neoneo-go/pkg/core/blockchain.go
2020-12-25 14:40:23 +03:00

1851 lines
60 KiB
Go

package core
import (
"bytes"
"errors"
"fmt"
"math"
"math/big"
"sort"
"sync"
"sync/atomic"
"time"
"github.com/nspcc-dev/neo-go/pkg/config"
"github.com/nspcc-dev/neo-go/pkg/core/block"
"github.com/nspcc-dev/neo-go/pkg/core/blockchainer"
"github.com/nspcc-dev/neo-go/pkg/core/dao"
"github.com/nspcc-dev/neo-go/pkg/core/interop"
"github.com/nspcc-dev/neo-go/pkg/core/mempool"
"github.com/nspcc-dev/neo-go/pkg/core/mpt"
"github.com/nspcc-dev/neo-go/pkg/core/native"
"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"
"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/encoding/bigint"
"github.com/nspcc-dev/neo-go/pkg/io"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
"github.com/nspcc-dev/neo-go/pkg/util"
"github.com/nspcc-dev/neo-go/pkg/vm"
"github.com/nspcc-dev/neo-go/pkg/vm/emit"
"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
"go.uber.org/zap"
)
// Tuning parameters.
const (
headerBatchCount = 2000
version = "0.1.0"
defaultMemPoolSize = 50000
defaultP2PNotaryRequestPayloadPoolSize = 1000
defaultMaxTraceableBlocks = 2102400 // 1 year of 15s blocks
verificationGasLimit = 100000000 // 1 GAS
)
var (
// ErrAlreadyExists is returned when trying to add some already existing
// transaction into the pool (not specifying whether it exists in the
// chain or mempool).
ErrAlreadyExists = errors.New("already exists")
// ErrOOM is returned when adding transaction to the memory pool because
// it reached its full capacity.
ErrOOM = errors.New("no space left in the memory pool")
// ErrPolicy is returned on attempt to add transaction that doesn't
// comply with node's configured policy into the mempool.
ErrPolicy = errors.New("not allowed by policy")
// ErrInvalidBlockIndex is returned when trying to add block with index
// other than expected height of the blockchain.
ErrInvalidBlockIndex error = errors.New("invalid block index")
// ErrHasConflicts is returned when trying to add some transaction which
// conflicts with other transaction in the chain or pool according to
// Conflicts attribute.
ErrHasConflicts = errors.New("has conflicts")
)
var (
persistInterval = 1 * time.Second
)
// Blockchain represents the blockchain. It maintans internal state representing
// the state of the ledger that can be accessed in various ways and changed by
// adding new blocks or headers.
type Blockchain struct {
config config.ProtocolConfiguration
// The only way chain state changes is by adding blocks, so we can't
// allow concurrent block additions. It differs from the next lock in
// that it's only for AddBlock method itself, the chain state is
// protected by the lock below, but holding it during all of AddBlock
// is too expensive (because the state only changes when persisting
// change cache).
addLock sync.Mutex
// This lock ensures blockchain immutability for operations that need
// that while performing their tasks. It's mostly used as a read lock
// with the only writer being the block addition logic.
lock sync.RWMutex
// Data access object for CRUD operations around storage.
dao *dao.Simple
// Current index/height of the highest block.
// Read access should always be called by BlockHeight().
// Write access should only happen in storeBlock().
blockHeight uint32
// Current top Block wrapped in an atomic.Value for safe access.
topBlock atomic.Value
// Current persisted block count.
persistedHeight uint32
// Number of headers stored in the chain file.
storedHeaderCount uint32
// Header hashes list with associated lock.
headerHashesLock sync.RWMutex
headerHashes []util.Uint256
// Stop synchronization mechanisms.
stopCh chan struct{}
runToExitCh chan struct{}
memPool *mempool.Pool
// postBlock is a set of callback methods which should be run under the Blockchain lock after new block is persisted.
// Block's transactions are passed via mempool.
postBlock []func(blockchainer.Blockchainer, *mempool.Pool, *block.Block)
sbCommittee keys.PublicKeys
log *zap.Logger
lastBatch *storage.MemBatch
contracts native.Contracts
// Notification subsystem.
events chan bcEvent
subCh chan interface{}
unsubCh chan interface{}
}
// bcEvent is an internal event generated by the Blockchain and then
// broadcasted to other parties. It joins the new block and associated
// invocation logs, all the other events visible from outside can be produced
// from this combination.
type bcEvent struct {
block *block.Block
appExecResults []*state.AppExecResult
}
// NewBlockchain returns a new blockchain object the will use the
// given Store as its underlying storage. For it to work correctly you need
// to spawn a goroutine for its Run method after this initialization.
func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration, log *zap.Logger) (*Blockchain, error) {
if log == nil {
return nil, errors.New("empty logger")
}
if cfg.MemPoolSize <= 0 {
cfg.MemPoolSize = defaultMemPoolSize
log.Info("mempool size is not set or wrong, setting default value", zap.Int("MemPoolSize", cfg.MemPoolSize))
}
if cfg.P2PSigExtensions && cfg.P2PNotaryRequestPayloadPoolSize <= 0 {
cfg.P2PNotaryRequestPayloadPoolSize = defaultP2PNotaryRequestPayloadPoolSize
log.Info("P2PNotaryRequestPayloadPool size is not set or wrong, setting default value", zap.Int("P2PNotaryRequestPayloadPoolSize", cfg.P2PNotaryRequestPayloadPoolSize))
}
if cfg.MaxTraceableBlocks == 0 {
cfg.MaxTraceableBlocks = defaultMaxTraceableBlocks
log.Info("MaxTraceableBlocks is not set or wrong, using default value", zap.Uint32("MaxTraceableBlocks", cfg.MaxTraceableBlocks))
}
committee, err := committeeFromConfig(cfg)
if err != nil {
return nil, err
}
bc := &Blockchain{
config: cfg,
dao: dao.NewSimple(s, cfg.Magic, cfg.StateRootInHeader),
stopCh: make(chan struct{}),
runToExitCh: make(chan struct{}),
memPool: mempool.New(cfg.MemPoolSize, 0),
sbCommittee: committee,
log: log,
events: make(chan bcEvent),
subCh: make(chan interface{}),
unsubCh: make(chan interface{}),
contracts: *native.NewContracts(cfg.P2PSigExtensions),
}
if err := bc.init(); err != nil {
return nil, err
}
return bc, nil
}
func (bc *Blockchain) init() error {
// If we could not find the version in the Store, we know that there is nothing stored.
ver, err := bc.dao.GetVersion()
if err != nil {
bc.log.Info("no storage version found! creating genesis block")
if err = bc.dao.PutVersion(version); err != nil {
return err
}
genesisBlock, err := createGenesisBlock(bc.config)
if err != nil {
return err
}
bc.headerHashes = []util.Uint256{genesisBlock.Hash()}
err = bc.dao.PutCurrentHeader(hashAndIndexToBytes(genesisBlock.Hash(), genesisBlock.Index))
if err != nil {
return err
}
if err := bc.dao.InitMPT(0, bc.config.KeepOnlyLatestState); err != nil {
return fmt.Errorf("can't init MPT: %w", err)
}
return bc.storeBlock(genesisBlock, nil)
}
if ver != version {
return fmt.Errorf("storage version mismatch betweeen %s and %s", version, ver)
}
// At this point there was no version found in the storage which
// implies a creating fresh storage with the version specified
// and the genesis block as first block.
bc.log.Info("restoring blockchain", zap.String("version", version))
bHeight, err := bc.dao.GetCurrentBlockHeight()
if err != nil {
return err
}
bc.blockHeight = bHeight
bc.persistedHeight = bHeight
if err = bc.dao.InitMPT(bHeight, bc.config.KeepOnlyLatestState); err != nil {
return fmt.Errorf("can't init MPT at height %d: %w", bHeight, err)
}
bc.headerHashes, err = bc.dao.GetHeaderHashes()
if err != nil {
return err
}
bc.storedHeaderCount = uint32(len(bc.headerHashes))
currHeaderHeight, currHeaderHash, err := bc.dao.GetCurrentHeaderHeight()
if err != nil {
return err
}
if bc.storedHeaderCount == 0 && currHeaderHeight == 0 {
bc.headerHashes = append(bc.headerHashes, currHeaderHash)
}
// There is a high chance that the Node is stopped before the next
// batch of 2000 headers was stored. Via the currentHeaders stored we can sync
// that with stored blocks.
