neo-go/pkg/core/blockchain.go
Roman Khimov 9571ecffac core: add proper asset issuer for UTXO assets
It just wasn't set which is wrong (AFmseVrdL9f9oyCzZefL9tG6UbvhPbdYzM was
always the issuer).
2021-02-12 00:01:00 +03:00

2509 lines
75 KiB
Go

package core
import (
"fmt"
"math"
"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/dao"
"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/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/io"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"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/pkg/errors"
"go.uber.org/zap"
)
// Tuning parameters.
const (
headerBatchCount = 2000
version = "0.0.9"
// This one comes from C# code and it's different from the constant used
// when creating an asset with Neo.Asset.Create interop call. It looks
// like 2000000 is coming from the decrementInterval, but C# code doesn't
// contain any relationship between the two, so we should follow this
// behavior.
registeredAssetLifetime = 2 * 2000000
defaultMemPoolSize = 50000
)
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")
)
var (
genAmount = []int{8, 7, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}
decrementInterval = 2000000
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
generationAmount []int
decrementInterval int
// All operations on headerList must be called from an
// headersOp to be routine safe.
headerList *HeaderHashList
// Only for operating on the headerList.
headersOp chan headersOpFunc
headersOpDone chan struct{}
// Stop synchronization mechanisms.
stopCh chan struct{}
runToExitCh chan struct{}
memPool mempool.Pool
// This lock protects concurrent access to keyCache.
keyCacheLock sync.RWMutex
// cache for block verification keys.
keyCache map[util.Uint160]map[string]*keys.PublicKey
log *zap.Logger
lastBatch *storage.MemBatch
// 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
}
type headersOpFunc func(headerList *HeaderHashList)
// 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.MaxFreeTransactionSize <= 0 {
cfg.MaxFreeTransactionSize = 0
log.Info("MaxFreeTransactionSize is not set or wrong, setting default value (unlimited)", zap.Int("MaxFreeTransactionSize", cfg.MaxFreeTransactionSize))
}
if cfg.MinimumNetworkFee < 0 {
cfg.MinimumNetworkFee = 0
log.Info("MinimumNetworkFee is not set or wrong, setting default value (0)", zap.String("MinimumNetworkFee", cfg.MinimumNetworkFee.String()))
}
if cfg.FeePerExtraByte <= 0 {
cfg.FeePerExtraByte = 0
log.Info("FeePerExtraByte is not set or wrong, setting default value", zap.Float64("FeePerExtraByte", cfg.FeePerExtraByte))
}
bc := &Blockchain{
config: cfg,
dao: dao.NewSimple(s),
headersOp: make(chan headersOpFunc),
headersOpDone: make(chan struct{}),
stopCh: make(chan struct{}),
runToExitCh: make(chan struct{}),
memPool: mempool.NewMemPool(cfg.MemPoolSize),
keyCache: make(map[util.Uint160]map[string]*keys.PublicKey),
log: log,
events: make(chan bcEvent),
subCh: make(chan interface{}),
unsubCh: make(chan interface{}),
generationAmount: genAmount,
decrementInterval: decrementInterval,
}
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.headerList = NewHeaderHashList(genesisBlock.Hash())
err = bc.dao.PutCurrentHeader(hashAndIndexToBytes(genesisBlock.Hash(), genesisBlock.Index))
if err != nil {
return err
}
if bc.config.EnableStateRoot {
if err := bc.dao.InitMPT(0, bc.config.KeepOnlyLatestState); err != nil {
return err
}
}
return bc.storeBlock(genesisBlock)
}
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 bc.config.EnableStateRoot {
if err = bc.dao.InitMPT(bHeight, bc.config.KeepOnlyLatestState); err != nil {
return errors.Wrapf(err, "can't init MPT at height %d", bHeight)
}
}
hashes, err := bc.dao.GetHeaderHashes()
if err != nil {
return err
}
bc.headerList = NewHeaderHashList(hashes...)
bc.storedHeaderCount = uint32(len(hashes))
currHeaderHeight, currHeaderHash, err := bc.dao.GetCurrentHeaderHeight()
if err != nil {
return err
}
if bc.storedHeaderCount == 0 && currHeaderHeight == 0 {
bc.headerList.Add(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 bc.headerList.Len() > 0 {
targetHash = bc.headerList.Get(bc.headerList.Len() - 1)
} else {
genesisBlock, err := createGenesisBlock(bc.config)
if err != nil {
return err
}
targetHash = genesisBlock.Hash()
bc.headerList.Add(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: %s", hash, err)
}
headers = append(headers, header)
hash = header.PrevHash
}
headerSliceReverse(headers)
for _, h := range headers {
if !h.Verify() {
return fmt.Errorf("bad header %d/%s in the storage", h.Index, h.Hash())
}
bc.headerList.Add(h.Hash())
}
}
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 op := <-bc.headersOp:
op(bc.headerList)
bc.headersOpDone <- struct{}{}
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 {
var aerIdx int
for _, tx := range event.block.Transactions {
if tx.Type == transaction.InvocationType {
aer := event.appExecResults[aerIdx]
if !aer.TxHash.Equals(tx.Hash()) {
panic("inconsistent application execution results")
}
aerIdx++
for ch := range executionFeed {
ch <- aer
}
if aer.VMState == "HALT" {
for i := range aer.Events {
for ch := range notificationFeed {
ch <- &aer.Events[i]
}
}
}
}
for ch := range txFeed {
ch <- tx
}
}
}
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() {
close(bc.stopCh)
<-bc.runToExitCh
}
// 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()
expectedHeight := bc.BlockHeight() + 1
if expectedHeight != block.Index {
return ErrInvalidBlockIndex
}
headerLen := bc.headerListLen()
if int(block.Index) == headerLen {
err := bc.addHeaders(bc.config.VerifyBlocks, block.Header())
if err != nil {
return err
}
}
if bc.config.VerifyBlocks {
err := block.Verify()
if err != nil {
return fmt.Errorf("block %s is invalid: %s", block.Hash().StringLE(), err)
}
if bc.config.VerifyTransactions {
for _, tx := range block.Transactions {
err := bc.VerifyTx(tx, block)
if err != nil {
return fmt.Errorf("transaction %s failed to verify: %s", tx.Hash().StringLE(), err)
}
}
}
}
return bc.storeBlock(block)
}
// 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) (err error) {
var (
start = time.Now()
batch = bc.dao.Store.Batch()
)
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: %v", err)
}
for _, h := range headers {
if err = bc.verifyHeader(h, lastHeader); err != nil {
return
}
lastHeader = h
}
}
bc.headersOp <- func(headerList *HeaderHashList) {
oldlen := headerList.Len()
for _, h := range headers {
if int(h.Index-1) >= headerList.Len() {
err = fmt.Errorf(
"height of received header %d is higher then the current header %d",
h.Index, headerList.Len(),
)
return
}
if int(h.Index) < headerList.Len() {
continue
}
if !h.Verify() {
err = fmt.Errorf("header %v is invalid", h)
return
}
if err = bc.processHeader(h, batch, headerList); err != nil {
return
}
}
if oldlen != headerList.Len() {
updateHeaderHeightMetric(headerList.Len() - 1)
if err = bc.dao.Store.PutBatch(batch); err != nil {
return
}
bc.log.Debug("done processing headers",
zap.Int("headerIndex", headerList.Len()-1),
zap.Uint32("blockHeight", bc.BlockHeight()),
zap.Duration("took", time.Since(start)))
}
}
<-bc.headersOpDone
return err
}
// processHeader processes the given header. Note that this is only thread safe
// if executed in headers operation.
func (bc *Blockchain) processHeader(h *block.Header, batch storage.Batch, headerList *HeaderHashList) error {
headerList.Add(h.Hash())
buf := io.NewBufBinWriter()
for int(h.Index)-headerBatchCount >= int(bc.storedHeaderCount) {
if err := headerList.Write(buf.BinWriter, int(bc.storedHeaderCount), headerBatchCount); err != nil {
return err
}
key := storage.AppendPrefixInt(storage.IXHeaderHashList, int(bc.storedHeaderCount))
batch.Put(key, buf.Bytes())
bc.storedHeaderCount += headerBatchCount
buf.Reset()
}
buf.Reset()
buf.BinWriter.WriteU32LE(0) // sys fee is yet to be calculated
h.EncodeBinary(buf.BinWriter)
if buf.Err != nil {
return buf.Err
}
key := storage.AppendPrefix(storage.DataBlock, h.Hash().BytesLE())
batch.Put(key, buf.Bytes())
batch.Put(storage.SYSCurrentHeader.Bytes(), hashAndIndexToBytes(h.Hash(), h.Index))
return nil
}
// bc.GetHeaderHash(int(endHeight)) returns sum of all system fees for blocks up to h.
