neo-go/pkg/network/server.go
2021-03-26 14:04:23 +03:00

1306 lines
36 KiB
Go

package network
import (
"crypto/rand"
"encoding/binary"
"errors"
"fmt"
mrand "math/rand"
"net"
"strconv"
"sync"
"time"
"github.com/nspcc-dev/neo-go/pkg/config/netmode"
"github.com/nspcc-dev/neo-go/pkg/consensus"
"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/network/capability"
"github.com/nspcc-dev/neo-go/pkg/network/extpool"
"github.com/nspcc-dev/neo-go/pkg/network/payload"
"github.com/nspcc-dev/neo-go/pkg/services/notary"
"github.com/nspcc-dev/neo-go/pkg/services/oracle"
"github.com/nspcc-dev/neo-go/pkg/services/stateroot"
"github.com/nspcc-dev/neo-go/pkg/util"
"go.uber.org/atomic"
"go.uber.org/zap"
)
const (
// peer numbers are arbitrary at the moment.
defaultMinPeers = 5
defaultAttemptConnPeers = 20
defaultMaxPeers = 100
maxBlockBatch = 200
minPoolCount = 30
)
var (
errAlreadyConnected = errors.New("already connected")
errIdenticalID = errors.New("identical node id")
errInvalidHandshake = errors.New("invalid handshake")
errInvalidNetwork = errors.New("invalid network")
errMaxPeers = errors.New("max peers reached")
errServerShutdown = errors.New("server shutdown")
errInvalidInvType = errors.New("invalid inventory type")
errInvalidHashStart = errors.New("invalid requested HashStart")
)
type (
// Server represents the local Node in the network. Its transport could
// be of any kind.
Server struct {
// ServerConfig holds the Server configuration.
ServerConfig
// id also known as the nonce of the server.
id uint32
// Network's magic number for correct message decoding.
network netmode.Magic
// stateRootInHeader specifies if block header contain state root.
stateRootInHeader bool
transport Transporter
discovery Discoverer
chain blockchainer.Blockchainer
bQueue *blockQueue
consensus consensus.Service
notaryRequestPool *mempool.Pool
extensiblePool *extpool.Pool
notaryFeer NotaryFeer
notaryModule *notary.Notary
lock sync.RWMutex
peers map[Peer]bool
// lastRequestedHeight contains last requested height.
lastRequestedHeight atomic.Uint32
register chan Peer
unregister chan peerDrop
quit chan struct{}
transactions chan *transaction.Transaction
consensusStarted *atomic.Bool
canHandleExtens *atomic.Bool
oracle *oracle.Oracle
stateRoot stateroot.Service
log *zap.Logger
}
peerDrop struct {
peer Peer
reason error
}
)
func randomID() uint32 {
buf := make([]byte, 4)
_, _ = rand.Read(buf)
return binary.BigEndian.Uint32(buf)
}
// NewServer returns a new Server, initialized with the given configuration.
func NewServer(config ServerConfig, chain blockchainer.Blockchainer, log *zap.Logger) (*Server, error) {
return newServerFromConstructors(config, chain, log, func(s *Server) Transporter {
return NewTCPTransport(s, net.JoinHostPort(s.ServerConfig.Address, strconv.Itoa(int(s.ServerConfig.Port))), s.log)
}, consensus.NewService, newDefaultDiscovery)
}
func newServerFromConstructors(config ServerConfig, chain blockchainer.Blockchainer, log *zap.Logger,
newTransport func(*Server) Transporter,
newConsensus func(consensus.Config) (consensus.Service, error),
newDiscovery func([]string, time.Duration, Transporter) Discoverer,
) (*Server, error) {
if log == nil {
return nil, errors.New("logger is a required parameter")
}
s := &Server{
ServerConfig: config,
chain: chain,
id: randomID(),
network: chain.GetConfig().Magic,
stateRootInHeader: chain.GetConfig().StateRootInHeader,
quit: make(chan struct{}),
register: make(chan Peer),
unregister: make(chan peerDrop),
peers: make(map[Peer]bool),
consensusStarted: atomic.NewBool(false),
canHandleExtens: atomic.NewBool(false),
extensiblePool: extpool.New(chain),
log: log,
transactions: make(chan *transaction.Transaction, 64),
}
if chain.P2PSigExtensionsEnabled() {
s.notaryFeer = NewNotaryFeer(chain)
s.notaryRequestPool = mempool.New(chain.GetConfig().P2PNotaryRequestPayloadPoolSize, 1, config.P2PNotaryCfg.Enabled)
chain.RegisterPostBlock(func(bc blockchainer.Blockchainer, txpool *mempool.Pool, _ *block.Block) {
s.notaryRequestPool.RemoveStale(func(t *transaction.Transaction) bool {
return bc.IsTxStillRelevant(t, txpool, true)
}, s.notaryFeer)
})
if config.P2PNotaryCfg.Enabled {
cfg := notary.Config{
MainCfg: config.P2PNotaryCfg,
