feat(lib/grandpa): fully verify justifications using GrandpaState (Ch…

…ainSafe#1544)

dot/core/digest.go

@@ -97,18 +97,20 @@ func NewDigestHandler(blockState BlockState, epochState EpochState, grandpaState
 }
 
 // Start starts the DigestHandler
-func (h *DigestHandler) Start() {
+func (h *DigestHandler) Start() error {
 	go h.handleBlockImport(h.ctx)
 	go h.handleBlockFinalisation(h.ctx)
+	return nil
 }
 
 // Stop stops the DigestHandler
-func (h *DigestHandler) Stop() {
+func (h *DigestHandler) Stop() error {
 	h.cancel()
 	h.blockState.UnregisterImportedChannel(h.importedID)
 	h.blockState.UnregisterFinalizedChannel(h.finalisedID)
 	close(h.imported)
 	close(h.finalised)
+	return nil
 }
 
 // NextGrandpaAuthorityChange returns the block number of the next upcoming grandpa authorities change.
@@ -145,6 +147,8 @@ func (h *DigestHandler) HandleConsensusDigest(d *types.ConsensusDigest, header *
 			return h.handleScheduledChange(d, header)
 		case types.GrandpaForcedChangeType:
 			return h.handleForcedChange(d, header)
+		case types.GrandpaOnDisabledType:
+			return nil // do nothing, as this is not implemented in substrate
 		case types.GrandpaPauseType:
 			return h.handlePause(d)
 		case types.GrandpaResumeType:
@@ -208,37 +212,49 @@ func (h *DigestHandler) handleBlockFinalisation(ctx context.Context) {
 
 func (h *DigestHandler) handleGrandpaChangesOnImport(num *big.Int) error {
 	resume := h.grandpaResume
-	if resume != nil && num.Cmp(resume.atBlock) == 0 {
+	if resume != nil && num.Cmp(resume.atBlock) > -1 {
 		h.grandpaResume = nil
 	}
 
 	fc := h.grandpaForcedChange
-	if fc != nil && num.Cmp(fc.atBlock) == 0 {
+	if fc != nil && num.Cmp(fc.atBlock) > -1 {
 		err := h.grandpaState.IncrementSetID()
 		if err != nil {
 			return err
 		}
 
 		h.grandpaForcedChange = nil
+		curr, err := h.grandpaState.GetCurrentSetID()
+		if err != nil {
+			return err
+		}
+
+		logger.Debug("incremented grandpa set ID", "set ID", curr)
 	}
 
 	return nil
 }
 
 func (h *DigestHandler) handleGrandpaChangesOnFinalization(num *big.Int) error {
 	pause := h.grandpaPause
-	if pause != nil && num.Cmp(pause.atBlock) == 0 {
+	if pause != nil && num.Cmp(pause.atBlock) > -1 {
 		h.grandpaPause = nil
 	}
 
 	sc := h.grandpaScheduledChange
-	if sc != nil && num.Cmp(sc.atBlock) == 0 {
+	if sc != nil && num.Cmp(sc.atBlock) > -1 {
 		err := h.grandpaState.IncrementSetID()
 		if err != nil {
 			return err
 		}
 
 		h.grandpaScheduledChange = nil
+		curr, err := h.grandpaState.GetCurrentSetID()
+		if err != nil {
+			return err
+		}
+
+		logger.Debug("incremented grandpa set ID", "set ID", curr)
 	}
 
 	// if blocks get finalised before forced change takes place, disregard it
@@ -281,7 +297,11 @@ func (h *DigestHandler) handleScheduledChange(d *types.ConsensusDigest, header *
 		return err
 	}
 