if currHeaderHeight >= bc.storedHeaderCount {
hash := currHeaderHash
var targetHash util.Uint256
if len(bc.headerHashes) > 0 {
targetHash = bc.headerHashes[len(bc.headerHashes)-1]
} else {
genesisBlock, err := createGenesisBlock(bc.config)
if err != nil {
return err
}
targetHash = genesisBlock.Hash()
bc.headerHashes = append(bc.headerHashes, targetHash)
}
headers := make([]*block.Header, 0)
for hash != targetHash {
header, err := bc.GetHeader(hash)
if err != nil {
return fmt.Errorf("could not get header %s: %w", hash, err)
}
headers = append(headers, header)
hash = header.PrevHash
}
headerSliceReverse(headers)
for _, h := range headers {
bc.headerHashes = append(bc.headerHashes, h.Hash())
}
}
err = bc.contracts.NEO.InitializeCache(bc, bc.dao)
if err != nil {
return fmt.Errorf("can't init cache for NEO native contract: %w", err)
}
err = bc.contracts.Management.InitializeCache(bc.dao)
if err != nil {
return fmt.Errorf("can't init cache for Management native contract: %w", err)
}
return nil
}
// Run runs chain loop, it needs to be run as goroutine and executing it is
// critical for correct Blockchain operation.
func (bc *Blockchain) Run() {
persistTimer := time.NewTimer(persistInterval)
defer func() {
persistTimer.Stop()
if err := bc.persist(); err != nil {
bc.log.Warn("failed to persist", zap.Error(err))
}
if err := bc.dao.Store.Close(); err != nil {
bc.log.Warn("failed to close db", zap.Error(err))
}
close(bc.runToExitCh)
}()
go bc.notificationDispatcher()
for {
select {
case <-bc.stopCh:
return
case <-persistTimer.C:
go func() {
err := bc.persist()
if err != nil {
bc.log.Warn("failed to persist blockchain", zap.Error(err))
}
persistTimer.Reset(persistInterval)
}()
}
}
}
// notificationDispatcher manages subscription to events and broadcasts new events.
func (bc *Blockchain) notificationDispatcher() {
var (
// These are just sets of subscribers, though modelled as maps
// for ease of management (not a lot of subscriptions is really
// expected, but maps are convenient for adding/deleting elements).
blockFeed = make(map[chan<- *block.Block]bool)
txFeed = make(map[chan<- *transaction.Transaction]bool)
notificationFeed = make(map[chan<- *state.NotificationEvent]bool)
executionFeed = make(map[chan<- *state.AppExecResult]bool)
)
for {
select {
case <-bc.stopCh:
return
case sub := <-bc.subCh:
switch ch := sub.(type) {
case chan<- *block.Block:
blockFeed[ch] = true
case chan<- *transaction.Transaction:
txFeed[ch] = true
case chan<- *state.NotificationEvent:
notificationFeed[ch] = true
case chan<- *state.AppExecResult:
executionFeed[ch] = true
default:
panic(fmt.Sprintf("bad subscription: %T", sub))
}
case unsub := <-bc.unsubCh:
switch ch := unsub.(type) {
case chan<- *block.Block:
delete(blockFeed, ch)
case chan<- *transaction.Transaction:
delete(txFeed, ch)
case chan<- *state.NotificationEvent:
delete(notificationFeed, ch)
case chan<- *state.AppExecResult:
delete(executionFeed, ch)
default:
panic(fmt.Sprintf("bad unsubscription: %T", unsub))
}
case event := <-bc.events:
// We don't want to waste time looping through transactions when there are no
// subscribers.
if len(txFeed) != 0 || len(notificationFeed) != 0 || len(executionFeed) != 0 {
aer := event.appExecResults[0]
if !aer.Container.Equals(event.block.Hash()) {
panic("inconsistent application execution results")
}
for ch := range executionFeed {
ch <- aer
}
for i := range aer.Events {
for ch := range notificationFeed {
ch <- &aer.Events[i]
}
}
aerIdx := 1
for _, tx := range event.block.Transactions {
aer := event.appExecResults[aerIdx]
if !aer.Container.Equals(tx.Hash()) {
panic("inconsistent application execution results")
}
aerIdx++
for ch := range executionFeed {
ch <- aer
}
if aer.VMState == vm.HaltState {
for i := range aer.Events {
for ch := range notificationFeed {
ch <- &aer.Events[i]
}
}
}
for ch := range txFeed {
ch <- tx
}
}
aer = event.appExecResults[aerIdx]
if !aer.Container.Equals(event.block.Hash()) {
panic("inconsistent application execution results")
}
for ch := range executionFeed {
ch <- aer
}
for i := range aer.Events {
for ch := range notificationFeed {
ch <- &aer.Events[i]
}
}
}
for ch := range blockFeed {
ch <- event.block
}
}
}
}
// Close stops Blockchain's internal loop, syncs changes to persistent storage
// and closes it. The Blockchain is no longer functional after the call to Close.
func (bc *Blockchain) Close() {
// If there is a block addition in progress, wait for it to finish and
// don't allow new ones.
bc.addLock.Lock()
close(bc.stopCh)
<-bc.runToExitCh
bc.addLock.Unlock()
}
// AddBlock accepts successive block for the Blockchain, verifies it and
// stores internally. Eventually it will be persisted to the backing storage.
func (bc *Blockchain) AddBlock(block *block.Block) error {
bc.addLock.Lock()
defer bc.addLock.Unlock()
var mp *mempool.Pool
expectedHeight := bc.BlockHeight() + 1
if expectedHeight != block.Index {
return fmt.Errorf("expected %d, got %d: %w", expectedHeight, block.Index, ErrInvalidBlockIndex)
}
if bc.config.StateRootInHeader != block.StateRootEnabled {
return fmt.Errorf("%w: %v != %v",
ErrHdrStateRootSetting, bc.config.StateRootInHeader, block.StateRootEnabled)
}
if bc.config.StateRootInHeader {
if sr := bc.dao.MPT.StateRoot(); block.PrevStateRoot != sr {
return fmt.Errorf("%w: %s != %s",
ErrHdrInvalidStateRoot, block.PrevStateRoot.StringLE(), sr.StringLE())
}
}
if block.Index == bc.HeaderHeight()+1 {
err := bc.addHeaders(bc.config.VerifyBlocks, block.Header())
if err != nil {
return err
}
}
if bc.config.VerifyBlocks {
merkle := block.ComputeMerkleRoot()
if !block.MerkleRoot.Equals(merkle) {
return errors.New("invalid block: MerkleRoot mismatch")
}
mp = mempool.New(len(block.Transactions), 0)
for _, tx := range block.Transactions {
var err error
// Transactions are verified before adding them
// into the pool, so there is no point in doing
// it again even if we're verifying in-block transactions.
if bc.memPool.ContainsKey(tx.Hash()) {
err = mp.Add(tx, bc)
if err == nil {
continue
}
} else {
err = bc.verifyAndPoolTx(tx, mp, bc)
}
if err != nil && bc.config.VerifyTransactions {
return fmt.Errorf("transaction %s failed to verify: %w", tx.Hash().StringLE(), err)
}
}
}
return bc.storeBlock(block, mp)
}
// AddHeaders processes the given headers and add them to the
// HeaderHashList. It expects headers to be sorted by index.
func (bc *Blockchain) AddHeaders(headers ...*block.Header) error {
return bc.addHeaders(bc.config.VerifyBlocks, headers...)