Chain: chain,
Log: log,
}
n, err := notary.NewNotary(cfg, s.network, s.notaryRequestPool, func(tx *transaction.Transaction) error {
if err := s.RelayTxn(tx); err != nil {
return fmt.Errorf("can't relay completed notary transaction: hash %s, error: %w", tx.Hash().StringLE(), err)
}
return nil
})
if err != nil {
return nil, fmt.Errorf("failed to create Notary module: %w", err)
}
s.notaryModule = n
chain.SetNotary(n)
}
} else if config.P2PNotaryCfg.Enabled {
return nil, errors.New("P2PSigExtensions are disabled, but Notary service is enable")
}
s.bQueue = newBlockQueue(maxBlockBatch, chain, log, func(b *block.Block) {
if !s.consensusStarted.Load() {
s.tryStartConsensus()
}
})
if config.StateRootCfg.Enabled && chain.GetConfig().StateRootInHeader {
return nil, errors.New("`StateRootInHeader` should be disabled when state service is enabled")
}
sr, err := stateroot.New(config.StateRootCfg, s.log, chain)
if err != nil {
return nil, fmt.Errorf("can't initialize StateRoot service: %w", err)
}
s.stateRoot = sr
if config.OracleCfg.Enabled {
orcCfg := oracle.Config{
Log: log,
Network: config.Net,
MainCfg: config.OracleCfg,
Chain: chain,
}
orc, err := oracle.NewOracle(orcCfg)
if err != nil {
return nil, fmt.Errorf("can't initialize Oracle module: %w", err)
}
orc.SetOnTransaction(func(tx *transaction.Transaction) {
if err := s.RelayTxn(tx); err != nil {
orc.Log.Error("can't pool oracle tx",
zap.String("hash", tx.Hash().StringLE()),
zap.Error(err))
}
})
s.oracle = orc
chain.SetOracle(orc)
}
srv, err := newConsensus(consensus.Config{
Logger: log,
Broadcast: s.handleNewPayload,
Chain: chain,
ProtocolConfiguration: chain.GetConfig(),
RequestTx: s.requestTx,
Wallet: config.Wallet,
TimePerBlock: config.TimePerBlock,
})
if err != nil {
return nil, err
}
s.consensus = srv
if config.StateRootCfg.Enabled {
s.stateRoot.SetRelayCallback(s.handleNewPayload)
}
if s.MinPeers < 0 {
s.log.Info("bad MinPeers configured, using the default value",
zap.Int("configured", s.MinPeers),
zap.Int("actual", defaultMinPeers))
s.MinPeers = defaultMinPeers
}
if s.MaxPeers <= 0 {
s.log.Info("bad MaxPeers configured, using the default value",
zap.Int("configured", s.MaxPeers),
zap.Int("actual", defaultMaxPeers))
s.MaxPeers = defaultMaxPeers
}
if s.AttemptConnPeers <= 0 {
s.log.Info("bad AttemptConnPeers configured, using the default value",
zap.Int("configured", s.AttemptConnPeers),
zap.Int("actual", defaultAttemptConnPeers))
s.AttemptConnPeers = defaultAttemptConnPeers
}
s.transport = newTransport(s)
s.discovery = newDiscovery(
s.Seeds,
s.DialTimeout,
s.transport,
)
return s, nil
}
// ID returns the servers ID.
func (s *Server) ID() uint32 {
return s.id
}
// Start will start the server and its underlying transport.
func (s *Server) Start(errChan chan error) {
s.log.Info("node started",
zap.Uint32("blockHeight", s.chain.BlockHeight()),
zap.Uint32("headerHeight", s.chain.HeaderHeight()))
s.tryStartConsensus()
s.initStaleMemPools()
go s.broadcastTxLoop()
if s.oracle != nil {
go s.oracle.Run()
}
if s.notaryModule != nil {
s.notaryRequestPool.RunSubscriptions()
go s.notaryModule.Run()
}
if s.StateRootCfg.Enabled {
s.stateRoot.Run()
}
go s.relayBlocksLoop()
go s.bQueue.run()
go s.transport.Accept()
setServerAndNodeVersions(s.UserAgent, strconv.FormatUint(uint64(s.id), 10))
s.run()
}
// Shutdown disconnects all peers and stops listening.
func (s *Server) Shutdown() {
s.log.Info("shutting down server", zap.Int("peers", s.PeerCount()))
s.transport.Close()
s.discovery.Close()
if s.consensusStarted.Load() {
s.consensus.Shutdown()
}
for p := range s.Peers() {
p.Disconnect(errServerShutdown)
}
s.bQueue.discard()
if s.StateRootCfg.Enabled {
s.stateRoot.Shutdown()
}
if s.oracle != nil {
s.oracle.Shutdown()
}
if s.notaryModule != nil {
s.notaryModule.Stop()
s.notaryRequestPool.StopSubscriptions()
}
close(s.quit)
}
// GetOracle returns oracle module instance.
func (s *Server) GetOracle() *oracle.Oracle {
return s.oracle
}
// GetStateRoot returns state root service instance.
func (s *Server) GetStateRoot() stateroot.Service {
return s.stateRoot
}
// UnconnectedPeers returns a list of peers that are in the discovery peer list
// but are not connected to the server.