// and 0 if no such block exists.
func (bc *Blockchain) getSystemFeeAmount(h util.Uint256) uint32 {
_, sf, _ := bc.dao.GetBlock(h)
return sf
}
// GetStateProof returns proof of having key in the MPT with the specified root.
func (bc *Blockchain) GetStateProof(root util.Uint256, key []byte) ([][]byte, error) {
if !bc.config.EnableStateRoot {
return nil, errors.New("state root feature is not enabled")
}
tr := mpt.NewTrie(mpt.NewHashNode(root), bc.config.KeepOnlyLatestState, 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) {
if !bc.config.EnableStateRoot {
return nil, errors.New("state root feature is not enabled")
}
return bc.dao.GetStateRoot(height)
}
// TODO: storeBlock needs some more love, its implemented as in the original
// project. This for the sake of development speed and understanding of what
// is happening here, quite allot as you can see :). If things are wired together
// and all tests are in place, we can make a more optimized and cleaner implementation.
func (bc *Blockchain) storeBlock(block *block.Block) error {
cache := dao.NewCached(bc.dao)
appExecResults := make([]*state.AppExecResult, 0, len(block.Transactions))
fee := bc.getSystemFeeAmount(block.PrevHash)
for _, tx := range block.Transactions {
fee += uint32(bc.SystemFee(tx).IntegralValue())
}
if err := cache.StoreAsBlock(block, fee); err != nil {
return err
}
if err := cache.StoreAsCurrentBlock(block); err != nil {
return err
}
for _, tx := range block.Transactions {
if err := cache.StoreAsTransaction(tx, block.Index); err != nil {
return err
}
if err := cache.PutUnspentCoinState(tx.Hash(), state.NewUnspentCoin(block.Index, tx)); err != nil {
return err
}
// Process TX outputs.
if err := processOutputs(tx, block, cache); err != nil {
return err
}
// Process TX inputs that are grouped by previous hash.
for _, inputs := range transaction.GroupInputsByPrevHash(tx.Inputs) {
prevHash := inputs[0].PrevHash
unspent, err := cache.GetUnspentCoinState(prevHash)
if err != nil {
return err
}
for _, input := range inputs {
if len(unspent.States) <= int(input.PrevIndex) {
return fmt.Errorf("bad input: %s/%d", input.PrevHash.StringLE(), input.PrevIndex)
}
if unspent.States[input.PrevIndex].State&state.CoinSpent != 0 {
return fmt.Errorf("double spend: %s/%d", input.PrevHash.StringLE(), input.PrevIndex)
}
unspent.States[input.PrevIndex].State |= state.CoinSpent
unspent.States[input.PrevIndex].SpendHeight = block.Index
prevTXOutput := &unspent.States[input.PrevIndex].Output
if err := processTransfer(cache, tx, block, prevTXOutput, true); err != nil {
return err
}
account, err := cache.GetAccountStateOrNew(prevTXOutput.ScriptHash)
if err != nil {
return err
}
if prevTXOutput.AssetID.Equals(GoverningTokenID()) {
err = account.Unclaimed.Put(&state.UnclaimedBalance{
Tx: input.PrevHash,
Index: input.PrevIndex,
Start: unspent.Height,
End: block.Index,
Value: prevTXOutput.Amount,
})
if err != nil {
return err
}
if err = processTXWithValidatorsSubtract(prevTXOutput, account, cache); err != nil {
return err
}
}
balancesLen := len(account.Balances[prevTXOutput.AssetID])
if balancesLen <= 1 {
delete(account.Balances, prevTXOutput.AssetID)
} else {
var index = -1
for i, balance := range account.Balances[prevTXOutput.AssetID] {
if balance.Tx.Equals(input.PrevHash) && balance.Index == input.PrevIndex {
index = i
break
}
}
if index >= 0 {
last := balancesLen - 1
if last > index {
account.Balances[prevTXOutput.AssetID][index] = account.Balances[prevTXOutput.AssetID][last]
}
account.Balances[prevTXOutput.AssetID] = account.Balances[prevTXOutput.AssetID][:last]
}
}
if err = cache.PutAccountState(account); err != nil {
return err
}
}
if err = cache.PutUnspentCoinState(prevHash, unspent); err != nil {
return err
}
}
// Process the underlying type of the TX.
switch t := tx.Data.(type) {
case *transaction.RegisterTX:
err := cache.PutAssetState(&state.Asset{
ID: tx.Hash(),
AssetType: t.AssetType,
Name: t.Name,
Amount: t.Amount,
Precision: t.Precision,
Owner: t.Owner,
Admin: t.Admin,
Issuer: t.Admin,
Expiration: bc.BlockHeight() + registeredAssetLifetime,
})
if err != nil {
return err
}
case *transaction.IssueTX:
for _, res := range bc.GetTransactionResults(tx) {
if res.Amount < 0 {
asset, err := cache.GetAssetState(res.AssetID)
if asset == nil || err != nil {
return fmt.Errorf("issue failed: no asset %s or error %s", res.AssetID, err)
}
asset.Available -= res.Amount
if err := cache.PutAssetState(asset); err != nil {
return err
}
}
}
case *transaction.ClaimTX:
// Remove claimed NEO from spent coins making it unavalaible for
// additional claims.
for _, input := range t.Claims {
scs, err := cache.GetUnspentCoinState(input.PrevHash)
if err == nil {
if len(scs.States) <= int(input.PrevIndex) {
err = errors.New("invalid claim index")
} else if scs.States[input.PrevIndex].State&state.CoinClaimed != 0 {
err = errors.New("double claim")
}
}
if err != nil {
// We can't really do anything about it
// as it's a transaction in a signed block.
bc.log.Warn("FALSE OR DOUBLE CLAIM",
zap.String("PrevHash", input.PrevHash.StringLE()),
zap.Uint16("PrevIndex", input.PrevIndex),
zap.String("tx", tx.Hash().StringLE()),
zap.Uint32("block", block.Index),
)
// "Strict" mode.
