func JoinSession(invitation protocol.SessionInvitation) (net.Conn, error) {
addr := net.JoinHostPort(net.IP(invitation.Address).String(), strconv.Itoa(int(invitation.Port)))
conn, err := dialer.Dial("tcp", addr)
if err != nil {
return nil, err
}
request := protocol.JoinSessionRequest{
Key: invitation.Key,
}
conn.SetDeadline(time.Now().Add(10 * time.Second))
err = protocol.WriteMessage(conn, request)
if err != nil {
return nil, err
}
message, err := protocol.ReadMessage(conn)
if err != nil {
return nil, err
}
conn.SetDeadline(time.Time{})
switch msg := message.(type) {
case protocol.Response:
if msg.Code != 0 {
return nil, fmt.Errorf("Incorrect response code %d: %s", msg.Code, msg.Message)
}
return conn, nil
default:
return nil, fmt.Errorf("protocol error: expecting response got %v", msg)
}
}
func tcpDialer(uri *url.URL, tlsCfg *tls.Config) (*tls.Conn, error) {
// Check that there is a port number in uri.Host, otherwise add one.
host, port, err := net.SplitHostPort(uri.Host)
if err != nil && strings.HasPrefix(err.Error(), "missing port") {
// addr is on the form "1.2.3.4"
uri.Host = net.JoinHostPort(uri.Host, "22000")
} else if err == nil && port == "" {
// addr is on the form "1.2.3.4:"
uri.Host = net.JoinHostPort(host, "22000")
}
// Don't try to resolve the address before dialing. The dialer may be a
// proxy, and we should let the proxy do the resolving in that case.
conn, err := dialer.Dial("tcp", uri.Host)
if err != nil {
l.Debugln(err)
return nil, err
}
tc := tls.Client(conn, tlsCfg)
err = tc.Handshake()
if err != nil {
tc.Close()
return nil, err
}
return tc, nil
}
func localIP(url *url.URL) (string, error) {
conn, err := dialer.Dial("tcp", url.Host)
if err != nil {
return "", err
}
defer conn.Close()
localIPAddress, _, err := net.SplitHostPort(conn.LocalAddr().String())
if err != nil {
return "", err
}
return localIPAddress, nil
}