fix: accept header at most 100ms earlier than timestamp (#1129)

* fix: address timing issue in system config worker

* make code easier to understand

* add 100ms header verification grace period to Clique

Author: Thegaram

consensus/clique/clique.go

@@ -254,8 +254,10 @@ func (c *Clique) verifyHeader(chain consensus.ChainHeaderReader, header *types.H
 	}
 	number := header.Number.Uint64()
 
-	// Don't waste time checking blocks from the future
-	if header.Time > uint64(time.Now().Unix()) {
+	// Don't waste time checking blocks from the future.
+	// We add 100ms leeway since the scroll_worker internal timers might trigger early.
+	now := time.Now()
+	if header.Time > uint64(now.Unix()) && time.Unix(int64(header.Time), 0).Sub(now) > 100*time.Millisecond {
 		return consensus.ErrFutureBlock
 	}
 	// Checkpoint blocks need to enforce zero beneficiary

consensus/system_contract/consensus.go

@@ -115,8 +115,10 @@ func (s *SystemContract) verifyHeader(chain consensus.ChainHeaderReader, header
 		return errUnknownBlock
 	}
 
-	// Don't waste time checking blocks from the future
-	if header.Time > uint64(time.Now().Unix()) {
+	// Don't waste time checking blocks from the future.
+	// We add 100ms leeway since the scroll_worker internal timers might trigger early.
+	now := time.Now()
+	if header.Time > uint64(now.Unix()) && time.Unix(int64(header.Time), 0).Sub(now) > 100*time.Millisecond {
 		return consensus.ErrFutureBlock
 	}
 	// Ensure that the coinbase is zero

miner/scroll_worker.go

@@ -464,6 +464,7 @@ func (w *worker) collectPendingL1Messages(startIndex uint64) []types.L1MessageTx
 			if len(l1MessagesV1) > 0 {
 				// backdate the block to the parent block's timestamp -> not yet EuclidV2
 				// TODO: might need to re-run Prepare here
+				log.Warn("Back-labeling header timestamp to ensure it precedes the EuclidV2 transition", "blockNumber", w.current.header.Number, "oldTime", w.current.header.Time, "newTime", parent.Time)
 				w.current.header.Time = parent.Time
 				return l1MessagesV1
 			}
@@ -541,6 +542,10 @@ func (w *worker) newWork(now time.Time, parentHash common.Hash, reorging bool, r
 		// clique with relaxed period uses time.Now() as the header.Time, calculate the deadline
 		deadline = time.Unix(int64(header.Time+w.chainConfig.Clique.Period), 0)
 	}
+	if w.chainConfig.SystemContract != nil && w.chainConfig.SystemContract.RelaxedPeriod {
+		// system contract with relaxed period uses time.Now() as the header.Time, calculate the deadline
+		deadline = time.Unix(int64(header.Time+w.chainConfig.SystemContract.Period), 0)
+	}
 
 	w.current = &work{
 		deadlineTimer:  time.NewTimer(time.Until(deadline)),

params/version.go

@@ -24,7 +24,7 @@ import (
 const (
 	VersionMajor = 5         // Major version component of the current release
 	VersionMinor = 8         // Minor version component of the current release
-	VersionPatch = 18        // Patch version component of the current release
+	VersionPatch = 19        // Patch version component of the current release
 	VersionMeta  = "mainnet" // Version metadata to append to the version string
 )