func (s *Server) UnconnectedPeers() []string {
return s.discovery.UnconnectedPeers()
}
// BadPeers returns a list of peers the are flagged as "bad" peers.
func (s *Server) BadPeers() []string {
return s.discovery.BadPeers()
}
// ConnectedPeers returns a list of currently connected peers.
func (s *Server) ConnectedPeers() []string {
s.lock.RLock()
defer s.lock.RUnlock()
peers := make([]string, 0, len(s.peers))
for k := range s.peers {
peers = append(peers, k.PeerAddr().String())
}
return peers
}
// run is a goroutine that starts another goroutine to manage protocol specifics
// while itself dealing with peers management (handling connects/disconnects).
func (s *Server) run() {
go s.runProto()
for {
if s.PeerCount() < s.MinPeers {
s.discovery.RequestRemote(s.AttemptConnPeers)
}
if s.discovery.PoolCount() < minPoolCount {
s.broadcastHPMessage(NewMessage(CMDGetAddr, payload.NewNullPayload()))
}
select {
case <-s.quit:
return
case p := <-s.register:
s.lock.Lock()
s.peers[p] = true
s.lock.Unlock()
peerCount := s.PeerCount()
s.log.Info("new peer connected", zap.Stringer("addr", p.RemoteAddr()), zap.Int("peerCount", peerCount))
if peerCount > s.MaxPeers {
s.lock.RLock()
// Pick a random peer and drop connection to it.
for peer := range s.peers {
// It will send us unregister signal.
go peer.Disconnect(errMaxPeers)
break
}
s.lock.RUnlock()
}
updatePeersConnectedMetric(s.PeerCount())
case drop := <-s.unregister:
s.lock.Lock()
if s.peers[drop.peer] {
delete(s.peers, drop.peer)
s.lock.Unlock()
s.log.Warn("peer disconnected",
zap.Stringer("addr", drop.peer.RemoteAddr()),
zap.String("reason", drop.reason.Error()),
zap.Int("peerCount", s.PeerCount()))
addr := drop.peer.PeerAddr().String()
if drop.reason == errIdenticalID {
s.discovery.RegisterBadAddr(addr)
} else if drop.reason == errAlreadyConnected {
// There is a race condition when peer can be disconnected twice for the this reason
// which can lead to no connections to peer at all. Here we check for such a possibility.
stillConnected := false
s.lock.RLock()
verDrop := drop.peer.Version()
addr := drop.peer.PeerAddr().String()
if verDrop != nil {
for peer := range s.peers {
ver := peer.Version()
// Already connected, drop this connection.
if ver != nil && ver.Nonce == verDrop.Nonce && peer.PeerAddr().String() == addr {
stillConnected = true
}
}
}
s.lock.RUnlock()
if !stillConnected {
s.discovery.UnregisterConnectedAddr(addr)
s.discovery.BackFill(addr)
}
} else {
s.discovery.UnregisterConnectedAddr(addr)
s.discovery.BackFill(addr)
}
updatePeersConnectedMetric(s.PeerCount())
} else {
// else the peer is already gone, which can happen
// because we have two goroutines sending signals here
s.lock.Unlock()
}
}
}
}
// runProto is a goroutine that manages server-wide protocol events.
func (s *Server) runProto() {
pingTimer := time.NewTimer(s.PingInterval)
for {
prevHeight := s.chain.BlockHeight()
select {
case <-s.quit:
return
case <-pingTimer.C:
if s.chain.BlockHeight() == prevHeight {
// Get a copy of s.peers to avoid holding a lock while sending.
for peer := range s.Peers() {
_ = peer.SendPing(NewMessage(CMDPing, payload.NewPing(s.id, s.chain.HeaderHeight())))
}
}
pingTimer.Reset(s.PingInterval)
}
}
}
func (s *Server) tryStartConsensus() {
if s.Wallet == nil || s.consensusStarted.Load() {
return
}
if s.IsInSync() {
s.log.Info("node reached synchronized state, starting consensus")
if s.consensusStarted.CAS(false, true) {
s.consensus.Start()
}
}
}
// Peers returns the current list of peers connected to
// the server.
func (s *Server) Peers() map[Peer]bool {
s.lock.RLock()
defer s.lock.RUnlock()
peers := make(map[Peer]bool, len(s.peers))
for k, v := range s.peers {
peers[k] = v
}
return peers
}
// PeerCount returns the number of current connected peers.
func (s *Server) PeerCount() int {
s.lock.RLock()
defer s.lock.RUnlock()
return len(s.peers)
}
// HandshakedPeersCount returns the number of connected peers
// which have already performed handshake.
func (s *Server) HandshakedPeersCount() int {
s.lock.RLock()
defer s.lock.RUnlock()
var count int
for p := range s.peers {
if p.Handshaked() {
count++
}
}
return count
}
// getVersionMsg returns current version message.
