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.
278 lines
6.1 KiB
278 lines
6.1 KiB
package p2p
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"sync/atomic"
|
|
"time"
|
|
|
|
. "github.com/tendermint/tendermint/binary"
|
|
. "github.com/tendermint/tendermint/common"
|
|
)
|
|
|
|
var pexErrInvalidMessage = errors.New("Invalid PEX message")
|
|
|
|
const (
|
|
pexCh = byte(0x00)
|
|
ensurePeersPeriodSeconds = 30
|
|
minNumOutboundPeers = 10
|
|
maxNumPeers = 50
|
|
)
|
|
|
|
/*
|
|
PeerManager handles PEX (peer exchange) and ensures that an
|
|
adequate number of peers are connected to the switch.
|
|
*/
|
|
type PeerManager struct {
|
|
sw *Switch
|
|
swEvents chan interface{}
|
|
book *AddrBook
|
|
quit chan struct{}
|
|
started uint32
|
|
stopped uint32
|
|
}
|
|
|
|
func NewPeerManager(sw *Switch, book *AddrBook) *PeerManager {
|
|
swEvents := make(chan interface{})
|
|
sw.AddEventListener("PeerManager.swEvents", swEvents)
|
|
pm := &PeerManager{
|
|
sw: sw,
|
|
swEvents: swEvents,
|
|
book: book,
|
|
quit: make(chan struct{}),
|
|
}
|
|
return pm
|
|
}
|
|
|
|
func (pm *PeerManager) Start() {
|
|
if atomic.CompareAndSwapUint32(&pm.started, 0, 1) {
|
|
log.Info("Starting PeerManager")
|
|
go pm.switchEventsHandler()
|
|
go pm.requestHandler()
|
|
go pm.ensurePeersHandler()
|
|
}
|
|
}
|
|
|
|
func (pm *PeerManager) Stop() {
|
|
if atomic.CompareAndSwapUint32(&pm.stopped, 0, 1) {
|
|
log.Info("Stopping PeerManager")
|
|
close(pm.quit)
|
|
close(pm.swEvents)
|
|
}
|
|
}
|
|
|
|
// Asks peer for more addresses.
|
|
func (pm *PeerManager) RequestPEX(peer *Peer) {
|
|
msg := &pexRequestMessage{}
|
|
tm := TypedMessage{msgTypeRequest, msg}
|
|
peer.TrySend(pexCh, tm.Bytes())
|
|
}
|
|
|
|
func (pm *PeerManager) SendAddrs(peer *Peer, addrs []*NetAddress) {
|
|
msg := &pexAddrsMessage{Addrs: addrs}
|
|
tm := TypedMessage{msgTypeAddrs, msg}
|
|
peer.Send(pexCh, tm.Bytes())
|
|
}
|
|
|
|
// For new outbound peers, announce our listener addresses if any,
|
|
// and if .book needs more addresses, ask for them.
|
|
func (pm *PeerManager) switchEventsHandler() {
|
|
for {
|
|
swEvent, ok := <-pm.swEvents
|
|
if !ok {
|
|
break
|
|
}
|
|
switch swEvent.(type) {
|
|
case SwitchEventNewPeer:
|
|
event := swEvent.(SwitchEventNewPeer)
|
|
if event.Peer.IsOutbound() {
|
|
pm.SendAddrs(event.Peer, pm.book.OurAddresses())
|
|
if pm.book.NeedMoreAddrs() {
|
|
pm.RequestPEX(event.Peer)
|
|
}
|
|
}
|
|
case SwitchEventDonePeer:
|
|
// TODO
|
|
}
|
|
}
|
|
}
|
|
|
|
// Ensures that sufficient peers are connected. (continuous)
|
|
func (pm *PeerManager) ensurePeersHandler() {
|
|
// fire once immediately.
|
|
pm.ensurePeers()
|
|
// fire periodically
|
|
timer := NewRepeatTimer(ensurePeersPeriodSeconds * time.Second)
|
|
FOR_LOOP:
|
|
for {
|
|
select {
|
|
case <-timer.Ch:
|
|
pm.ensurePeers()
|
|
case <-pm.quit:
|
|
break FOR_LOOP
|
|
}
|
|
}
|
|
|
|
// Cleanup
|
|
timer.Stop()
|
|
}
|
|
|
|
// Ensures that sufficient peers are connected. (once)
|
|
func (pm *PeerManager) ensurePeers() {
|
|
numOutPeers, _, numDialing := pm.sw.NumPeers()
|
|
numToDial := minNumOutboundPeers - (numOutPeers + numDialing)
|
|
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; i < 3; j++ {
|
|
picked = pm.book.PickAddress(newBias)
|
|
if picked == nil {
|
|
return
|
|
}
|
|
if toDial.Has(picked.String()) ||
|
|
pm.sw.IsDialing(picked) ||
|
|
pm.sw.Peers().Has(picked) {
|
|
continue
|
|
} else {
|
|
break
|
|
}
|
|
}
|
|
if picked == nil {
|
|
continue
|
|
}
|
|
toDial.Set(picked.String(), picked)
|
|
}
|
|
|
|
// Dial picked addresses
|
|
for _, item := range toDial.Values() {
|
|
picked := item.(*NetAddress)
|
|
go func() {
|
|
_, err := pm.sw.DialPeerWithAddress(picked)
|
|
if err != nil {
|
|
pm.book.MarkAttempt(picked)
|
|
}
|
|
}()
|
|
}
|
|
}
|
|
|
|
// Handles incoming PEX messages.
