1 files changed, 70 insertions, 10 deletions

diff --git a/libgo/go/net/ipsock_plan9.go b/libgo/go/net/ipsock_plan9.go
index 93f0f4e..2308236 100644
--- a/libgo/go/net/ipsock_plan9.go
+++ b/libgo/go/net/ipsock_plan9.go
@@ -57,17 +57,17 @@ func parsePlan9Addr(s string) (ip IP, iport int, err error) {
 			return nil, 0, &ParseError{Type: "IP address", Text: s}
 		}
 	}
-	p, _, ok := dtoi(s[i+1:])
+	p, plen, ok := dtoi(s[i+1:])
 	if !ok {
 		return nil, 0, &ParseError{Type: "port", Text: s}
 	}
 	if p < 0 || p > 0xFFFF {
-		return nil, 0, &AddrError{Err: "invalid port", Addr: string(p)}
+		return nil, 0, &AddrError{Err: "invalid port", Addr: s[i+1 : i+1+plen]}
 	}
 	return addr, p, nil
 }
 
-func readPlan9Addr(proto, filename string) (addr Addr, err error) {
+func readPlan9Addr(net, filename string) (addr Addr, err error) {
 	var buf [128]byte
 
 	f, err := os.Open(filename)
@@ -83,13 +83,19 @@ func readPlan9Addr(proto, filename string) (addr Addr, err error) {
 	if err != nil {
 		return
 	}
-	switch proto {
-	case "tcp":
+	switch net {
+	case "tcp4", "udp4":
+		if ip.Equal(IPv6zero) {
+			ip = ip[:IPv4len]
+		}
+	}
+	switch net {
+	case "tcp", "tcp4", "tcp6":
 		addr = &TCPAddr{IP: ip, Port: port}
-	case "udp":
+	case "udp", "udp4", "udp6":
 		addr = &UDPAddr{IP: ip, Port: port}
 	default:
-		return nil, UnknownNetworkError(proto)
+		return nil, UnknownNetworkError(net)
 	}
 	return addr, nil
 }
@@ -199,7 +205,11 @@ func dialPlan9Blocking(ctx context.Context, net string, laddr, raddr Addr) (fd *
 	if err != nil {
 		return nil, err
 	}
-	_, err = f.WriteString("connect " + dest)
+	if la := plan9LocalAddr(laddr); la == "" {
+		err = hangupCtlWrite(ctx, proto, f, "connect "+dest)
+	} else {
+		err = hangupCtlWrite(ctx, proto, f, "connect "+dest+" "+la)
+	}
 	if err != nil {
 		f.Close()
 		return nil, err
@@ -209,7 +219,7 @@ func dialPlan9Blocking(ctx context.Context, net string, laddr, raddr Addr) (fd *
 		f.Close()
 		return nil, err
 	}
-	laddr, err = readPlan9Addr(proto, netdir+"/"+proto+"/"+name+"/local")
+	laddr, err = readPlan9Addr(net, netdir+"/"+proto+"/"+name+"/local")
 	if err != nil {
 		data.Close()
 		f.Close()
@@ -229,7 +239,7 @@ func listenPlan9(ctx context.Context, net string, laddr Addr) (fd *netFD, err er
 		f.Close()
 		return nil, &OpError{Op: "announce", Net: net, Source: laddr, Addr: nil, Err: err}
 	}
-	laddr, err = readPlan9Addr(proto, netdir+"/"+proto+"/"+name+"/local")
+	laddr, err = readPlan9Addr(net, netdir+"/"+proto+"/"+name+"/local")
 	if err != nil {
 		f.Close()
 		return nil, err
@@ -303,3 +313,53 @@ func toLocal(a Addr, net string) Addr {
 	}
 	return a
 }
+
+// plan9LocalAddr returns a Plan 9 local address string.
+// See setladdrport at https://9p.io/sources/plan9/sys/src/9/ip/devip.c.
+func plan9LocalAddr(addr Addr) string {
+	var ip IP
+	port := 0
+	switch a := addr.(type) {
+	case *TCPAddr:
+		if a != nil {
+			ip = a.IP
+			port = a.Port
+		}
+	case *UDPAddr:
+		if a != nil {
+			ip = a.IP
+			port = a.Port
+		}
+	}
+	if len(ip) == 0 || ip.IsUnspecified() {
+		if port == 0 {
+			return ""
+		}
+		return itoa(port)
+	}
+	return ip.String() + "!" + itoa(port)
+}
+
+func hangupCtlWrite(ctx context.Context, proto string, ctl *os.File, msg string) error {
+	if proto != "tcp" {
+		_, err := ctl.WriteString(msg)
+		return err
+	}
+	written := make(chan struct{})
+	errc := make(chan error)
+	go func() {
+		select {
+		case <-ctx.Done():
+			ctl.WriteString("hangup")
+			errc <- mapErr(ctx.Err())
+		case <-written:
+			errc <- nil
+		}
+	}()
+	_, err := ctl.WriteString(msg)
+	close(written)
+	if e := <-errc; err == nil && e != nil { // we hung up
+		return e
+	}
+	return err
+}