func (s *Server) getVersionMsg() (*Message, error) {
port, err := s.Port()
if err != nil {
return nil, err
}
capabilities := []capability.Capability{
{
Type: capability.TCPServer,
Data: &capability.Server{
Port: port,
},
},
}
if s.Relay {
capabilities = append(capabilities, capability.Capability{
Type: capability.FullNode,
Data: &capability.Node{
StartHeight: s.chain.BlockHeight(),
},
})
}
payload := payload.NewVersion(
s.Net,
s.id,
s.UserAgent,
capabilities,
)
return NewMessage(CMDVersion, payload), nil
}
// IsInSync answers the question of whether the server is in sync with the
// network or not (at least how the server itself sees it). The server operates
// with the data that it has, the number of peers (that has to be more than
// minimum number) and height of these peers (our chain has to be not lower
// than 2/3 of our peers have). Ideally we would check for the highest of the
// peers, but the problem is that they can lie to us and send whatever height
// they want to.
func (s *Server) IsInSync() bool {
var peersNumber int
var notHigher int
if s.MinPeers == 0 {
return true
}
ourLastBlock := s.chain.BlockHeight()
s.lock.RLock()
for p := range s.peers {
if p.Handshaked() {
peersNumber++
if ourLastBlock >= p.LastBlockIndex() {
notHigher++
}
}
}
s.lock.RUnlock()
// Checking bQueue would also be nice, but it can be filled with garbage
// easily at the moment.
return peersNumber >= s.MinPeers && (3*notHigher > 2*peersNumber) // && s.bQueue.length() == 0
}
// When a peer sends out his version we reply with verack after validating
// the version.
func (s *Server) handleVersionCmd(p Peer, version *payload.Version) error {
err := p.HandleVersion(version)
if err != nil {
return err
}
if s.id == version.Nonce {
return errIdenticalID
}
// Make sure both server and peer are operating on
// the same network.
if s.Net != version.Magic {
return errInvalidNetwork
}
peerAddr := p.PeerAddr().String()
s.discovery.RegisterConnectedAddr(peerAddr)
s.lock.RLock()
for peer := range s.peers {
if p == peer {
continue
}
ver := peer.Version()
// Already connected, drop this connection.
if ver != nil && ver.Nonce == version.Nonce && peer.PeerAddr().String() == peerAddr {
s.lock.RUnlock()
return errAlreadyConnected
}
}
s.lock.RUnlock()
return p.SendVersionAck(NewMessage(CMDVerack, payload.NewNullPayload()))
}
// handleBlockCmd processes the received block received from its peer.
func (s *Server) handleBlockCmd(p Peer, block *block.Block) error {
return s.bQueue.putBlock(block)
}
// handlePing processes ping request.
func (s *Server) handlePing(p Peer, ping *payload.Ping) error {
err := p.HandlePing(ping)
if err != nil {
return err
}
if s.chain.BlockHeight() < ping.LastBlockIndex {
err = s.requestBlocks(p)
if err != nil {
return err
}
}
return p.EnqueueP2PMessage(NewMessage(CMDPong, payload.NewPing(s.chain.BlockHeight(), s.id)))
}
// handlePing processes pong request.
func (s *Server) handlePong(p Peer, pong *payload.Ping) error {
err := p.HandlePong(pong)
if err != nil {
return err
}
if s.chain.BlockHeight() < pong.LastBlockIndex {
return s.requestBlocks(p)
}
return nil
}
// handleInvCmd processes the received inventory.
func (s *Server) handleInvCmd(p Peer, inv *payload.Inventory) error {
reqHashes := make([]util.Uint256, 0)
var typExists = map[payload.InventoryType]func(util.Uint256) bool{
payload.TXType: s.chain.HasTransaction,
payload.BlockType: s.chain.HasBlock,
payload.ExtensibleType: func(h util.Uint256) bool {
cp := s.extensiblePool.Get(h)
return cp != nil
},
payload.P2PNotaryRequestType: func(h util.Uint256) bool {
return s.notaryRequestPool.ContainsKey(h)
},
}
if exists := typExists[inv.Type]; exists != nil {
for _, hash := range inv.Hashes {
if !exists(hash) {
reqHashes = append(reqHashes, hash)
}
}
}
if len(reqHashes) > 0 {
msg := NewMessage(CMDGetData, payload.NewInventory(inv.Type, reqHashes))
pkt, err := msg.Bytes()
if err != nil {
return err
}
if inv.Type == payload.ExtensibleType {
return p.EnqueueHPPacket(true, pkt)
}
return p.EnqueueP2PPacket(pkt)
}
return nil
}
// handleMempoolCmd handles getmempool command.
func (s *Server) handleMempoolCmd(p Peer) error {
txs := s.chain.GetMemPool().GetVerifiedTransactions()
hs := make([]util.Uint256, 0, payload.MaxHashesCount)
for i := range txs {
hs = append(hs, txs[i].Hash())
if len(hs) < payload.MaxHashesCount && i != len(txs)-1 {
continue
}
msg := NewMessage(CMDInv, payload.NewInventory(payload.TXType, hs))
err := p.EnqueueP2PMessage(msg)
if err != nil {
return err
}
hs = hs[:0]
}
return nil
}
// handleInvCmd processes the received inventory.
