fix(babe): Add support for versioned NextConfigData decoding

dot/digest/digest.go

@@ -201,17 +201,23 @@ func (h *Handler) handleBabeConsensusDigest(digest scale.VaryingDataType, header
 	case types.BABEOnDisabled:
 		return nil
 
-	case types.NextConfigData:
-		currEpoch, err := h.epochState.GetEpochForBlock(header)
+	case types.VersionedNextConfigData:
+		nextVersionedConfigData := digestValue.(types.VersionedNextConfigData)
+		nextConfigDataVersion, err := nextVersionedConfigData.Value()
 		if err != nil {
-			return fmt.Errorf("cannot get epoch for block %d (%s): %w",
-				header.Number, headerHash, err)
+			return fmt.Errorf("getting digest value: %w", err)
 		}
 
-		nextEpoch := currEpoch + 1
-		h.epochState.StoreBABENextConfigData(nextEpoch, headerHash, val)
-		h.logger.Debugf("stored BABENextConfigData data: %v for hash: %s to epoch: %d", digest, headerHash, nextEpoch)
-		return nil
+		if nextConfigData, ok := nextConfigDataVersion.(types.NextConfigDataV1); ok {
+			currEpoch, err := h.epochState.GetEpochForBlock(header)
+			if err != nil {
+				return fmt.Errorf("cannot get epoch for block %d (%s): %w", header.Number, headerHash, err)
+			}
+			nextEpoch := currEpoch + 1
+			h.epochState.StoreBABENextConfigData(nextEpoch, headerHash, nextConfigData)
+			h.logger.Debugf("stored BABENextConfigData data: %v for hash: %s to epoch: %d", digest, headerHash, nextEpoch)
+			return nil
+		}
 	}
 
 	return errors.New("invalid consensus digest data")

dot/digest/digest_integration_test.go

@@ -381,13 +381,16 @@ func TestHandler_HandleNextEpochData(t *testing.T) {
 
 func TestHandler_HandleNextConfigData(t *testing.T) {
 	var digest = types.NewBabeConsensusDigest()
-	nextConfigData := types.NextConfigData{
+	nextConfigData := types.NextConfigDataV1{
 		C1:             1,
 		C2:             8,
 		SecondarySlots: 1,
 	}
 
-	err := digest.Set(nextConfigData)
+	VersionedNextConfigData := types.NewVersionedNextConfigData()
+	VersionedNextConfigData.Set(nextConfigData)
+
+	err := digest.Set(VersionedNextConfigData)
 	require.NoError(t, err)
 
 	data, err := scale.Marshal(digest)
@@ -428,12 +431,20 @@ func TestHandler_HandleNextConfigData(t *testing.T) {
 
 	digestValue, err := digest.Value()
 	require.NoError(t, err)
-	act, ok := digestValue.(types.NextConfigData)
+	nextVersionedConfigData, ok := digestValue.(types.VersionedNextConfigData)
+	if !ok {
+		t.Fatal()
+	}
+
+	decodedNextConfigData, err := nextVersionedConfigData.Value()
+	require.NoError(t, err)
+
+	decodedNextConfigDataV1, ok := decodedNextConfigData.(types.NextConfigDataV1)
 	if !ok {
 		t.Fatal()
 	}
 
 	stored, err := handler.epochState.(*state.EpochState).GetConfigData(targetEpoch, nil)
 	require.NoError(t, err)
-	require.Equal(t, act.ToConfigData(), stored)
+	require.Equal(t, decodedNextConfigDataV1.ToConfigData(), stored)
 }

dot/digest/interfaces.go

@@ -23,7 +23,7 @@ type BlockState interface {
 type EpochState interface {
 	GetEpochForBlock(header *types.Header) (uint64, error)
 	StoreBABENextEpochData(epoch uint64, hash common.Hash, nextEpochData types.NextEpochData)
-	StoreBABENextConfigData(epoch uint64, hash common.Hash, nextEpochData types.NextConfigData)
+	StoreBABENextConfigData(epoch uint64, hash common.Hash, nextEpochData types.NextConfigDataV1)
 	FinalizeBABENextEpochData(finalizedHeader *types.Header) error
 	FinalizeBABENextConfigData(finalizedHeader *types.Header) error
 }

dot/state/epoch.go

@@ -63,7 +63,7 @@ type EpochState struct {
 
 	nextConfigDataLock sync.RWMutex
 	// nextConfigData follows the format map[epoch]map[block hash]next config data
-	nextConfigData nextEpochMap[types.NextConfigData]
+	nextConfigData nextEpochMap[types.NextConfigDataV1]
 }
 
