let mut features = ChannelFeatures::known(); - features.set_require_unknown_bits(); + fn sanity_test_unknown_bits() { + let mut features = ChannelFeatures::empty(); + assert!(!features.requires_unknown_bits()); + assert!(!features.supports_unknown_bits()); + + features.set_required_unknown_bits(); assert!(features.requires_unknown_bits()); - features.clear_require_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(); + assert!(!features.requires_unknown_bits()); + assert!(features.supports_unknown_bits()); } #[test] - fn test_node_with_known_relevant_init_flags() { - // Create an InitFeatures with initial_routing_sync supported. - let init_features = InitFeatures::known(); + fn convert_to_context_with_relevant_flags() { + let init_features = InitFeatures::known().clear_upfront_shutdown_script(); assert!(init_features.initial_routing_sync()); + assert!(!init_features.supports_upfront_shutdown_script()); - // Attempt to pull out non-node-context feature flags from these InitFeatures. - let res = NodeFeatures::with_known_relevant_init_flags(&init_features); - + let node_features: NodeFeatures = init_features.to_context(); { - // Check that the flags are as expected: optional_data_loss_protect, - // option_upfront_shutdown_script, var_onion_optin, payment_secret, and - // basic_mpp. - assert_eq!(res.flags.len(), 3); - assert_eq!(res.flags[0], 0b00100010); - assert_eq!(res.flags[1], 0b10000010); - assert_eq!(res.flags[2], 0b00000010); + // 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); } - // Check that the initial_routing_sync feature was correctly blanked out. - let new_features: InitFeatures = Features::from_le_bytes(res.flags); - assert!(!new_features.initial_routing_sync()); + // 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 + let features: InitFeatures = node_features.to_context_internal(); + assert!(!features.initial_routing_sync()); + assert!(!features.supports_upfront_shutdown_script()); } }