}
// addHeaders is an internal implementation of AddHeaders (`verify` parameter
// tells it to verify or not verify given headers).
func (bc *Blockchain) addHeaders(verify bool, headers ...*block.Header) error {
var (
start = time.Now()
batch = bc.dao.Store.Batch()
err error
)
if len(headers) > 0 {
var i int
curHeight := bc.HeaderHeight()
for i = range headers {
if headers[i].Index > curHeight {
break
}
}
headers = headers[i:]
}
if len(headers) == 0 {
return nil
} else if verify {
// Verify that the chain of the headers is consistent.
var lastHeader *block.Header
if lastHeader, err = bc.GetHeader(headers[0].PrevHash); err != nil {
return fmt.Errorf("previous header was not found: %w", err)
}
for _, h := range headers {
if err = bc.verifyHeader(h, lastHeader); err != nil {
return err
}
lastHeader = h
}
}
buf := io.NewBufBinWriter()
bc.headerHashesLock.Lock()
defer bc.headerHashesLock.Unlock()
oldlen := len(bc.headerHashes)
var lastHeader *block.Header
for _, h := range headers {
if int(h.Index) != len(bc.headerHashes) {
continue
}
bc.headerHashes = append(bc.headerHashes, h.Hash())
h.EncodeBinary(buf.BinWriter)
if buf.Err != nil {
return buf.Err
}
key := storage.AppendPrefix(storage.DataBlock, h.Hash().BytesBE())
batch.Put(key, buf.Bytes())
buf.Reset()
lastHeader = h
}
if oldlen != len(bc.headerHashes) {
for int(lastHeader.Index)-headerBatchCount >= int(bc.storedHeaderCount) {
buf.WriteArray(bc.headerHashes[bc.storedHeaderCount : bc.storedHeaderCount+headerBatchCount])
if buf.Err != nil {
return buf.Err
}
key := storage.AppendPrefixInt(storage.IXHeaderHashList, int(bc.storedHeaderCount))
batch.Put(key, buf.Bytes())
bc.storedHeaderCount += headerBatchCount
}
batch.Put(storage.SYSCurrentHeader.Bytes(), hashAndIndexToBytes(lastHeader.Hash(), lastHeader.Index))
updateHeaderHeightMetric(len(bc.headerHashes) - 1)
if err = bc.dao.Store.PutBatch(batch); err != nil {
return err
}
bc.log.Debug("done processing headers",
zap.Int("headerIndex", len(bc.headerHashes)-1),
zap.Uint32("blockHeight", bc.BlockHeight()),
zap.Duration("took", time.Since(start)))
}
return nil
}
// GetStateProof returns proof of having key in the MPT with the specified root.
func (bc *Blockchain) GetStateProof(root util.Uint256, key []byte) ([][]byte, error) {
tr := mpt.NewTrie(mpt.NewHashNode(root), false, storage.NewMemCachedStore(bc.dao.Store))
return tr.GetProof(key)
}
// GetStateRoot returns state root for a given height.
func (bc *Blockchain) GetStateRoot(height uint32) (*state.MPTRootState, error) {
return bc.dao.GetStateRoot(height)
}
// storeBlock performs chain update using the block given, it executes all
// transactions with all appropriate side-effects and updates Blockchain state.
// This is the only way to change Blockchain state.
func (bc *Blockchain) storeBlock(block *block.Block, txpool *mempool.Pool) error {
cache := dao.NewCached(bc.dao)
writeBuf := io.NewBufBinWriter()
appExecResults := make([]*state.AppExecResult, 0, 2+len(block.Transactions))
if err := cache.StoreAsBlock(block, writeBuf); err != nil {
return err
}
writeBuf.Reset()
if err := cache.StoreAsCurrentBlock(block, writeBuf); err != nil {
return err
}
writeBuf.Reset()
aer, err := bc.runPersist(bc.contracts.GetPersistScript(), block, cache, trigger.OnPersist)
if err != nil {
return fmt.Errorf("onPersist failed: %w", err)
}
appExecResults = append(appExecResults, aer)
err = cache.PutAppExecResult(aer, writeBuf)
if err != nil {
return fmt.Errorf("failed to store onPersist exec result: %w", err)
}
writeBuf.Reset()
for _, tx := range block.Transactions {
if err := cache.StoreAsTransaction(tx, block.Index, writeBuf); err != nil {
return err
}
writeBuf.Reset()
systemInterop := bc.newInteropContext(trigger.Application, cache, block, tx)
v := systemInterop.SpawnVM()
v.LoadScriptWithFlags(tx.Script, smartcontract.All)
v.SetPriceGetter(bc.getPrice)
v.GasLimit = tx.SystemFee
err := v.Run()
var faultException string
if !v.HasFailed() {
_, err := systemInterop.DAO.Persist()
if err != nil {
return fmt.Errorf("failed to persist invocation results: %w", err)
}
for j := range systemInterop.Notifications {
bc.handleNotification(&systemInterop.Notifications[j], cache, block, tx.Hash())
}
} else {
bc.log.Warn("contract invocation failed",
zap.String("tx", tx.Hash().StringLE()),
zap.Uint32("block", block.Index),
zap.Error(err))
faultException = err.Error()
}
aer := &state.AppExecResult{
Container: tx.Hash(),
Execution: state.Execution{
Trigger: trigger.Application,
VMState: v.State(),
GasConsumed: v.GasConsumed(),
Stack: v.Estack().ToArray(),
Events: systemInterop.Notifications,
FaultException: faultException,
},
}
appExecResults = append(appExecResults, aer)
err = cache.PutAppExecResult(aer, writeBuf)
if err != nil {
return fmt.Errorf("failed to store tx exec result: %w", err)
}
writeBuf.Reset()
if bc.config.P2PSigExtensions {
for _, attr := range tx.GetAttributes(transaction.ConflictsT) {
hash := attr.Value.(*transaction.Conflicts).Hash
dummyTx := transaction.NewTrimmedTX(hash)
dummyTx.Version = transaction.DummyVersion
if err = cache.StoreAsTransaction(dummyTx, block.Index, writeBuf); err != nil {
return fmt.Errorf("failed to store conflicting transaction %s for transaction %s: %w", hash.StringLE(), tx.Hash().StringLE(), err)
}
writeBuf.Reset()
}
}
}
aer, err = bc.runPersist(bc.contracts.GetPostPersistScript(), block, cache, trigger.PostPersist)
if err != nil {
return fmt.Errorf("postPersist failed: %w", err)
}
appExecResults = append(appExecResults, aer)
err = cache.AppendAppExecResult(aer, writeBuf)
if err != nil {
return fmt.Errorf("failed to store postPersist exec result: %w", err)
}
writeBuf.Reset()
d := cache.DAO.(*dao.Simple)
if err := d.UpdateMPT(); err != nil {
return fmt.Errorf("error while trying to apply MPT changes: %w", err)
}
root := d.MPT.StateRoot()
var prevHash util.Uint256
if block.Index > 0 {
prev, err := bc.dao.GetStateRoot(block.Index - 1)
if err != nil {
return fmt.Errorf("can't get previous state root: %w", err)
}
prevHash = hash.DoubleSha256(prev.GetSignedPart())
}
err = bc.AddStateRoot(&state.MPTRoot{
MPTRootBase: state.MPTRootBase{
Index: block.Index,
PrevHash: prevHash,
Root: root,
},
})
if err != nil {
return err
}
if bc.config.SaveStorageBatch {
bc.lastBatch = cache.DAO.GetBatch()
}
if bc.config.RemoveUntraceableBlocks {
if block.Index > bc.config.MaxTraceableBlocks {
index := block.Index - bc.config.MaxTraceableBlocks // is at least 1
err := cache.DeleteBlock(bc.headerHashes[index], writeBuf)
if err != nil {
bc.log.Warn("error while removing old block",
zap.Uint32("index", index),
zap.Error(err))
}
writeBuf.Reset()
}
}
bc.lock.Lock()
_, err = cache.Persist()
if err != nil {
bc.lock.Unlock()
return err
}
bc.dao.MPT.Flush()
// Every persist cycle we also compact our in-memory MPT.
persistedHeight := atomic.LoadUint32(&bc.persistedHeight)
if persistedHeight == block.Index-1 {
// 10 is good and roughly estimated to fit remaining trie into 1M of memory.
bc.dao.MPT.Collapse(10)
}
bc.topBlock.Store(block)
atomic.StoreUint32(&bc.blockHeight, block.Index)
bc.memPool.RemoveStale(func(tx *transaction.Transaction) bool { return bc.IsTxStillRelevant(tx, txpool, false) }, bc)
for _, f := range bc.postBlock {
f(bc, txpool, block)
}
bc.lock.Unlock()
updateBlockHeightMetric(block.Index)
// Genesis block is stored when Blockchain is not yet running, so there
// is no one to read this event. And it doesn't make much sense as event
// anyway.
