add observer

listener/ftcp/listener.go

@@ -12,6 +12,7 @@ import (
 	limiter "github.com/go-gost/x/limiter/traffic/wrapper"
 	metrics "github.com/go-gost/x/metrics/wrapper"
 	"github.com/go-gost/x/registry"
+	stats "github.com/go-gost/x/stats/wrapper"
 	"github.com/xtaci/tcpraw"
 )
 
@@ -52,6 +53,7 @@ func (l *ftcpListener) Init(md md.Metadata) (err error) {
 		return
 	}
 	conn = metrics.WrapPacketConn(l.options.Service, conn)
+	conn = stats.WrapPacketConn(conn, l.options.Stats)
 	conn = admission.WrapPacketConn(l.options.Admission, conn)
 	conn = limiter.WrapPacketConn(l.options.TrafficLimiter, conn)