neoneo-go/pkg/network/server.go
2020-11-20 17:16:32 +03:00

993 lines
26 KiB
Go

package network
import (
"crypto/rand"
"encoding/binary"
"errors"
"fmt"
"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"
"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/transaction"
"github.com/nspcc-dev/neo-go/pkg/network/capability"
"github.com/nspcc-dev/neo-go/pkg/network/payload"
"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
lock sync.RWMutex
peers map[Peer]bool
register chan Peer
unregister chan peerDrop
quit chan struct{}
transactions chan *transaction.Transaction
consensusStarted *atomic.Bool
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) {
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),
log: log,
transactions: make(chan *transaction.Transaction, 64),
}
s.bQueue = newBlockQueue(maxBlockBatch, chain, log, func(b *block.Block) {
if !s.consensusStarted.Load() {
s.tryStartConsensus()
}
})
srv, err := consensus.NewService(consensus.Config{
Logger: log,
Broadcast: s.handleNewPayload,
Chain: chain,
RequestTx: s.requestTx,
Wallet: config.Wallet,
TimePerBlock: config.TimePerBlock,
})
if err != nil {
return nil, err
}
s.consensus = srv
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 = NewTCPTransport(s, net.JoinHostPort(config.Address, strconv.Itoa(int(config.Port))), s.log)
s.discovery = NewDefaultDiscovery(
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.initStaleTxMemPool()
go s.broadcastTxLoop()
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()
close(s.quit)
}
// 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 {
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, nil))
}
// 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.ConsensusType: func(h util.Uint256) bool {
cp := s.consensus.GetPayload(h)
return cp != nil
},
}
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.ConsensusType {
return p.EnqueueHPPacket(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.ConsensusType:
if cp := s.consensus.GetPayload(hash); cp != nil {
msg = NewMessage(CMDConsensus, cp)
}
}
if msg != nil {
pkt, err := msg.Bytes()
if err == nil {
if inv.Type == payload.ConsensusType {
err = p.EnqueueHPPacket(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)
}
// handleConsensusCmd processes received consensus payload.
// It never returns an error.
func (s *Server) handleConsensusCmd(cp *consensus.Payload) error {
s.consensus.OnPayload(cp)
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) == RelaySucceed {
s.consensus.OnTransaction(tx)
s.broadcastTX(tx)
}
return nil
}
// handleAddrCmd will process received addresses.
func (s *Server) handleAddrCmd(p Peer, addrs *payload.AddressList) error {
for _, a := range addrs.Addrs {
addr, err := a.GetTCPAddress()
if err == nil {
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.
func (s *Server) requestBlocks(p Peer) error {
payload := payload.NewGetBlockByIndex(s.chain.BlockHeight()+1, -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() || 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 CMDConsensus:
cp := msg.Payload.(*consensus.Payload)
return s.handleConsensusCmd(cp)
case CMDTX:
tx := msg.Payload.(*transaction.Transaction)
return s.handleTxCmd(tx)
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 *consensus.Payload) {
msg := NewMessage(CMDInv, payload.NewInventory(payload.ConsensusType, []util.Uint256{p.Hash()}))
// It's high priority because it directly affects consensus process,
// even though it's just an inv.
s.broadcastHPMessage(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)
}
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, []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
}
for peer := range peers {
if peerOK != nil && !peerOK(peer) {
continue
}
// Who cares about these messages anyway?
_ = send(peer, pkt)
}
}
// 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
})
}
}
}
// verifyAndPoolTX verifies the TX and adds it to the local mempool.
func (s *Server) verifyAndPoolTX(t *transaction.Transaction) RelayReason {
if err := s.chain.PoolTx(t); err != nil {
switch {
case errors.Is(err, core.ErrAlreadyExists):
return RelayAlreadyExists
case errors.Is(err, core.ErrOOM):
return RelayOutOfMemory
case errors.Is(err, core.ErrPolicy):
return RelayPolicyFail
default:
return RelayInvalid
}
}
return RelaySucceed
}
// 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) RelayReason {
ret := s.verifyAndPoolTX(t)
if ret == RelaySucceed {
s.broadcastTX(t)
}
return ret
}
// broadcastTX broadcasts an inventory message about new transaction.
func (s *Server) broadcastTX(t *transaction.Transaction) {
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)
}
// initStaleTxMemPool initializes mempool for stale tx processing.
func (s *Server) initStaleTxMemPool() {
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)
}
// 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
}