 // NewEpochStateFromGenesis returns a new EpochState given information for the first epoch, fetched from the runtime
@@ -92,7 +92,7 @@ func NewEpochStateFromGenesis(db *chaindb.BadgerDB, blockState *BlockState,
 		db:             epochDB,
 		epochLength:    genesisConfig.EpochLength,
 		nextEpochData:  make(nextEpochMap[types.NextEpochData]),
-		nextConfigData: make(nextEpochMap[types.NextConfigData]),
+		nextConfigData: make(nextEpochMap[types.NextConfigDataV1]),
 	}
 
 	auths, err := types.BABEAuthorityRawToAuthority(genesisConfig.GenesisAuthorities)
@@ -153,7 +153,7 @@ func NewEpochState(db *chaindb.BadgerDB, blockState *BlockState) (*EpochState, e
 		epochLength:    epochLength,
 		skipToEpoch:    skipToEpoch,
 		nextEpochData:  make(nextEpochMap[types.NextEpochData]),
-		nextConfigData: make(nextEpochMap[types.NextConfigData]),
+		nextConfigData: make(nextEpochMap[types.NextConfigDataV1]),
 	}, nil
 }
 
@@ -383,7 +383,7 @@ func (s *EpochState) getConfigDataFromDatabase(epoch uint64) (*types.ConfigData,
 	return info, nil
 }
 
-type nextEpochMap[T types.NextEpochData | types.NextConfigData] map[uint64]map[common.Hash]T
+type nextEpochMap[T types.NextEpochData | types.NextConfigDataV1] map[uint64]map[common.Hash]T
 
 func (nem nextEpochMap[T]) Retrieve(blockState *BlockState, epoch uint64, header *types.Header) (*T, error) {
 	atEpoch, has := nem[epoch]
@@ -505,13 +505,13 @@ func (s *EpochState) StoreBABENextEpochData(epoch uint64, hash common.Hash, next
 }
 
 // StoreBABENextConfigData stores the types.NextConfigData under epoch and hash keys
-func (s *EpochState) StoreBABENextConfigData(epoch uint64, hash common.Hash, nextConfigData types.NextConfigData) {
+func (s *EpochState) StoreBABENextConfigData(epoch uint64, hash common.Hash, nextConfigData types.NextConfigDataV1) {
 	s.nextConfigDataLock.Lock()
 	defer s.nextConfigDataLock.Unlock()
 
 	_, has := s.nextConfigData[epoch]
 	if !has {
-		s.nextConfigData[epoch] = make(map[common.Hash]types.NextConfigData)
+		s.nextConfigData[epoch] = make(map[common.Hash]types.NextConfigDataV1)
 	}
 	s.nextConfigData[epoch][hash] = nextConfigData
 }
@@ -641,7 +641,7 @@ func (s *EpochState) FinalizeBABENextConfigData(finalizedHeader *types.Header) e
 // findFinalizedHeaderForEpoch given a specific epoch (the key) will go through the hashes looking
 // for a database persisted hash (belonging to the finalized chain)
 // which contains the right configuration or data to be persisted and safely used
-func findFinalizedHeaderForEpoch[T types.NextConfigData | types.NextEpochData](
+func findFinalizedHeaderForEpoch[T types.NextConfigDataV1 | types.NextEpochData](
 	nextEpochMap map[uint64]map[common.Hash]T, es *EpochState, epoch uint64) (next *T, err error) {
 	hashes, has := nextEpochMap[epoch]
 	if !has {

