You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
265 lines
6.3 KiB
265 lines
6.3 KiB
package p2p
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"fmt"
|
|
"math/rand"
|
|
"reflect"
|
|
"time"
|
|
|
|
. "github.com/tendermint/go-common"
|
|
"github.com/tendermint/go-wire"
|
|
)
|
|
|
|
var pexErrInvalidMessage = errors.New("Invalid PEX message")
|
|
|
|
const (
|
|
PexChannel = byte(0x00)
|
|
ensurePeersPeriodSeconds = 30
|
|
minNumOutboundPeers = 10
|
|
maxPexMessageSize = 1048576 // 1MB
|
|
)
|
|
|
|
/*
|
|
PEXReactor handles PEX (peer exchange) and ensures that an
|
|
adequate number of peers are connected to the switch.
|
|
*/
|
|
type PEXReactor struct {
|
|
BaseReactor
|
|
|
|
sw *Switch
|
|
book *AddrBook
|
|
}
|
|
|
|
func NewPEXReactor(book *AddrBook) *PEXReactor {
|
|
pexR := &PEXReactor{
|
|
book: book,
|
|
}
|
|
pexR.BaseReactor = *NewBaseReactor(log, "PEXReactor", pexR)
|
|
return pexR
|
|
}
|
|
|
|
func (pexR *PEXReactor) OnStart() error {
|
|
pexR.BaseReactor.OnStart()
|
|
pexR.book.Start()
|
|
go pexR.ensurePeersRoutine()
|
|
return nil
|
|
}
|
|
|
|
func (pexR *PEXReactor) OnStop() {
|
|
pexR.BaseReactor.OnStop()
|
|
pexR.book.Stop()
|
|
}
|
|
|
|
// Implements Reactor
|
|
func (pexR *PEXReactor) GetChannels() []*ChannelDescriptor {
|
|
return []*ChannelDescriptor{
|
|
&ChannelDescriptor{
|
|
ID: PexChannel,
|
|
Priority: 1,
|
|
SendQueueCapacity: 10,
|
|
},
|
|
}
|
|
}
|
|
|
|
// Implements Reactor
|
|
func (pexR *PEXReactor) AddPeer(peer *Peer) {
|
|
// Add the peer to the address book
|
|
netAddr, err := NewNetAddressString(peer.ListenAddr)
|
|
if err != nil {
|
|
// this should never happen
|
|
log.Error("Error in AddPeer: invalid peer address", "addr", peer.ListenAddr, "error", err)
|
|
return
|
|
}
|
|
|
|
if peer.IsOutbound() {
|
|
if pexR.book.NeedMoreAddrs() {
|
|
pexR.RequestPEX(peer)
|
|
}
|
|
} else {
|
|
// For inbound connections, the peer is its own source
|
|
// (For outbound peers, the address is already in the books)
|
|
pexR.book.AddAddress(netAddr, netAddr)
|
|
}
|
|
}
|
|
|
|
// Implements Reactor
|
|
func (pexR *PEXReactor) RemovePeer(peer *Peer, reason interface{}) {
|
|
// TODO
|
|
}
|
|
|
|
// Implements Reactor
|
|
// Handles incoming PEX messages.
|
|
func (pexR *PEXReactor) Receive(chID byte, src *Peer, msgBytes []byte) {
|
|
|
|
// decode message
|
|
_, msg, err := DecodeMessage(msgBytes)
|
|
if err != nil {
|
|
log.Warn("Error decoding message", "error", err)
|
|
return
|
|
}
|
|
log.Notice("Received message", "msg", msg)
|
|
|
|
switch msg := msg.(type) {
|
|
case *pexRequestMessage:
|
|
// src requested some peers.
|
|
// TODO: prevent abuse.
|
|
pexR.SendAddrs(src, pexR.book.GetSelection())
|
|
case *pexAddrsMessage:
|
|
// We received some peer addresses from src.
|
|
// TODO: prevent abuse.
|
|
// (We don't want to get spammed with bad peers)
|
|
srcAddr := src.Connection().RemoteAddress
|
|
for _, addr := range msg.Addrs {
|
|
if addr != nil {
|
|
pexR.book.AddAddress(addr, srcAddr)
|
|
}
|
|
}
|
|
default:
|
|
log.Warn(Fmt("Unknown message type %v", reflect.TypeOf(msg)))
|
|
}
|
|
}
|
|
|
|
// Asks peer for more addresses.
|
|
func (pexR *PEXReactor) RequestPEX(peer *Peer) {
|
|
peer.Send(PexChannel, struct{ PexMessage }{&pexRequestMessage{}})
|
|
}
|
|
|
|
func (pexR *PEXReactor) SendAddrs(peer *Peer, addrs []*NetAddress) {
|
|
peer.Send(PexChannel, struct{ PexMessage }{&pexAddrsMessage{Addrs: addrs}})
|
|
}
|
|
|
|
// Ensures that sufficient peers are connected. (continuous)
|
|
func (pexR *PEXReactor) ensurePeersRoutine() {
|
|
// Randomize when routine starts
|
|
time.Sleep(time.Duration(rand.Int63n(500*ensurePeersPeriodSeconds)) * time.Millisecond)
|
|
|
|
// fire once immediately.
