Fix S3

Signed-off-by: Naohiro Yoshida <naohiro.yoshida@datachain.jp>

Author: Naohiro Yoshida

light-client/src/errors.rs

@@ -141,6 +141,8 @@ pub enum Error {
     UnexpectedMissingForkSpecInCurrentEpochCalculation(BlockNumber, alloc::boxed::Box<Error>),
     UnexpectedMissingForkSpecInPreviousEpochCalculation(BlockNumber, alloc::boxed::Box<Error>),
     UnexpectedPreviousEpochInCalculatingNextEpoch(BlockNumber, BlockNumber, BlockNumber),
+    MustBeEpoch(BlockNumber, ForkSpec),
+    MustNotBeEpoch(BlockNumber, ForkSpec),
 
     // Misbehaviour
     MissingHeader1,
@@ -506,6 +508,12 @@ impl core::fmt::Display for Error {
             Error::UnexpectedEpochInfo(e1, e2) => {
                 write!(f, "UnexpectedEpochInfo : {} {}", e1, e2)
             }
+            Error::MustBeEpoch(e1, e2) => {
+                write!(f, "MustBeEpoch : {} {:?}", e1, e2)
+            }
+            Error::MustNotBeEpoch(e1, e2) => {
+                write!(f, "MustNotBeEpoch : {} {:?}", e1, e2)
+            }
         }
     }
 }

light-client/src/header/eth_header.rs

@@ -361,6 +361,29 @@ impl ETHHeader {
         }
     }
 
+    pub fn verify_epoch_info(&self) -> Result<(), Error> {
+        let be = self
+            .boundary_epochs
+            .as_ref()
+            .ok_or(Error::MissingBoundaryEpochs(self.number))?;
+        if self.number == be.current_epoch_block_number(self.number) {
+            if !self.is_epoch() {
+                return Err(Error::MustBeEpoch(
+                    self.number,
+                    be.current_fork_spec().clone(),
+                ));
+            }
+        } else {
+            if self.is_epoch() {
+                return Err(Error::MustNotBeEpoch(
+                    self.number,
+                    be.current_fork_spec().clone(),
+                ));
+            }
+        }
+        Ok(())
+    }
+
     // https://github.com/bnb-chain/BEPs/blob/master/BEPs/BEP-520.md#411-millisecond-representation-in-block-header
     pub fn milli_timestamp(&self) -> u64 {
         let mut milliseconds: u64 = 0;
@@ -999,4 +1022,29 @@ pub(crate) mod test {
             _ => unreachable!("invalid error {:?}", err),
         }
     }
+
+    #[rstest]
+    #[case::localnet(localnet())]
+    fn test_error_verify_epoch_info(#[case] hp: Box<dyn Network>) {
+        let mut header = hp.epoch_header();
+        header.epoch = None;
+        let err = header.verify_epoch_info().unwrap_err();
+        match err {
+            Error::MustBeEpoch(number, _fs) => {
+                assert_eq!(number, header.number);
+            }
+            _ => unreachable!("invalid error {:?}", err),
+        }
+
+        let mut header = hp.epoch_header();
+        header.epoch = Some(Epoch::new(vec![].into(), 1));
+        header.number += 1;
+        let err = header.verify_epoch_info().unwrap_err();
+        match err {
+            Error::MustNotBeEpoch(number, _fs) => {
+                assert_eq!(number, header.number);
+            }
+            _ => unreachable!("invalid error {:?}", err),
+        }
+    }
 }

light-client/src/header/mod.rs

@@ -82,6 +82,8 @@ impl Header {
         }
         // Ensure HF height is required for target without seeking next headers
         self.headers.target.set_boundary_epochs(&fork_specs)?;
+        // Verify epoch is really epoch
+        self.headers.target.verify_epoch_info()?;
 
         // Try to set HF height
         if !fork_specs.is_empty() {
@@ -97,9 +99,11 @@ impl Header {
             }
         }
 
-        // Set boundary epoch to verify header size.
         for header in &mut self.headers.all {
-            header.set_boundary_epochs(&fork_specs)?
+            // Set boundary epoch to verify header size.
+            header.set_boundary_epochs(&fork_specs)?;
+            // Verify epoch is really epoch
+            header.verify_epoch_info()?;
         }
 
         self.fork_specs = fork_specs;