Check if invoices contain unknown required features

[rust-lightning] / lightning / src / ln / features.rs

diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs
index eb0100db675de8842e1d317d4a2b9c5c6e7b9ab1..c0eb8f68ac541c4ed5181713686141bd7d287139 100644 (file)
--- a/lightning/src/ln/features.rs
+++ b/lightning/src/ln/features.rs
@@ -22,6 +22,7 @@
 //! [BOLT #9]: https://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md
 //! [messages]: crate::ln::msgs
 
+use io;
 use prelude::*;
 use core::{cmp, fmt};
 use core::marker::PhantomData;
@@ -89,6 +90,28 @@ mod sealed {
                                        )*
                                ];
                        }
+
+                       impl alloc::fmt::Display for Features<$context> {
+                               fn fmt(&self, fmt: &mut alloc::fmt::Formatter) -> Result<(), alloc::fmt::Error> {
+                                       $(
+                                               $(
+                                                       fmt.write_fmt(format_args!("{}: {}, ", stringify!($required_feature),
+                                                               if <$context as $required_feature>::requires_feature(&self.flags) { "required" }
+                                                               else if <$context as $required_feature>::supports_feature(&self.flags) { "supported" }
+                                                               else { "not supported" }))?;
+                                               )*
+                                               $(
+                                                       fmt.write_fmt(format_args!("{}: {}, ", stringify!($optional_feature),
+                                                               if <$context as $optional_feature>::requires_feature(&self.flags) { "required" }
+                                                               else if <$context as $optional_feature>::supports_feature(&self.flags) { "supported" }
+                                                               else { "not supported" }))?;
+                                               )*
+                                       )*
+                                       fmt.write_fmt(format_args!("unknown flags: {}",
+                                               if self.requires_unknown_bits() { "required" }
+                                               else if self.supports_unknown_bits() { "supported" } else { "none" }))
+                               }
+                       }
                };
        }
 
@@ -361,7 +384,7 @@ pub type InvoiceFeatures = Features<sealed::InvoiceContext>;
 
 impl InitFeatures {
        /// 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> {
+       pub(crate) fn write_up_to_13<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                let len = cmp::min(2, self.flags.len());
                w.size_hint(len + 2);
                (len as u16).write(w)?;
@@ -525,7 +548,9 @@ impl<T: sealed::Context> Features<T> {
                &self.flags
        }
 
-       pub(crate) fn requires_unknown_bits(&self) -> bool {
+       /// Returns true if this `Features` object contains unknown feature flags which are set as
+       /// "required".
+       pub fn requires_unknown_bits(&self) -> bool {
                // 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();
@@ -566,6 +591,7 @@ impl<T: sealed::DataLossProtect> Features<T> {
        pub(crate) fn requires_data_loss_protect(&self) -> bool {
                <T as sealed::DataLossProtect>::requires_feature(&self.flags)
        }
+       #[cfg(test)]
        pub(crate) fn supports_data_loss_protect(&self) -> bool {
                <T as sealed::DataLossProtect>::supports_feature(&self.flags)
        }
@@ -669,7 +695,7 @@ impl<T: sealed::ShutdownAnySegwit> Features<T> {
 }
 
 impl<T: sealed::Context> Writeable for Features<T> {
-       fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
+       fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                w.size_hint(self.flags.len() + 2);
                (self.flags.len() as u16).write(w)?;
                for f in self.flags.iter().rev() { // Swap back to big-endian
@@ -680,7 +706,7 @@ impl<T: sealed::Context> Writeable for Features<T> {
 }
 
 impl<T: sealed::Context> Readable for Features<T> {
-       fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
+       fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
                let mut flags: Vec<u8> = Readable::read(r)?;
                flags.reverse(); // Swap to little-endian
                Ok(Self {