CHECK_ERROR(SSLSetIOFuncs, c->ssl_context, tls_read_cb, tls_write_cb);
CHECK_ERROR(SSLSetConnection, c->ssl_context, h);
while (1) {
CHECK_ERROR(SSLSetIOFuncs, c->ssl_context, tls_read_cb, tls_write_cb);
CHECK_ERROR(SSLSetConnection, c->ssl_context, h);
while (1) {