X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Ffeatures.rs;h=9ab53b4ae82c808745fec6b9d6e71a4cc9502650;hb=c2347d61b442e6ea78b48a18d04dda7171a6c6e8;hp=50d8e38157871bf40f0ab416cdd28c92eaf1bfb7;hpb=c94e53d9ddd65816b29af07ac075f542f0f5b37f;p=rust-lightning diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs index 50d8e381..9ab53b4a 100644 --- a/lightning/src/ln/features.rs +++ b/lightning/src/ln/features.rs @@ -29,6 +29,18 @@ mod sealed { // You should just use the type aliases instead. 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 @@ -69,7 +81,7 @@ impl InitFeatures { /// Create a Features with the features we support pub fn supported() -> InitFeatures { InitFeatures { - flags: vec![2 | 1 << 5], + flags: vec![2 | 1 << 5, 1 << (9-8) | 1 << (15 - 8), 1 << (17 - 8*2)], mark: PhantomData, } } @@ -132,25 +144,32 @@ impl NodeFeatures { #[cfg(not(feature = "fuzztarget"))] pub(crate) fn supported() -> NodeFeatures { NodeFeatures { - flags: vec![2 | 1 << 5], + flags: vec![2 | 1 << 5, 1 << (9 - 8) | 1 << (15 - 8), 1 << (17 - 8*2)], mark: PhantomData, } } #[cfg(feature = "fuzztarget")] pub fn supported() -> NodeFeatures { NodeFeatures { - flags: vec![2 | 1 << 5], + 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. + /// Be sure to blank out features that are unknown to us. 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); + for (i, feature_byte)in init_ctx.flags.iter().enumerate() { + match i { + // Blank out initial_routing_sync (feature bits 2/3), gossip_queries (6/7), + // gossip_queries_ex (10/11), option_static_remotekey (12/13), and + // payment_secret (14/15) + 0 => flags.push(feature_byte & 0b00110011), + 1 => flags.push(feature_byte & 0b00000011), + _ => (), + } } Self { flags, mark: PhantomData, } } @@ -183,8 +202,16 @@ impl Features { pub(crate) fn requires_unknown_bits(&self) -> bool { self.flags.iter().enumerate().any(|(idx, &byte)| { (match idx { - 0 => (byte & 0b00010100), - 1 => (byte & 0b01010100), + // Unknown bits are even bits which we don't understand, we list ones which we do + // here: + // unknown, upfront_shutdown_script, unknown (actually initial_routing_sync, but it + // is only valid as an optional feature), and data_loss_protect: + 0 => (byte & 0b01000100), + // payment_secret, unknown, unknown, var_onion_optin: + 1 => (byte & 0b00010100), + // unknown, unknown, unknown, basic_mpp: + 2 => (byte & 0b01010100), + // fallback, all even bits set: _ => (byte & 0b01010101), }) != 0 }) @@ -193,8 +220,13 @@ impl Features { pub(crate) fn supports_unknown_bits(&self) -> bool { self.flags.iter().enumerate().any(|(idx, &byte)| { (match idx { + // unknown, upfront_shutdown_script, initial_routing_sync (is only valid as an + // optional feature), and data_loss_protect: 0 => (byte & 0b11000100), - 1 => (byte & 0b11111100), + // payment_secret, unknown, unknown, var_onion_optin: + 1 => (byte & 0b00111100), + // unknown, unknown, unknown, basic_mpp: + 2 => (byte & 0b11111100), _ => byte, }) != 0 }) @@ -208,16 +240,19 @@ 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); } @@ -240,6 +275,12 @@ 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 @@ -253,6 +294,24 @@ impl Features { } } +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 that we can use it (ie that the recipient + // supports payment_secret). + pub(crate) fn payment_secret(&self) -> bool { + self.flags.len() > 1 && (self.flags[1] & (3 << (14-8))) != 0 + } +} + +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 { fn write(&self, w: &mut W) -> Result<(), ::std::io::Error> { w.size_hint(self.flags.len() + 2); @@ -264,8 +323,8 @@ impl Writeable for Features { } } -impl Readable for Features { - fn read(r: &mut R) -> Result { +impl Readable for Features { + fn read(r: &mut R) -> Result { let mut flags: Vec = Readable::read(r)?; flags.reverse(); // Swap to little-endian Ok(Self { @@ -274,3 +333,63 @@ impl Readable for Features { }) } } + +#[cfg(test)] +mod tests { + use super::{ChannelFeatures, InitFeatures, NodeFeatures, Features}; + + #[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()); + + assert!(InitFeatures::supported().supports_variable_length_onion()); + assert!(NodeFeatures::supported().supports_variable_length_onion()); + + 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()); + } + + #[test] + fn test_node_with_known_relevant_init_flags() { + // Create an InitFeatures with initial_routing_sync supported. + let mut init_features = InitFeatures::supported(); + init_features.set_initial_routing_sync(); + + // Attempt to pull out non-node-context feature flags from these InitFeatures. + let res = NodeFeatures::with_known_relevant_init_flags(&init_features); + + { + // Check that the flags are as expected: optional_data_loss_protect, + // option_upfront_shutdown_script, and var_onion_optin set. + assert_eq!(res.flags[0], 0b00100010); + assert_eq!(res.flags[1], 0b00000010); + assert_eq!(res.flags.len(), 2); + } + + // 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()); + } +}