if bc.config.VerifyTransactions {
return err
}
break
}
acc, err := cache.GetAccountState(scs.States[input.PrevIndex].ScriptHash)
if err != nil {
return err
}
scs.States[input.PrevIndex].State |= state.CoinClaimed
if err = cache.PutUnspentCoinState(input.PrevHash, scs); err != nil {
return err
}
changed := acc.Unclaimed.Remove(input.PrevHash, input.PrevIndex)
if !changed {
bc.log.Warn("no spent coin in the account",
zap.String("tx", tx.Hash().StringLE()),
zap.String("input", input.PrevHash.StringLE()),
zap.String("account", acc.ScriptHash.String()))
} else if err := cache.PutAccountState(acc); err != nil {
return err
}
}
case *transaction.EnrollmentTX:
if err := processEnrollmentTX(cache, t); err != nil {
return err
}
case *transaction.StateTX:
if err := processStateTX(cache, t); err != nil {
return err
}
case *transaction.PublishTX:
var properties smartcontract.PropertyState
if t.NeedStorage {
properties |= smartcontract.HasStorage
}
contract := &state.Contract{
Script: t.Script,
ParamList: t.ParamList,
ReturnType: t.ReturnType,
Properties: properties,
Name: t.Name,
CodeVersion: t.CodeVersion,
Author: t.Author,
Email: t.Email,
Description: t.Description,
}
if err := cache.PutContractState(contract); err != nil {
return err
}
case *transaction.InvocationTX:
systemInterop := bc.newInteropContext(trigger.Application, cache, block, tx)
v := systemInterop.SpawnVM()
v.SetCheckedHash(tx.VerificationHash().BytesBE())
v.LoadScript(t.Script)
v.SetPriceGetter(getPrice)
gasLimit := bc.config.GetFreeGas(block.Index)
if gasLimit > 0 {
v.SetGasLimit(gasLimit + t.Gas)
}
err := v.Run()
if !v.HasFailed() {
_, err := systemInterop.dao.Persist()
if err != nil {
return errors.Wrap(err, "failed to persist invocation results")
}
var index uint32
for _, note := range systemInterop.notifications {
transfer, err := state.NEP5TransferFromNotification(note, tx.Hash(), block.Index, block.Timestamp, index)
if err != nil {
continue
}
bc.processNEP5Transfer(cache, transfer)
index++
}
} else {
bc.log.Warn("contract invocation failed",
zap.String("tx", tx.Hash().StringLE()),
zap.Uint32("block", block.Index),
zap.Error(err))
}
aer := &state.AppExecResult{
TxHash: tx.Hash(),
Trigger: trigger.Application,
VMState: v.State(),
GasConsumed: v.GasConsumed(),
Stack: v.Estack().ToContractParameters(),
Events: systemInterop.notifications,
}
appExecResults = append(appExecResults, aer)
err = cache.PutAppExecResult(aer)
if err != nil {
return errors.Wrap(err, "failed to Store notifications")
}
}
}
if bc.config.EnableStateRoot {
root := bc.dao.MPT.StateRoot()
var prevHash util.Uint256
if block.Index > 0 {
prev, err := bc.dao.GetStateRoot(block.Index - 1)
if err != nil {
return errors.WithMessagef(err, "can't get previous state root")
}
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()
}
bc.lock.Lock()
_, err := cache.Persist()
if err != nil {
bc.lock.Unlock()
return err
}
if bc.config.EnableStateRoot {
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(bc.isTxStillRelevant, block.Index)
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 appendSingleTransfer(cache *dao.Cached, acc util.Uint160, tr *state.Transfer) error {
index, err := cache.GetNextTransferBatch(acc)
if err != nil {
return err
}
isBig, err := cache.AppendTransfer(acc, index, tr)
if err != nil {
return err
}
if isBig {
if err := cache.PutNextTransferBatch(acc, index+1); err != nil {
return err
}
}
return nil
}
// processTransfer processes single UTXO transfer. Totals is a slice of neo (0) and gas (1) total transfer amount.
func processTransfer(cache *dao.Cached, tx *transaction.Transaction, b *block.Block, out *transaction.Output,
isSent bool) error {
isGoverning := out.AssetID.Equals(GoverningTokenID())
if !isGoverning && !out.AssetID.Equals(UtilityTokenID()) {
return nil
}
var amount = int64(out.Amount)
// NEO has no fractional part and Fixed8 representation is just misleading here.
if isGoverning {
amount = out.Amount.IntegralValue()
}
tr := &state.Transfer{
IsGoverning: isGoverning,
IsSent: isSent,
Amount: amount,
Block: b.Index,
Timestamp: b.Timestamp,
Tx: tx.Hash(),
}
index, err := cache.GetNextTransferBatch(out.ScriptHash)
if err != nil {
return err
}
isBig, err := cache.AppendTransfer(out.ScriptHash, index, tr)
if err != nil {
return err
}
if isBig {
return cache.PutNextTransferBatch(out.ScriptHash, index+1)
}
return nil
}
func (bc *Blockchain) processNEP5Transfer(cache *dao.Cached, transfer *state.NEP5Transfer) {
if !transfer.From.Equals(util.Uint160{}) {
balances, err := cache.GetNEP5Balances(transfer.From)
if err != nil {
return
}
bs := balances.Trackers[transfer.Asset]
bs.Balance -= transfer.Amount
bs.LastUpdatedBlock = transfer.Block
balances.Trackers[transfer.Asset] = bs
transfer.Amount = -transfer.Amount
isBig, err := cache.AppendNEP5Transfer(transfer.From, balances.NextTransferBatch, transfer)
if err != nil {
return
}
transfer.Amount = -transfer.Amount
if isBig {
balances.NextTransferBatch++
}
if err := cache.PutNEP5Balances(transfer.From, balances); err != nil {
return
}
}
if !transfer.To.Equals(util.Uint160{}) {
balances, err := cache.GetNEP5Balances(transfer.To)
if err != nil {
return
}
bs := balances.Trackers[transfer.Asset]
bs.Balance += transfer.Amount
bs.LastUpdatedBlock = transfer.Block
balances.Trackers[transfer.Asset] = bs
isBig, err := cache.AppendNEP5Transfer(transfer.To, balances.NextTransferBatch, transfer)
if err != nil {
return
}
if isBig {
balances.NextTransferBatch++
}
if err := cache.PutNEP5Balances(transfer.To, balances); err != nil {
return
}
}
}
// ForEachTransfer executes f for each transfer in log.
func (bc *Blockchain) ForEachTransfer(acc util.Uint160, tr *state.Transfer, f func() (bool, error)) error {
nb, err := bc.dao.GetNextTransferBatch(acc)
if err != nil {
return nil
}
for i := int(nb); i >= 0; i-- {
lg, err := bc.dao.GetTransferLog(acc, uint32(i))
if err != nil {
return nil
}
cont, err := lg.ForEach(state.TransferSize, tr, f)
if err != nil {
return err
}
if !cont {
break
}
}
return nil
}
// ForEachNEP5Transfer executes f for each nep5 transfer in log.
func (bc *Blockchain) ForEachNEP5Transfer(acc util.Uint160, tr *state.NEP5Transfer, f func() (bool, error)) error {
balances, err := bc.dao.GetNEP5Balances(acc)
if err != nil {
return nil
}
for i := int(balances.NextTransferBatch); i >= 0; i-- {
lg, err := bc.dao.GetNEP5TransferLog(acc, uint32(i))
if err != nil {
return nil
}
cont, err := lg.ForEach(state.NEP5TransferSize, tr, f)
if err != nil {
return err
}
if !cont {
break
}
}
return nil
}
// GetNEP5Balances returns NEP5 balances for the acc.
func (bc *Blockchain) GetNEP5Balances(acc util.Uint160) *state.NEP5Balances {
bs, err := bc.dao.GetNEP5Balances(acc)
if err != nil {
return nil
}
return bs
}
// GetNEP5Metadata returns NEP5 metadata for the contract h.
