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 {}
+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 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 the various feature context types
+ pub trait Context {}
+ impl Context for InitContext {}
+ impl Context for NodeContext {}
+ impl Context for ChannelContext {}
-/// An internal trait capturing FeatureContextInit and FeatureContextNode
-pub trait FeatureContextInitNode : FeatureContext {}
-impl FeatureContextInitNode for FeatureContextInit {}
-impl FeatureContextInitNode for FeatureContextNode {}
+ 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 {}
+}
/// Tracks the set of features which a node implements, templated by the context in which it
/// appears.
-pub struct Features<T: FeatureContext> {
+pub struct Features<T: sealed::Context> {
/// Note that, for convinience, flags is LITTLE endian (despite being big-endian on the wire)
flags: Vec<u8>,
mark: PhantomData<T>,
}
-impl<T: FeatureContext> Clone for Features<T> {
+impl<T: sealed::Context> Clone for Features<T> {
fn clone(&self) -> Self {
Self {
flags: self.flags.clone(),
}
}
}
-impl<T: FeatureContext> PartialEq for Features<T> {
+impl<T: sealed::Context> PartialEq for Features<T> {
fn eq(&self, o: &Self) -> bool {
self.flags.eq(&o.flags)
}
}
-impl<T: FeatureContext> fmt::Debug for Features<T> {
+impl<T: sealed::Context> fmt::Debug for Features<T> {
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<FeatureContextInit>;
+pub type InitFeatures = Features<sealed::InitContext>;
/// A feature message as it appears in a node_announcement message
-pub type NodeFeatures = Features<FeatureContextNode>;
+pub type NodeFeatures = Features<sealed::NodeContext>;
/// A feature message as it appears in a channel_announcement message
-pub type ChannelFeatures = Features<FeatureContextChannel>;
+pub type ChannelFeatures = Features<sealed::ChannelContext>;
-impl<T: FeatureContextInitNode> Features<T> {
+impl InitFeatures {
/// Create a Features with the features we support
#[cfg(not(feature = "fuzztarget"))]
- pub(crate) fn supported() -> Features<T> {
- Features {
+ pub(crate) fn supported() -> InitFeatures {
+ InitFeatures {
flags: vec![2 | 1 << 5],
mark: PhantomData,
}
}
#[cfg(feature = "fuzztarget")]
- pub fn supported() -> Features<T> {
- Features {
+ pub fn supported() -> InitFeatures {
+ InitFeatures {
flags: vec![2 | 1 << 5],
mark: PhantomData,
}
}
+
+ /// Writes all features present up to, and including, 13.
+ pub(crate) fn write_up_to_13<W: Writer>(&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(())
+ }
+
+ /// 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 Features<FeatureContextChannel> {
+impl ChannelFeatures {
/// Create a Features with the features we support
#[cfg(not(feature = "fuzztarget"))]
- pub(crate) fn supported() -> Features<FeatureContextChannel> {
- Features {
+ pub(crate) fn supported() -> ChannelFeatures {
+ ChannelFeatures {
flags: Vec::new(),
mark: PhantomData,
}
}
#[cfg(feature = "fuzztarget")]
- pub fn supported() -> Features<FeatureContextChannel> {
- Features {
+ pub fn supported() -> ChannelFeatures {
+ ChannelFeatures {
flags: Vec::new(),
mark: PhantomData,
}
}
}
-impl<T: FeatureContext> Features<T> {
+impl NodeFeatures {
+ /// Create a Features with the features we support
+ #[cfg(not(feature = "fuzztarget"))]
+ pub(crate) fn supported() -> NodeFeatures {
+ NodeFeatures {
+ flags: vec![2 | 1 << 5],
+ mark: PhantomData,
+ }
+ }
+ #[cfg(feature = "fuzztarget")]
+ pub fn supported() -> NodeFeatures {
+ NodeFeatures {
+ flags: vec![2 | 1 << 5],
+ mark: PhantomData,
+ }
+ }
+}
+
+impl<T: sealed::Context> Features<T> {
/// Create a blank Features with no features set
pub fn empty() -> Features<T> {
Features {
}
}
-impl<T: FeatureContextInitNode> Features<T> {
+impl<T: sealed::DataLossProtect> Features<T> {
pub(crate) fn supports_data_loss_protect(&self) -> bool {
self.flags.len() > 0 && (self.flags[0] & 3) != 0
}
+}
+impl<T: sealed::UpfrontShutdownScript> Features<T> {
pub(crate) fn supports_upfront_shutdown_script(&self) -> bool {
self.flags.len() > 0 && (self.flags[0] & (3 << 4)) != 0
}
}
}
-impl Features<FeatureContextInit> {
+impl<T: sealed::InitialRoutingSync> Features<T> {
pub(crate) fn initial_routing_sync(&self) -> bool {
self.flags.len() > 0 && (self.flags[0] & (1 << 3)) != 0
}
self.flags[0] |= 1 << 3;
}
}
-
- /// Writes all features present up to, and including, 13.
- pub(crate) fn write_up_to_13<W: Writer>(&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(())
- }
-
- /// 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<T: FeatureContext> Writeable for Features<T> {
+impl<T: sealed::Context> Writeable for Features<T> {
fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
w.size_hint(self.flags.len() + 2);
(self.flags.len() as u16).write(w)?;
}
}
-impl<R: ::std::io::Read, T: FeatureContext> Readable<R> for Features<T> {
+impl<R: ::std::io::Read, T: sealed::Context> Readable<R> for Features<T> {
fn read(r: &mut R) -> Result<Self, DecodeError> {
let mut flags: Vec<u8> = Readable::read(r)?;
flags.reverse(); // Swap to little-endian