if block.Index != 0 {
bc.events <- bcEvent{block, appExecResults}
}
return nil
}
func (bc *Blockchain) runPersist(script []byte, block *block.Block, cache *dao.Cached, trig trigger.Type) (*state.AppExecResult, error) {
systemInterop := bc.newInteropContext(trig, cache, block, nil)
v := systemInterop.SpawnVM()
v.LoadScriptWithFlags(script, smartcontract.WriteStates|smartcontract.AllowCall)
v.SetPriceGetter(bc.getPrice)
if err := v.Run(); err != nil {
return nil, fmt.Errorf("VM has failed: %w", err)
} else if _, err := systemInterop.DAO.Persist(); err != nil {
return nil, fmt.Errorf("can't save changes: %w", err)
}
for i := range systemInterop.Notifications {
bc.handleNotification(&systemInterop.Notifications[i], cache, block, block.Hash())
}
return &state.AppExecResult{
Container: block.Hash(), // application logs can be retrieved by block hash
Execution: state.Execution{
Trigger: trig,
VMState: v.State(),
GasConsumed: v.GasConsumed(),
Stack: v.Estack().ToArray(),
Events: systemInterop.Notifications,
},
}, nil
}
func (bc *Blockchain) handleNotification(note *state.NotificationEvent, d *dao.Cached, b *block.Block, h util.Uint256) {
if note.Name != "Transfer" {
return
}
arr, ok := note.Item.Value().([]stackitem.Item)
if !ok || len(arr) != 3 {
return
}
var from []byte
fromValue := arr[0].Value()
// we don't have `from` set when we are minting tokens
if fromValue != nil {
from, ok = fromValue.([]byte)
if !ok {
return
}
}
var to []byte
toValue := arr[1].Value()
// we don't have `to` set when we are burning tokens
if toValue != nil {
to, ok = toValue.([]byte)
if !ok {
return
}
}
amount, ok := arr[2].Value().(*big.Int)
if !ok {
bs, ok := arr[2].Value().([]byte)
if !ok {
return
}
amount = bigint.FromBytes(bs)
}
bc.processNEP17Transfer(d, h, b, note.ScriptHash, from, to, amount)
}
func parseUint160(addr []byte) util.Uint160 {
if u, err := util.Uint160DecodeBytesBE(addr); err == nil {
return u
}
return util.Uint160{}
}
func (bc *Blockchain) processNEP17Transfer(cache *dao.Cached, h util.Uint256, b *block.Block, sc util.Uint160, from, to []byte, amount *big.Int) {
toAddr := parseUint160(to)
fromAddr := parseUint160(from)
var id int32
nativeContract := bc.contracts.ByHash(sc)
if nativeContract != nil {
id = nativeContract.Metadata().ContractID
} else {
assetContract, err := bc.contracts.Management.GetContract(cache, sc)
if err != nil {
return
}
id = assetContract.ID
}
transfer := &state.NEP17Transfer{
Asset: id,
From: fromAddr,
To: toAddr,
Block: b.Index,
Timestamp: b.Timestamp,
Tx: h,
}
if !fromAddr.Equals(util.Uint160{}) {
balances, err := cache.GetNEP17Balances(fromAddr)
if err != nil {
return
}
bs := balances.Trackers[id]
bs.Balance = *new(big.Int).Sub(&bs.Balance, amount)
bs.LastUpdatedBlock = b.Index
balances.Trackers[id] = bs
transfer.Amount = *new(big.Int).Sub(&transfer.Amount, amount)
isBig, err := cache.AppendNEP17Transfer(fromAddr, balances.NextTransferBatch, transfer)
if err != nil {
return
}
if isBig {
balances.NextTransferBatch++
}
if err := cache.PutNEP17Balances(fromAddr, balances); err != nil {
return
}
}
if !toAddr.Equals(util.Uint160{}) {
balances, err := cache.GetNEP17Balances(toAddr)
if err != nil {
return
}
bs := balances.Trackers[id]
bs.Balance = *new(big.Int).Add(&bs.Balance, amount)
bs.LastUpdatedBlock = b.Index
balances.Trackers[id] = bs
transfer.Amount = *amount
isBig, err := cache.AppendNEP17Transfer(toAddr, balances.NextTransferBatch, transfer)
if err != nil {
return
}
if isBig {
balances.NextTransferBatch++
}
if err := cache.PutNEP17Balances(toAddr, balances); err != nil {
return
}
}
}
// ForEachNEP17Transfer executes f for each nep17 transfer in log.
func (bc *Blockchain) ForEachNEP17Transfer(acc util.Uint160, f func(*state.NEP17Transfer) (bool, error)) error {
balances, err := bc.dao.GetNEP17Balances(acc)
if err != nil {
return nil
}
for i := int(balances.NextTransferBatch); i >= 0; i-- {
lg, err := bc.dao.GetNEP17TransferLog(acc, uint32(i))
if err != nil {
return nil
}
cont, err := lg.ForEach(f)
if err != nil {
return err
}
if !cont {
break
}
}
return nil
}
// GetNEP17Balances returns NEP17 balances for the acc.
func (bc *Blockchain) GetNEP17Balances(acc util.Uint160) *state.NEP17Balances {
bs, err := bc.dao.GetNEP17Balances(acc)
if err != nil {
return nil
}
return bs
}
// GetUtilityTokenBalance returns utility token (GAS) balance for the acc.
func (bc *Blockchain) GetUtilityTokenBalance(acc util.Uint160) *big.Int {
bs, err := bc.dao.GetNEP17Balances(acc)
if err != nil {
return big.NewInt(0)
}
balance := bs.Trackers[bc.contracts.GAS.ContractID].Balance
return &balance
}
// GetGoverningTokenBalance returns governing token (NEO) balance and the height
// of the last balance change for the account.
func (bc *Blockchain) GetGoverningTokenBalance(acc util.Uint160) (*big.Int, uint32) {
bs, err := bc.dao.GetNEP17Balances(acc)
if err != nil {
return big.NewInt(0), 0
}
neo := bs.Trackers[bc.contracts.NEO.ContractID]
return &neo.Balance, neo.LastUpdatedBlock
}
// GetNotaryBalance returns Notary deposit amount for the specified account.
func (bc *Blockchain) GetNotaryBalance(acc util.Uint160) *big.Int {
return bc.contracts.Notary.BalanceOf(bc.dao, acc)
}
// GetNotaryContractScriptHash returns Notary native contract hash.
func (bc *Blockchain) GetNotaryContractScriptHash() util.Uint160 {
if bc.P2PSigExtensionsEnabled() {
return bc.contracts.Notary.Hash
}
return util.Uint160{}
}
// GetNotaryDepositExpiration returns Notary deposit expiration height for the specified account.
func (bc *Blockchain) GetNotaryDepositExpiration(acc util.Uint160) uint32 {
return bc.contracts.Notary.ExpirationOf(bc.dao, acc)
}
// LastBatch returns last persisted storage batch.
func (bc *Blockchain) LastBatch() *storage.MemBatch {
return bc.lastBatch
}
// persist flushes current in-memory Store contents to the persistent storage.
func (bc *Blockchain) persist() error {
var (
start = time.Now()
persisted int
err error
)
persisted, err = bc.dao.Persist()
if err != nil {
return err
}
if persisted > 0 {
bHeight, err := bc.dao.GetCurrentBlockHeight()
if err != nil {
return err
}
oldHeight := atomic.SwapUint32(&bc.persistedHeight, bHeight)
diff := bHeight - oldHeight
storedHeaderHeight, _, err := bc.dao.GetCurrentHeaderHeight()
if err != nil {
return err
}
bc.log.Info("blockchain persist completed",
zap.Uint32("persistedBlocks", diff),
zap.Int("persistedKeys", persisted),
zap.Uint32("headerHeight", storedHeaderHeight),
zap.Uint32("blockHeight", bHeight),
zap.Duration("took", time.Since(start)))
// update monitoring metrics.
updatePersistedHeightMetric(bHeight)
}
return nil
}
// GetTransaction returns a TX and its height by the given hash. The height is MaxUint32 if tx is in the mempool.
func (bc *Blockchain) GetTransaction(hash util.Uint256) (*transaction.Transaction, uint32, error) {
if tx, ok := bc.memPool.TryGetValue(hash); ok {
return tx, math.MaxUint32, nil // the height is not actually defined for memPool transaction.