|
|
pexR.ensurePeers()
|
|
// fire periodically
|
|
timer := NewRepeatTimer("pex", ensurePeersPeriodSeconds*time.Second)
|
|
FOR_LOOP:
|
|
for {
|
|
select {
|
|
case <-timer.Ch:
|
|
pexR.ensurePeers()
|
|
case <-pexR.Quit:
|
|
break FOR_LOOP
|
|
}
|
|
}
|
|
|
|
// Cleanup
|
|
timer.Stop()
|
|
}
|
|
|
|
// Ensures that sufficient peers are connected. (once)
|
|
func (pexR *PEXReactor) ensurePeers() {
|
|
numOutPeers, _, numDialing := pexR.Switch.NumPeers()
|
|
numToDial := minNumOutboundPeers - (numOutPeers + numDialing)
|
|
log.Info("Ensure peers", "numOutPeers", numOutPeers, "numDialing", numDialing, "numToDial", numToDial)
|
|
if numToDial <= 0 {
|
|
return
|
|
}
|
|
toDial := NewCMap()
|
|
|
|
// Try to pick numToDial addresses to dial.
|
|
// TODO: improve logic.
|
|
for i := 0; i < numToDial; i++ {
|
|
newBias := MinInt(numOutPeers, 8)*10 + 10
|
|
var picked *NetAddress
|
|
// Try to fetch a new peer 3 times.
|
|
// This caps the maximum number of tries to 3 * numToDial.
|
|
for j := 0; j < 3; j++ {
|
|
try := pexR.book.PickAddress(newBias)
|
|
if try == nil {
|
|
break
|
|
}
|
|
alreadySelected := toDial.Has(try.IP.String())
|
|
alreadyDialing := pexR.Switch.IsDialing(try)
|
|
alreadyConnected := pexR.Switch.Peers().Has(try.IP.String())
|
|
if alreadySelected || alreadyDialing || alreadyConnected {
|
|
/*
|
|
log.Info("Cannot dial address", "addr", try,
|
|
"alreadySelected", alreadySelected,
|
|
"alreadyDialing", alreadyDialing,
|
|
"alreadyConnected", alreadyConnected)
|
|
*/
|
|
continue
|
|
} else {
|
|
log.Info("Will dial address", "addr", try)
|
|
picked = try
|
|
break
|
|
}
|
|
}
|
|
if picked == nil {
|
|
continue
|
|
}
|
|
toDial.Set(picked.IP.String(), picked)
|
|
}
|
|
|
|
// Dial picked addresses
|
|
for _, item := range toDial.Values() {
|
|
go func(picked *NetAddress) {
|
|
_, err := pexR.Switch.DialPeerWithAddress(picked)
|
|
if err != nil {
|
|
pexR.book.MarkAttempt(picked)
|
|
}
|
|
}(item.(*NetAddress))
|
|
}
|
|
|
|
// If we need more addresses, pick a random peer and ask for more.
|
|
if pexR.book.NeedMoreAddrs() {
|
|
if peers := pexR.Switch.Peers().List(); len(peers) > 0 {
|
|
i := rand.Int() % len(peers)
|
|
peer := peers[i]
|
|
log.Info("No addresses to dial. Sending pexRequest to random peer", "peer", peer)
|
|
pexR.RequestPEX(peer)
|
|
}
|
|
}
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// Messages
|
|
|
|
const (
|
|
msgTypeRequest = byte(0x01)
|
|
msgTypeAddrs = byte(0x02)
|
|
)
|
|
|
|
type PexMessage interface{}
|
|
|
|
var _ = wire.RegisterInterface(
|
|
struct{ PexMessage }{},
|
|
wire.ConcreteType{&pexRequestMessage{}, msgTypeRequest},
|
|
wire.ConcreteType{&pexAddrsMessage{}, msgTypeAddrs},
|
|
)
|
|
|
|
func DecodeMessage(bz []byte) (msgType byte, msg PexMessage, err error) {
|
|
msgType = bz[0]
|
|
n := new(int)
|
|
r := bytes.NewReader(bz)
|
|
msg = wire.ReadBinary(struct{ PexMessage }{}, r, maxPexMessageSize, n, &err).(struct{ PexMessage }).PexMessage
|
|
return
|
|
}
|
|
|
|
/*
|
|
A pexRequestMessage requests additional peer addresses.
|
|
*/
|
|
type pexRequestMessage struct {
|
|
}
|
|
|
|
func (m *pexRequestMessage) String() string {
|
|
return "[pexRequest]"
|
|
}
|
|
|
|
/*
|
|
A message with announced peer addresses.
|
|
*/
|
|
type pexAddrsMessage struct {
|
|
Addrs []*NetAddress
|
|
}
|
|
|
|
func (m *pexAddrsMessage) String() string {
|
|
return fmt.Sprintf("[pexAddrs %v]", m.Addrs)
|
|
}
|