// Note: it is currently saved only for migrated contracts.
func (bc *Blockchain) GetNEP5Metadata(h util.Uint160) (*state.NEP5Metadata, error) {
return bc.dao.GetNEP5Metadata(h)
}
// LastBatch returns last persisted storage batch.
func (bc *Blockchain) LastBatch() *storage.MemBatch {
return bc.lastBatch
}
// processOutputs processes transaction outputs.
func processOutputs(tx *transaction.Transaction, b *block.Block, dao *dao.Cached) error {
for index, output := range tx.Outputs {
account, err := dao.GetAccountStateOrNew(output.ScriptHash)
if err != nil {
return err
}
account.Balances[output.AssetID] = append(account.Balances[output.AssetID], state.UnspentBalance{
Tx: tx.Hash(),
Index: uint16(index),
Value: output.Amount,
})
if err = dao.PutAccountState(account); err != nil {
return err
}
if err = processTXWithValidatorsAdd(&output, account, dao); err != nil {
return err
}
if err = processTransfer(dao, tx, b, &output, false); err != nil {
return err
}
}
return nil
}
func processTXWithValidatorsAdd(output *transaction.Output, account *state.Account, dao *dao.Cached) error {
if output.AssetID.Equals(GoverningTokenID()) && len(account.Votes) > 0 {
return modAccountVotes(account, dao, output.Amount)
}
return nil
}
func processTXWithValidatorsSubtract(output *transaction.Output, account *state.Account, dao *dao.Cached) error {
if output.AssetID.Equals(GoverningTokenID()) && len(account.Votes) > 0 {
return modAccountVotes(account, dao, -output.Amount)
}
return nil
}
// modAccountVotes adds given value to given account voted validators.
func modAccountVotes(account *state.Account, dao *dao.Cached, value util.Fixed8) error {
for _, vote := range account.Votes {
validator, err := dao.GetValidatorStateOrNew(vote)
if err != nil {
return err
}
validator.Votes += value
if validator.UnregisteredAndHasNoVotes() {
if err := dao.DeleteValidatorState(validator); err != nil {
return err
}
} else {
if err := dao.PutValidatorState(validator); err != nil {
return err
}
}
}
if len(account.Votes) > 0 {
vc, err := dao.GetValidatorsCount()
if err != nil {
return err
}
vc[len(account.Votes)-1] += value
err = dao.PutValidatorsCount(vc)
if err != nil {
return err
}
}
return nil
}
func processValidatorStateDescriptor(descriptor *transaction.StateDescriptor, dao *dao.Cached) error {
publicKey := &keys.PublicKey{}
err := publicKey.DecodeBytes(descriptor.Key)
if err != nil {
return err
}
validatorState, err := dao.GetValidatorStateOrNew(publicKey)
if err != nil {
return err
}
if descriptor.Field == "Registered" {
if len(descriptor.Value) == 1 {
validatorState.Registered = descriptor.Value[0] != 0
return dao.PutValidatorState(validatorState)
}
return errors.New("bad descriptor value")
}
return nil
}
func processAccountStateDescriptor(descriptor *transaction.StateDescriptor, dao *dao.Cached) error {
hash, err := util.Uint160DecodeBytesBE(descriptor.Key)
if err != nil {
return err
}
account, err := dao.GetAccountStateOrNew(hash)
if err != nil {
return err
}
if descriptor.Field == "Votes" {
balance := account.GetBalanceValues()[GoverningTokenID()]
if err = modAccountVotes(account, dao, -balance); err != nil {
return err
}
votes := keys.PublicKeys{}
err := votes.DecodeBytes(descriptor.Value)
if err != nil {
return err
}
if len(votes) > state.MaxValidatorsVoted {
return errors.New("voting candidate limit exceeded")
}
if len(votes) > 0 {
account.Votes = votes
for _, vote := range account.Votes {
validatorState, err := dao.GetValidatorStateOrNew(vote)
if err != nil {
return err
}
validatorState.Votes += balance
if err = dao.PutValidatorState(validatorState); err != nil {
return err
}
}
vc, err := dao.GetValidatorsCount()
if err != nil {
return err
}
vc[len(account.Votes)-1] += balance
err = dao.PutValidatorsCount(vc)
if err != nil {
return err
}
} else {
account.Votes = nil
}
return dao.PutAccountState(account)
}
return nil
}
// 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
}
func (bc *Blockchain) headerListLen() (n int) {
bc.headersOp <- func(headerList *HeaderHashList) {
n = headerList.Len()
}
<-bc.headersOpDone
return
}
// 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)
}
// GetAppExecResult returns application execution result by the given
// tx hash.
func (bc *Blockchain) GetAppExecResult(hash util.Uint256) (*state.AppExecResult, error) {
return bc.dao.GetAppExecResult(hash)
}
// GetStorageItem returns an item from storage.
func (bc *Blockchain) GetStorageItem(scripthash util.Uint160, key []byte) *state.StorageItem {
return bc.dao.GetStorageItem(scripthash, key)
}
// GetStorageItems returns all storage items for a given scripthash.
func (bc *Blockchain) GetStorageItems(hash util.Uint160) (map[string]*state.StorageItem, error) {
siMap, err := bc.dao.GetStorageItems(hash, nil)
if err != nil {
return nil, err
}
m := make(map[string]*state.StorageItem)
for i := range siMap {
val := siMap[i].StorageItem
m[string(siMap[i].Key)] = &val
}
return m, nil
}
// 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 {
if tb, ok := topBlock.(*block.Block); ok && tb.Hash().Equals(hash) {
return tb, nil
}
}
block, _, err := bc.dao.GetBlock(hash)
if err != nil {
return nil, err
}
if len(block.Transactions) == 0 {
return nil, fmt.Errorf("only header is available")
}
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 {
if tb, ok := topBlock.(*block.Block); ok && 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 {
return bc.memPool.ContainsKey(hash) || bc.dao.HasTransaction(hash)
}
// 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() (hash util.Uint256) {
bc.headersOp <- func(headerList *HeaderHashList) {
hash = headerList.Get(int(bc.BlockHeight()))
}
<-bc.headersOpDone
return
}
// CurrentHeaderHash returns the hash of the latest known header.
func (bc *Blockchain) CurrentHeaderHash() (hash util.Uint256) {
bc.headersOp <- func(headerList *HeaderHashList) {
hash = headerList.Last()
}
<-bc.headersOpDone
return
}
// GetHeaderHash returns the hash from the headerList by its
// height/index.
func (bc *Blockchain) GetHeaderHash(i int) (hash util.Uint256) {
bc.headersOp <- func(headerList *HeaderHashList) {
hash = headerList.Get(i)
}
<-bc.headersOpDone
return
}
// 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 {
return uint32(bc.headerListLen() - 1)
}
// GetAssetState returns asset state from its assetID.
func (bc *Blockchain) GetAssetState(assetID util.Uint256) *state.Asset {
asset, err := bc.dao.GetAssetState(assetID)
if asset == nil && err != storage.ErrKeyNotFound {
bc.log.Warn("failed to get asset state",
zap.Stringer("asset", assetID),
zap.Error(err))
}
return asset
}
// GetContractState returns contract by its script hash.
func (bc *Blockchain) GetContractState(hash util.Uint160) *state.Contract {
contract, err := bc.dao.GetContractState(hash)
if contract == nil && err != storage.ErrKeyNotFound {
bc.log.Warn("failed to get contract state", zap.Error(err))
}
return contract
}
// GetAccountState returns the account state from its script hash.
func (bc *Blockchain) GetAccountState(scriptHash util.Uint160) *state.Account {
as, err := bc.dao.GetAccountState(scriptHash)
if as == nil && err != storage.ErrKeyNotFound {
bc.log.Warn("failed to get account state", zap.Error(err))
}
return as
}
// GetUnspentCoinState returns unspent coin state for given tx hash.
func (bc *Blockchain) GetUnspentCoinState(hash util.Uint256) *state.UnspentCoin {
ucs, err := bc.dao.GetUnspentCoinState(hash)
if ucs == nil && err != storage.ErrKeyNotFound {
bc.log.Warn("failed to get unspent coin state", zap.Error(err))
}
return ucs
}
// 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 which can be claimed for a transaction with value.
// First return value is GAS generated between startHeight and endHeight.
