--- /dev/null
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+#ifndef _RLM_RADIUS_H
+#define _RLM_RADIUS_H
+#include <freeradius-devel/connection.h>
+
+/*
+ * $Id$
+ *
+ * @file rlm_radius.h
+ * @brief Structures for the RADIUS client packets
+ *
+ * @copyright 2017 Alan DeKok <aland@freeradius.org>
+ */
+
+/** Process a request through a client socket.
+ *
+ * This function typically encodes the packet, writes it to a socket,
+ * inserts itself into event list with a read / timeout, and returns
+ * RLM_MODULE_YIELD.
+ */
+typedef rlm_rcode_t (*fr_radius_client_process)(void *instance, REQUEST *request);
+
+/** Public structure describing an I/O path for an outgoing socket.
+ *
+ * This structure is exported by client I/O modules e.g. rlm_radius_udp.
+ */
+typedef struct fr_radius_client_io_t {
+ RAD_MODULE_COMMON; //!< Common fields to all loadable modules.
+
+ fr_app_bootstrap_t bootstrap;
+ fr_app_instantiate_t instantiate;
+ module_thread_t thread_instantiate; //!< Callback to configure a module's instance for
+ //!< a new worker thread.
+ fr_connection_init_t init; //!< initialize a socket using thread instance data
+ fr_connection_open_t open; //!< open a socket using thread instance data
+ fr_connection_close_t close; //!< close a socket using thread instance data
+ fr_radius_client_process process; //!< process a packet through a socket using thread instance data
+} fr_radius_client_io_t;
+
+#endif /* _RLM_RADIUS_H */