package stateroot import ( "encoding/binary" "errors" "fmt" "sync" "github.com/nspcc-dev/neo-go/pkg/config" "github.com/nspcc-dev/neo-go/pkg/config/netmode" "github.com/nspcc-dev/neo-go/pkg/core/mpt" "github.com/nspcc-dev/neo-go/pkg/core/state" "github.com/nspcc-dev/neo-go/pkg/core/storage" "github.com/nspcc-dev/neo-go/pkg/core/transaction" "github.com/nspcc-dev/neo-go/pkg/crypto/hash" "github.com/nspcc-dev/neo-go/pkg/crypto/keys" "github.com/nspcc-dev/neo-go/pkg/util" "go.uber.org/atomic" "go.uber.org/zap" ) type ( // VerifierFunc is a function that allows to check witness of account // for Hashable item with GAS limit. VerifierFunc func(util.Uint160, hash.Hashable, *transaction.Witness, int64) (int64, error) // Module represents module for local processing of state roots. Module struct { Store *storage.MemCachedStore network netmode.Magic srInHead bool mpt *mpt.Trie verifier VerifierFunc log *zap.Logger currentLocal atomic.Value localHeight atomic.Uint32 validatedHeight atomic.Uint32 mtx sync.RWMutex keys []keyCache updateValidatorsCb func(height uint32, publicKeys keys.PublicKeys) } keyCache struct { height uint32 validatorsKeys keys.PublicKeys validatorsHash util.Uint160 validatorsScript []byte } ) // NewModule returns new instance of stateroot module. func NewModule(cfg config.ProtocolConfiguration, verif VerifierFunc, log *zap.Logger, s *storage.MemCachedStore) *Module { return &Module{ network: cfg.Magic, srInHead: cfg.StateRootInHeader, verifier: verif, log: log, Store: s, } } // GetState returns value at the specified key fom the MPT with the specified root. func (s *Module) GetState(root util.Uint256, key []byte) ([]byte, error) { tr := mpt.NewTrie(mpt.NewHashNode(root), false, storage.NewMemCachedStore(s.Store)) return tr.Get(key) } // FindStates returns set of key-value pairs with key matching the prefix starting // from the `prefix`+`start` path from MPT trie with the specified root. `max` is // the maximum number of elements to be returned. If nil `start` specified, then // item with key equals to prefix is included into result; if empty `start` specified, // then item with key equals to prefix is not included into result. func (s *Module) FindStates(root util.Uint256, prefix, start []byte, max int) ([]storage.KeyValue, error) { tr := mpt.NewTrie(mpt.NewHashNode(root), false, storage.NewMemCachedStore(s.Store)) return tr.Find(prefix, start, max) } // GetStateProof returns proof of having key in the MPT with the specified root. func (s *Module) GetStateProof(root util.Uint256, key []byte) ([][]byte, error) { tr := mpt.NewTrie(mpt.NewHashNode(root), false, storage.NewMemCachedStore(s.Store)) return tr.GetProof(key) } // GetStateRoot returns state root for a given height. func (s *Module) GetStateRoot(height uint32) (*state.MPTRoot, error) { return s.getStateRoot(makeStateRootKey(height)) } // CurrentLocalStateRoot returns hash of the local state root. func (s *Module) CurrentLocalStateRoot() util.Uint256 { return s.currentLocal.Load().(util.Uint256) } // CurrentLocalHeight returns height of the local state root. func (s *Module) CurrentLocalHeight() uint32 { return s.localHeight.Load() } // CurrentValidatedHeight returns current state root validated height. func (s *Module) CurrentValidatedHeight() uint32 { return s.validatedHeight.Load() } // Init initializes state root module at the given height. func (s *Module) Init(height uint32, enableRefCount bool) error { data, err := s.Store.Get([]byte{byte(storage.DataMPT), prefixValidated}) if err == nil { s.validatedHeight.Store(binary.LittleEndian.Uint32(data)) } if