neo-go/pkg/consensus/consensus.go
Roman Khimov b7d2b659b4 network: get blocks directly from the chain for rebroadcasting
Simplify network<->consensus relations, also broadcast blocks received by
other means like RPC.
2020-05-25 00:27:39 +03:00

487 lines
13 KiB
Go

package consensus
import (
"errors"
"sort"
"time"
"github.com/nspcc-dev/dbft"
"github.com/nspcc-dev/dbft/block"
"github.com/nspcc-dev/dbft/crypto"
"github.com/nspcc-dev/dbft/merkle"
"github.com/nspcc-dev/dbft/payload"
coreb "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/mempool"
"github.com/nspcc-dev/neo-go/pkg/core/transaction"
"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/util"
"github.com/nspcc-dev/neo-go/pkg/vm/emit"
"github.com/nspcc-dev/neo-go/pkg/wallet"
"go.uber.org/zap"
)
// cacheMaxCapacity is the default cache capacity taken
// from C# implementation https://github.com/neo-project/neo/blob/master/neo/Ledger/Blockchain.cs#L64
const cacheMaxCapacity = 100
// defaultTimePerBlock is a period between blocks which is used in NEO.
const defaultTimePerBlock = 15 * time.Second
// Service represents consensus instance.
type Service interface {
// Start initializes dBFT and starts event loop for consensus service.
// It must be called only when sufficient amount of peers are connected.
Start()
// OnPayload is a callback to notify Service about new received payload.
OnPayload(p *Payload)
// OnTransaction is a callback to notify Service about new received transaction.
OnTransaction(tx *transaction.Transaction)
// GetPayload returns Payload with specified hash if it is present in the local cache.
GetPayload(h util.Uint256) *Payload
}
type service struct {
Config
log *zap.Logger
// cache is a fifo cache which stores recent payloads.
cache *relayCache
// txx is a fifo cache which stores miner transactions.
txx *relayCache
dbft *dbft.DBFT
// messages and transactions are channels needed to process
// everything in single thread.
messages chan Payload
transactions chan *transaction.Transaction
// blockEvents is used to pass a new block event to the consensus
// process.
blockEvents chan *coreb.Block
lastProposal []util.Uint256
wallet *wallet.Wallet
}
// Config is a configuration for consensus services.
type Config struct {
// Logger is a logger instance.
Logger *zap.Logger
// Broadcast is a callback which is called to notify server
// about new consensus payload to sent.
Broadcast func(p *Payload)
// Chain is a core.Blockchainer instance.
Chain blockchainer.Blockchainer
// RequestTx is a callback to which will be called
// when a node lacks transactions present in a block.
RequestTx func(h ...util.Uint256)
// TimePerBlock minimal time that should pass before next block is accepted.
TimePerBlock time.Duration
// Wallet is a local-node wallet configuration.
Wallet *wallet.Config
}
// NewService returns new consensus.Service instance.
func NewService(cfg Config) (Service, error) {
if cfg.TimePerBlock <= 0 {
cfg.TimePerBlock = defaultTimePerBlock
}
if cfg.Logger == nil {
return nil, errors.New("empty logger")
}
srv := &service{
Config: cfg,
log: cfg.Logger,
cache: newFIFOCache(cacheMaxCapacity),
txx: newFIFOCache(cacheMaxCapacity),
messages: make(chan Payload, 100),
transactions: make(chan *transaction.Transaction, 100),
blockEvents: make(chan *coreb.Block, 1),
}
if cfg.Wallet == nil {
return srv, nil
}
var err error
if srv.wallet, err = wallet.NewWalletFromFile(cfg.Wallet.Path); err != nil {
return nil, err
}
defer srv.wallet.Close()
srv.dbft = dbft.New(
dbft.WithLogger(srv.log),
dbft.WithSecondsPerBlock(cfg.TimePerBlock),
dbft.WithGetKeyPair(srv.getKeyPair),
dbft.WithTxPerBlock(10000),
dbft.WithRequestTx(cfg.RequestTx),
dbft.WithGetTx(srv.getTx),
dbft.WithGetVerified(srv.getVerifiedTx),
dbft.WithBroadcast(srv.broadcast),
dbft.WithProcessBlock(srv.processBlock),
dbft.WithVerifyBlock(srv.verifyBlock),
dbft.WithGetBlock(srv.getBlock),
dbft.WithWatchOnly(func() bool { return false }),
dbft.WithNewBlockFromContext(newBlockFromContext),
