X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;ds=sidebyside;f=lightning%2Fsrc%2Fln%2Ffeatures.rs;h=641c1ffb6f6230fcd0ec6b8f294a78a15c66be1b;hb=7728d3b6a86db7a12d591c8947fbe88a94fdffdd;hp=ac9af1434012be9abdca4ce6bad85d76b3464345;hpb=cd5a11fe0d56fc6520fe94bad2cb5ea461608442;p=rust-lightning diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs index ac9af143..641c1ffb 100644 --- a/lightning/src/ln/features.rs +++ b/lightning/src/ln/features.rs @@ -8,63 +8,50 @@ use std::marker::PhantomData; use ln::msgs::DecodeError; use util::ser::{Readable, Writeable, Writer}; -/// The context in which a Feature object appears determines which bits of features the node -/// supports will be set. We use this when creating our own Feature objects to select which bits to -/// set and when passing around Feature objects to ensure the bits we're checking for are -/// available. -/// -/// This Context represents when the Feature appears in the init message, sent between peers and not -/// rumored around the P2P network. -pub struct FeatureContextInit {} -/// The context in which a Feature object appears determines which bits of features the node -/// supports will be set. We use this when creating our own Feature objects to select which bits to -/// set and when passing around Feature objects to ensure the bits we're checking for are -/// available. -/// -/// This Context represents when the Feature appears in the node_announcement message, as it is -/// rumored around the P2P network. -pub struct FeatureContextNode {} -/// The context in which a Feature object appears determines which bits of features the node -/// supports will be set. We use this when creating our own Feature objects to select which bits to -/// set and when passing around Feature objects to ensure the bits we're checking for are -/// available. -/// -/// This Context represents when the Feature appears in the ChannelAnnouncement message, as it is -/// rumored around the P2P network. -pub struct FeatureContextChannel {} -/// The context in which a Feature object appears determines which bits of features the node -/// supports will be set. We use this when creating our own Feature objects to select which bits to -/// set and when passing around Feature objects to ensure the bits we're checking for are -/// available. -/// -/// This Context represents when the Feature appears in an invoice, used to determine the different -/// options available for routing a payment. -/// -/// Note that this is currently unused as invoices come to us via a different crate and are not -/// native to rust-lightning directly. -pub struct FeatureContextInvoice {} - -/// An internal trait capturing the various future context types -pub trait FeatureContext {} -impl FeatureContext for FeatureContextInit {} -impl FeatureContext for FeatureContextNode {} -impl FeatureContext for FeatureContextChannel {} -impl FeatureContext for FeatureContextInvoice {} - -/// An internal trait capturing FeatureContextInit and FeatureContextNode -pub trait FeatureContextInitNode : FeatureContext {} -impl FeatureContextInitNode for FeatureContextInit {} -impl FeatureContextInitNode for FeatureContextNode {} +mod sealed { // You should just use the type aliases instead. + pub struct InitContext {} + pub struct NodeContext {} + pub struct ChannelContext {} + + /// An internal trait capturing the various feature context types + pub trait Context {} + impl Context for InitContext {} + impl Context for NodeContext {} + impl Context for ChannelContext {} + + pub trait DataLossProtect: Context {} + impl DataLossProtect for InitContext {} + impl DataLossProtect for NodeContext {} + + pub trait InitialRoutingSync: Context {} + impl InitialRoutingSync for InitContext {} + + pub trait UpfrontShutdownScript: Context {} + impl UpfrontShutdownScript for InitContext {} + impl UpfrontShutdownScript for NodeContext {} + + pub trait VariableLengthOnion: Context {} + impl VariableLengthOnion for InitContext {} + impl VariableLengthOnion for NodeContext {} + + pub trait PaymentSecret: Context {} + impl PaymentSecret for InitContext {} + impl PaymentSecret for NodeContext {} + + pub trait BasicMPP: Context {} + impl BasicMPP for InitContext {} + impl BasicMPP for NodeContext {} +} /// Tracks the set of features which a node implements, templated by the context in which it /// appears. -pub struct Features { +pub struct Features { /// Note that, for convinience, flags is LITTLE endian (despite being big-endian on the wire) flags: Vec, mark: PhantomData, } -impl Clone for Features { +impl Clone for Features { fn clone(&self) -> Self { Self { flags: self.flags.clone(), @@ -72,61 +59,116 @@ impl Clone for Features { } } } -impl PartialEq for Features { +impl PartialEq for Features { fn eq(&self, o: &Self) -> bool { self.flags.eq(&o.flags) } } -impl fmt::Debug for Features { +impl fmt::Debug for Features { fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> { self.flags.fmt(fmt) } } /// A feature message as it appears in an init message -pub type InitFeatures = Features; +pub type InitFeatures = Features; /// A feature message as it appears in a node_announcement message -pub type NodeFeatures = Features; +pub type NodeFeatures = Features; /// A feature message as it appears in a channel_announcement message -pub type ChannelFeatures = Features; +pub type ChannelFeatures = Features; + +impl InitFeatures { + /// Create a Features with the features we support + pub fn supported() -> InitFeatures { + InitFeatures { + flags: vec![2 | 1 << 5, 1 << (9-8) | 1 << (15 - 8), 1 << (17 - 8*2)], + mark: PhantomData, + } + } + + /// Writes all features present up to, and including, 13. + pub(crate) fn write_up_to_13(&self, w: &mut W) -> Result<(), ::std::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 { + self.flags[i].write(w)?; + } else { + // On byte 1, we want up-to-and-including-bit-13, 0-indexed, which is + // up-to-and-including-bit-5, 0-indexed, on this byte: + (self.flags[i] & 0b00_11_11_11).write(w)?; + } + } + Ok(()) + } -impl Features { + /// 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 + } +} + +impl ChannelFeatures { /// Create a Features with the features we support #[cfg(not(feature = "fuzztarget"))] - pub(crate) fn supported() -> Features { - Features { - flags: vec![2 | 1 << 5], + pub(crate) fn supported() -> ChannelFeatures { + ChannelFeatures { + flags: Vec::new(), mark: PhantomData, } } #[cfg(feature = "fuzztarget")] - pub fn supported() -> Features { - Features { - flags: vec![2 | 1 << 5], + pub fn supported() -> ChannelFeatures { + ChannelFeatures { + flags: Vec::new(), mark: PhantomData, } } + + /// 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 Features { +impl NodeFeatures { /// Create a Features with the features we support #[cfg(not(feature = "fuzztarget"))] - pub(crate) fn supported() -> Features { - Features { - flags: Vec::new(), + pub(crate) fn supported() -> NodeFeatures { + NodeFeatures { + flags: vec![2 | 1 << 5, 1 << (9-8) | 1 << (15 - 8), 1 << (17 - 8*2)], mark: PhantomData, } } #[cfg(feature = "fuzztarget")] - pub fn supported() -> Features { - Features { - flags: Vec::new(), + pub fn supported() -> NodeFeatures { + NodeFeatures { + flags: vec![2 | 1 << 5, 1 << (9-8) | 1 << (15 - 8), 1 << (17 - 8*2)], mark: PhantomData, } } + + /// 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. + pub(crate) fn with_known_relevant_init_flags(init_ctx: &InitFeatures) -> Self { + let mut flags = Vec::new(); + if init_ctx.flags.len() > 0 { + // Pull out data_loss_protect and upfront_shutdown_script (bits 0, 1, 4, and 5) + flags.push(init_ctx.flags.last().unwrap() & 0b00110011); + } + Self { flags, mark: PhantomData, } + } } -impl Features { +impl Features { /// Create a blank Features with no features set pub fn empty() -> Features { Features { @@ -152,13 +194,23 @@ impl Features { pub(crate) fn requires_unknown_bits(&self) -> bool { self.flags.iter().enumerate().any(|(idx, &byte)| { - ( idx != 0 && (byte & 0x55) != 0 ) || ( idx == 0 && (byte & 0x14) != 0 ) + (match idx { + 0 => (byte & 0b01000100), + 1 => (byte & 0b00010100), + 2 => (byte & 0b01010100), + _ => (byte & 0b01010101), + }) != 0 }) } pub(crate) fn supports_unknown_bits(&self) -> bool { self.flags.iter().enumerate().any(|(idx, &byte)| { - ( idx != 0 && byte != 0 ) || ( idx == 0 && (byte & 0xc4) != 0 ) + (match idx { + 0 => (byte & 0b11000100), + 1 => (byte & 0b00111100), + 2 => (byte & 0b11111100), + _ => byte, + }) != 0 }) } @@ -170,27 +222,32 @@ impl Features { #[cfg(test)] pub(crate) fn set_require_unknown_bits(&mut self) { - let newlen = cmp::max(2, self.flags.len()); + let newlen = cmp::max(3, self.flags.len()); self.flags.resize(newlen, 0u8); - self.flags[1] |= 0x40; + self.flags[2] |= 0x40; } #[cfg(test)] pub(crate) fn clear_require_unknown_bits(&mut self) { - let newlen = cmp::max(2, self.flags.len()); + let newlen = cmp::max(3, self.flags.len()); self.flags.resize(newlen, 0u8); - self.flags[1] &= !0x40; + 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); } } } -impl Features { +impl Features { pub(crate) fn supports_data_loss_protect(&self) -> bool { self.flags.len() > 0 && (self.flags[0] & 3) != 0 } +} +impl Features { pub(crate) fn supports_upfront_shutdown_script(&self) -> bool { self.flags.len() > 0 && (self.flags[0] & (3 << 4)) != 0 } @@ -200,7 +257,13 @@ impl Features { } } -impl Features { +impl Features { + pub(crate) fn supports_variable_length_onion(&self) -> bool { + self.flags.len() > 1 && (self.flags[1] & 3) != 0 + } +} + +impl Features { pub(crate) fn initial_routing_sync(&self) -> bool { self.flags.len() > 0 && (self.flags[0] & (1 << 3)) != 0 } @@ -211,34 +274,26 @@ impl Features { self.flags[0] |= 1 << 3; } } +} - /// Writes all features present up to, and including, 13. - pub(crate) fn write_up_to_13(&self, w: &mut W) -> Result<(), ::std::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 { - self.flags[i].write(w)?; - } else { - (self.flags[i] & ((1 << (14 - 8)) - 1)).write(w)?; - } - } - Ok(()) +impl Features { + #[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 all the way through that we can do MPP. + pub(crate) fn payment_secret(&self) -> bool { + self.flags.len() > 1 && (self.flags[1] & (3 << (12-8))) != 0 } +} - /// 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 (feature, o_feature) in self.flags.iter_mut().zip(o.flags.iter()) { - *feature |= *o_feature; - } - self +impl Features { + // We currently never test for this since we don't actually *generate* multipath routes. + #[allow(dead_code)] + pub(crate) fn basic_mpp(&self) -> bool { + self.flags.len() > 2 && (self.flags[2] & (3 << (16-8*2))) != 0 } } -impl Writeable for Features { +impl Writeable for Features { fn write(&self, w: &mut W) -> Result<(), ::std::io::Error> { w.size_hint(self.flags.len() + 2); (self.flags.len() as u16).write(w)?; @@ -249,7 +304,7 @@ impl Writeable for Features { } } -impl Readable for Features { +impl Readable for Features { fn read(r: &mut R) -> Result { let mut flags: Vec = Readable::read(r)?; flags.reverse(); // Swap to little-endian @@ -259,3 +314,38 @@ impl Readable for Features { }) } } + +#[cfg(test)] +mod tests { + use super::{ChannelFeatures, InitFeatures, NodeFeatures}; + + #[test] + fn sanity_test_our_features() { + assert!(!ChannelFeatures::supported().requires_unknown_bits()); + assert!(!ChannelFeatures::supported().supports_unknown_bits()); + assert!(!InitFeatures::supported().requires_unknown_bits()); + assert!(!InitFeatures::supported().supports_unknown_bits()); + assert!(!NodeFeatures::supported().requires_unknown_bits()); + assert!(!NodeFeatures::supported().supports_unknown_bits()); + + assert!(InitFeatures::supported().supports_upfront_shutdown_script()); + assert!(NodeFeatures::supported().supports_upfront_shutdown_script()); + + assert!(InitFeatures::supported().supports_data_loss_protect()); + assert!(NodeFeatures::supported().supports_data_loss_protect()); + + let mut init_features = InitFeatures::supported(); + init_features.set_initial_routing_sync(); + assert!(!init_features.requires_unknown_bits()); + assert!(!init_features.supports_unknown_bits()); + } + + #[test] + fn sanity_test_unkown_bits_testing() { + let mut features = ChannelFeatures::supported(); + features.set_require_unknown_bits(); + assert!(features.requires_unknown_bits()); + features.clear_require_unknown_bits(); + assert!(!features.requires_unknown_bits()); + } +}