X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Ffeatures.rs;h=400888ff9784ff0f8217de151f5b4f24d23509a7;hb=38a2186cb6091f4b041bf18c3fd0e3f714db93b7;hp=ca8150b09cfa580d69e55550cc6661b3068ea15c;hpb=1279c6807c1439262f83bf1922e998dc81be7532;p=rust-lightning diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs index ca8150b0..400888ff 100644 --- a/lightning/src/ln/features.rs +++ b/lightning/src/ln/features.rs @@ -65,6 +65,12 @@ //! [BOLT-3](https://github.com/lightning/bolts/blob/master/03-transactions.md) for more //! information). //! +//! LDK knows about the following features, but does not support them: +//! - `AnchorsNonzeroFeeHtlcTx` - the initial version of anchor outputs, which was later found to be +//! vulnerable (see this +//! [mailing list post](https://lists.linuxfoundation.org/pipermail/lightning-dev/2020-September/002796.html) +//! for more information). +//! //! [BOLT #9]: https://github.com/lightning/bolts/blob/master/09-features.md //! [messages]: crate::ln::msgs @@ -134,7 +140,7 @@ mod sealed { // Byte 1 VariableLengthOnion | StaticRemoteKey | PaymentSecret, // Byte 2 - BasicMPP | Wumbo | AnchorsZeroFeeHtlcTx, + BasicMPP | Wumbo | AnchorsNonzeroFeeHtlcTx | AnchorsZeroFeeHtlcTx, // Byte 3 ShutdownAnySegwit, // Byte 4 @@ -150,7 +156,7 @@ mod sealed { // Byte 1 VariableLengthOnion | StaticRemoteKey | PaymentSecret, // Byte 2 - BasicMPP | Wumbo | AnchorsZeroFeeHtlcTx, + BasicMPP | Wumbo | AnchorsNonzeroFeeHtlcTx | AnchorsZeroFeeHtlcTx, // Byte 3 ShutdownAnySegwit, // Byte 4 @@ -196,7 +202,7 @@ mod sealed { // Byte 1 StaticRemoteKey, // Byte 2 - AnchorsZeroFeeHtlcTx, + AnchorsNonzeroFeeHtlcTx | AnchorsZeroFeeHtlcTx, // Byte 3 , // Byte 4 @@ -378,6 +384,9 @@ mod sealed { define_feature!(19, Wumbo, [InitContext, NodeContext], "Feature flags for `option_support_large_channel` (aka wumbo channels).", set_wumbo_optional, set_wumbo_required, supports_wumbo, requires_wumbo); + define_feature!(21, AnchorsNonzeroFeeHtlcTx, [InitContext, NodeContext, ChannelTypeContext], + "Feature flags for `option_anchors_nonzero_fee_htlc_tx`.", set_anchors_nonzero_fee_htlc_tx_optional, + set_anchors_nonzero_fee_htlc_tx_required, supports_anchors_nonzero_fee_htlc_tx, requires_anchors_nonzero_fee_htlc_tx); define_feature!(23, AnchorsZeroFeeHtlcTx, [InitContext, NodeContext, ChannelTypeContext], "Feature flags for `option_anchors_zero_fee_htlc_tx`.", set_anchors_zero_fee_htlc_tx_optional, set_anchors_zero_fee_htlc_tx_required, supports_anchors_zero_fee_htlc_tx, requires_anchors_zero_fee_htlc_tx); @@ -422,8 +431,10 @@ pub struct Features { mark: PhantomData, } -impl Features { - pub(crate) fn or(mut self, o: Self) -> Self { +impl core::ops::BitOr for Features { + type Output = Self; + + fn bitor(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()) { @@ -451,6 +462,16 @@ impl PartialEq for Features { self.flags.eq(&o.flags) } } +impl PartialOrd for Features { + fn partial_cmp(&self, other: &Self) -> Option { + self.flags.partial_cmp(&other.flags) + } +} +impl Ord for Features { + fn cmp(&self, other: &Self) -> cmp::Ordering { + self.flags.cmp(&other.flags) + } +} impl fmt::Debug for Features { fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> { self.flags.fmt(fmt) @@ -523,11 +544,17 @@ impl InvoiceFeatures { /// [`PaymentParameters::for_keysend`], thus omitting the need for payers to manually construct an /// `InvoiceFeatures` for [`find_route`]. /// + /// MPP keysend is not widely