-	return h.grandpaState.SetNextChange(types.NewGrandpaVotersFromAuthorities(auths), big.NewInt(0).Add(header.Number, big.NewInt(int64(sc.Delay))))
+	logger.Debug("setting GrandpaScheduledChange", "at block", big.NewInt(0).Add(header.Number, big.NewInt(int64(sc.Delay))))
+	return h.grandpaState.SetNextChange(
+		types.NewGrandpaVotersFromAuthorities(auths),
+		big.NewInt(0).Add(header.Number, big.NewInt(int64(sc.Delay))),
+	)
 }
 
 func (h *DigestHandler) handleForcedChange(d *types.ConsensusDigest, header *types.Header) error {
@@ -318,6 +338,7 @@ func (h *DigestHandler) handleForcedChange(d *types.ConsensusDigest, header *typ
 		return err
 	}
 
+	logger.Debug("setting GrandpaForcedChange", "at block", big.NewInt(0).Add(header.Number, big.NewInt(int64(fc.Delay))))
 	return h.grandpaState.SetNextChange(
 		types.NewGrandpaVotersFromAuthorities(auths),
 		big.NewInt(0).Add(header.Number, big.NewInt(int64(fc.Delay))),

dot/core/interface.go

@@ -99,4 +99,5 @@ type GrandpaState interface {
 	IncrementSetID() error
 	SetNextPause(number *big.Int) error
 	SetNextResume(number *big.Int) error
+	GetCurrentSetID() (uint64, error)
 }

dot/network/sync.go

@@ -793,7 +793,7 @@ func (q *syncQueue) handleBlockAnnounceHandshake(blockNum uint32, from peer.ID)
 
 func (q *syncQueue) handleBlockAnnounce(msg *BlockAnnounceMessage, from peer.ID) {
 	q.updatePeerScore(from, 1)
-	logger.Info("received BlockAnnounce", "number", msg.Number, "from", from)
+	logger.Debug("received BlockAnnounce", "number", msg.Number, "from", from)
 
 	header, err := types.NewHeader(msg.ParentHash, msg.StateRoot, msg.ExtrinsicsRoot, msg.Number, msg.Digest)
 	if err != nil {

dot/node.go

@@ -241,6 +241,7 @@ func NewNode(cfg *Config, ks *keystore.GlobalKeystore, stopFunc func()) (*Node,
 	if err != nil {
 		return nil, err
 	}
+	nodeSrvcs = append(nodeSrvcs, dh)
 
 	// create GRANDPA service
 	fg, err := createGRANDPAService(cfg, rt, stateSrvc, dh, ks.Gran, networkSrvc)

dot/state/block_notify.go

@@ -125,7 +125,7 @@ func (bs *BlockState) notifyFinalized(hash common.Hash) {
 		return
 	}
 
-	logger.Trace("notifying finalised block chans...", "chans", bs.finalised)
+	logger.Debug("notifying finalised block chans...", "chans", bs.finalised)
 
 	for _, ch := range bs.finalised {
 		go func(ch chan<- *types.Header) {

dot/state/grandpa.go

@@ -59,6 +59,11 @@ func NewGrandpaStateFromGenesis(db chaindb.Database, genesisAuthorities []*types
 		return nil, err
 	}
 
+	err = s.setSetIDChangeAtBlock(genesisSetID, big.NewInt(0))
+	if err != nil {
+		return nil, err
+	}
+
 	return s, nil
 }
 
@@ -180,6 +185,49 @@ func (s *GrandpaState) GetSetIDChange(setID uint64) (*big.Int, error) {
 	return big.NewInt(0).SetBytes(num), nil
 }
 
+// GetSetIDByBlockNumber returns the set ID for a given block number
+func (s *GrandpaState) GetSetIDByBlockNumber(num *big.Int) (uint64, error) {
+	curr, err := s.GetCurrentSetID()
+	if err != nil {
+		return 0, err
+	}
+
+	for {
+		changeUpper, err := s.GetSetIDChange(curr + 1)
+		if err == chaindb.ErrKeyNotFound {
+			if curr == 0 {
+				return 0, nil
+			}
+			curr = curr - 1
+			continue
+		}
+		if err != nil {
+			return 0, err
+		}
+
+		changeLower, err := s.GetSetIDChange(curr)
+		if err != nil {
+			return 0, err
+		}
+
+		// if the given block number is greater or equal to the block number of the set ID change,
+		// return the current set ID
+		if num.Cmp(changeUpper) < 1 && num.Cmp(changeLower) == 1 {
+			return curr, nil
+		}
+
+		if num.Cmp(changeUpper) == 1 {
+			return curr + 1, nil
+		}
+
+		curr = curr - 1
+
+		if int(curr) < 0 {
+			return 0, nil
+		}
+	}
+}
+
 // SetNextPause sets the next grandpa pause at the given block number
 func (s *GrandpaState) SetNextPause(number *big.Int) error {
 	return s.db.Put(pauseKey, number.Bytes())