func (s *Server) handleGetDataCmd(p Peer, inv *payload.Inventory) error {
var notFound []util.Uint256
for _, hash := range inv.Hashes {
var msg *Message
switch inv.Type {
case payload.TXType:
tx, _, err := s.chain.GetTransaction(hash)
if err == nil {
msg = NewMessage(CMDTX, tx)
} else {
notFound = append(notFound, hash)
}
case payload.BlockType:
b, err := s.chain.GetBlock(hash)
if err == nil {
msg = NewMessage(CMDBlock, b)
} else {
notFound = append(notFound, hash)
}
case payload.ExtensibleType:
if cp := s.extensiblePool.Get(hash); cp != nil {
msg = NewMessage(CMDExtensible, cp)
}
case payload.P2PNotaryRequestType:
if nrp, ok := s.notaryRequestPool.TryGetData(hash); ok { // already have checked P2PSigExtEnabled
msg = NewMessage(CMDP2PNotaryRequest, nrp.(*payload.P2PNotaryRequest))
} else {
notFound = append(notFound, hash)
}
}
if msg != nil {
pkt, err := msg.Bytes()
if err == nil {
if inv.Type == payload.ExtensibleType {
err = p.EnqueueHPPacket(true, pkt)
} else {
err = p.EnqueueP2PPacket(pkt)
}
}
if err != nil {
return err
}
}
}
if len(notFound) != 0 {
return p.EnqueueP2PMessage(NewMessage(CMDNotFound, payload.NewInventory(inv.Type, notFound)))
}
return nil
}
// handleGetBlocksCmd processes the getblocks request.
func (s *Server) handleGetBlocksCmd(p Peer, gb *payload.GetBlocks) error {
count := gb.Count
if gb.Count < 0 || gb.Count > payload.MaxHashesCount {
count = payload.MaxHashesCount
}
start, err := s.chain.GetHeader(gb.HashStart)
if err != nil {
return err
}
blockHashes := make([]util.Uint256, 0)
for i := start.Index + 1; i <= start.Index+uint32(count); i++ {
hash := s.chain.GetHeaderHash(int(i))
if hash.Equals(util.Uint256{}) {
break
}
blockHashes = append(blockHashes, hash)
}
if len(blockHashes) == 0 {
return nil
}
payload := payload.NewInventory(payload.BlockType, blockHashes)
msg := NewMessage(CMDInv, payload)
return p.EnqueueP2PMessage(msg)
}
// handleGetBlockByIndexCmd processes the getblockbyindex request.
func (s *Server) handleGetBlockByIndexCmd(p Peer, gbd *payload.GetBlockByIndex) error {
count := gbd.Count
if gbd.Count < 0 || gbd.Count > payload.MaxHashesCount {
count = payload.MaxHashesCount
}
for i := gbd.IndexStart; i < gbd.IndexStart+uint32(count); i++ {
hash := s.chain.GetHeaderHash(int(i))
if hash.Equals(util.Uint256{}) {
break
}
b, err := s.chain.GetBlock(hash)
if err != nil {
break
}
msg := NewMessage(CMDBlock, b)
if err = p.EnqueueP2PMessage(msg); err != nil {
return err
}
}
return nil
}
// handleGetHeadersCmd processes the getheaders request.
func (s *Server) handleGetHeadersCmd(p Peer, gh *payload.GetBlockByIndex) error {
if gh.IndexStart > s.chain.HeaderHeight() {
return nil
}
count := gh.Count
if gh.Count < 0 || gh.Count > payload.MaxHeadersAllowed {
count = payload.MaxHeadersAllowed
}
resp := payload.Headers{}
resp.Hdrs = make([]*block.Header, 0, count)
for i := gh.IndexStart; i < gh.IndexStart+uint32(count); i++ {
hash := s.chain.GetHeaderHash(int(i))
if hash.Equals(util.Uint256{}) {
break
}
header, err := s.chain.GetHeader(hash)
if err != nil {
break
}
resp.Hdrs = append(resp.Hdrs, header)
}
if len(resp.Hdrs) == 0 {
return nil
}
msg := NewMessage(CMDHeaders, &resp)
return p.EnqueueP2PMessage(msg)
}
// handleExtensibleCmd processes received extensible payload.
func (s *Server) handleExtensibleCmd(e *payload.Extensible) error {
if !s.canHandleExtens.Load() {
if !s.IsInSync() {
return nil
}
s.canHandleExtens.Store(true)
}
ok, err := s.extensiblePool.Add(e)
if err != nil {
return err
}
if !ok { // payload is already in cache
return nil
}
switch e.Category {
case consensus.Category:
s.consensus.OnPayload(e)
case stateroot.Category:
err := s.stateRoot.OnPayload(e)
if err != nil {
return err
}
default:
return errors.New("invalid category")
}
msg := NewMessage(CMDInv, payload.NewInventory(payload.ExtensibleType, []util.Uint256{e.Hash()}))
if e.Category == consensus.Category {
s.broadcastHPMessage(msg)
} else {
s.broadcastMessage(msg)
}
return nil
}
// handleTxCmd processes received transaction.