dbft.WithCurrentHeight(cfg.Chain.BlockHeight),
dbft.WithCurrentBlockHash(cfg.Chain.CurrentBlockHash),
dbft.WithGetValidators(srv.getValidators),
dbft.WithGetConsensusAddress(srv.getConsensusAddress),
dbft.WithNewConsensusPayload(func() payload.ConsensusPayload { p := new(Payload); p.message = &message{}; return p }),
dbft.WithNewPrepareRequest(func() payload.PrepareRequest { return new(prepareRequest) }),
dbft.WithNewPrepareResponse(func() payload.PrepareResponse { return new(prepareResponse) }),
dbft.WithNewChangeView(func() payload.ChangeView { return new(changeView) }),
dbft.WithNewCommit(func() payload.Commit { return new(commit) }),
dbft.WithNewRecoveryRequest(func() payload.RecoveryRequest { return new(recoveryRequest) }),
dbft.WithNewRecoveryMessage(func() payload.RecoveryMessage { return new(recoveryMessage) }),
)
if srv.dbft == nil {
return nil, errors.New("can't initialize dBFT")
}
return srv, nil
}
var (
_ block.Transaction = (*transaction.Transaction)(nil)
_ block.Block = (*neoBlock)(nil)
)
func (s *service) Start() {
s.dbft.Start()
s.Chain.SubscribeForBlocks(s.blockEvents)
go s.eventLoop()
}
func (s *service) eventLoop() {
for {
select {
case hv := <-s.dbft.Timer.C():
s.log.Debug("timer fired",
zap.Uint32("height", hv.Height),
zap.Uint("view", uint(hv.View)))
s.dbft.OnTimeout(hv)
case msg := <-s.messages:
fields := []zap.Field{
zap.Uint16("from", msg.validatorIndex),
zap.Stringer("type", msg.Type()),
}
if msg.Type() == payload.RecoveryMessageType {
rec := msg.GetRecoveryMessage().(*recoveryMessage)
if rec.preparationHash == nil {
req := rec.GetPrepareRequest(&msg, s.dbft.Validators, uint16(s.dbft.PrimaryIndex))
if req != nil {
h := req.Hash()
rec.preparationHash = &h
}
}
fields = append(fields,
zap.Int("#preparation", len(rec.preparationPayloads)),
zap.Int("#commit", len(rec.commitPayloads)),
zap.Int("#changeview", len(rec.changeViewPayloads)),
zap.Bool("#request", rec.prepareRequest != nil),
zap.Bool("#hash", rec.preparationHash != nil))
}
s.log.Debug("received message", fields...)
s.dbft.OnReceive(&msg)
case tx := <-s.transactions:
s.dbft.OnTransaction(tx)
case b := <-s.blockEvents:
// We also receive our own blocks here, so check for index.
if b.Index >= s.dbft.BlockIndex {
s.log.Debug("new block in the chain",
zap.Uint32("dbft index", s.dbft.BlockIndex),
zap.Uint32("chain index", s.Chain.BlockHeight()))
s.dbft.InitializeConsensus(0)
}
}
}
}
func (s *service) validatePayload(p *Payload) bool {
validators := s.getValidators()
if int(p.validatorIndex) >= len(validators) {
return false
}
pub := validators[p.validatorIndex]
h := pub.(*publicKey).GetScriptHash()
return p.Verify(h)
}
func (s *service) getKeyPair(pubs []crypto.PublicKey) (int, crypto.PrivateKey, crypto.PublicKey) {
for i := range pubs {
sh := pubs[i].(*publicKey).GetScriptHash()
acc := s.wallet.GetAccount(sh)
if acc == nil {
continue
}
key, err := keys.NEP2Decrypt(acc.EncryptedWIF, s.Config.Wallet.Password)
if err != nil {
continue
}
return i, &privateKey{PrivateKey: key}, &publicKey{PublicKey: key.PublicKey()}
}
return -1, nil, nil
}
// OnPayload handles Payload receive.
func (s *service) OnPayload(cp *Payload) {
log := s.log.With(zap.Stringer("hash", cp.Hash()))
if !s.validatePayload(cp) {
log.Debug("can't validate payload")
return
} else if s.cache.Has(cp.Hash()) {
log.Debug("payload is already in cache")
return
}
s.Config.Broadcast(cp)
s.cache.Add(cp)
if s.dbft == nil {
log.Debug("dbft is nil")
return
}
// decode payload data into message
if cp.message == nil {
if err := cp.decodeData(); err != nil {
log.Debug("can't decode payload data")
return
}
}
// we use switch here because other payloads could be possibly added in future
switch cp.Type() {
case payload.PrepareRequestType:
req := cp.GetPrepareRequest().(*prepareRequest)
s.lastProposal = req.transactionHashes
}
s.messages <- *cp
}
func (s *service) OnTransaction(tx *transaction.Transaction) {
if s.dbft != nil {
s.transactions <- tx
}
}
// GetPayload returns payload stored in cache.
