go/consensus/tendermint: Add support for state sync

.changelog/2880.feature.md

@@ -0,0 +1 @@
+go/consensus/tendermint: Add support for state sync

go/consensus/tendermint/abci/mux.go

@@ -31,6 +31,7 @@ import (
 	"github.com/oasisprotocol/oasis-core/go/consensus/tendermint/api"
 	epochtime "github.com/oasisprotocol/oasis-core/go/epochtime/api"
 	genesis "github.com/oasisprotocol/oasis-core/go/genesis/api"
+	"github.com/oasisprotocol/oasis-core/go/storage/mkvs/checkpoint"
 	upgrade "github.com/oasisprotocol/oasis-core/go/upgrade/api"
 )
 
@@ -881,6 +882,223 @@ func (mux *abciMux) Commit() types.ResponseCommit {
 	}
 }
 
+func (mux *abciMux) ListSnapshots(req types.RequestListSnapshots) types.ResponseListSnapshots {
+	// Get a list of all current checkpoints.
+	cps, err := mux.state.storage.Checkpointer().GetCheckpoints(mux.state.ctx, &checkpoint.GetCheckpointsRequest{
+		Version: 1,
+	})
+	if err != nil {
+		mux.logger.Error("failed to get checkpoints",
+			"err", err,
+		)
+		return types.ResponseListSnapshots{}
+	}
+
+	var rsp types.ResponseListSnapshots
+	for _, cp := range cps {
+		cpHash := cp.EncodedHash()
+
+		rsp.Snapshots = append(rsp.Snapshots, &types.Snapshot{
+			Height:   cp.Root.Version,
+			Format:   uint32(cp.Version),
+			Chunks:   uint32(len(cp.Chunks)),
+			Hash:     cpHash[:],
+			Metadata: cbor.Marshal(cp),
+		})
+	}
+
+	return rsp
+}
+
+func (mux *abciMux) OfferSnapshot(req types.RequestOfferSnapshot) types.ResponseOfferSnapshot {
+	if req.Snapshot == nil {
+		return types.ResponseOfferSnapshot{Result: types.ResponseOfferSnapshot_REJECT}
+	}
+	if req.Snapshot.Format != 1 {
+		mux.logger.Warn("received snapshot with unsupported version",
+			"version", req.Snapshot.Format,
+		)
+		return types.ResponseOfferSnapshot{Result: types.ResponseOfferSnapshot_REJECT_FORMAT}
+	}
+
+	// Decode checkpoint metadata hash and sanity check against the request.
+	var metadataHash hash.Hash
+	metadataHash.FromBytes(req.Snapshot.Metadata)
+	var h hash.Hash
+	if err := h.UnmarshalBinary(req.Snapshot.Hash); err != nil {
+		mux.logger.Warn("received snapshot with malformed hash",
+			"err", err,
+		)
+		return types.ResponseOfferSnapshot{Result: types.ResponseOfferSnapshot_REJECT}
+	}
+	if !metadataHash.Equal(&h) {
+		mux.logger.Warn("received snapshot with mismatching hash",
+			"expected_hash", h,
+			"hash", metadataHash,
+		)
+		return types.ResponseOfferSnapshot{Result: types.ResponseOfferSnapshot_REJECT}
+	}
+
+	// Decode checkpoint metadata.
+	var cp checkpoint.Metadata
+	if err := cbor.Unmarshal(req.Snapshot.Metadata, &cp); err != nil {
+		mux.logger.Warn("received snapshot with malformed metadata",
+			"err", err,
+		)
+		return types.ResponseOfferSnapshot{Result: types.ResponseOfferSnapshot_REJECT}
+	}
+
+	// Number of chunks must match.
+	if int(req.Snapshot.Chunks) != len(cp.Chunks) {
+		mux.logger.Warn("received snapshot with mismatching number of chunks",
+			"expected_chunks", len(cp.Chunks),
+			"chunks", req.Snapshot.Chunks,
+		)
+		return types.ResponseOfferSnapshot{Result: types.ResponseOfferSnapshot_REJECT}
+	}
+	// Root hash must match.
+	var appHash hash.Hash
+	if err := appHash.UnmarshalBinary(req.AppHash); err != nil {
+		// NOTE: This should never happen as it indicates a problem with Tendermint.
+		mux.logger.Error("received request with malformed hash",
+			"err", err,
+		)
+		return types.ResponseOfferSnapshot{Result: types.ResponseOfferSnapshot_ABORT}
+	}
+	if !cp.Root.Hash.Equal(&appHash) {
+		mux.logger.Warn("received snapshot with mismatching root hash",
+			"expected_root", appHash,
+			"root", cp.Root.Hash,
+		)
+		return types.ResponseOfferSnapshot{Result: types.ResponseOfferSnapshot_REJECT}
+	}
+
+	// Snapshot seems correct (e.g., it is for the correct root), start the restoration process.
+	if err := mux.state.storage.Checkpointer().StartRestore(mux.state.ctx, &cp); err != nil {
+		mux.logger.Error("failed to start restore",
+			"err", err,
+		)
+		return types.ResponseOfferSnapshot{Result: types.ResponseOfferSnapshot_ABORT}
+	}
+
+	mux.logger.Info("started state restore process",
+		"root", cp.Root,
+	)
+
+	return types.ResponseOfferSnapshot{Result: types.ResponseOfferSnapshot_ACCEPT}
+}
+
+func (mux *abciMux) LoadSnapshotChunk(req types.RequestLoadSnapshotChunk) types.ResponseLoadSnapshotChunk {
+	// Fetch the metadata for the specified checkpoint.
+	cps, err := mux.state.storage.Checkpointer().GetCheckpoints(mux.state.ctx, &checkpoint.GetCheckpointsRequest{