supported yet, so we parameterize support to allow the user to + /// choose whether their router should find multi-part routes. + /// /// [`PaymentParameters::for_keysend`]: crate::routing::router::PaymentParameters::for_keysend /// [`find_route`]: crate::routing::router::find_route - pub(crate) fn for_keysend() -> InvoiceFeatures { + pub(crate) fn for_keysend(allow_mpp: bool) -> InvoiceFeatures { let mut res = InvoiceFeatures::empty(); res.set_variable_length_onion_optional(); + if allow_mpp { + res.set_basic_mpp_optional(); + } res } } @@ -685,6 +712,25 @@ impl Features { self.flags.iter().any(|&byte| (byte & 0b10_10_10_10) != 0) } + /// Returns true if this `Features` object contains required features unknown by `other`. + pub fn requires_unknown_bits_from(&self, other: &Features) -> bool { + // Bitwise AND-ing with all even bits set except for known features will select required + // unknown features. + self.flags.iter().enumerate().any(|(i, &byte)| { + const REQUIRED_FEATURES: u8 = 0b01_01_01_01; + const OPTIONAL_FEATURES: u8 = 0b10_10_10_10; + let unknown_features = if i < other.flags.len() { + // Form a mask similar to !T::KNOWN_FEATURE_MASK only for `other` + !(other.flags[i] + | ((other.flags[i] >> 1) & REQUIRED_FEATURES) + | ((other.flags[i] << 1) & OPTIONAL_FEATURES)) + } else { + 0b11_11_11_11 + }; + (byte & (REQUIRED_FEATURES & unknown_features)) != 0 + }) + } + /// Returns true if this `Features` object contains unknown feature flags which are set as /// "required". pub fn requires_unknown_bits(&self) -> bool { @@ -733,6 +779,50 @@ impl Features { } true } + + /// Sets a required custom feature bit. Errors if `bit` is outside the custom range as defined + /// by [bLIP 2] or if it is a known `T` feature. + /// + /// Note: Required bits are even. If an odd bit is given, then the corresponding even bit will + /// be set instead (i.e., `bit - 1`). + /// + /// [bLIP 2]: https://github.com/lightning/blips/blob/master/blip-0002.md#feature-bits + pub fn set_required_custom_bit(&mut self, bit: usize) -> Result<(), ()> { + self.set_custom_bit(bit - (bit % 2)) + } + + /// Sets an optional custom feature bit. Errors if `bit` is outside the custom range as defined + /// by [bLIP 2] or if it is a known `T` feature. + /// + /// Note: Optional bits are odd. If an even bit is given, then the corresponding odd bit will be + /// set instead (i.e., `bit + 1`). + /// + /// [bLIP 2]: https://github.com/lightning/blips/blob/master/blip-0002.md#feature-bits + pub fn set_optional_custom_bit(&mut self, bit: usize) -> Result<(), ()> { + self.set_custom_bit(bit + (1 - (bit % 2))) + } + + fn set_custom_bit(&mut self, bit: usize) -> Result<(), ()> { + if bit < 256 { + return Err(()); + } + + let byte_offset = bit / 8; + let mask = 1 << (bit - 8 * byte_offset); + if byte_offset < T::KNOWN_FEATURE_MASK.len() { + if (T::KNOWN_FEATURE_MASK[byte_offset] & mask) != 0 { + return Err(()); + } + } + + if self.flags.len() <= byte_offset { + self.flags.resize(byte_offset + 1, 0u8); + } + + self.flags[byte_offset] |= mask; + + Ok(()) + } } impl Features { @@ -859,6 +949,43 @@ mod tests { assert!(features.supports_unknown_bits()); } + #[test] + fn requires_unknown_bits_from() { + let mut features1 = InitFeatures::empty(); + let mut features2 = InitFeatures::empty(); + assert!(!features1.requires_unknown_bits_from(&features2)); + assert!(!features2.requires_unknown_bits_from(&features1)); + + features1.set_data_loss_protect_required(); + assert!