}
return bc.dao.GetTransaction(hash)
}
// GetAppExecResults returns application execution results with the specified trigger by the given
// tx hash or block hash.
func (bc *Blockchain) GetAppExecResults(hash util.Uint256, trig trigger.Type) ([]state.AppExecResult, error) {
return bc.dao.GetAppExecResults(hash, trig)
}
// GetStorageItem returns an item from storage.
func (bc *Blockchain) GetStorageItem(id int32, key []byte) *state.StorageItem {
return bc.dao.GetStorageItem(id, key)
}
// GetStorageItems returns all storage items for a given contract id.
func (bc *Blockchain) GetStorageItems(id int32) (map[string]*state.StorageItem, error) {
return bc.dao.GetStorageItems(id)
}
// GetBlock returns a Block by the given hash.
func (bc *Blockchain) GetBlock(hash util.Uint256) (*block.Block, error) {
topBlock := bc.topBlock.Load()
if topBlock != nil {
tb := topBlock.(*block.Block)
if tb.Hash().Equals(hash) {
return tb, nil
}
}
block, err := bc.dao.GetBlock(hash)
if err != nil {
return nil, err
}
for _, tx := range block.Transactions {
stx, _, err := bc.dao.GetTransaction(tx.Hash())
if err != nil {
return nil, err
}
*tx = *stx
}
return block, nil
}
// GetHeader returns data block header identified with the given hash value.
func (bc *Blockchain) GetHeader(hash util.Uint256) (*block.Header, error) {
topBlock := bc.topBlock.Load()
if topBlock != nil {
tb := topBlock.(*block.Block)
if tb.Hash().Equals(hash) {
return tb.Header(), nil
}
}
block, err := bc.dao.GetBlock(hash)
if err != nil {
return nil, err
}
return block.Header(), nil
}
// HasTransaction returns true if the blockchain contains he given
// transaction hash.
func (bc *Blockchain) HasTransaction(hash util.Uint256) bool {
if bc.memPool.ContainsKey(hash) {
return true
}
return bc.dao.HasTransaction(hash) == dao.ErrAlreadyExists
}
// HasBlock returns true if the blockchain contains the given
// block hash.
func (bc *Blockchain) HasBlock(hash util.Uint256) bool {
if header, err := bc.GetHeader(hash); err == nil {
return header.Index <= bc.BlockHeight()
}
return false
}
// CurrentBlockHash returns the highest processed block hash.
func (bc *Blockchain) CurrentBlockHash() util.Uint256 {
topBlock := bc.topBlock.Load()
if topBlock != nil {
tb := topBlock.(*block.Block)
return tb.Hash()
}
return bc.GetHeaderHash(int(bc.BlockHeight()))
}
// CurrentHeaderHash returns the hash of the latest known header.
func (bc *Blockchain) CurrentHeaderHash() util.Uint256 {
bc.headerHashesLock.RLock()
hash := bc.headerHashes[len(bc.headerHashes)-1]
bc.headerHashesLock.RUnlock()
return hash
}
// GetHeaderHash returns hash of the header/block with specified index, if
// Blockchain doesn't have a hash for this height, zero Uint256 value is returned.
func (bc *Blockchain) GetHeaderHash(i int) util.Uint256 {
bc.headerHashesLock.RLock()
defer bc.headerHashesLock.RUnlock()
hashesLen := len(bc.headerHashes)
if hashesLen <= i {
return util.Uint256{}
}
return bc.headerHashes[i]
}
// BlockHeight returns the height/index of the highest block.
func (bc *Blockchain) BlockHeight() uint32 {
return atomic.LoadUint32(&bc.blockHeight)
}
// HeaderHeight returns the index/height of the highest header.
func (bc *Blockchain) HeaderHeight() uint32 {
bc.headerHashesLock.RLock()
n := len(bc.headerHashes)
bc.headerHashesLock.RUnlock()
return uint32(n - 1)
}
// GetContractState returns contract by its script hash.
func (bc *Blockchain) GetContractState(hash util.Uint160) *state.Contract {
contract, err := bc.contracts.Management.GetContract(bc.dao, hash)
if contract == nil && err != storage.ErrKeyNotFound {
bc.log.Warn("failed to get contract state", zap.Error(err))
}
return contract
}
// GetContractScriptHash returns contract script hash by its ID.
func (bc *Blockchain) GetContractScriptHash(id int32) (util.Uint160, error) {
return bc.dao.GetContractScriptHash(id)
}
// GetNativeContractScriptHash returns native contract script hash by its name.
func (bc *Blockchain) GetNativeContractScriptHash(name string) (util.Uint160, error) {
c := bc.contracts.ByName(name)
if c != nil {
return c.Metadata().Hash, nil
}
return util.Uint160{}, errors.New("Unknown native contract")
}
// GetConfig returns the config stored in the blockchain.
func (bc *Blockchain) GetConfig() config.ProtocolConfiguration {
return bc.config
}
// SubscribeForBlocks adds given channel to new block event broadcasting, so when
// there is a new block added to the chain you'll receive it via this channel.
// Make sure it's read from regularly as not reading these events might affect
// other Blockchain functions.
func (bc *Blockchain) SubscribeForBlocks(ch chan<- *block.Block) {
bc.subCh <- ch
}
// SubscribeForTransactions adds given channel to new transaction event
// broadcasting, so when there is a new transaction added to the chain (in a
// block) you'll receive it via this channel. Make sure it's read from regularly
// as not reading these events might affect other Blockchain functions.
func (bc *Blockchain) SubscribeForTransactions(ch chan<- *transaction.Transaction) {
bc.subCh <- ch
}
// SubscribeForNotifications adds given channel to new notifications event
// broadcasting, so when an in-block transaction execution generates a
// notification you'll receive it via this channel. Only notifications from
// successful transactions are broadcasted, if you're interested in failed
// transactions use SubscribeForExecutions instead. Make sure this channel is
// read from regularly as not reading these events might affect other Blockchain
// functions.
func (bc *Blockchain) SubscribeForNotifications(ch chan<- *state.NotificationEvent) {
bc.subCh <- ch
}
// SubscribeForExecutions adds given channel to new transaction execution event
// broadcasting, so when an in-block transaction execution happens you'll receive
// the result of it via this channel. Make sure it's read from regularly as not
// reading these events might affect other Blockchain functions.
func (bc *Blockchain) SubscribeForExecutions(ch chan<- *state.AppExecResult) {
bc.subCh <- ch
}
// UnsubscribeFromBlocks unsubscribes given channel from new block notifications,
// you can close it afterwards. Passing non-subscribed channel is a no-op.
func (bc *Blockchain) UnsubscribeFromBlocks(ch chan<- *block.Block) {
bc.unsubCh <- ch
}
// UnsubscribeFromTransactions unsubscribes given channel from new transaction
// notifications, you can close it afterwards. Passing non-subscribed channel is
// a no-op.
func (bc *Blockchain) UnsubscribeFromTransactions(ch chan<- *transaction.Transaction) {
bc.unsubCh <- ch
}
// UnsubscribeFromNotifications unsubscribes given channel from new
// execution-generated notifications, you can close it afterwards. Passing
// non-subscribed channel is a no-op.
func (bc *Blockchain) UnsubscribeFromNotifications(ch chan<- *state.NotificationEvent) {
bc.unsubCh <- ch
}
// UnsubscribeFromExecutions unsubscribes given channel from new execution
// notifications, you can close it afterwards. Passing non-subscribed channel is
// a no-op.
func (bc *Blockchain) UnsubscribeFromExecutions(ch chan<- *state.AppExecResult) {
bc.unsubCh <- ch
}
// CalculateClaimable calculates the amount of GAS generated by owning specified
// amount of NEO between specified blocks.
func (bc *Blockchain) CalculateClaimable(acc util.Uint160, endHeight uint32) (*big.Int, error) {
return bc.contracts.NEO.CalculateBonus(bc.dao, acc, endHeight)
}
// FeePerByte returns transaction network fee per byte.
func (bc *Blockchain) FeePerByte() int64 {
return bc.contracts.Policy.GetFeePerByteInternal(bc.dao)
}
// GetMemPool returns the memory pool of the blockchain.
func (bc *Blockchain) GetMemPool() *mempool.Pool {
return bc.memPool
}
// ApplyPolicyToTxSet applies configured policies to given transaction set. It
// expects slice to be ordered by fee and returns a subslice of it.