+		Version:     uint16(req.Format),
+		RootVersion: &req.Height,
+	})
+	if err != nil {
+		mux.logger.Error("failed to get checkpoints",
+			"err", err,
+		)
+		return types.ResponseLoadSnapshotChunk{}
+	}
+	if len(cps) != 1 {
+		mux.logger.Error("failed to get checkpoints",
+			"cps", len(cps),
+		)
+		return types.ResponseLoadSnapshotChunk{}
+	}
+
+	// Fetch the chunk itself.
+	chunk, err := cps[0].GetChunkMetadata(uint64(req.Chunk))
+	if err != nil {
+		mux.logger.Error("failed to get chunk metadata",
+			"err", err,
+		)
+		return types.ResponseLoadSnapshotChunk{}
+	}
+	var buf bytes.Buffer
+	if err := mux.state.storage.Checkpointer().GetCheckpointChunk(mux.state.ctx, chunk, &buf); err != nil {
+		mux.logger.Error("failed to get chunk",
+			"err", err,
+		)
+		return types.ResponseLoadSnapshotChunk{}
+	}
+
+	return types.ResponseLoadSnapshotChunk{Chunk: buf.Bytes()}
+}
+
+func (mux *abciMux) ApplySnapshotChunk(req types.RequestApplySnapshotChunk) types.ResponseApplySnapshotChunk {
+	cp := mux.state.storage.Checkpointer().GetCurrentCheckpoint()
+
+	mux.logger.Debug("attempting to restore a chunk",
+		"root", cp.Root,
+		"index", req.Index,
+	)
+
+	buf := bytes.NewBuffer(req.Chunk)
+	done, err := mux.state.storage.Checkpointer().RestoreChunk(mux.state.ctx, uint64(req.Index), buf)
+	switch {
+	case err == nil:
+	case errors.Is(err, checkpoint.ErrNoRestoreInProgress):
+		// This should never happen.
+		mux.logger.Error("ApplySnapshotChunk called without OfferSnapshot, aborting state sync")
+		return types.ResponseApplySnapshotChunk{Result: types.ResponseApplySnapshotChunk_ABORT}
+	case errors.Is(err, checkpoint.ErrChunkAlreadyRestored):
+		return types.ResponseApplySnapshotChunk{Result: types.ResponseApplySnapshotChunk_ACCEPT}
+	case errors.Is(err, checkpoint.ErrChunkCorrupted):
+		// Corrupted chunk, refetch.
+		mux.logger.Warn("received corrupted chunk",
+			"sender", req.Sender,
+			"index", req.Index,
+			"err", err,
+		)
+
+		return types.ResponseApplySnapshotChunk{
+			RefetchChunks: []uint32{req.Index},
+			// TODO: Consider banning the sender.
+			Result: types.ResponseApplySnapshotChunk_RETRY,
+		}
+	case errors.Is(err, checkpoint.ErrChunkProofVerificationFailed):
+		// Chunk was as specified in the manifest but did not match the reported root. In this case
+		// we need to abort processing the given snapshot.
+		mux.logger.Warn("chunk contains invalid proof, snapshot is bad",
+			"err", err,
+		)
+
+		return types.ResponseApplySnapshotChunk{Result: types.ResponseApplySnapshotChunk_REJECT_SNAPSHOT}
+	default:
+		// Unspecified error during restoration.
+		mux.logger.Error("error during chunk restoration, aborting state sync",
+			"err", err,
+		)
+
+		return types.ResponseApplySnapshotChunk{Result: types.ResponseApplySnapshotChunk_ABORT}
+	}
+
+	// Check if we are done with the restoration. In this case, finalize the root.
+	if done {
+		err = mux.state.storage.NodeDB().Finalize(mux.state.ctx, cp.Root.Version, []hash.Hash{cp.Root.Hash})
+		if err != nil {
+			mux.logger.Error("failed to finalize restored root",
+				"err", err,
+			)
+			return types.ResponseApplySnapshotChunk{Result: types.ResponseApplySnapshotChunk_ABORT}
+		}
+
+		if err = mux.state.doApplyStateSync(cp.Root); err != nil {
+			mux.logger.Error("failed to apply state sync root",
+				"err", err,
+			)
+			return types.ResponseApplySnapshotChunk{Result: types.ResponseApplySnapshotChunk_ABORT}
+		}
+
+		mux.logger.Info("successfully synced state",
+			"root", cp.Root,
+		)
+	}
+
+	return types.ResponseApplySnapshotChunk{Result: types.ResponseApplySnapshotChunk_ACCEPT}
+}
+
 func (mux *abciMux) doCleanup() {
 	mux.state.doCleanup()
 

go/consensus/tendermint/abci/state.go

@@ -248,6 +248,24 @@ func (s *applicationState) doInitChain(now time.Time) error {
 	return s.doCommitOrInitChainLocked(now)
 }
 
+func (s *applicationState) doApplyStateSync(root storage.Root) error {
+	s.blockLock.Lock()
+	defer s.blockLock.Unlock()
+
+	s.stateRoot = root
+
+	s.deliverTxTree.Close()
+	s.deliverTxTree = mkvs.NewWithRoot(nil, s.storage.NodeDB(), root, mkvs.WithoutWriteLog())
+	s.checkTxTree.Close()
+	s.checkTxTree = mkvs.NewWithRoot(nil, s.storage.NodeDB(), root, mkvs.WithoutWriteLog())
+
+	if err := s.doCommitOrInitChainLocked(time.Time{}); err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func (s *applicationState) doCommit(now time.Time) (uint64, error) {
 	s.blockLock.Lock()
 	defer s.blockLock.Unlock()