eth/catalyst: set the correct LatestValidHash (#24855)

* eth/catalyst: set the correct LatestValidHash

* eth/catalyst: core: return LVH during reorg, rework invalid teminal block

* eth/catalyst: nitpicks

Author: MariusVanDerWijden

core/beacon/errors.go

@@ -16,7 +16,10 @@
 
 package beacon
 
-import "github.com/ethereum/go-ethereum/rpc"
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/rpc"
+)
 
 var (
 	// VALID is returned by the engine API in the following calls:
@@ -38,13 +41,13 @@ var (
 	//   - newPayloadV1: if the payload was accepted, but not processed (side chain)
 	ACCEPTED = "ACCEPTED"
 
-	INVALIDBLOCKHASH     = "INVALID_BLOCK_HASH"
-	INVALIDTERMINALBLOCK = "INVALID_TERMINAL_BLOCK"
+	INVALIDBLOCKHASH = "INVALID_BLOCK_HASH"
 
 	GenericServerError = rpc.CustomError{Code: -32000, ValidationError: "Server error"}
 	UnknownPayload     = rpc.CustomError{Code: -32001, ValidationError: "Unknown payload"}
 	InvalidTB          = rpc.CustomError{Code: -32002, ValidationError: "Invalid terminal block"}
 
-	STATUS_INVALID = ForkChoiceResponse{PayloadStatus: PayloadStatusV1{Status: INVALID}, PayloadID: nil}
-	STATUS_SYNCING = ForkChoiceResponse{PayloadStatus: PayloadStatusV1{Status: SYNCING}, PayloadID: nil}
+	STATUS_INVALID         = ForkChoiceResponse{PayloadStatus: PayloadStatusV1{Status: INVALID}, PayloadID: nil}
+	STATUS_SYNCING         = ForkChoiceResponse{PayloadStatus: PayloadStatusV1{Status: SYNCING}, PayloadID: nil}
+	INVALID_TERMINAL_BLOCK = PayloadStatusV1{Status: INVALID, LatestValidHash: &common.Hash{}}
 )

core/blockchain.go

@@ -1480,7 +1480,8 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals, setHead bool)
 		} else {
 			// We're post-merge and the parent is pruned, try to recover the parent state
 			log.Debug("Pruned ancestor", "number", block.Number(), "hash", block.Hash())
-			return it.index, bc.recoverAncestors(block)
+			_, err := bc.recoverAncestors(block)
+			return it.index, err
 		}
 	// First block is future, shove it (and all children) to the future queue (unknown ancestor)
 	case errors.Is(err, consensus.ErrFutureBlock) || (errors.Is(err, consensus.ErrUnknownAncestor) && bc.futureBlocks.Contains(it.first().ParentHash())):
@@ -1849,7 +1850,8 @@ func (bc *BlockChain) insertSideChain(block *types.Block, it *insertIterator) (i
 // recoverAncestors finds the closest ancestor with available state and re-execute
 // all the ancestor blocks since that.
 // recoverAncestors is only used post-merge.
-func (bc *BlockChain) recoverAncestors(block *types.Block) error {
+// We return the hash of the latest block that we could correctly validate.
+func (bc *BlockChain) recoverAncestors(block *types.Block) (common.Hash, error) {
 	// Gather all the sidechain hashes (full blocks may be memory heavy)
 	var (
 		hashes  []common.Hash
@@ -1864,18 +1866,18 @@ func (bc *BlockChain) recoverAncestors(block *types.Block) error {
 		// If the chain is terminating, stop iteration
 		if bc.insertStopped() {
 			log.Debug("Abort during blocks iteration")
-			return errInsertionInterrupted
+			return common.Hash{}, errInsertionInterrupted
 		}
 	}
 	if parent == nil {
-		return errors.New("missing parent")
+		return common.Hash{}, errors.New("missing parent")
 	}
 	// Import all the pruned blocks to make the state available
 	for i := len(hashes) - 1; i >= 0; i-- {
 		// If the chain is terminating, stop processing blocks
 		if bc.insertStopped() {
 			log.Debug("Abort during blocks processing")
-			return errInsertionInterrupted
+			return common.Hash{}, errInsertionInterrupted
 		}
 		var b *types.Block
 		if i == 0 {
@@ -1884,10 +1886,10 @@ func (bc *BlockChain) recoverAncestors(block *types.Block) error {
 			b = bc.GetBlock(hashes[i], numbers[i])
 		}
 		if _, err := bc.insertChain(types.Blocks{b}, false, false); err != nil {
-			return err
+			return b.ParentHash(), err
 		}
 	}
-	return nil
+	return block.Hash(), nil
 }
 