func (bc *Blockchain) ApplyPolicyToTxSet(txes []*transaction.Transaction) []*transaction.Transaction {
maxTx := bc.contracts.Policy.GetMaxTransactionsPerBlockInternal(bc.dao)
if maxTx != 0 && len(txes) > int(maxTx) {
txes = txes[:maxTx]
}
maxBlockSize := bc.contracts.Policy.GetMaxBlockSizeInternal(bc.dao)
maxBlockSysFee := bc.contracts.Policy.GetMaxBlockSystemFeeInternal(bc.dao)
var (
blockSize uint32
sysFee int64
)
blockSize = uint32(io.GetVarSize(new(block.Block)) + io.GetVarSize(len(txes)+1))
for i, tx := range txes {
blockSize += uint32(tx.Size())
sysFee += tx.SystemFee
if blockSize > maxBlockSize || sysFee > maxBlockSysFee {
txes = txes[:i]
break
}
}
return txes
}
// Various errors that could be returns upon header verification.
var (
ErrHdrHashMismatch = errors.New("previous header hash doesn't match")
ErrHdrIndexMismatch = errors.New("previous header index doesn't match")
ErrHdrInvalidTimestamp = errors.New("block is not newer than the previous one")
ErrHdrStateRootSetting = errors.New("state root setting mismatch")
ErrHdrInvalidStateRoot = errors.New("state root for previous block is invalid")
)
func (bc *Blockchain) verifyHeader(currHeader, prevHeader *block.Header) error {
if prevHeader.Hash() != currHeader.PrevHash {
return ErrHdrHashMismatch
}
if prevHeader.Index+1 != currHeader.Index {
return ErrHdrIndexMismatch
}
if prevHeader.Timestamp >= currHeader.Timestamp {
return ErrHdrInvalidTimestamp
}
return bc.verifyHeaderWitnesses(currHeader, prevHeader)
}
// Various errors that could be returned upon verification.
var (
ErrTxExpired = errors.New("transaction has expired")
ErrInsufficientFunds = errors.New("insufficient funds")
ErrTxSmallNetworkFee = errors.New("too small network fee")
ErrTxTooBig = errors.New("too big transaction")
ErrMemPoolConflict = errors.New("invalid transaction due to conflicts with the memory pool")
ErrTxInvalidWitnessNum = errors.New("number of signers doesn't match witnesses")
ErrInvalidAttribute = errors.New("invalid attribute")
)
// verifyAndPoolTx verifies whether a transaction is bonafide or not and tries
// to add it to the mempool given.
func (bc *Blockchain) verifyAndPoolTx(t *transaction.Transaction, pool *mempool.Pool, feer mempool.Feer, data ...interface{}) error {
height := bc.BlockHeight()
isPartialTx := data != nil
if t.ValidUntilBlock <= height || !isPartialTx && t.ValidUntilBlock > height+transaction.MaxValidUntilBlockIncrement {
return fmt.Errorf("%w: ValidUntilBlock = %d, current height = %d", ErrTxExpired, t.ValidUntilBlock, height)
}
// Policying.
if err := bc.contracts.Policy.CheckPolicy(bc.dao, t); err != nil {
// Only one %w can be used.
return fmt.Errorf("%w: %v", ErrPolicy, err)
}
size := t.Size()
if size > transaction.MaxTransactionSize {
return fmt.Errorf("%w: (%d > MaxTransactionSize %d)", ErrTxTooBig, size, transaction.MaxTransactionSize)
}
needNetworkFee := int64(size) * bc.FeePerByte()
if bc.P2PSigExtensionsEnabled() {
attrs := t.GetAttributes(transaction.NotaryAssistedT)
if len(attrs) != 0 {
na := attrs[0].Value.(*transaction.NotaryAssisted)
needNetworkFee += (int64(na.NKeys) + 1) * transaction.NotaryServiceFeePerKey
}
}
netFee := t.NetworkFee - needNetworkFee
if netFee < 0 {
return fmt.Errorf("%w: net fee is %v, need %v", ErrTxSmallNetworkFee, t.NetworkFee, needNetworkFee)
}
// check that current tx wasn't included in the conflicts attributes of some other transaction which is already in the chain
if err := bc.dao.HasTransaction(t.Hash()); err != nil {
switch {
case errors.Is(err, dao.ErrAlreadyExists):
return fmt.Errorf("blockchain: %w", ErrAlreadyExists)
case errors.Is(err, dao.ErrHasConflicts):
return fmt.Errorf("blockchain: %w", ErrHasConflicts)
default:
return err
}
}
err := bc.verifyTxWitnesses(t, nil, isPartialTx)
if err != nil {
return err
}
if err := bc.verifyTxAttributes(t, isPartialTx); err != nil {
return err
}
err = pool.Add(t, feer, data...)
if err != nil {
switch {
case errors.Is(err, mempool.ErrConflict):
return ErrMemPoolConflict
case errors.Is(err, mempool.ErrDup):
return fmt.Errorf("mempool: %w", ErrAlreadyExists)
case errors.Is(err, mempool.ErrInsufficientFunds):
return ErrInsufficientFunds
case errors.Is(err, mempool.ErrOOM):
return ErrOOM
case errors.Is(err, mempool.ErrConflictsAttribute):
return fmt.Errorf("mempool: %w: %s", ErrHasConflicts, err)
default:
return err
}
}
return nil
}
func (bc *Blockchain) verifyTxAttributes(tx *transaction.Transaction, isPartialTx bool) error {
for i := range tx.Attributes {
switch attrType := tx.Attributes[i].Type; attrType {
case transaction.HighPriority:
h := bc.contracts.NEO.GetCommitteeAddress()
if !tx.HasSigner(h) {
return fmt.Errorf("%w: high priority tx is not signed by committee", ErrInvalidAttribute)
}
case transaction.OracleResponseT:
h, err := bc.contracts.Oracle.GetScriptHash(bc.dao)
if err != nil || h.Equals(util.Uint160{}) {
return fmt.Errorf("%w: %v", ErrInvalidAttribute, err)
}
hasOracle := false
for i := range tx.Signers {
if tx.Signers[i].Scopes != transaction.None {
return fmt.Errorf("%w: oracle tx has invalid signer scope", ErrInvalidAttribute)
}
if tx.Signers[i].Account.Equals(h) {
hasOracle = true
}
}
if !hasOracle {
return fmt.Errorf("%w: oracle tx is not signed by oracle nodes", ErrInvalidAttribute)
}
if !bytes.Equal(tx.Script, native.GetOracleResponseScript()) {
return fmt.Errorf("%w: oracle tx has invalid script", ErrInvalidAttribute)
}
resp := tx.Attributes[i].Value.(*transaction.OracleResponse)
req, err := bc.contracts.Oracle.GetRequestInternal(bc.dao, resp.ID)
if err != nil {
return fmt.Errorf("%w: oracle tx points to invalid request: %v", ErrInvalidAttribute, err)
}
if uint64(tx.NetworkFee+tx.SystemFee) < req.GasForResponse {
return fmt.Errorf("%w: oracle tx has insufficient gas", ErrInvalidAttribute)
}
case transaction.NotValidBeforeT:
if !bc.config.P2PSigExtensions {
return fmt.Errorf("%w: NotValidBefore attribute was found, but P2PSigExtensions are disabled", ErrInvalidAttribute)
}
nvb := tx.Attributes[i].Value.(*transaction.NotValidBefore).Height
if isPartialTx {
maxNVBDelta := bc.contracts.Notary.GetMaxNotValidBeforeDelta(bc.dao)
if bc.BlockHeight()+maxNVBDelta < nvb {
return fmt.Errorf("%w: partially-filled transaction should become valid not less then %d blocks after current chain's height %d", ErrInvalidAttribute, maxNVBDelta, bc.BlockHeight())
}
if nvb+maxNVBDelta < tx.ValidUntilBlock {
return fmt.Errorf("%w: partially-filled transaction should be valid during less than %d blocks", ErrInvalidAttribute, maxNVBDelta)
}
} else {
if height := bc.BlockHeight(); height < nvb {
return fmt.Errorf("%w: transaction is not yet valid: NotValidBefore = %d, current height = %d", ErrInvalidAttribute, nvb, height)
}
}
case transaction.ConflictsT:
if !bc.config.P2PSigExtensions {
return fmt.Errorf("%w: Conflicts attribute was found, but P2PSigExtensions are disabled", ErrInvalidAttribute)
}
conflicts := tx.Attributes[i].Value.(*transaction.Conflicts)
if err := bc.dao.HasTransaction(conflicts.Hash); errors.Is(err, dao.ErrAlreadyExists) {
return fmt.Errorf("%w: conflicting transaction %s is already on chain", ErrInvalidAttribute, conflicts.Hash.StringLE())
}
case transaction.NotaryAssistedT:
if !bc.config.P2PSigExtensions {
return fmt.Errorf("%w: NotaryAssisted attribute was found, but P2PSigExtensions are disabled", ErrInvalidAttribute)
}
if !tx.HasSigner(bc.contracts.Notary.Hash) {
return fmt.Errorf("%w: NotaryAssisted attribute was found, but transaction is not signed by the Notary native contract", ErrInvalidAttribute)
}
default:
if !bc.config.ReservedAttributes && attrType >= transaction.ReservedLowerBound && attrType <= transaction.ReservedUpperBound {
return fmt.Errorf("%w: attribute of reserved type was found, but ReservedAttributes are disabled", ErrInvalidAttribute)
}
}
}
return nil
}
// IsTxStillRelevant is a callback for mempool transaction filtering after the
// new block addition. It returns false for transactions added by the new block
// (passed via txpool) and does witness reverification for non-standard
// contracts. It operates under the assumption that full transaction verification
// was already done so we don't need to check basic things like size, input/output
// correctness, presence in blocks before the new one, etc.