// It never returns an error.
func (s *Server) handleTxCmd(tx *transaction.Transaction) error {
// It's OK for it to fail for various reasons like tx already existing
// in the pool.
if s.verifyAndPoolTX(tx) == nil {
s.consensus.OnTransaction(tx)
s.broadcastTX(tx, nil)
}
return nil
}
// handleP2PNotaryRequestCmd process received P2PNotaryRequest payload.
func (s *Server) handleP2PNotaryRequestCmd(r *payload.P2PNotaryRequest) error {
if !s.chain.P2PSigExtensionsEnabled() {
return errors.New("P2PNotaryRequestCMD was received, but P2PSignatureExtensions are disabled")
}
// It's OK for it to fail for various reasons like request already existing
// in the pool.
s.RelayP2PNotaryRequest(r)
return nil
}
// RelayP2PNotaryRequest adds given request to the pool and relays. It does not check
// P2PSigExtensions enabled.
func (s *Server) RelayP2PNotaryRequest(r *payload.P2PNotaryRequest) error {
err := s.verifyAndPoolNotaryRequest(r)
if err == nil {
s.broadcastP2PNotaryRequestPayload(nil, r)
}
return err
}
// verifyAndPoolNotaryRequest verifies NotaryRequest payload and adds it to the payload mempool.
func (s *Server) verifyAndPoolNotaryRequest(r *payload.P2PNotaryRequest) error {
return s.chain.PoolTxWithData(r.FallbackTransaction, r, s.notaryRequestPool, s.notaryFeer, verifyNotaryRequest)
}
// verifyNotaryRequest is a function for state-dependant P2PNotaryRequest payload verification which is executed before ordinary blockchain's verification.
func verifyNotaryRequest(bc blockchainer.Blockchainer, _ *transaction.Transaction, data interface{}) error {
r := data.(*payload.P2PNotaryRequest)
payer := r.FallbackTransaction.Signers[1].Account
if err := bc.VerifyWitness(payer, r, &r.Witness, bc.GetPolicer().GetMaxVerificationGAS()); err != nil {
return fmt.Errorf("bad P2PNotaryRequest payload witness: %w", err)
}
notaryHash := bc.GetNotaryContractScriptHash()
if r.FallbackTransaction.Sender() != notaryHash {
return errors.New("P2PNotary contract should be a sender of the fallback transaction")
}
depositExpiration := bc.GetNotaryDepositExpiration(payer)
if r.FallbackTransaction.ValidUntilBlock >= depositExpiration {
return fmt.Errorf("fallback transaction is valid after deposit is unlocked: ValidUntilBlock is %d, deposit lock expires at %d", r.FallbackTransaction.ValidUntilBlock, depositExpiration)
}
return nil
}
func (s *Server) broadcastP2PNotaryRequestPayload(_ *transaction.Transaction, data interface{}) {
r := data.(*payload.P2PNotaryRequest) // we can guarantee that cast is successful
msg := NewMessage(CMDInv, payload.NewInventory(payload.P2PNotaryRequestType, []util.Uint256{r.FallbackTransaction.Hash()}))
s.broadcastMessage(msg)
}
// handleAddrCmd will process received addresses.
func (s *Server) handleAddrCmd(p Peer, addrs *payload.AddressList) error {
if !p.CanProcessAddr() {
return errors.New("unexpected addr received")
}
dups := make(map[string]bool)
for _, a := range addrs.Addrs {
addr, err := a.GetTCPAddress()
if err == nil && !dups[addr] {
dups[addr] = true
s.discovery.BackFill(addr)
}
}
return nil
}
// handleGetAddrCmd sends to the peer some good addresses that we know of.
func (s *Server) handleGetAddrCmd(p Peer) error {
addrs := s.discovery.GoodPeers()
if len(addrs) > payload.MaxAddrsCount {
addrs = addrs[:payload.MaxAddrsCount]
}
alist := payload.NewAddressList(len(addrs))
ts := time.Now()
for i, addr := range addrs {
// we know it's a good address, so it can't fail
netaddr, _ := net.ResolveTCPAddr("tcp", addr.Address)
alist.Addrs[i] = payload.NewAddressAndTime(netaddr, ts, addr.Capabilities)
}
return p.EnqueueP2PMessage(NewMessage(CMDAddr, alist))
}
// requestBlocks sends a CMDGetBlockByIndex message to the peer
// to sync up in blocks. A maximum of maxBlockBatch will
// send at once. Two things we need to take care of:
// 1. If possible, blocks should be fetched in parallel.
// height..+500 to one peer, height+500..+1000 to another etc.
// 2. Every block must eventually be fetched even if peer sends no answer.
// Thus the following algorithm is used:
// 1. Block range is divided into chunks of payload.MaxHashesCount.
// 2. Send requests for chunk in increasing order.