dot/state/grandpa_test.go

@@ -46,6 +46,10 @@ func TestNewGrandpaStateFromGenesis(t *testing.T) {
 	auths, err := gs.GetAuthorities(currSetID)
 	require.NoError(t, err)
 	require.Equal(t, testAuths, auths)
+
+	num, err := gs.GetSetIDChange(0)
+	require.NoError(t, err)
+	require.Equal(t, big.NewInt(0), num)
 }
 
 func TestGrandpaState_SetNextChange(t *testing.T) {
@@ -81,3 +85,40 @@ func TestGrandpaState_IncrementSetID(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, genesisSetID+1, setID)
 }
+
+func TestGrandpaState_GetSetIDByBlockNumber(t *testing.T) {
+	db := NewInMemoryDB(t)
+	gs, err := NewGrandpaStateFromGenesis(db, testAuths)
+	require.NoError(t, err)
+
+	testAuths2 := []*types.GrandpaVoter{
+		{Key: kr.Bob().Public().(*ed25519.PublicKey), ID: 0},
+	}
+
+	err = gs.SetNextChange(testAuths2, big.NewInt(100))
+	require.NoError(t, err)
+
+	setID, err := gs.GetSetIDByBlockNumber(big.NewInt(50))
+	require.NoError(t, err)
+	require.Equal(t, genesisSetID, setID)
+
+	setID, err = gs.GetSetIDByBlockNumber(big.NewInt(100))
+	require.NoError(t, err)
+	require.Equal(t, genesisSetID, setID)
+
+	setID, err = gs.GetSetIDByBlockNumber(big.NewInt(101))
+	require.NoError(t, err)
+	require.Equal(t, genesisSetID+1, setID)
+
+	err = gs.IncrementSetID()
+	require.NoError(t, err)
+
+	setID, err = gs.GetSetIDByBlockNumber(big.NewInt(100))
+	require.NoError(t, err)
+	require.Equal(t, genesisSetID, setID)
+
+	setID, err = gs.GetSetIDByBlockNumber(big.NewInt(101))
+	require.NoError(t, err)
+	require.Equal(t, genesisSetID+1, setID)
+
+}

dot/state/service.go

@@ -218,6 +218,30 @@ func (s *Service) Rewind(toBlock int64) error {
 		return err
 	}
 
+	// update the current grandpa set ID
+	prevSetID, err := s.Grandpa.GetCurrentSetID()
+	if err != nil {
+		return err
+	}
+
+	newSetID, err := s.Grandpa.GetSetIDByBlockNumber(header.Number)
+	if err != nil {
+		return err
+	}
+
+	err = s.Grandpa.setCurrentSetID(newSetID)
+	if err != nil {
+		return err
+	}
+
+	// remove previously set grandpa changes, need to go up to prevSetID+1 in case of a scheduled change
+	for i := newSetID + 1; i <= prevSetID+1; i++ {
+		err = s.Grandpa.db.Del(setIDChangeKey(i))
+		if err != nil {
+			return err
+		}
+	}
+
 	return s.Base.StoreBestBlockHash(newHead)
 }
 

dot/state/service_test.go

@@ -28,6 +28,7 @@ import (
 	"github.com/ChainSafe/gossamer/lib/trie"
 	"github.com/ChainSafe/gossamer/lib/utils"
 