func (bc *Blockchain) IsTxStillRelevant(t *transaction.Transaction, txpool *mempool.Pool, isPartialTx bool) bool {
var recheckWitness bool
var curheight = bc.BlockHeight()
if t.ValidUntilBlock <= curheight {
return false
}
if txpool == nil {
if bc.dao.HasTransaction(t.Hash()) != nil {
return false
}
} else if txpool.HasConflicts(t, bc) {
return false
}
if err := bc.verifyTxAttributes(t, isPartialTx); err != nil {
return false
}
for i := range t.Scripts {
if !vm.IsStandardContract(t.Scripts[i].VerificationScript) {
recheckWitness = true
break
}
}
if recheckWitness {
return bc.verifyTxWitnesses(t, nil, isPartialTx) == nil
}
return true
}
// AddStateRoot add new (possibly unverified) state root to the blockchain.
func (bc *Blockchain) AddStateRoot(r *state.MPTRoot) error {
our, err := bc.GetStateRoot(r.Index)
if err == nil {
if our.Flag == state.Verified {
return bc.updateStateHeight(r.Index)
} else if r.Witness == nil && our.Witness != nil {
r.Witness = our.Witness
}
}
if err := bc.verifyStateRoot(r); err != nil {
return fmt.Errorf("invalid state root: %w", err)
}
if r.Index > bc.BlockHeight() { // just put it into the store for future checks
return bc.dao.PutStateRoot(&state.MPTRootState{
MPTRoot: *r,
Flag: state.Unverified,
})
}
flag := state.Unverified
if r.Witness != nil {
if err := bc.verifyStateRootWitness(r); err != nil {
return fmt.Errorf("can't verify signature: %w", err)
}
flag = state.Verified
}
err = bc.dao.PutStateRoot(&state.MPTRootState{
MPTRoot: *r,
Flag: flag,
})
if err != nil {
return err
}
return bc.updateStateHeight(r.Index)
}
func (bc *Blockchain) updateStateHeight(newHeight uint32) error {
h, err := bc.dao.GetCurrentStateRootHeight()
if err != nil {
return fmt.Errorf("can't get current state root height: %w", err)
} else if newHeight == h+1 {
updateStateHeightMetric(newHeight)
return bc.dao.PutCurrentStateRootHeight(h + 1)
}
return nil
}
// verifyStateRoot checks if state root is valid.
func (bc *Blockchain) verifyStateRoot(r *state.MPTRoot) error {
if r.Index == 0 {
return nil
}
prev, err := bc.GetStateRoot(r.Index - 1)
if err != nil {
return errors.New("can't get previous state root")
} else if !r.PrevHash.Equals(hash.DoubleSha256(prev.GetSignedPart())) {
return errors.New("previous hash mismatch")
} else if prev.Version != r.Version {
return errors.New("version mismatch")
}
return nil
}
// verifyStateRootWitness verifies that state root signature is correct.
func (bc *Blockchain) verifyStateRootWitness(r *state.MPTRoot) error {
b, err := bc.GetBlock(bc.GetHeaderHash(int(r.Index)))
if err != nil {
return err
}
return bc.VerifyWitness(b.NextConsensus, r, r.Witness, bc.contracts.Policy.GetMaxVerificationGas(bc.dao))
}
// VerifyTx verifies whether transaction is bonafide or not relative to the
// current blockchain state. Note that this verification is completely isolated
// from the main node's mempool.
func (bc *Blockchain) VerifyTx(t *transaction.Transaction) error {
var mp = mempool.New(1, 0)
bc.lock.RLock()
defer bc.lock.RUnlock()
return bc.verifyAndPoolTx(t, mp, bc)
}
// PoolTx verifies and tries to add given transaction into the mempool. If not
// given, the default mempool is used. Passing multiple pools is not supported.
func (bc *Blockchain) PoolTx(t *transaction.Transaction, pools ...*mempool.Pool) error {
var pool = bc.memPool
bc.lock.RLock()
defer bc.lock.RUnlock()
// Programmer error.
if len(pools) > 1 {
panic("too many pools given")
}
if len(pools) == 1 {
pool = pools[0]
}
return bc.verifyAndPoolTx(t, pool, bc)
}
// PoolTxWithData verifies and tries to add given transaction with additional data into the mempool.
func (bc *Blockchain) PoolTxWithData(t *transaction.Transaction, data interface{}, mp *mempool.Pool, feer mempool.Feer, verificationFunction func(bc blockchainer.Blockchainer, tx *transaction.Transaction, data interface{}) error) error {
bc.lock.RLock()
defer bc.lock.RUnlock()
if verificationFunction != nil {
err := verificationFunction(bc, t, data)
if err != nil {
return err
}
}
return bc.verifyAndPoolTx(t, mp, feer, data)
}
//GetStandByValidators returns validators from the configuration.
func (bc *Blockchain) GetStandByValidators() keys.PublicKeys {
return bc.sbCommittee[:bc.config.ValidatorsCount].Copy()
}
// GetStandByCommittee returns standby committee from the configuration.
func (bc *Blockchain) GetStandByCommittee() keys.PublicKeys {
return bc.sbCommittee.Copy()
}
// GetCommittee returns the sorted list of public keys of nodes in committee.
func (bc *Blockchain) GetCommittee() (keys.PublicKeys, error) {
pubs := bc.contracts.NEO.GetCommitteeMembers()
sort.Sort(pubs)
return pubs, nil
}
// GetValidators returns current validators.
func (bc *Blockchain) GetValidators() ([]*keys.PublicKey, error) {
return bc.contracts.NEO.ComputeNextBlockValidators(bc, bc.dao)
}
// GetNextBlockValidators returns next block validators.
func (bc *Blockchain) GetNextBlockValidators() ([]*keys.PublicKey, error) {
return bc.contracts.NEO.GetNextBlockValidatorsInternal(), nil
}
// GetEnrollments returns all registered validators.
func (bc *Blockchain) GetEnrollments() ([]state.Validator, error) {
return bc.contracts.NEO.GetCandidates(bc.dao)
}
// GetTestVM returns a VM and a Store setup for a test run of some sort of code.
func (bc *Blockchain) GetTestVM(t trigger.Type, tx *transaction.Transaction, b *block.Block) *vm.VM {
d := bc.dao.GetWrapped().(*dao.Simple)
d.MPT = nil
systemInterop := bc.newInteropContext(t, d, b, tx)
vm := systemInterop.SpawnVM()
vm.SetPriceGetter(bc.getPrice)
return vm
}
// Various witness verification errors.
var (
ErrWitnessHashMismatch = errors.New("witness hash mismatch")
ErrNativeContractWitness = errors.New("native contract witness must have empty verification script")
ErrVerificationFailed = errors.New("signature check failed")
ErrInvalidSignature = fmt.Errorf("%w: invalid signature", ErrVerificationFailed)
ErrUnknownVerificationContract = errors.New("unknown verification contract")
ErrInvalidVerificationContract = errors.New("verification contract is missing `verify` method")
)
// initVerificationVM initializes VM for witness check.