// 3. After all requests were sent, request random height.
func (s *Server) requestBlocks(p Peer) error {
var currHeight = s.chain.BlockHeight()
var peerHeight = p.LastBlockIndex()
var needHeight uint32
// lastRequestedHeight can only be increased.
for {
old := s.lastRequestedHeight.Load()
if old <= currHeight {
needHeight = currHeight + 1
if !s.lastRequestedHeight.CAS(old, needHeight) {
continue
}
} else if old < currHeight+(blockCacheSize-payload.MaxHashesCount) {
needHeight = currHeight + 1
if peerHeight > old+payload.MaxHashesCount {
needHeight = old + payload.MaxHashesCount
if !s.lastRequestedHeight.CAS(old, needHeight) {
continue
}
}
} else {
index := mrand.Intn(blockCacheSize / payload.MaxHashesCount)
needHeight = currHeight + 1 + uint32(index*payload.MaxHashesCount)
}
break
}
payload := payload.NewGetBlockByIndex(needHeight, -1)
return p.EnqueueP2PMessage(NewMessage(CMDGetBlockByIndex, payload))
}
// handleMessage processes the given message.
func (s *Server) handleMessage(peer Peer, msg *Message) error {
s.log.Debug("got msg",
zap.Stringer("addr", peer.RemoteAddr()),
zap.String("type", msg.Command.String()))
if peer.Handshaked() {
if inv, ok := msg.Payload.(*payload.Inventory); ok {
if !inv.Type.Valid(s.chain.P2PSigExtensionsEnabled()) || len(inv.Hashes) == 0 {
return errInvalidInvType
}
}
switch msg.Command {
case CMDAddr:
addrs := msg.Payload.(*payload.AddressList)
return s.handleAddrCmd(peer, addrs)
case CMDGetAddr:
// it has no payload
return s.handleGetAddrCmd(peer)
case CMDGetBlocks:
gb := msg.Payload.(*payload.GetBlocks)
return s.handleGetBlocksCmd(peer, gb)
case CMDGetBlockByIndex:
gbd := msg.Payload.(*payload.GetBlockByIndex)
return s.handleGetBlockByIndexCmd(peer, gbd)
case CMDGetData:
inv := msg.Payload.(*payload.Inventory)
return s.handleGetDataCmd(peer, inv)
case CMDGetHeaders:
gh := msg.Payload.(*payload.GetBlockByIndex)
return s.handleGetHeadersCmd(peer, gh)
case CMDInv:
inventory := msg.Payload.(*payload.Inventory)
return s.handleInvCmd(peer, inventory)
case CMDMempool:
// no payload
return s.handleMempoolCmd(peer)
case CMDBlock:
block := msg.Payload.(*block.Block)
return s.handleBlockCmd(peer, block)
case CMDExtensible:
cp := msg.Payload.(*payload.Extensible)
return s.handleExtensibleCmd(cp)
case CMDTX:
tx := msg.Payload.(*transaction.Transaction)
return s.handleTxCmd(tx)
case CMDP2PNotaryRequest:
r := msg.Payload.(*payload.P2PNotaryRequest)
return s.handleP2PNotaryRequestCmd(r)
case CMDPing:
ping := msg.Payload.(*payload.Ping)
return s.handlePing(peer, ping)
case CMDPong:
pong := msg.Payload.(*payload.Ping)
return s.handlePong(peer, pong)
case CMDVersion, CMDVerack:
return fmt.Errorf("received '%s' after the handshake", msg.Command.String())
}
} else {
switch msg.Command {
case CMDVersion:
version := msg.Payload.(*payload.Version)
return s.handleVersionCmd(peer, version)
case CMDVerack:
err := peer.HandleVersionAck()
if err != nil {
return err
}
go peer.StartProtocol()
s.tryStartConsensus()
default:
return fmt.Errorf("received '%s' during handshake", msg.Command.String())
}
}
return nil
}
func (s *Server) handleNewPayload(p *payload.Extensible) {
_, err := s.extensiblePool.Add(p)
if err != nil {
s.log.Error("created payload is not valid", zap.Error(err))
return
}
msg := NewMessage(CMDInv, payload.NewInventory(payload.ExtensibleType, []util.Uint256{p.Hash()}))
switch p.Category {
case consensus.Category:
// It's high priority because it directly affects consensus process,
// even though it's just an inv.
s.broadcastHPMessage(msg)
default:
s.broadcastMessage(msg)
}
}
func (s *Server) requestTx(hashes ...util.Uint256) {
if len(hashes) == 0 {
return
}
for i := 0; i <= len(hashes)/payload.MaxHashesCount; i++ {
start := i * payload.MaxHashesCount
stop := (i + 1) * payload.MaxHashesCount
if stop > len(hashes) {
stop = len(hashes)
}
if start == stop {
break
}
msg := NewMessage(CMDGetData, payload.NewInventory(payload.TXType, hashes[start:stop]))
// It's high priority because it directly affects consensus process,
// even though it's getdata.
s.broadcastHPMessage(msg)
}
}
// iteratePeersWithSendMsg sends given message to all peers using two functions
// passed, one is to send the message and the other is to filtrate peers (the
// peer is considered invalid if it returns false).
func (s *Server) iteratePeersWithSendMsg(msg *Message, send func(Peer, bool, []byte) error, peerOK func(Peer) bool) {
// Get a copy of s.peers to avoid holding a lock while sending.