height == 0 { s.mpt = mpt.NewTrie(nil, enableRefCount, s.Store) s.currentLocal.Store(util.Uint256{}) return nil } r, err := s.getStateRoot(makeStateRootKey(height)) if err != nil { return err } s.currentLocal.Store(r.Root) s.localHeight.Store(r.Index) s.mpt = mpt.NewTrie(mpt.NewHashNode(r.Root), enableRefCount, s.Store) return nil } // CleanStorage removes all MPT-related data from the storage (MPT nodes, validated stateroots) // except local stateroot for the current height and GC flag. This method is aimed to clean // outdated MPT data before state sync process can be started. // Note: this method is aimed to be called for genesis block only, an error is returned otherwice. func (s *Module) CleanStorage() error { if s.localHeight.Load() != 0 { return fmt.Errorf("can't clean MPT data for non-genesis block: expected local stateroot height 0, got %d", s.localHeight.Load()) } b := s.Store.Batch() s.Store.Seek(storage.SeekRange{Prefix: []byte{byte(storage.DataMPT)}}, func(k, _ []byte) { // #1468, but don't need to copy here, because it is done by Store. b.Delete(k) }) err := s.Store.PutBatch(b) if err != nil { return fmt.Errorf("failed to remove outdated MPT-reated items: %w", err) } currentLocal := s.currentLocal.Load().(util.Uint256) if !currentLocal.Equals(util.Uint256{}) { err := s.addLocalStateRoot(s.Store, &state.MPTRoot{ Index: s.localHeight.Load(), Root: currentLocal, }) if err != nil { return fmt.Errorf("failed to store current local stateroot: %w", err) } } return nil } // JumpToState performs jump to the state specified by given stateroot index. func (s *Module) JumpToState(sr *state.MPTRoot, enableRefCount bool) error { if err := s.addLocalStateRoot(s.Store, sr); err != nil { return fmt.Errorf("failed to store local state root: %w", err) } data := make([]byte, 4) binary.LittleEndian.PutUint32(data, sr.Index) if err := s.Store.Put([]byte{byte(storage.DataMPT), prefixValidated}, data); err != nil { return fmt.Errorf("failed to store validated height: %w", err) } s.validatedHeight.Store(sr.Index) s.currentLocal.Store(sr.Root) s.localHeight.Store(sr.Index) s.mpt = mpt.NewTrie(mpt.NewHashNode(sr.Root), enableRefCount, s.Store) return nil } // AddMPTBatch updates using provided batch. func (s *Module) AddMPTBatch(index uint32, b mpt.Batch, cache *storage.MemCachedStore) (*mpt.Trie, *state.MPTRoot, error) { mpt := *s.mpt mpt.Store = cache if _, err := mpt.PutBatch(b); err != nil { return nil, nil, err } mpt.Flush() sr := &state.MPTRoot{ Index: index, Root: mpt.StateRoot(), } err := s.addLocalStateRoot(cache, sr) if err != nil { return nil, nil, err } return &mpt, sr, err } // UpdateCurrentLocal updates local caches using provided state root. func (s *Module) UpdateCurrentLocal(mpt *mpt.Trie, sr *state.MPTRoot) { s.mpt = mpt s.currentLocal.Store(sr.Root) s.localHeight.Store(sr.Index) if s.srInHead { s.validatedHeight.Store(sr.Index) updateStateHeightMetric(sr.Index) } } // VerifyStateRoot checks if state root is valid. func (s *Module) VerifyStateRoot(r *state.MPTRoot) error { _, err := s.getStateRoot(makeStateRootKey(r.Index - 1)) if err != nil { return errors.New("can't get previous state root") } if len(r.Witness) != 1 { return errors.New("no witness") } return s.verifyWitness(r) } const maxVerificationGAS = 2_00000000 // verifyWitness verifies state root witness. func (s *Module) verifyWitness(r *state.MPTRoot) error { s.mtx.Lock() h := s.getKeyCacheForHeight(r.Index).validatorsHash s.mtx.Unlock() _, err := s.verifier(h, r, &r.Witness[0], maxVerificationGAS) return err }