func (bc *Blockchain) initVerificationVM(ic *interop.Context, hash util.Uint160, witness *transaction.Witness) error {
v := ic.VM
if len(witness.VerificationScript) != 0 {
if witness.ScriptHash() != hash {
return ErrWitnessHashMismatch
}
if bc.contracts.ByHash(hash) != nil {
return ErrNativeContractWitness
}
v.LoadScriptWithFlags(witness.VerificationScript, smartcontract.NoneFlag)
} else {
cs, err := ic.GetContract(hash)
if err != nil {
return ErrUnknownVerificationContract
}
md := cs.Manifest.ABI.GetMethod(manifest.MethodVerify)
if md == nil {
return ErrInvalidVerificationContract
}
initMD := cs.Manifest.ABI.GetMethod(manifest.MethodInit)
v.LoadScriptWithHash(cs.Script, hash, smartcontract.ReadStates)
v.Jump(v.Context(), md.Offset)
if cs.ID <= 0 {
w := io.NewBufBinWriter()
emit.Opcodes(w.BinWriter, opcode.DEPTH, opcode.PACK)
emit.String(w.BinWriter, manifest.MethodVerify)
if w.Err != nil {
return w.Err
}
v.LoadScript(w.Bytes())
} else if initMD != nil {
v.Call(v.Context(), initMD.Offset)
}
}
v.LoadScript(witness.InvocationScript)
return nil
}
// VerifyWitness checks that w is a correct witness for c signed by h.
func (bc *Blockchain) VerifyWitness(h util.Uint160, c crypto.Verifiable, w *transaction.Witness, gas int64) error {
ic := bc.newInteropContext(trigger.Verification, bc.dao, nil, nil)
ic.Container = c
_, err := bc.verifyHashAgainstScript(h, w, ic, gas)
return err
}
// verifyHashAgainstScript verifies given hash against the given witness and returns the amount of GAS consumed.
func (bc *Blockchain) verifyHashAgainstScript(hash util.Uint160, witness *transaction.Witness, interopCtx *interop.Context, gas int64) (int64, error) {
gasPolicy := bc.contracts.Policy.GetMaxVerificationGas(interopCtx.DAO)
if gas > gasPolicy {
gas = gasPolicy
}
vm := interopCtx.SpawnVM()
vm.SetPriceGetter(bc.getPrice)
vm.GasLimit = gas
if err := bc.initVerificationVM(interopCtx, hash, witness); err != nil {
return 0, err
}
err := vm.Run()
if vm.HasFailed() {
return 0, fmt.Errorf("%w: vm execution has failed: %v", ErrVerificationFailed, err)
}
resEl := vm.Estack().Pop()
if resEl != nil {
res, err := resEl.Item().TryBool()
if err != nil {
return 0, fmt.Errorf("%w: invalid return value", ErrVerificationFailed)
}
if vm.Estack().Len() != 0 {
return 0, fmt.Errorf("%w: expected exactly one returned value", ErrVerificationFailed)
}
if !res {
return vm.GasConsumed(), ErrInvalidSignature
}
} else {
return 0, fmt.Errorf("%w: no result returned from the script", ErrVerificationFailed)
}
return vm.GasConsumed(), nil
}
// verifyTxWitnesses verifies the scripts (witnesses) that come with a given
// transaction. It can reorder them by ScriptHash, because that's required to
// match a slice of script hashes from the Blockchain. Block parameter
// is used for easy interop access and can be omitted for transactions that are
// not yet added into any block.
// Golang implementation of VerifyWitnesses method in C# (https://github.com/neo-project/neo/blob/master/neo/SmartContract/Helper.cs#L87).
func (bc *Blockchain) verifyTxWitnesses(t *transaction.Transaction, block *block.Block, isPartialTx bool) error {
if len(t.Signers) != len(t.Scripts) {
return fmt.Errorf("%w: %d vs %d", ErrTxInvalidWitnessNum, len(t.Signers), len(t.Scripts))
}
interopCtx := bc.newInteropContext(trigger.Verification, bc.dao, block, t)
gasLimit := t.NetworkFee - int64(t.Size())*bc.FeePerByte()
if bc.P2PSigExtensionsEnabled() {
attrs := t.GetAttributes(transaction.NotaryAssistedT)
if len(attrs) != 0 {
na := attrs[0].Value.(*transaction.NotaryAssisted)
gasLimit -= (int64(na.NKeys) + 1) * transaction.NotaryServiceFeePerKey
}
}
for i := range t.Signers {
gasConsumed, err := bc.verifyHashAgainstScript(t.Signers[i].Account, &t.Scripts[i], interopCtx, gasLimit)
if err != nil &&
!(i == 0 && isPartialTx && errors.Is(err, ErrInvalidSignature)) { // it's OK for partially-filled transaction with dummy first witness.
return fmt.Errorf("witness #%d: %w", i, err)
}
gasLimit -= gasConsumed
}
return nil
}
// verifyHeaderWitnesses is a block-specific implementation of VerifyWitnesses logic.
func (bc *Blockchain) verifyHeaderWitnesses(currHeader, prevHeader *block.Header) error {
var hash util.Uint160
if prevHeader == nil && currHeader.PrevHash.Equals(util.Uint256{}) {
hash = currHeader.Script.ScriptHash()
} else {
hash = prevHeader.NextConsensus
}
return bc.VerifyWitness(hash, currHeader, &currHeader.Script, verificationGasLimit)
}
// GoverningTokenHash returns the governing token (NEO) native contract hash.
func (bc *Blockchain) GoverningTokenHash() util.Uint160 {
return bc.contracts.NEO.Hash
}
// UtilityTokenHash returns the utility token (GAS) native contract hash.
func (bc *Blockchain) UtilityTokenHash() util.Uint160 {
return bc.contracts.GAS.Hash
}
// ManagementContractHash returns management contract's hash.
func (bc *Blockchain) ManagementContractHash() util.Uint160 {
return bc.contracts.Management.Hash
}
func hashAndIndexToBytes(h util.Uint256, index uint32) []byte {
buf := io.NewBufBinWriter()
buf.WriteBytes(h.BytesLE())
buf.WriteU32LE(index)
return buf.Bytes()
}
func (bc *Blockchain) newInteropContext(trigger trigger.Type, d dao.DAO, block *block.Block, tx *transaction.Transaction) *interop.Context {
ic := interop.NewContext(trigger, bc, d, bc.contracts.Management.GetContract, bc.contracts.Contracts, block, tx, bc.log)
ic.Functions = [][]interop.Function{systemInterops, neoInterops}
switch {
case tx != nil:
ic.Container = tx
case block != nil:
ic.Container = block
}
return ic
}
// P2PSigExtensionsEnabled defines whether P2P signature extensions are enabled.
func (bc *Blockchain) P2PSigExtensionsEnabled() bool {
return bc.config.P2PSigExtensions
}
// RegisterPostBlock appends provided function to the list of functions which should be run after new block
// is stored.
func (bc *Blockchain) RegisterPostBlock(f func(blockchainer.Blockchainer, *mempool.Pool, *block.Block)) {
bc.postBlock = append(bc.postBlock, f)
}
// -- start Policer.
// GetPolicer provides access to policy values via Policer interface.
func (bc *Blockchain) GetPolicer() blockchainer.Policer {
return bc
}
// GetBaseExecFee return execution price for `NOP`.
func (bc *Blockchain) GetBaseExecFee() int64 {
return bc.contracts.Policy.GetExecFeeFactorInternal(bc.dao)
}
// GetMaxBlockSize returns maximum allowed block size from native Policy contract.
func (bc *Blockchain) GetMaxBlockSize() uint32 {
return bc.contracts.Policy.GetMaxBlockSizeInternal(bc.dao)
}
// GetMaxBlockSystemFee returns maximum block system fee from native Policy contract.
func (bc *Blockchain) GetMaxBlockSystemFee() int64 {
return bc.contracts.Policy.GetMaxBlockSystemFeeInternal(bc.dao)
}
// GetMaxVerificationGAS returns maximum verification GAS Policy limit.
func (bc *Blockchain) GetMaxVerificationGAS() int64 {
return bc.contracts.Policy.GetMaxVerificationGas(bc.dao)
}
// GetStoragePrice returns current storage price.
func (bc *Blockchain) GetStoragePrice() int64 {
return bc.contracts.Policy.GetStoragePriceInternal(bc.dao)
}
// -- end Policer.