static ssize_t gtls_push(void *s, const void *buf, size_t len)
{
  curl_socket_t sock = *(curl_socket_t *)s;
  ssize_t ret = swrite(sock, buf, len);
  return ret;
}
static ssize_t gtls_push(void *s, const void *buf, size_t len)
{
  curl_socket_t sock = *(curl_socket_t *)s;
  ssize_t ret = swrite(sock, buf, len);
  return ret;
}