// Second return value is GAS returned from accumulated SystemFees between startHeight and endHeight.
func (bc *Blockchain) CalculateClaimable(value util.Fixed8, startHeight, endHeight uint32) (util.Fixed8, util.Fixed8, error) {
var amount util.Fixed8
di := uint32(bc.decrementInterval)
ustart := startHeight / di
if genSize := uint32(len(bc.generationAmount)); ustart < genSize {
uend := endHeight / di
iend := endHeight % di
if uend >= genSize {
uend = genSize - 1
iend = di
} else if iend == 0 {
uend--
iend = di
}
istart := startHeight % di
for ustart < uend {
amount += util.Fixed8(di-istart) * util.Fixed8(bc.generationAmount[ustart])
ustart++
istart = 0
}
amount += util.Fixed8(iend-istart) * util.Fixed8(bc.generationAmount[ustart])
}
if startHeight == 0 {
startHeight++
}
h := bc.GetHeaderHash(int(startHeight - 1))
feeStart := bc.getSystemFeeAmount(h)
h = bc.GetHeaderHash(int(endHeight - 1))
feeEnd := bc.getSystemFeeAmount(h)
sysFeeTotal := util.Fixed8(feeEnd - feeStart)
ratio := value / 100000000
return amount * ratio, sysFeeTotal * ratio, nil
}
// References maps transaction's inputs into a slice of InOuts, effectively
// joining each Input with the corresponding Output.
// @TODO: unfortunately we couldn't attach this method to the Transaction struct in the
// transaction package because of a import cycle problem. Perhaps we should think to re-design
// the code base to avoid this situation.
func (bc *Blockchain) References(t *transaction.Transaction) ([]transaction.InOut, error) {
return bc.references(t.Inputs)
}
// references is an internal implementation of References that operates directly
// on a slice of Input.
func (bc *Blockchain) references(ins []transaction.Input) ([]transaction.InOut, error) {
references := make([]transaction.InOut, 0, len(ins))
for _, inputs := range transaction.GroupInputsByPrevHash(ins) {
prevHash := inputs[0].PrevHash
unspent, err := bc.dao.GetUnspentCoinState(prevHash)
if err != nil {
return nil, errors.New("bad input reference")
}
for _, in := range inputs {
if int(in.PrevIndex) > len(unspent.States)-1 {
return nil, errors.New("bad input reference")
}
references = append(references, transaction.InOut{In: *in, Out: unspent.States[in.PrevIndex].Output})
}
}
return references, nil
}
// FeePerByte returns network fee divided by the size of the transaction.
func (bc *Blockchain) FeePerByte(t *transaction.Transaction) util.Fixed8 {
return bc.NetworkFee(t).Div(int64(io.GetVarSize(t)))
}
// NetworkFee returns network fee.
func (bc *Blockchain) NetworkFee(t *transaction.Transaction) util.Fixed8 {
// https://github.com/neo-project/neo/blob/master-2.x/neo/Network/P2P/Payloads/ClaimTransaction.cs#L16
if t.Type == transaction.ClaimType || t.Type == transaction.MinerType {
return 0
}
inputAmount := util.Fixed8FromInt64(0)
refs, err := bc.References(t)
if err != nil {
return inputAmount
}
for i := range refs {
if refs[i].Out.AssetID == UtilityTokenID() {
inputAmount = inputAmount.Add(refs[i].Out.Amount)
}
}
outputAmount := util.Fixed8FromInt64(0)
for _, txOutput := range t.Outputs {
if txOutput.AssetID == UtilityTokenID() {
outputAmount = outputAmount.Add(txOutput.Amount)
}
}
return inputAmount.Sub(outputAmount).Sub(bc.SystemFee(t))
}
// SystemFee returns system fee.
func (bc *Blockchain) SystemFee(t *transaction.Transaction) util.Fixed8 {
if t.Type == transaction.InvocationType {
inv := t.Data.(*transaction.InvocationTX)
if inv.Version >= 1 {
return inv.Gas
}
}
return bc.GetConfig().SystemFee.TryGetValue(t.Type)
}
// IsLowPriority checks given fee for being less than configured
// LowPriorityThreshold.
func (bc *Blockchain) IsLowPriority(fee util.Fixed8) bool {
return fee < util.Fixed8FromFloat(bc.GetConfig().LowPriorityThreshold)
}
// 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 []mempool.TxWithFee) []mempool.TxWithFee {
maxTx := bc.config.GetMaxTxPerBlock(bc.BlockHeight())
if maxTx != 0 && len(txes) > maxTx {
txes = txes[:maxTx]
}
maxFree := bc.config.GetMaxFreeTxPerBlock(bc.BlockHeight())
if maxFree != 0 && len(txes) > maxFree {
// Transactions are sorted by fee, so we just find the first free one.
freeStart := sort.Search(len(txes), func(i int) bool {
return txes[i].Fee == 0
})
if freeStart+maxFree < len(txes) {
txes = txes[:freeStart+maxFree]
}
}
return txes
}
func (bc *Blockchain) verifyHeader(currHeader, prevHeader *block.Header) error {
if prevHeader.Hash() != currHeader.PrevHash {
return errors.New("previous header hash doesn't match")
}
if prevHeader.Index+1 != currHeader.Index {
return errors.New("previous header index doesn't match")
}
if prevHeader.Timestamp >= currHeader.Timestamp {
return errors.New("block is not newer than the previous one")
}
return bc.verifyHeaderWitnesses(currHeader, prevHeader)
}
// verifyTx verifies whether a transaction is bonafide or not.