dot/state/epoch_test.go

@@ -446,7 +446,7 @@ func TestStoreAndFinalizeBabeNextConfigData(t *testing.T) {
 
 	tests := map[string]struct {
 		finalizedHeader      *types.Header
-		inMemoryEpoch        []inMemoryBABEData[types.NextConfigData]
+		inMemoryEpoch        []inMemoryBABEData[types.NextConfigDataV1]
 		finalizedEpoch       uint64
 		expectErr            error
 		shouldRemainInMemory int
@@ -455,15 +455,15 @@ func TestStoreAndFinalizeBabeNextConfigData(t *testing.T) {
 			shouldRemainInMemory: 1,
 			finalizedEpoch:       2,
 			finalizedHeader:      finalizedHeader,
-			inMemoryEpoch: []inMemoryBABEData[types.NextConfigData]{
+			inMemoryEpoch: []inMemoryBABEData[types.NextConfigDataV1]{
 				{
 					epoch: 1,
 					hashes: []common.Hash{
 						common.MustHexToHash("0x9da3ce2785da743bfbc13449db7dcb7a69c07ca914276d839abe7bedc6ac8fed"),
 						common.MustHexToHash("0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3"),
 						common.MustHexToHash("0xc0096358534ec8d21d01d34b836eed476a1c343f8724fa2153dc0725ad797a90"),
 					},
-					nextData: []types.NextConfigData{
+					nextData: []types.NextConfigDataV1{
 						{
 							C1:             1,
 							C2:             2,
@@ -488,7 +488,7 @@ func TestStoreAndFinalizeBabeNextConfigData(t *testing.T) {
 						common.MustHexToHash("0xd380bee22de487a707cbda65dd9d4e2188f736908c42cf390c8919d4f7fc547c"),
 						finalizedHeaderHash,
 					},
-					nextData: []types.NextConfigData{
+					nextData: []types.NextConfigDataV1{
 						{
 							C1:             1,
 							C2:             2,
@@ -511,7 +511,7 @@ func TestStoreAndFinalizeBabeNextConfigData(t *testing.T) {
 					hashes: []common.Hash{
 						common.MustHexToHash("0xab5c9230a7dde8bb90a6728ba4a0165423294dac14336b1443f865b796ff682c"),
 					},
-					nextData: []types.NextConfigData{
+					nextData: []types.NextConfigDataV1{
 						{
 							C1:             1,
 							C2:             2,
@@ -526,15 +526,15 @@ func TestStoreAndFinalizeBabeNextConfigData(t *testing.T) {
 			finalizedEpoch:       2,
 			finalizedHeader:      finalizedHeader, // finalize when the hash does not exist
 			expectErr:            errHashNotPersisted,
-			inMemoryEpoch: []inMemoryBABEData[types.NextConfigData]{
+			inMemoryEpoch: []inMemoryBABEData[types.NextConfigDataV1]{
 				{
 					epoch: 2,
 					hashes: []common.Hash{
 						common.MustHexToHash("0x9da3ce2785da743bfbc13449db7dcb7a69c07ca914276d839abe7bedc6ac8fed"),
 						common.MustHexToHash("0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3"),
 						common.MustHexToHash("0xc0096358534ec8d21d01d34b836eed476a1c343f8724fa2153dc0725ad797a90"),
 					},
-					nextData: []types.NextConfigData{
+					nextData: []types.NextConfigDataV1{
 						{
 							C1:             1,
 							C2:             2,
@@ -558,7 +558,7 @@ func TestStoreAndFinalizeBabeNextConfigData(t *testing.T) {
 			shouldRemainInMemory: 0,
 			finalizedEpoch:       1, // try to finalize an epoch that does not exist
 			finalizedHeader:      finalizedHeader,
-			inMemoryEpoch:        []inMemoryBABEData[types.NextConfigData]{},
+			inMemoryEpoch:        []inMemoryBABEData[types.NextConfigDataV1]{},
 		},
 	}
 

dot/types/consensus_digest.go

@@ -11,7 +11,7 @@ import (
 
 // NewBabeConsensusDigest constructs a vdt representing a babe consensus digest
 func NewBabeConsensusDigest() scale.VaryingDataType {
-	return scale.MustNewVaryingDataType(NextEpochData{}, BABEOnDisabled{}, NextConfigData{})
+	return scale.MustNewVaryingDataType(NextEpochData{}, BABEOnDisabled{}, NewVersionedNextConfigData())
 }
 
 // NewGrandpaConsensusDigest constructs a vdt representing a grandpa consensus digest
@@ -126,27 +126,67 @@ func (b BABEOnDisabled) String() string {
 	return fmt.Sprintf("BABEOnDisabled{ID=%d}", b.ID)
 }
 
-// NextConfigData is the digest that contains changes to the BABE configuration.
+// NextConfigDataV1 is the digest that contains changes to the BABE configuration.
 // It is potentially included in the first block of an epoch to describe the next epoch.
-type NextConfigData struct {
+type NextConfigDataV1 struct {
 	C1             uint64
 	C2             uint64
 	SecondarySlots byte
 }
 
 // Index returns VDT index
-func (NextConfigData) Index() uint { return 3 } //skipcq: GO-W1029
+func (NextConfigDataV1) Index() uint { return 1 } //skipcq: GO-W1029
 
-func (d NextConfigData) String() string { //skipcq: GO-W1029
+func (d NextConfigDataV1) String() string { //skipcq: GO-W1029
 	return fmt.Sprintf("NextConfigData{C1=%d, C2=%d, SecondarySlots=%d}",
 		d.C1, d.C2, d.SecondarySlots)
 }
 
