SO_REUSEPORT is applied only to multicast UDP ports

[nncp.git] / src / mcd.go

diff --git a/src/mcd.go b/src/mcd.go
index be40f42de1edd50f03e0a1bc5d045ce88bf76bb5..60ca6a5521010933c3b62a5cc0dd61bf368fed37 100644 (file)
--- a/src/mcd.go
+++ b/src/mcd.go
@@ -176,20 +176,24 @@ func (ctx *Ctx) MCDRx(ifiName string) error {
 }
 
 func (ctx *Ctx) MCDTx(ifiName string, port int, interval time.Duration) error {
-       conn, err := net.DialUDP("udp",
-               &net.UDPAddr{Port: port, Zone: ifiName},
-               &net.UDPAddr{IP: mcdIP, Port: MCDPort, Zone: ifiName},
-       )
+       ifi, err := net.InterfaceByName(ifiName)
+       if err != nil {
+               return err
+       }
+       addr := &net.UDPAddr{IP: mcdIP, Port: port, Zone: ifiName}
+       conn, err := net.ListenMulticastUDP("udp", ifi, addr)
        if err != nil {
                return err
        }
+
+       dst := &net.UDPAddr{IP: mcdIP, Port: MCDPort, Zone: ifiName}
        var buf bytes.Buffer
        mcd := MCD{Magic: MagicNNCPDv1.B, Sender: ctx.Self.Id}
        if _, err := xdr.Marshal(&buf, mcd); err != nil {
                panic(err)
        }
        if interval == 0 {
-               _, err = conn.Write(buf.Bytes())
+               _, err = conn.WriteTo(buf.Bytes(), dst)
                return err
        }
        go func() {
@@ -201,7 +205,7 @@ func (ctx *Ctx) MCDTx(ifiName string, port int, interval time.Duration) error {
                                        ifiName, MCDPort, port,
                                )
                        })
-                       _, err = conn.Write(buf.Bytes())
+                       _, err = conn.WriteTo(buf.Bytes(), dst)
                        if err != nil {
                                ctx.LogE("mcd", les, err, func(les LEs) string {
                                        return fmt.Sprintf("MCD on %s/%d/%d", ifiName, MCDPort, port)