func (bc *Blockchain) verifyTx(t *transaction.Transaction, block *block.Block) error {
if io.GetVarSize(t) > transaction.MaxTransactionSize {
return errors.Errorf("invalid transaction size = %d. It shoud be less then MaxTransactionSize = %d", io.GetVarSize(t), transaction.MaxTransactionSize)
}
if transaction.HaveDuplicateInputs(t.Inputs) {
return errors.New("invalid transaction's inputs")
}
if block == nil {
if ok := bc.memPool.Verify(t); !ok {
return errors.New("invalid transaction due to conflicts with the memory pool")
}
}
if bc.dao.IsDoubleSpend(t) {
return errors.New("invalid transaction caused by double spending")
}
if err := bc.verifyOutputs(t); err != nil {
return errors.Wrap(err, "wrong outputs")
}
refs, err := bc.References(t)
if err != nil {
return err
}
results := refsAndOutsToResults(refs, t.Outputs)
if err := bc.verifyResults(t, results); err != nil {
return err
}
for _, a := range t.Attributes {
if a.Usage == transaction.ECDH02 || a.Usage == transaction.ECDH03 {
return errors.Errorf("invalid attribute's usage = %s ", a.Usage)
}
}
switch t.Type {
case transaction.ClaimType:
claim := t.Data.(*transaction.ClaimTX)
if transaction.HaveDuplicateInputs(claim.Claims) {
return errors.New("duplicate claims")
}
if bc.dao.IsDoubleClaim(claim) {
return errors.New("double claim")
}
if err := bc.verifyClaims(t, results); err != nil {
return err
}
case transaction.InvocationType:
inv := t.Data.(*transaction.InvocationTX)
if inv.Gas.FractionalValue() != 0 {
return errors.New("invocation gas can only be integer")
}
case transaction.StateType:
stx := t.Data.(*transaction.StateTX)
for _, desc := range stx.Descriptors {
switch desc.Type {
case transaction.Account:
if desc.Field != "Votes" {
return errors.New("bad field in account descriptor")
}
votes := keys.PublicKeys{}
err := votes.DecodeBytes(desc.Value)
if err != nil {
return err
}
if len(votes) > state.MaxValidatorsVoted {
return errors.New("voting candidate limit exceeded")
}
hash, err := util.Uint160DecodeBytesBE(desc.Key)
if err != nil {
return err
}
account, err := bc.dao.GetAccountStateOrNew(hash)
if err != nil {
return err
}
if account.IsFrozen {
return errors.New("account is frozen")
}
if votes.Len() > 0 {
balance := account.GetBalanceValues()[GoverningTokenID()]
if balance == 0 {
return errors.New("no governing tokens available to vote")
}
validators, err := bc.GetEnrollments()
if err != nil {
return err
}
for _, k := range votes {
var isRegistered bool
for i := range validators {
if k.Equal(validators[i].PublicKey) {
isRegistered = true
break
}
}
if !isRegistered {
return errors.New("vote for unregistered validator")
}
}
}
case transaction.Validator:
if desc.Field != "Registered" {
return errors.New("bad field in validator descriptor")
}
default:
return errors.New("bad descriptor type")
}
}
}
return bc.verifyTxWitnesses(t, block)
}
func (bc *Blockchain) verifyClaims(tx *transaction.Transaction, results []*transaction.Result) (err error) {
t := tx.Data.(*transaction.ClaimTX)
var result *transaction.Result
for i := range results {
if results[i].AssetID == UtilityTokenID() {
result = results[i]
break
}
}
if result == nil || result.Amount.GreaterThan(0) {
return errors.New("invalid output in claim tx")
}
bonus, err := bc.calculateBonus(t.Claims)
if err == nil && bonus != -result.Amount {
return fmt.Errorf("wrong bonus calculated in claim tx: %s != %s",
bonus.String(), (-result.Amount).String())
}
return err
}
func (bc *Blockchain) calculateBonus(claims []transaction.Input) (util.Fixed8, error) {
unclaimed := []*spentCoin{}
inputs := transaction.GroupInputsByPrevHash(claims)
for _, group := range inputs {
h := group[0].PrevHash
unspent, err := bc.dao.GetUnspentCoinState(h)
if err != nil {
return 0, err
}
for _, c := range group {
if len(unspent.States) <= int(c.PrevIndex) {
return 0, fmt.Errorf("can't find spent coins for %s (%d)", c.PrevHash.StringLE(), c.PrevIndex)
}
if unspent.States[c.PrevIndex].State&state.CoinSpent == 0 {
return 0, fmt.Errorf("not spent yet: %s/%d", c.PrevHash.StringLE(), c.PrevIndex)
}
if unspent.States[c.PrevIndex].State&state.CoinClaimed != 0 {
return 0, fmt.Errorf("already claimed: %s/%d", c.PrevHash.StringLE(), c.PrevIndex)
}
unclaimed = append(unclaimed, &spentCoin{
Output: &unspent.States[c.PrevIndex].Output,
StartHeight: unspent.Height,
EndHeight: unspent.States[c.PrevIndex].SpendHeight,
})
}
}
return bc.calculateBonusInternal(unclaimed)
}
func (bc *Blockchain) calculateBonusInternal(scs []*spentCoin) (util.Fixed8, error) {
var claimed util.Fixed8
for _, sc := range scs {
gen, sys, err := bc.CalculateClaimable(sc.Output.Amount, sc.StartHeight, sc.EndHeight)
if err != nil {
return 0, err
}
claimed += gen + sys
}
return claimed, nil
}
// isTxStillRelevant is a callback for mempool transaction filtering after the
// new block addition. It returns false for transactions already present in the
// chain (added by the new block), transactions using some inputs that are
// already used (double spends) 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, etc.
func (bc *Blockchain) isTxStillRelevant(t *transaction.Transaction) bool {
var recheckWitness bool
if bc.dao.HasTransaction(t.Hash()) {
return false
}
if bc.dao.IsDoubleSpend(t) {
return false
}
if t.Type == transaction.ClaimType {
claim := t.Data.(*transaction.ClaimTX)
if bc.dao.IsDoubleClaim(claim) {
return false
}
}
for i := range t.Scripts {
if !vm.IsStandardContract(t.Scripts[i].VerificationScript) {
recheckWitness = true
break
}
}
if recheckWitness {
return bc.verifyTxWitnesses(t, nil) == nil
}
return true
}
// StateHeight returns height of the verified state root.
func (bc *Blockchain) StateHeight() uint32 {
h, _ := bc.dao.GetCurrentStateRootHeight()
return h
}
// AddStateRoot add new (possibly unverified) state root to the blockchain.
func (bc *Blockchain) AddStateRoot(r *state.MPTRoot) error {
if !bc.config.EnableStateRoot {
bc.log.Warn("state root is being added but not enabled in config")
return nil
}
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 errors.WithMessage(err, "invalid state root")
}
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 errors.WithMessage(err, "can't verify signature")
}
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 errors.WithMessage(err, "can't get current state root height")
} else if (h < bc.config.StateRootEnableIndex && newHeight == bc.config.StateRootEnableIndex) || newHeight == h+1 {
updateStateHeightMetric(newHeight)
return bc.dao.PutCurrentStateRootHeight(newHeight)
}
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
}
interopCtx := bc.newInteropContext(trigger.Verification, bc.dao, nil, nil)
return bc.verifyHashAgainstScript(b.NextConsensus, r.Witness, hash.Sha256(r.GetSignedPart()), interopCtx, true)
}
// VerifyTx verifies whether a transaction is bonafide or not. 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 Verify method in C# (https://github.com/neo-project/neo/blob/master/neo/Network/P2P/Payloads/Transaction.cs#L270).
func (bc *Blockchain) VerifyTx(t *transaction.Transaction, block *block.Block) error {
bc.lock.RLock()
defer bc.lock.RUnlock()
return bc.verifyTx(t, block)
}
// PoolTx verifies and tries to add given transaction into the mempool.
func (bc *Blockchain) PoolTx(t *transaction.Transaction) error {
bc.lock.RLock()
defer bc.lock.RUnlock()
if bc.HasTransaction(t.Hash()) {
return ErrAlreadyExists
}
if err := bc.verifyTx(t, nil); err != nil {
return err
}
// Policying.
