forked from libp2p/go-libp2p
/
ping.go
129 lines (106 loc) · 2.1 KB
/
ping.go
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package ping
import (
"bytes"
"context"
"errors"
"io"
"time"
u "github.com/ipfs/go-ipfs-util"
logging "github.com/ipfs/go-log"
host "github.com/libp2p/go-libp2p-host"
inet "github.com/libp2p/go-libp2p-net"
peer "github.com/libp2p/go-libp2p-peer"
)
var log = logging.Logger("ping")
const PingSize = 32
const ID = "/ipfs/ping/1.0.0"
const pingTimeout = time.Second * 60
type PingService struct {
Host host.Host
}
func NewPingService(h host.Host) *PingService {
ps := &PingService{h}
h.SetStreamHandler(ID, ps.PingHandler)
return ps
}
func (p *PingService) PingHandler(s inet.Stream) {
buf := make([]byte, PingSize)
errCh := make(chan error, 1)
defer close(errCh)
timer := time.NewTimer(pingTimeout)
defer timer.Stop()
go func() {
select {
case <-timer.C:
log.Debug("ping timeout")
case err, ok := <-errCh:
if ok {
log.Debug(err)
} else {
log.Error("ping loop failed without error")
}
}
s.Reset()
}()
for {
_, err := io.ReadFull(s, buf)
if err != nil {
errCh <- err
return
}
_, err = s.Write(buf)
if err != nil {
errCh <- err
return
}
timer.Reset(pingTimeout)
}
}
func (ps *PingService) Ping(ctx context.Context, p peer.ID) (<-chan time.Duration, error) {
s, err := ps.Host.NewStream(ctx, p, ID)
if err != nil {
return nil, err
}
out := make(chan time.Duration)
go func() {
defer close(out)
defer s.Reset()
for {
select {
case <-ctx.Done():
return
default:
t, err := ping(s)
if err != nil {
log.Debugf("ping error: %s", err)
return
}
ps.Host.Peerstore().RecordLatency(p, t)
select {
case out <- t:
case <-ctx.Done():
return
}
}
}
}()
return out, nil
}
func ping(s inet.Stream) (time.Duration, error) {
buf := make([]byte, PingSize)
u.NewTimeSeededRand().Read(buf)
before := time.Now()
_, err := s.Write(buf)
if err != nil {
return 0, err
}
rbuf := make([]byte, PingSize)
_, err = io.ReadFull(s, rbuf)
if err != nil {
return 0, err
}
if !bytes.Equal(buf, rbuf) {
return 0, errors.New("ping packet was incorrect!")
}
return time.Since(before), nil
}