|
|
func (pm *PeerManager) requestHandler() {
|
|
|
|
for {
|
|
inBytes, ok := pm.sw.Receive(pexCh) // {Peer, Time, Packet}
|
|
if !ok {
|
|
// Client has stopped
|
|
break
|
|
}
|
|
|
|
// decode message
|
|
msg := decodeMessage(inBytes.Bytes)
|
|
log.Info("requestHandler received %v", msg)
|
|
|
|
switch msg.(type) {
|
|
case *pexRequestMessage:
|
|
// inBytes.MConn._peer requested some peers.
|
|
// TODO: prevent abuse.
|
|
addrs := pm.book.GetSelection()
|
|
msg := &pexAddrsMessage{Addrs: addrs}
|
|
tm := TypedMessage{msgTypeRequest, msg}
|
|
queued := inBytes.MConn._peer.TrySend(pexCh, tm.Bytes())
|
|
if !queued {
|
|
// ignore
|
|
}
|
|
case *pexAddrsMessage:
|
|
// We received some peer addresses from inBytes.MConn._peer.
|
|
// TODO: prevent abuse.
|
|
// (We don't want to get spammed with bad peers)
|
|
srcAddr := inBytes.MConn._peer.RemoteAddress()
|
|
for _, addr := range msg.(*pexAddrsMessage).Addrs {
|
|
pm.book.AddAddress(addr, srcAddr)
|
|
}
|
|
default:
|
|
// Ignore unknown message.
|
|
// pm.sw.StopPeerForError(inBytes.MConn._peer, pexErrInvalidMessage)
|
|
}
|
|
}
|
|
|
|
// Cleanup
|
|
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
|
|
/* Messages */
|
|
|
|
const (
|
|
msgTypeUnknown = Byte(0x00)
|
|
msgTypeRequest = Byte(0x01)
|
|
msgTypeAddrs = Byte(0x02)
|
|
)
|
|
|
|
// TODO: check for unnecessary extra bytes at the end.
|
|
func decodeMessage(bz ByteSlice) (msg interface{}) {
|
|
// log.Debug("decoding msg bytes: %X", bz)
|
|
switch Byte(bz[0]) {
|
|
case msgTypeRequest:
|
|
return &pexRequestMessage{}
|
|
case msgTypeAddrs:
|
|
return readPexAddrsMessage(bytes.NewReader(bz[1:]))
|
|
default:
|
|
return nil
|
|
}
|
|
}
|
|
|
|
/*
|
|
A pexRequestMessage requests additional peer addresses.
|
|
*/
|
|
type pexRequestMessage struct {
|
|
}
|
|
|
|
func (m *pexRequestMessage) WriteTo(w io.Writer) (n int64, err error) {
|
|
return // nothing to write.
|
|
}
|
|
|
|
func (m *pexRequestMessage) String() string {
|
|
return "[pexRequest]"
|
|
}
|
|
|
|
/*
|
|
A message with announced peer addresses.
|
|
*/
|
|
type pexAddrsMessage struct {
|
|
Addrs []*NetAddress
|
|
}
|
|
|
|
func readPexAddrsMessage(r io.Reader) *pexAddrsMessage {
|
|
numAddrs := int(ReadUInt32(r))
|
|
addrs := []*NetAddress{}
|
|
for i := 0; i < numAddrs; i++ {
|
|
addr := ReadNetAddress(r)
|
|
addrs = append(addrs, addr)
|
|
}
|
|
return &pexAddrsMessage{
|
|
Addrs: addrs,
|
|
}
|
|
}
|
|
|
|
func (m *pexAddrsMessage) WriteTo(w io.Writer) (n int64, err error) {
|
|
n, err = WriteTo(UInt32(len(m.Addrs)), w, n, err)
|
|
for _, addr := range m.Addrs {
|
|
n, err = WriteTo(addr, w, n, err)
|
|
}
|
|
return
|
|
}
|
|
|
|
func (m *pexAddrsMessage) String() string {
|
|
return fmt.Sprintf("[pexAddrs %v]", m.Addrs)
|
|
}
|