 // collectLogs collects the logs that were generated or removed during
@@ -2090,24 +2092,24 @@ func (bc *BlockChain) InsertBlockWithoutSetHead(block *types.Block) error {
 // SetCanonical rewinds the chain to set the new head block as the specified
 // block. It's possible that the state of the new head is missing, and it will
 // be recovered in this function as well.
-func (bc *BlockChain) SetCanonical(head *types.Block) error {
+func (bc *BlockChain) SetCanonical(head *types.Block) (common.Hash, error) {
 	if !bc.chainmu.TryLock() {
-		return errChainStopped
+		return common.Hash{}, errChainStopped
 	}
 	defer bc.chainmu.Unlock()
 
 	// Re-execute the reorged chain in case the head state is missing.
 	if !bc.HasState(head.Root()) {
-		if err := bc.recoverAncestors(head); err != nil {
-			return err
+		if latestValidHash, err := bc.recoverAncestors(head); err != nil {
+			return latestValidHash, err
 		}
 		log.Info("Recovered head state", "number", head.Number(), "hash", head.Hash())
 	}
 	// Run the reorg if necessary and set the given block as new head.
 	start := time.Now()
 	if head.ParentHash() != bc.CurrentBlock().Hash() {
 		if err := bc.reorg(bc.CurrentBlock(), head); err != nil {
-			return err
+			return common.Hash{}, err
 		}
 	}
 	bc.writeHeadBlock(head)
@@ -2130,7 +2132,7 @@ func (bc *BlockChain) SetCanonical(head *types.Block) error {
 		context = append(context, []interface{}{"age", common.PrettyAge(timestamp)}...)
 	}
 	log.Info("Chain head was updated", context...)
-	return nil
+	return head.Hash(), nil
 }
 
 func (bc *BlockChain) updateFutureBlocks() {

eth/catalyst/api.go

@@ -132,14 +132,14 @@ func (api *ConsensusAPI) ForkchoiceUpdatedV1(update beacon.ForkchoiceStateV1, pa
 		}
 		if td.Cmp(ttd) < 0 || (block.NumberU64() > 0 && ptd.Cmp(ttd) > 0) {
 			log.Error("Refusing beacon update to pre-merge", "number", block.NumberU64(), "hash", update.HeadBlockHash, "diff", block.Difficulty(), "age", common.PrettyAge(time.Unix(int64(block.Time()), 0)))
-			return beacon.ForkChoiceResponse{PayloadStatus: beacon.PayloadStatusV1{Status: beacon.INVALIDTERMINALBLOCK}, PayloadID: nil}, nil
+			return beacon.ForkChoiceResponse{PayloadStatus: beacon.INVALID_TERMINAL_BLOCK, PayloadID: nil}, nil
 		}
 	}
 
