Detect reorgs during event processing

etherman/etherman.go

@@ -364,7 +364,10 @@ func (etherMan *Client) updateGlobalExitRootEvent(ctx context.Context, vLog type
  gExitRoot.GlobalExitRoot = hash(globalExitRoot.MainnetExitRoot, globalExitRoot.RollupExitRoot)
 
  if len(*blocks) == 0 || ((*blocks)[len(*blocks)-1].BlockHash != vLog.BlockHash || (*blocks)[len(*blocks)-1].BlockNumber != vLog.BlockNumber) {
- block := prepareBlock(fullBlock)
+ block, err := prepareBlock(&vLog, fullBlock)
+ if err != nil {
+ return err
+ }
  block.GlobalExitRoots = append(block.GlobalExitRoots, gExitRoot)
  *blocks = append(*blocks, block)
  } else if (*blocks)[len(*blocks)-1].BlockHash == vLog.BlockHash && (*blocks)[len(*blocks)-1].BlockNumber == vLog.BlockNumber {
@@ -522,7 +525,7 @@ func (etherMan *Client) GetPreconfirmations(ctx context.Context, prevBatch state
  return nil, nil, err
  }
 
- err = etherMan.appendSequencedBatches(ctx, []SequencedBatch{batch}, batch.BlockNumber, &blocks, &order)
+ err = etherMan.appendSequencedBatches(ctx, []SequencedBatch{batch}, batch.BlockNumber, nil, &blocks, &order)
  if err != nil {
  return nil, nil, err
  }
@@ -553,14 +556,14 @@ func (etherMan *Client) newBlocksEvent(ctx context.Context, prevBatch *state.L2B
  if err != nil {
  return fmt.Errorf("error decoding the sequences: %v", err)
  }
- err = etherMan.appendSequencedBatches(ctx, sequences, vLog.BlockNumber, blocks, blocksOrder)
+ err = etherMan.appendSequencedBatches(ctx, sequences, vLog.BlockNumber, &vLog, blocks, blocksOrder)
  if err != nil {
  return err
  }
  return nil
 }
 
-func (etherMan *Client) appendSequencedBatches(ctx context.Context, sequences []SequencedBatch, blockNumber uint64, blocks *[]Block, blocksOrder *map[common.Hash][]Order) error {
+func (etherMan *Client) appendSequencedBatches(ctx context.Context, sequences []SequencedBatch, blockNumber uint64, vLog *types.Log, blocks *[]Block, blocksOrder *map[common.Hash][]Order) error {
  if len(*blocks) == 0 || (*blocks)[len(*blocks)-1].BlockNumber != blockNumber {
  // Sanity check: if we got a new L1 block number, it should be increasing.
  if len(*blocks) > 0 && blockNumber < (*blocks)[len(*blocks)-1].BlockNumber {
@@ -571,7 +574,10 @@ func (etherMan *Client) appendSequencedBatches(ctx context.Context, sequences []
  if err != nil {
  return fmt.Errorf("error getting hashParent. BlockNumber: %d. Error: %w", blockNumber, err)
  }
- block := prepareBlock(fullBlock)
+ block, err := prepareBlock(vLog, fullBlock)
+ if err != nil {
+ return err
+ }
  block.SequencedBatches = append(block.SequencedBatches, sequences)
  *blocks = append(*blocks, block)
  } else {
@@ -788,7 +794,10 @@ func (etherMan *Client) verifyBatchesTrustedAggregatorEvent(ctx context.Context,
  if err != nil {
  return fmt.Errorf("error getting hashParent. BlockNumber: %d. Error: %w", vLog.BlockNumber, err)
  }
- block := prepareBlock(fullBlock)
+ block, err := prepareBlock(&vLog, fullBlock)
+ if err != nil {
+ return err
+ }
  block.VerifiedBatches = append(block.VerifiedBatches, trustedVerifyBatch)
  *blocks = append(*blocks, block)
  } else if (*blocks)[len(*blocks)-1].BlockHash == vLog.BlockHash && (*blocks)[len(*blocks)-1].BlockNumber == vLog.BlockNumber {
@@ -805,13 +814,25 @@ func (etherMan *Client) verifyBatchesTrustedAggregatorEvent(ctx context.Context,
  return nil
 }
 
-func prepareBlock(fullBlock *types.Block) Block {
+// Capture relevant information about an L1 block from which we just processed an event.
+//
+// Optionally, the `vLog` containing the event may be provided, in which case the hash of
+// `fullBlock` will be compared against the `BlockHash` from the log, and an error will be raised if
+// they do not match. This can happen in the event of an L1 reorg.
+//
+// When processing events that originated off-chain (such as preconfirmations from the Espresso
+// Sequencer) and therefore are not affected by L1 reorgs, `vLog` may be `nil`.
+func prepareBlock(vLog *types.Log, fullBlock *types.Block) (Block, error) {
  var block Block
+
+ if vLog != nil && vLog.BlockHash != fullBlock.Hash() {
+ return block, fmt.Errorf("possible reorg: block hash %v does not match event log %v", fullBlock.Hash(), vLog)
+ }
  block.BlockNumber = fullBlock.Number().Uint64()
  block.BlockHash = fullBlock.Hash()
  block.ParentHash = fullBlock.ParentHash()
  block.ReceivedAt = time.Unix(int64(fullBlock.Time()), 0)
- return block
+ return block, nil
 }
 
 func hash(data ...[32]byte) [32]byte {