+	"github.com/ChainSafe/chaindb"
 	log "github.com/ChainSafe/log15"
 	"github.com/stretchr/testify/require"
 )
@@ -229,13 +230,38 @@ func TestService_Rewind(t *testing.T) {
 	err = serv.Start()
 	require.NoError(t, err)
 
+	err = serv.Grandpa.setCurrentSetID(3)
+	require.NoError(t, err)
+
+	err = serv.Grandpa.setSetIDChangeAtBlock(1, big.NewInt(5))
+	require.NoError(t, err)
+
+	err = serv.Grandpa.setSetIDChangeAtBlock(2, big.NewInt(8))
+	require.NoError(t, err)
+
+	err = serv.Grandpa.setSetIDChangeAtBlock(3, big.NewInt(10))
+	require.NoError(t, err)
+
 	AddBlocksToState(t, serv.Block, 12)
 	err = serv.Rewind(6)
 	require.NoError(t, err)
 
 	num, err := serv.Block.BestBlockNumber()
 	require.NoError(t, err)
 	require.Equal(t, big.NewInt(6), num)
+
+	setID, err := serv.Grandpa.GetCurrentSetID()
+	require.NoError(t, err)
+	require.Equal(t, uint64(1), setID)
+
+	_, err = serv.Grandpa.GetSetIDChange(1)
+	require.NoError(t, err)
+
+	_, err = serv.Grandpa.GetSetIDChange(2)
+	require.Equal(t, chaindb.ErrKeyNotFound, err)
+
+	_, err = serv.Grandpa.GetSetIDChange(3)
+	require.Equal(t, chaindb.ErrKeyNotFound, err)
 }
 
 func TestService_Import(t *testing.T) {

dot/sync/interface.go

@@ -69,8 +69,6 @@ type BlockProducer interface {
 
 // DigestHandler is the interface for the consensus digest handler
 type DigestHandler interface {
-	Start()
-	Stop()
 	HandleConsensusDigest(*types.ConsensusDigest, *types.Header) error
 }
 

dot/sync/syncer.go

@@ -207,6 +207,11 @@ func (s *Service) ProcessBlockData(data []*types.BlockData) (int, error) {
 				return i, err
 			}
 
+			// handle consensus digests for authority changes
+			if s.digestHandler != nil {
+				s.handleDigests(header)
+			}
+
 			if bd.Justification != nil && bd.Justification.Exists() {
 				logger.Debug("handling Justification...", "number", header.Number, "hash", bd.Hash)
 				s.handleJustification(header, bd.Justification.Value())
@@ -427,13 +432,13 @@ func (s *Service) handleDigests(header *types.Header) {
 		if d.Type() == types.ConsensusDigestType {
 			cd, ok := d.(*types.ConsensusDigest)
 			if !ok {
-				logger.Error("handleDigests", "index", i, "error", "cannot cast invalid consensus digest item")
+				logger.Error("handleDigests", "block number", header.Number, "index", i, "error", "cannot cast invalid consensus digest item")
 				continue
 			}
 
 			err := s.digestHandler.HandleConsensusDigest(cd, header)
 			if err != nil {
-				logger.Error("handleDigests", "index", i, "digest", cd, "error", err)
+				logger.Error("handleDigests", "block number", header.Number, "index", i, "digest", cd, "error", err)
 			}
 		}
 	}

dot/telemetry/telemetry.go

@@ -114,11 +114,7 @@ func (h *Handler) SendBlockImport(bestHash string, height *big.Int) {
 
 func (h *Handler) sendTelemtry() {
 	for _, c := range h.wsConn {
-		err := c.WriteMessage(websocket.TextMessage, h.buf.Bytes())
-		if err != nil {
-			// TODO (ed) determine how to handle this error
-			fmt.Printf("ERROR connecting to telemetry %v\n", err)
-		}
+		_ = c.WriteMessage(websocket.TextMessage, h.buf.Bytes())
 	}
 	h.buf.Reset()
 }