if t.Type != transaction.ClaimType {
txSize := io.GetVarSize(t)
maxFree := bc.config.MaxFreeTransactionSize
netFee := bc.NetworkFee(t)
if maxFree != 0 && txSize > maxFree {
if bc.IsLowPriority(netFee) ||
netFee < (util.Fixed8FromFloat(bc.config.LowPriorityThreshold)+util.Fixed8FromFloat(bc.config.FeePerExtraByte)*util.Fixed8(txSize-maxFree)) {
return ErrPolicy
}
}
if t.Type == transaction.InvocationType && netFee < bc.config.MinimumNetworkFee {
return ErrPolicy
}
}
if err := bc.memPool.Add(t, bc); err != nil {
switch err {
case mempool.ErrOOM:
return ErrOOM
case mempool.ErrConflict:
return ErrAlreadyExists
default:
return err
}
}
return nil
}
func (bc *Blockchain) verifyOutputs(t *transaction.Transaction) error {
for assetID, outputs := range t.GroupOutputByAssetID() {
assetState := bc.GetAssetState(assetID)
if assetState == nil {
return fmt.Errorf("no asset state for %s", assetID.StringLE())
}
if assetState.Expiration < bc.blockHeight+1 && assetState.AssetType != transaction.GoverningToken && assetState.AssetType != transaction.UtilityToken {
return fmt.Errorf("asset %s expired", assetID.StringLE())
}
for _, out := range outputs {
if int64(out.Amount)%int64(math.Pow10(8-int(assetState.Precision))) != 0 {
return fmt.Errorf("output is not compliant with %s asset precision", assetID.StringLE())
}
}
}
return nil
}
func (bc *Blockchain) verifyResults(t *transaction.Transaction, results []*transaction.Result) error {
var resultsDestroy []*transaction.Result
var resultsIssue []*transaction.Result
for _, re := range results {
if re.Amount.GreaterThan(util.Fixed8(0)) {
resultsDestroy = append(resultsDestroy, re)
}
if re.Amount.LessThan(util.Fixed8(0)) {
resultsIssue = append(resultsIssue, re)
}
}
if len(resultsDestroy) > 1 {
return errors.New("tx has more than 1 destroy output")
}
if len(resultsDestroy) == 1 && resultsDestroy[0].AssetID != UtilityTokenID() {
return errors.New("tx destroys non-utility token")
}
sysfee := bc.SystemFee(t)
if sysfee.GreaterThan(util.Fixed8(0)) {
if len(resultsDestroy) == 0 {
return fmt.Errorf("system requires to pay %s fee, but tx pays nothing", sysfee.String())
}
if resultsDestroy[0].Amount.LessThan(sysfee) {
return fmt.Errorf("system requires to pay %s fee, but tx pays %s only", sysfee.String(), resultsDestroy[0].Amount.String())
}
}
switch t.Type {
case transaction.MinerType, transaction.ClaimType:
for _, r := range resultsIssue {
if r.AssetID != UtilityTokenID() {
return errors.New("miner or claim tx issues non-utility tokens")
}
}
break
case transaction.IssueType:
for _, r := range resultsIssue {
if r.AssetID == UtilityTokenID() {
return errors.New("issue tx issues utility tokens")
}
asset, err := bc.dao.GetAssetState(r.AssetID)
if asset == nil || err != nil {
return errors.New("invalid asset in issue tx")
}
if asset.Available < r.Amount {
return errors.New("trying to issue more than available")
}
}
break
default:
if len(resultsIssue) > 0 {
return errors.New("non issue/miner/claim tx issues tokens")
}
break
}
return nil
}
// GetTransactionResults returns the transaction results aggregate by assetID.
// Golang of GetTransationResults method in C# (https://github.com/neo-project/neo/blob/master/neo/Network/P2P/Payloads/Transaction.cs#L207)
func (bc *Blockchain) GetTransactionResults(t *transaction.Transaction) []*transaction.Result {
references, err := bc.References(t)
if err != nil {
return nil
}
return refsAndOutsToResults(references, t.Outputs)
}
// mapReferencesToResults returns cumulative results of transaction based in its
// references and outputs.
func refsAndOutsToResults(references []transaction.InOut, outputs []transaction.Output) []*transaction.Result {
var results []*transaction.Result
tempResult := make(map[util.Uint256]util.Fixed8)
for _, inout := range references {
c := tempResult[inout.Out.AssetID]
tempResult[inout.Out.AssetID] = c.Add(inout.Out.Amount)
}
for _, output := range outputs {
c := tempResult[output.AssetID]
tempResult[output.AssetID] = c.Sub(output.Amount)
}
results = []*transaction.Result{} // this assignment is necessary. (Most of the time amount == 0 and results is the empty slice.)
for assetID, amount := range tempResult {
if amount != util.Fixed8(0) {
results = append(results, &transaction.Result{
AssetID: assetID,
Amount: amount,
})
}
}
return results
}
//GetStandByValidators returns validators from the configuration.
func (bc *Blockchain) GetStandByValidators() (keys.PublicKeys, error) {
return getValidators(bc.config)
}
// GetValidators returns validators.
// Golang implementation of GetValidators method in C# (https://github.com/neo-project/neo/blob/c64748ecbac3baeb8045b16af0d518398a6ced24/neo/Persistence/Snapshot.cs#L182)
func (bc *Blockchain) GetValidators(txes ...*transaction.Transaction) ([]*keys.PublicKey, error) {
cache := dao.NewCached(bc.dao)
if len(txes) > 0 {
for _, tx := range txes {
// iterate through outputs
for index, output := range tx.Outputs {
accountState, err := cache.GetAccountStateOrNew(output.ScriptHash)
if err != nil {
return nil, err
}
accountState.Balances[output.AssetID] = append(accountState.Balances[output.AssetID], state.UnspentBalance{
Tx: tx.Hash(),
Index: uint16(index),
Value: output.Amount,
})
if err := cache.PutAccountState(accountState); err != nil {
return nil, err
}
if err = processTXWithValidatorsAdd(&output, accountState, cache); err != nil {
return nil, err
}
}
// group inputs by the same previous hash and iterate through inputs
group := make(map[util.Uint256][]*transaction.Input)
for i := range tx.Inputs {
hash := tx.Inputs[i].PrevHash
group[hash] = append(group[hash], &tx.Inputs[i])
}
for hash, inputs := range group {
unspent, err := cache.GetUnspentCoinState(hash)
if err != nil {
return nil, err
}
// process inputs
for _, input := range inputs {
prevOutput := &unspent.States[input.PrevIndex].Output
accountState, err := cache.GetAccountStateOrNew(prevOutput.ScriptHash)
if err != nil {
return nil, err
}
// process account state votes: if there are any -> validators will be updated.
if err = processTXWithValidatorsSubtract(prevOutput, accountState, cache); err != nil {
return nil, err
}
delete(accountState.Balances, prevOutput.AssetID)
if err = cache.PutAccountState(accountState); err != nil {
return nil, err
}
}
}
switch t := tx.Data.(type) {
case *transaction.EnrollmentTX:
if err := processEnrollmentTX(cache, t); err != nil {
return nil, err
}
case *transaction.StateTX:
if err := processStateTX(cache, t); err != nil {
return nil, err
}
}
}
}
validators := cache.GetValidators()
sort.Slice(validators, func(i, j int) bool {
// Unregistered validators go to the end of the list.
if validators[i].Registered != validators[j].Registered {
return validators[i].Registered
}
// The most-voted validators should end up in the front of the list.
if validators[i].Votes != validators[j].Votes {
return validators[i].Votes > validators[j].Votes
}
// Ties are broken with public keys.
return validators[i].PublicKey.Cmp(validators[j].PublicKey) == -1
})
validatorsCount, err := cache.GetValidatorsCount()
if err != nil {
return nil, err
}
count := validatorsCount.GetWeightedAverage()
standByValidators, err := bc.GetStandByValidators()
if err != nil {
return nil, err
}
if count < len(standByValidators) {
count = len(standByValidators)
}
uniqueSBValidators := standByValidators.Unique()
result := keys.PublicKeys{}
for _, validator := range validators {
if validator.RegisteredAndHasVotes() || uniqueSBValidators.Contains(validator.PublicKey) {
result = append(result, validator.PublicKey)
}
}
if result.Len() >= count {
result = result[:count]
} else {
for i := 0; i < uniqueSBValidators.Len() && result.Len() < count; i++ {
if !result.Contains(uniqueSBValidators[i]) {
result = append(result, uniqueSBValidators[i])
}
}
}
sort.Sort(result)
return result, nil
}
// GetEnrollments returns all registered validators and non-registered SB validators
func (bc *Blockchain) GetEnrollments() ([]*state.Validator, error) {
validators := bc.dao.GetValidators()
standByValidators, err := bc.GetStandByValidators()
if err != nil {
return nil, err
}
uniqueSBValidators := standByValidators.Unique()
var result []*state.Validator
for _, validator := range validators {
if validator.Registered {
result = append(result, validator)
}
}
for _, sBValidator := range uniqueSBValidators {
isAdded := false
for _, v := range result {
if v.PublicKey == sBValidator {
isAdded = true
break
}
}
if !isAdded {
result = append(result, &state.Validator{
PublicKey: sBValidator,
Registered: false,
Votes: 0,
})
}
}
return result, nil
}
func processStateTX(dao *dao.Cached, tx *transaction.StateTX) error {
for _, desc := range tx.Descriptors {
switch desc.Type {
case transaction.Account:
if err := processAccountStateDescriptor(desc, dao); err != nil {
return err
}
case transaction.Validator:
if err := processValidatorStateDescriptor(desc, dao); err != nil {
return err
}
}
}
return nil
}
func processEnrollmentTX(dao *dao.Cached, tx *transaction.EnrollmentTX) error {
validatorState, err := dao.GetValidatorStateOrNew(&tx.PublicKey)
if err != nil {
return err
}
validatorState.Registered = true
return dao.PutValidatorState(validatorState)
}
// GetScriptHashesForVerifying returns all the ScriptHashes of a transaction which will be use
// to verify whether the transaction is bonafide or not.
