feat(sync): Validate bad blocks

dot/services.go

@@ -441,6 +441,11 @@ func (nodeBuilder) newSyncService(cfg *Config, st *state.Service, fg BlockJustif
 		return nil, err
 	}
 
+	genesisData, err := st.Base.LoadGenesisData()
+	if err != nil {
+		return nil, err
+	}
+
 	syncCfg := &sync.Config{
 		LogLvl:             cfg.Log.SyncLvl,
 		Network:            net,
@@ -454,6 +459,7 @@ func (nodeBuilder) newSyncService(cfg *Config, st *state.Service, fg BlockJustif
 		MaxPeers:           cfg.Network.MaxPeers,
 		SlotDuration:       slotDuration,
 		Telemetry:          telemetryMailer,
+		BadBlocks:          genesisData.BadBlocks,
 	}
 
 	return sync.NewService(syncCfg)

dot/sync/chain_processor.go

@@ -55,6 +55,7 @@ type chainProcessorConfig struct {
 	finalityGadget     FinalityGadget
 	blockImportHandler BlockImportHandler
 	telemetry          Telemetry
+	badBlocks          []string
 }
 
 func newChainProcessor(cfg chainProcessorConfig) *chainProcessor {

dot/sync/chain_sync.go

@@ -17,6 +17,7 @@ import (
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
+	"golang.org/x/exp/slices"
 
 	"github.com/ChainSafe/gossamer/dot/network"
 	"github.com/ChainSafe/gossamer/dot/peerset"
@@ -165,6 +166,7 @@ type chainSync struct {
 	logSyncTickerC <-chan time.Time // channel as field for unit testing
 	logSyncStarted bool
 	logSyncDone    chan struct{}
+	badBlocks      []string
 }
 
 type chainSyncConfig struct {
@@ -174,6 +176,7 @@ type chainSyncConfig struct {
 	pendingBlocks      DisjointBlockSet
 	minPeers, maxPeers int
 	slotDuration       time.Duration
+	badBlocks          []string
 }
 
 func newChainSync(cfg chainSyncConfig) *chainSync {
@@ -204,6 +207,7 @@ func newChainSync(cfg chainSyncConfig) *chainSync {
 		logSyncTicker:    logSyncTicker,
 		logSyncTickerC:   logSyncTicker.C,
 		logSyncDone:      make(chan struct{}),
+		badBlocks:        cfg.badBlocks,
 	}
 }
 
@@ -829,6 +833,7 @@ func (cs *chainSync) determineSyncPeers(req *network.BlockRequestMessage, peersT
 // It checks the following:
 //   - the response is not empty
 //   - the response contains all the expected fields
+//   - the block is not contained in the bad block list
 //   - each block has the correct parent, ie. the response constitutes a valid chain
 func (cs *chainSync) validateResponse(req *network.BlockRequestMessage,
 	resp *network.BlockResponseMessage, p peer.ID) error {
@@ -929,6 +934,11 @@ func (cs *chainSync) validateBlockData(req *network.BlockRequestMessage, bd *typ
 
 	requestedData := req.RequestedData
 
+	if slices.Contains(cs.badBlocks, bd.Hash.String()) {
+		logger.Errorf("Rejecting known bad block Number: %d Hash: %s", bd.Number(), bd.Hash)
+		return errBadBlock
+	}
+
 	if (requestedData&network.RequestedDataHeader) == 1 && bd.Header == nil {
 		cs.network.ReportPeer(peerset.ReputationChange{
 			Value:  peerset.IncompleteHeaderValue,

dot/sync/errors.go

@@ -34,4 +34,5 @@ var (
 	errFailedToGetParent            = errors.New("failed to get parent header")
 	errStartAndEndMismatch          = errors.New("request start and end hash are not on the same chain")
 	errFailedToGetDescendant        = errors.New("failed to find descendant block")
+	errBadBlock                     = errors.New("known bad block")
 )

dot/sync/syncer.go

@@ -36,6 +36,7 @@ type Config struct {
 	MinPeers, MaxPeers int
 	SlotDuration       time.Duration
 	Telemetry          Telemetry
+	BadBlocks          []string
 }
 
 // NewService returns a new *sync.Service
@@ -67,6 +68,7 @@ func NewService(cfg *Config) (*Service, error) {
 		finalityGadget:     cfg.FinalityGadget,
 		blockImportHandler: cfg.BlockImportHandler,
 		telemetry:          cfg.Telemetry,
+		badBlocks:          cfg.BadBlocks,
 	}
 	chainProcessor := newChainProcessor(cpCfg)