peers := s.Peers()
if len(peers) == 0 {
return
}
pkt, err := msg.Bytes()
if err != nil {
return
}
success := make(map[Peer]bool, len(peers))
okCount := 0
sentCount := 0
for peer := range peers {
if peerOK != nil && !peerOK(peer) {
success[peer] = false
continue
}
okCount++
if err := send(peer, false, pkt); err != nil {
continue
}
if msg.Command == CMDGetAddr {
peer.AddGetAddrSent()
}
success[peer] = true
sentCount++
}
// Send to at least 2/3 of good peers.
if 3*sentCount >= 2*okCount {
return
}
// Perform blocking send now.
for peer := range peers {
if _, ok := success[peer]; ok || peerOK != nil && !peerOK(peer) {
continue
}
if err := send(peer, true, pkt); err != nil {
continue
}
if msg.Command == CMDGetAddr {
peer.AddGetAddrSent()
}
sentCount++
if 3*sentCount >= 2*okCount {
return
}
}
}
// broadcastMessage sends the message to all available peers.
func (s *Server) broadcastMessage(msg *Message) {
s.iteratePeersWithSendMsg(msg, Peer.EnqueuePacket, nil)
}
// broadcastHPMessage sends the high-priority message to all available peers.
func (s *Server) broadcastHPMessage(msg *Message) {
s.iteratePeersWithSendMsg(msg, Peer.EnqueueHPPacket, nil)
}
// relayBlocksLoop subscribes to new blocks in the ledger and broadcasts them
// to the network. Intended to be run as a separate goroutine.
func (s *Server) relayBlocksLoop() {
ch := make(chan *block.Block, 2) // Some buffering to smooth out possible egressing delays.
s.chain.SubscribeForBlocks(ch)
for {
select {
case <-s.quit:
s.chain.UnsubscribeFromBlocks(ch)
return
case b := <-ch:
msg := NewMessage(CMDInv, payload.NewInventory(payload.BlockType, []util.Uint256{b.Hash()}))
// Filter out nodes that are more current (avoid spamming the network
// during initial sync).
s.iteratePeersWithSendMsg(msg, Peer.EnqueuePacket, func(p Peer) bool {
return p.Handshaked() && p.LastBlockIndex() < b.Index
})
s.extensiblePool.RemoveStale(b.Index)
}
}
}
// verifyAndPoolTX verifies the TX and adds it to the local mempool.
func (s *Server) verifyAndPoolTX(t *transaction.Transaction) error {
return s.chain.PoolTx(t)
}
// RelayTxn a new transaction to the local node and the connected peers.
// Reference: the method OnRelay in C#: https://github.com/neo-project/neo/blob/master/neo/Network/P2P/LocalNode.cs#L159
func (s *Server) RelayTxn(t *transaction.Transaction) error {
err := s.verifyAndPoolTX(t)
if err == nil {
s.broadcastTX(t, nil)
}
return err
}
// broadcastTX broadcasts an inventory message about new transaction.
func (s *Server) broadcastTX(t *transaction.Transaction, _ interface{}) {
select {
case s.transactions <- t:
case <-s.quit:
}
}
func (s *Server) broadcastTxHashes(hs []util.Uint256) {
msg := NewMessage(CMDInv, payload.NewInventory(payload.TXType, hs))
// We need to filter out non-relaying nodes, so plain broadcast
// functions don't fit here.
s.iteratePeersWithSendMsg(msg, Peer.EnqueuePacket, Peer.IsFullNode)
}
// initStaleMemPools initializes mempools for stale tx/payload processing.
func (s *Server) initStaleMemPools() {
cfg := s.chain.GetConfig()
threshold := 5
if cfg.ValidatorsCount*2 > threshold {
threshold = cfg.ValidatorsCount * 2
}
mp := s.chain.GetMemPool()
mp.SetResendThreshold(uint32(threshold), s.broadcastTX)
if s.chain.P2PSigExtensionsEnabled() {
s.notaryRequestPool.SetResendThreshold(uint32(threshold), s.broadcastP2PNotaryRequestPayload)
}
}
// broadcastTxLoop is a loop for batching and sending
// transactions hashes in an INV payload.
func (s *Server) broadcastTxLoop() {
const (
batchTime = time.Millisecond * 50
batchSize = 32
)
txs := make([]util.Uint256, 0, batchSize)
var timer *time.Timer
timerCh := func() <-chan time.Time {
if timer == nil {
return nil
}
return timer.C
}
broadcast := func() {
s.broadcastTxHashes(txs)
txs = txs[:0]
if timer != nil {
timer.Stop()
}
}
for {
select {
case <-s.quit:
loop:
for {
select {
case <-s.transactions:
default:
break loop
}
}
return
case <-timerCh():
if len(txs) > 0 {
broadcast()
}
case tx := <-s.transactions:
if len(txs) == 0 {
timer = time.NewTimer(batchTime)
}
txs = append(txs, tx.Hash())
if len(txs) == batchSize {
broadcast()
}
}
}
}
// Port returns actual server port. It may differs from that of server.Config.
func (s *Server) Port() (uint16, error) {
var port uint16
_, portStr, err := net.SplitHostPort(s.transport.Address())
if err != nil {
port = s.ServerConfig.Port
} else {
p, err := strconv.ParseUint(portStr, 10, 16)
if err != nil {
return 0, err
}
port = uint16(p)
}
return port, nil
}