// Golang implementation of GetScriptHashesForVerifying method in C# (https://github.com/neo-project/neo/blob/master/neo/Network/P2P/Payloads/Transaction.cs#L190)
func (bc *Blockchain) GetScriptHashesForVerifying(t *transaction.Transaction) ([]util.Uint160, error) {
references, err := bc.References(t)
if err != nil {
return nil, err
}
hashes := make(map[util.Uint160]bool)
for i := range references {
hashes[references[i].Out.ScriptHash] = true
}
for _, a := range t.Attributes {
if a.Usage == transaction.Script {
h, err := util.Uint160DecodeBytesBE(a.Data)
if err != nil {
return nil, err
}
if _, ok := hashes[h]; !ok {
hashes[h] = true
}
}
}
for a, outputs := range t.GroupOutputByAssetID() {
as := bc.GetAssetState(a)
if as == nil {
return nil, errors.New("Invalid operation")
}
if as.AssetType&transaction.DutyFlag != 0 {
for _, o := range outputs {
h := o.ScriptHash
if _, ok := hashes[h]; !ok {
hashes[h] = true
}
}
}
}
switch t.Type {
case transaction.ClaimType:
claim := t.Data.(*transaction.ClaimTX)
refs, err := bc.references(claim.Claims)
if err != nil {
return nil, err
}
for i := range refs {
hashes[refs[i].Out.ScriptHash] = true
}
case transaction.EnrollmentType:
etx := t.Data.(*transaction.EnrollmentTX)
hashes[etx.PublicKey.GetScriptHash()] = true
case transaction.IssueType:
for _, res := range refsAndOutsToResults(references, t.Outputs) {
if res.Amount < 0 {
asset, err := bc.dao.GetAssetState(res.AssetID)
if asset == nil || err != nil {
return nil, errors.New("invalid asset in issue tx")
}
hashes[asset.Issuer] = true
}
}
case transaction.RegisterType:
reg := t.Data.(*transaction.RegisterTX)
hashes[reg.Owner.GetScriptHash()] = true
case transaction.StateType:
stx := t.Data.(*transaction.StateTX)
for _, desc := range stx.Descriptors {
switch desc.Type {
case transaction.Account:
if desc.Field != "Votes" {
return nil, errors.New("bad account state descriptor")
}
hash, err := util.Uint160DecodeBytesBE(desc.Key)
if err != nil {
return nil, err
}
hashes[hash] = true
case transaction.Validator:
if desc.Field != "Registered" {
return nil, errors.New("bad validator state descriptor")
}
key := &keys.PublicKey{}
err := key.DecodeBytes(desc.Key)
if err != nil {
return nil, err
}
hashes[key.GetScriptHash()] = true
}
}
}
// convert hashes to []util.Uint160
hashesResult := make([]util.Uint160, 0, len(hashes))
for h := range hashes {
hashesResult = append(hashesResult, h)
}
return hashesResult, nil
}
// GetTestVM returns a VM and a Store setup for a test run of some sort of code.
func (bc *Blockchain) GetTestVM(tx *transaction.Transaction) *vm.VM {
systemInterop := bc.newInteropContext(trigger.Application, bc.dao, nil, tx)
vm := systemInterop.SpawnVM()
vm.SetPriceGetter(getPrice)
return vm
}
// ScriptFromWitness returns verification script for provided witness.
// If hash is not equal to the witness script hash, error is returned.
func ScriptFromWitness(hash util.Uint160, witness *transaction.Witness) ([]byte, error) {
verification := witness.VerificationScript
if len(verification) == 0 {
bb := io.NewBufBinWriter()
emit.AppCall(bb.BinWriter, hash, false)
verification = bb.Bytes()
} else if h := witness.ScriptHash(); hash != h {
return nil, errors.New("witness hash mismatch")
}
return verification, nil
}
// verifyHashAgainstScript verifies given hash against the given witness.
func (bc *Blockchain) verifyHashAgainstScript(hash util.Uint160, witness *transaction.Witness, checkedHash util.Uint256, interopCtx *interopContext, useKeys bool) error {
verification, err := ScriptFromWitness(hash, witness)
if err != nil {
return err
}
vm := interopCtx.SpawnVM()
vm.SetCheckedHash(checkedHash.BytesBE())
vm.LoadScript(verification)
vm.LoadScript(witness.InvocationScript)
if useKeys {
bc.keyCacheLock.RLock()
if bc.keyCache[hash] != nil {
vm.SetPublicKeys(bc.keyCache[hash])
}
bc.keyCacheLock.RUnlock()
}
err = vm.Run()
if vm.HasFailed() {
return errors.Errorf("vm failed to execute the script with error: %s", err)
}
resEl := vm.Estack().Pop()
if resEl != nil {
res, err := resEl.TryBool()
if err != nil {
return err
}
if !res {
return errors.Errorf("signature check failed")
}
if useKeys {
bc.keyCacheLock.RLock()
_, ok := bc.keyCache[hash]
bc.keyCacheLock.RUnlock()
if !ok {
bc.keyCacheLock.Lock()
bc.keyCache[hash] = vm.GetPublicKeys()
bc.keyCacheLock.Unlock()
}
}
} else {
return errors.Errorf("no result returned from the script")
}
return 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).
// Unfortunately the IVerifiable interface could not be implemented because we can't move the References method in blockchain.go to the transaction.go file.
func (bc *Blockchain) verifyTxWitnesses(t *transaction.Transaction, block *block.Block) error {
hashes, err := bc.GetScriptHashesForVerifying(t)
if err != nil {
return err
}
witnesses := t.Scripts
if len(hashes) != len(witnesses) {
return errors.Errorf("expected len(hashes) == len(witnesses). got: %d != %d", len(hashes), len(witnesses))
}
sort.Slice(hashes, func(i, j int) bool { return hashes[i].Less(hashes[j]) })
sort.Slice(witnesses, func(i, j int) bool { return witnesses[i].ScriptHash().Less(witnesses[j].ScriptHash()) })
interopCtx := bc.newInteropContext(trigger.Verification, bc.dao, block, t)
for i := 0; i < len(hashes); i++ {
err := bc.verifyHashAgainstScript(hashes[i], &witnesses[i], t.VerificationHash(), interopCtx, false)
if err != nil {
numStr := fmt.Sprintf("witness #%d", i)
return errors.Wrap(err, numStr)
}
}
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
}
interopCtx := bc.newInteropContext(trigger.Verification, bc.dao, nil, nil)
return bc.verifyHashAgainstScript(hash, &currHeader.Script, currHeader.VerificationHash(), interopCtx, true)
}
func hashAndIndexToBytes(h util.Uint256, index uint32) []byte {
buf := io.NewBufBinWriter()
buf.WriteBytes(h.BytesLE())
buf.WriteU32LE(index)
return buf.Bytes()
}
func (bc *Blockchain) secondsPerBlock() int {
return bc.config.SecondsPerBlock
}
func (bc *Blockchain) newInteropContext(trigger trigger.Type, d dao.DAO, block *block.Block, tx *transaction.Transaction) *interopContext {
return newInteropContext(trigger, bc, d, block, tx, bc.log)
}