func (s *service) GetPayload(h util.Uint256) *Payload {
p := s.cache.Get(h)
if p == nil {
return (*Payload)(nil)
}
cp := *p.(*Payload)
return &cp
}
func (s *service) broadcast(p payload.ConsensusPayload) {
if err := p.(*Payload).Sign(s.dbft.Priv.(*privateKey)); err != nil {
s.log.Warn("can't sign consensus payload", zap.Error(err))
}
s.cache.Add(p)
s.Config.Broadcast(p.(*Payload))
}
func (s *service) getTx(h util.Uint256) block.Transaction {
if tx := s.txx.Get(h); tx != nil {
return tx.(*transaction.Transaction)
}
tx, _, _ := s.Config.Chain.GetTransaction(h)
// this is needed because in case of absent tx dBFT expects to
// get nil interface, not a nil pointer to any concrete type
if tx != nil {
return tx
}
return nil
}
func (s *service) verifyBlock(b block.Block) bool {
coreb := &b.(*neoBlock).Block
for _, tx := range coreb.Transactions {
if err := s.Chain.VerifyTx(tx, coreb); err != nil {
s.log.Warn("invalid transaction in proposed block",
zap.Stringer("hash", tx.Hash()),
zap.Error(err))
return false
}
}
return true
}
func (s *service) processBlock(b block.Block) {
bb := &b.(*neoBlock).Block
bb.Script = *(s.getBlockWitness(bb))
if err := s.Chain.AddBlock(bb); err != nil {
// The block might already be added via the regular network
// interaction.
if _, errget := s.Chain.GetBlock(bb.Hash()); errget != nil {
s.log.Warn("error on add block", zap.Error(err))
}
}
}
func (s *service) getBlockWitness(b *coreb.Block) *transaction.Witness {
dctx := s.dbft.Context
pubs := convertKeys(dctx.Validators)
sigs := make(map[*keys.PublicKey][]byte)
for i := range pubs {
if p := dctx.CommitPayloads[i]; p != nil && p.ViewNumber() == dctx.ViewNumber {
sigs[pubs[i]] = p.GetCommit().Signature()
}
}
m := s.dbft.Context.M()
verif, err := smartcontract.CreateMultiSigRedeemScript(m, pubs)
if err != nil {
s.log.Warn("can't create multisig redeem script", zap.Error(err))
return nil
}
sort.Sort(keys.PublicKeys(pubs))
buf := io.NewBufBinWriter()
for i, j := 0, 0; i < len(pubs) && j < m; i++ {
if sig, ok := sigs[pubs[i]]; ok {
emit.Bytes(buf.BinWriter, sig)
j++
}
}
return &transaction.Witness{
InvocationScript: buf.Bytes(),
VerificationScript: verif,
}
}
func (s *service) getBlock(h util.Uint256) block.Block {
b, err := s.Chain.GetBlock(h)
if err != nil {
return nil
}
return &neoBlock{Block: *b}
}
func (s *service) getVerifiedTx(count int) []block.Transaction {
pool := s.Config.Chain.GetMemPool()
var txx []mempool.TxWithFee
if s.dbft.ViewNumber > 0 {
txx = make([]mempool.TxWithFee, 0, len(s.lastProposal))
for i := range s.lastProposal {
if tx, fee, ok := pool.TryGetValue(s.lastProposal[i]); ok {
txx = append(txx, mempool.TxWithFee{Tx: tx, Fee: fee})
}
}
if len(txx) < len(s.lastProposal)/2 {
txx = pool.GetVerifiedTransactions()
}
} else {
txx = pool.GetVerifiedTransactions()
}
if len(txx) > 0 {
txx = s.Config.Chain.ApplyPolicyToTxSet(txx)
}
res := make([]block.Transaction, len(txx))
for i := range txx {
res[i] = txx[i].Tx
}
return res
}
func (s *service) getValidators(_ ...block.Transaction) []crypto.PublicKey {
var (
pKeys []*keys.PublicKey
err error
)
pKeys, err = s.Chain.GetValidators()
if err != nil {
s.log.Error("error while trying to get validators", zap.Error(err))
}
pubs := make([]crypto.PublicKey, len(pKeys))
for i := range pKeys {
pubs[i] = &publicKey{PublicKey: pKeys[i]}
}
return pubs
}
func (s *service) getConsensusAddress(validators ...crypto.PublicKey) (h util.Uint160) {
pubs := convertKeys(validators)
script, err := smartcontract.CreateMultiSigRedeemScript(s.dbft.M(), pubs)
if err != nil {
return
}
return crypto.Hash160(script)
}
func convertKeys(validators []crypto.PublicKey) (pubs []*keys.PublicKey) {
pubs = make([]*keys.PublicKey, len(validators))
for i, k := range validators {
pubs[i] = k.(*publicKey).PublicKey
}
return
}
func newBlockFromContext(ctx *dbft.Context) block.Block {
block := new(neoBlock)
if ctx.TransactionHashes == nil {
return nil
}
block.Block.Timestamp = ctx.Timestamp / 1000000
block.Block.Index = ctx.BlockIndex
block.Block.NextConsensus = ctx.NextConsensus
block.Block.PrevHash = ctx.PrevHash
block.Block.Version = ctx.Version
block.Block.ConsensusData.Nonce = ctx.Nonce
primaryIndex := uint32(ctx.PrimaryIndex)
block.Block.ConsensusData.PrimaryIndex = primaryIndex
consensusData := coreb.ConsensusData{
PrimaryIndex: primaryIndex,
Nonce: ctx.Nonce,
}
mt := merkle.NewMerkleTree(append([]util.Uint256{consensusData.Hash()}, ctx.TransactionHashes...)...)
block.Block.MerkleRoot = mt.Root().Hash
return block
}