 	if rawdb.ReadCanonicalHash(api.eth.ChainDb(), block.NumberU64()) != update.HeadBlockHash {
 		// Block is not canonical, set head.
-		if err := api.eth.BlockChain().SetCanonical(block); err != nil {
-			return beacon.STATUS_INVALID, err
+		if latestValid, err := api.eth.BlockChain().SetCanonical(block); err != nil {
+			return beacon.ForkChoiceResponse{PayloadStatus: beacon.PayloadStatusV1{Status: beacon.INVALID, LatestValidHash: &latestValid}}, err
 		}
 	} else {
 		// If the head block is already in our canonical chain, the beacon client is
@@ -176,6 +176,14 @@ func (api *ConsensusAPI) ForkchoiceUpdatedV1(update beacon.ForkchoiceStateV1, pa
 			return beacon.STATUS_INVALID, errors.New("safe head not canonical")
 		}
 	}
+
+	valid := func(id *beacon.PayloadID) beacon.ForkChoiceResponse {
+		return beacon.ForkChoiceResponse{
+			PayloadStatus: beacon.PayloadStatusV1{Status: beacon.VALID, LatestValidHash: &update.HeadBlockHash},
+			PayloadID:     id,
+		}
+	}
+
 	// If payload generation was requested, create a new block to be potentially
 	// sealed by the beacon client. The payload will be requested later, and we
 	// might replace it arbitrarily many times in between.
@@ -186,25 +194,15 @@ func (api *ConsensusAPI) ForkchoiceUpdatedV1(update beacon.ForkchoiceStateV1, pa
 		data, err := api.assembleBlock(update.HeadBlockHash, payloadAttributes)
 		if err != nil {
 			log.Error("Failed to create sealing payload", "err", err)
-			return api.validForkChoiceResponse(nil), err // valid setHead, invalid payload
+			return valid(nil), err // valid setHead, invalid payload
 		}
 		id := computePayloadId(update.HeadBlockHash, payloadAttributes)
 		api.localBlocks.put(id, data)
 
 		log.Info("Created payload for sealing", "id", id, "elapsed", time.Since(start))
-		return api.validForkChoiceResponse(&id), nil
-	}
-	return api.validForkChoiceResponse(nil), nil
-}
-
-// validForkChoiceResponse returns the ForkChoiceResponse{VALID}
-// with the latest valid hash and an optional payloadID.
-func (api *ConsensusAPI) validForkChoiceResponse(id *beacon.PayloadID) beacon.ForkChoiceResponse {
-	currentHash := api.eth.BlockChain().CurrentBlock().Hash()
-	return beacon.ForkChoiceResponse{
-		PayloadStatus: beacon.PayloadStatusV1{Status: beacon.VALID, LatestValidHash: &currentHash},
-		PayloadID:     id,
+		return valid(&id), nil
 	}
+	return valid(nil), nil
 }
 
 // ExchangeTransitionConfigurationV1 checks the given configuration against
@@ -291,7 +289,7 @@ func (api *ConsensusAPI) NewPayloadV1(params beacon.ExecutableDataV1) (beacon.Pa
 	)
 	if td.Cmp(ttd) < 0 {
 		log.Warn("Ignoring pre-merge payload", "number", params.Number, "hash", params.BlockHash, "td", td, "ttd", ttd)
-		return beacon.PayloadStatusV1{Status: beacon.INVALIDTERMINALBLOCK}, nil
+		return beacon.INVALID_TERMINAL_BLOCK, nil
 	}
 	if block.Time() <= parent.Time() {
 		log.Warn("Invalid timestamp", "parent", block.Time(), "block", block.Time())

eth/catalyst/api_test.go

@@ -136,7 +136,7 @@ func TestSetHeadBeforeTotalDifficulty(t *testing.T) {
 	}
 	if resp, err := api.ForkchoiceUpdatedV1(fcState, nil); err != nil {
 		t.Errorf("fork choice updated should not error: %v", err)
-	} else if resp.PayloadStatus.Status != beacon.INVALIDTERMINALBLOCK {
+	} else if resp.PayloadStatus.Status != beacon.INVALID_TERMINAL_BLOCK.Status {
 		t.Errorf("fork choice updated before total terminal difficulty should be INVALID")
 	}
 }