package net import ( "b612.me/starlog" "context" "fmt" "net" "strings" "sync/atomic" ) type NatTesterServer struct { MainPort string AltPort string MainIP string AltIP string LogPath string stopCtx context.Context stopFn context.CancelFunc maina *net.UDPConn mainb *net.UDPConn alt *net.UDPConn running int32 } func (n *NatTesterServer) Run() error { if atomic.LoadInt32(&n.running) > 0 { starlog.Errorln("already running") return fmt.Errorf("already running") } atomic.StoreInt32(&n.running, 1) defer atomic.StoreInt32(&n.running, 0) if n.LogPath != "" { starlog.SetLogFile(n.LogPath, starlog.Std, true) starlog.Infof("Log file set to %s\n", n.LogPath) } starlog.Infof("MainPort: %s\n", n.MainPort) starlog.Infof("AltPort: %s\n", n.AltPort) tmp, err := net.Dial("udp", "8.8.8.8:53") if err != nil { return err } starlog.Infof("Current Output IP: %s\n", tmp.LocalAddr().(*net.UDPAddr).IP.String()) tmp.Close() n.stopCtx, n.stopFn = context.WithCancel(context.Background()) mainaaddr, err := net.ResolveUDPAddr("udp", n.MainIP+":"+n.MainPort) if err != nil { return err } mainbaddr, err := net.ResolveUDPAddr("udp", n.MainIP+":"+n.AltPort) if err != nil { return err } n.maina, err = net.ListenUDP("udp", mainaaddr) if err != nil { return err } starlog.Infof("UDP MainIP:MainPort Listening on %s\n", n.maina.LocalAddr().String()) n.mainb, err = net.ListenUDP("udp", mainbaddr) if err != nil { return err } starlog.Infof("UDP MainIP:AltPort Listening on %s\n", n.mainb.LocalAddr().String()) altaddr, err := net.ResolveUDPAddr("udp", n.AltIP+":"+n.AltPort) if err != nil { return err } n.alt, err = net.ListenUDP("udp", altaddr) if err != nil { return err } starlog.Infof("UDP AltIP:AltPort Listening on %s\n", n.alt.LocalAddr().String()) go func() { for { select { case <-n.stopCtx.Done(): starlog.Infoln("Stopping,Reason: Context Done") return default: } buf := make([]byte, 1024) num, r, e := n.alt.ReadFromUDP(buf) if e != nil { continue } go n.Analyse(n.alt, r, strings.Split(string(buf[:num]), "::")) } }() for { select { case <-n.stopCtx.Done(): starlog.Infoln("Stopping,Reason: Context Done") n.maina.Close() n.mainb.Close() n.alt.Close() return nil default: } buf := make([]byte, 1024) num, r, e := n.maina.ReadFromUDP(buf) if e != nil { continue } go n.Analyse(n.maina, r, strings.Split(string(buf[:num]), "::")) } } func (n *NatTesterServer) Analyse(c *net.UDPConn, r *net.UDPAddr, cmds []string) error { switch cmds[0] { case "ip": c.WriteToUDP([]byte("ip::"+r.String()), r) starlog.Infof("Recv IP Request from %s,Local: %s\n", r.String(), c.LocalAddr().String()) case "startnat1": n.alt.WriteToUDP([]byte("stage1"), r) starlog.Infof("Start NAT1 Test from %s,Recv Local:%s Send Local:%s\n", r.String(), c.LocalAddr().String(), n.alt.LocalAddr().String()) case "startnat2": n.mainb.WriteToUDP([]byte("stage2"), r) starlog.Infof("Start NAT2 Test from %s,Recv Local:%s Send Local:%s\n", r.String(), c.LocalAddr().String(), n.mainb.LocalAddr().String()) case "startnat3": n.maina.WriteToUDP([]byte("stage3"), r) starlog.Infof("Start NAT3 Test from %s,Recv Local:%s Send Local:%s\n", r.String(), c.LocalAddr().String(), n.maina.LocalAddr().String()) } return nil }