func echoTCPIdent(tt *tunneltest.TunnelTest, echo, ident string) (string, error) {
addr := tt.Addr(ident)
if addr == nil {
return "", fmt.Errorf("tunnel %q does not exist", ident)
}
s := addr.String()
ip := tt.Tunnels[ident].IP
if ip != nil {
_, port, err := net.SplitHostPort(s)
if err != nil {
return "", err
}
s = net.JoinHostPort(ip.String(), port)
}
c, err := dialTCP(s)
if err != nil {
return "", err
}
c.out <- echo
select {
case reply := <-c.in:
return reply, nil
case <-time.After(tcpTimeout):
return "", fmt.Errorf("timed out waiting for reply from %s (%s) after %v", s, addr, tcpTimeout)
}
}