 // ToConfigData returns the NextConfigData as ConfigData
-func (d *NextConfigData) ToConfigData() *ConfigData { //skipcq: GO-W1029
+func (d *NextConfigDataV1) ToConfigData() *ConfigData { //skipcq: GO-W1029
 	return &ConfigData{
 		C1:             d.C1,
 		C2:             d.C2,
 		SecondarySlots: d.SecondarySlots,
 	}
 }
+
+// VersionedNextConfigData represents the enum of next config data consensus digest messages
+type VersionedNextConfigData scale.VaryingDataType
+
+// Index returns VDT index
+func (VersionedNextConfigData) Index() uint { return 3 }
+
+// Value returns the current VDT value
+func (vncd *VersionedNextConfigData) Value() (val scale.VaryingDataTypeValue, err error) {
+	vdt := scale.VaryingDataType(*vncd)
+	return vdt.Value()
+}
+
+// Set updates the current VDT value to be `val`
+func (vncd *VersionedNextConfigData) Set(val scale.VaryingDataTypeValue) (err error) {
+	vdt := scale.VaryingDataType(*vncd)
+	err = vdt.Set(val)
+	if err != nil {
+		return fmt.Errorf("setting varying data type value: %w", err)
+	}
+	*vncd = VersionedNextConfigData(vdt)
+	return nil
+}
+
+// String returns the string representation for the current VDT value
+func (vncd VersionedNextConfigData) String() string {
+	val, err := vncd.Value()
+	if err != nil {
+		return "VersionedNextConfigData()"
+	}
+
+	return fmt.Sprintf("VersionedNextConfigData(%s)", val)
+}
+
+// NewVersionedNextConfigData creates a new VersionedNextConfigData instance
+func NewVersionedNextConfigData() VersionedNextConfigData {
+	vdt := scale.MustNewVaryingDataType(NextConfigDataV1{})
+
+	return VersionedNextConfigData(vdt)
+}

dot/types/consensus_digest_test.go

@@ -46,3 +46,25 @@ func TestBabeEncodeAndDecode(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, d, dec)
 }
+
+func TestBabeDecodeVersionedNextConfigData(t *testing.T) {
+	enc := common.MustHexToBytes("0x03010100000000000000040000000000000002")
+
+	var dec = NewBabeConsensusDigest()
+	err := scale.Unmarshal(enc, &dec)
+	require.NoError(t, err)
+
+	decValue, err := dec.Value()
+	require.NoError(t, err)
+
+	nextVersionedConfigData := decValue.(VersionedNextConfigData)
+
+	nextConfigData, err := nextVersionedConfigData.Value()
+	require.NoError(t, err)
+
+	nextConfigDataV1 := nextConfigData.(NextConfigDataV1)
+
+	require.GreaterOrEqual(t, 1, int(nextConfigDataV1.C1))
+	require.GreaterOrEqual(t, 4, int(nextConfigDataV1.C2))
+	require.GreaterOrEqual(t, 2, int(nextConfigDataV1.SecondarySlots))
+}

lib/babe/verify_integration_test.go

@@ -544,7 +544,7 @@ func TestVerifyForkBlocksWithRespectiveEpochData(t *testing.T) {
 	aliceBlockNextEpoch := types.NextEpochData{
 		Authorities: authorities[3:],
 	}
-	aliceBlockNextConfigData := types.NextConfigData{
+	aliceBlockNextConfigData := types.NextConfigDataV1{
 		C1:             9,
 		C2:             10,
 		SecondarySlots: 1,
@@ -555,7 +555,7 @@ func TestVerifyForkBlocksWithRespectiveEpochData(t *testing.T) {
 	bobBlockNextEpoch := types.NextEpochData{
 		Authorities: authorities[6:],
 	}
-	bobBlockNextConfigData := types.NextConfigData{
+	bobBlockNextConfigData := types.NextConfigDataV1{
 		C1:             3,
 		C2:             8,
 		SecondarySlots: 1,
@@ -672,7 +672,7 @@ func TestVerifyForkBlocksWithRespectiveEpochData(t *testing.T) {
 // blocks that contains different consensus messages digests
 func issueConsensusDigestsBlockFromGenesis(t *testing.T, genesisHeader *types.Header,
 	kp *sr25519.Keypair, stateService *state.Service,
-	nextEpoch types.NextEpochData, nextConfig types.NextConfigData) *types.Header {
+	nextEpoch types.NextEpochData, nextConfig types.NextConfigDataV1) *types.Header {
 	t.Helper()
 
 	output, proof, err := kp.VrfSign(makeTranscript(Randomness{}, uint64(0), 0))
@@ -691,7 +691,11 @@ func issueConsensusDigestsBlockFromGenesis(t *testing.T, genesisHeader *types.He
 	require.NoError(t, babeConsensusDigestNextEpoch.Set(nextEpoch))
 
 	babeConsensusDigestNextConfigData := types.NewBabeConsensusDigest()
-	require.NoError(t, babeConsensusDigestNextConfigData.Set(nextConfig))
+
+	versionedNextConfigData := types.NewVersionedNextConfigData()
+	versionedNextConfigData.Set(nextConfig)
+
+	require.NoError(t, babeConsensusDigestNextConfigData.Set(versionedNextConfigData))
 
 	nextEpochData, err := scale.Marshal(babeConsensusDigestNextEpoch)
 	require.NoError(t, err)