func newUDP(priv *ecdsa.PrivateKey, c conn, natm nat.Interface, nodeDBPath string) (*Table, *udp, error) {
udp := &udp{
conn: c,
priv: priv,
closing: make(chan struct{}),
gotreply: make(chan reply),
addpending: make(chan *pending),
}
realaddr := c.LocalAddr().(*net.UDPAddr)
if natm != nil {
if !realaddr.IP.IsLoopback() {
go nat.Map(natm, udp.closing, "udp", realaddr.Port, realaddr.Port, "ethereum discovery")
}
// TODO: react to external IP changes over time.
if ext, err := natm.ExternalIP(); err == nil {
realaddr = &net.UDPAddr{IP: ext, Port: realaddr.Port}
}
}
// TODO: separate TCP port
udp.ourEndpoint = makeEndpoint(realaddr, uint16(realaddr.Port))
tab, err := newTable(udp, PubkeyID(&priv.PublicKey), realaddr, nodeDBPath)
if err != nil {
return nil, nil, err
}
udp.Table = tab
go udp.loop()
go udp.readLoop()
return udp.Table, udp, nil
}
func (srv *Server) startListening() error {
// Launch the TCP listener.
listener, err := net.Listen("tcp", srv.ListenAddr)
if err != nil {
return err
}
laddr := listener.Addr().(*net.TCPAddr)
srv.ListenAddr = laddr.String()
srv.listener = listener
srv.loopWG.Add(1)
go srv.listenLoop()
// Map the TCP listening port if NAT is configured.
if !laddr.IP.IsLoopback() && srv.NAT != nil {
srv.loopWG.Add(1)
go func() {
nat.Map(srv.NAT, srv.quit, "tcp", laddr.Port, laddr.Port, "ethereum p2p")
srv.loopWG.Done()
}()
}
return nil
}