(features1.requires_unknown_bits_from(&features2)); + assert!(!features2.requires_unknown_bits_from(&features1)); + + features2.set_data_loss_protect_optional(); + assert!(!features1.requires_unknown_bits_from(&features2)); + assert!(!features2.requires_unknown_bits_from(&features1)); + + features2.set_gossip_queries_required(); + assert!(!features1.requires_unknown_bits_from(&features2)); + assert!(features2.requires_unknown_bits_from(&features1)); + + features1.set_gossip_queries_optional(); + assert!(!features1.requires_unknown_bits_from(&features2)); + assert!(!features2.requires_unknown_bits_from(&features1)); + + features1.set_variable_length_onion_required(); + assert!(features1.requires_unknown_bits_from(&features2)); + assert!(!features2.requires_unknown_bits_from(&features1)); + + features2.set_variable_length_onion_optional(); + assert!(!features1.requires_unknown_bits_from(&features2)); + assert!(!features2.requires_unknown_bits_from(&features1)); + + features1.set_basic_mpp_required(); + features2.set_wumbo_required(); + assert!(features1.requires_unknown_bits_from(&features2)); + assert!(features2.requires_unknown_bits_from(&features1)); + } + #[test] fn convert_to_context_with_relevant_flags() { let mut init_features = InitFeatures::empty(); @@ -871,12 +998,12 @@ mod tests { init_features.set_payment_secret_required(); init_features.set_basic_mpp_optional(); init_features.set_wumbo_optional(); + init_features.set_anchors_zero_fee_htlc_tx_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(); - init_features.set_anchors_zero_fee_htlc_tx_optional(); assert!(init_features.initial_routing_sync()); assert!(!init_features.supports_upfront_shutdown_script()); @@ -887,7 +1014,7 @@ mod tests { // Check that the flags are as expected: // - option_data_loss_protect (req) // - var_onion_optin (req) | static_remote_key (req) | payment_secret(req) - // - basic_mpp | wumbo + // - basic_mpp | wumbo | anchors_zero_fee_htlc_tx // - opt_shutdown_anysegwit // - onion_messages // - option_channel_type | option_scid_alias @@ -935,6 +1062,36 @@ mod tests { assert!(features.supports_payment_secret()); } + #[test] + fn set_custom_bits() { + let mut features = InvoiceFeatures::empty(); + features.set_variable_length_onion_optional(); + assert_eq!(features.flags[1], 0b00000010); + + assert!(features.set_optional_custom_bit(255).is_err()); + assert!(features.set_required_custom_bit(256).is_ok()); + assert!(features.set_required_custom_bit(258).is_ok()); + assert_eq!(features.flags[31], 0b00000000); + assert_eq!(features.flags[32], 0b00000101); + + let known_bit = ::EVEN_BIT; + let byte_offset = ::BYTE_OFFSET; + assert_eq!(byte_offset, 1); + assert_eq!(features.flags[byte_offset], 0b00000010); + assert!(features.set_required_custom_bit(known_bit).is_err()); + assert_eq!(features.flags[byte_offset], 0b00000010); + + let mut features = InvoiceFeatures::empty(); + assert!(features.set_optional_custom_bit(256).is_ok()); + assert!(features.set_optional_custom_bit(259).is_ok()); + assert_eq!(features.flags[32], 0b00001010); + + let mut features = InvoiceFeatures::empty(); + assert!(features.set_required_custom_bit(257).is_ok()); + assert!(features.set_required_custom_bit(258).is_ok()); + assert_eq!(features.flags[32], 0b00000101); + } + #[test] fn encodes_features_without_length() { let features = OfferFeatures::from_le_bytes(vec![1, 2, 3, 4, 5, 42, 100, 101]);