eap-radius: Add ability to configure RADIUS retransmission behavior

Closes strongswan/strongswan#19.

conf/plugins/eap-radius.opt

@@ -80,6 +80,15 @@ charon.plugins.eap-radius.secret =
 charon.plugins.eap-radius.server =
 	IP/Hostname of RADIUS server.
 
+charon.plugins.eap-radius.retransmit_base = 1.4
+	Base to use for calculating exponential back off.
+
+charon.plugins.eap-radius.retransmit_timeout = 2.0
+	Timeout in seconds before sending first retransmit.
+
+charon.plugins.eap-radius.retransmit_tries = 4
+	Number of times to retransmit a packet before giving up.
+
 charon.plugins.eap-radius.servers {}
 	Section to specify multiple RADIUS servers.
 
@@ -88,7 +97,9 @@ charon.plugins.eap-radius.servers {}
 	specified for each server. A server's IP/Hostname can be configured using
 	the **address** option. The **acct_port** [1813] option can be used to
 	specify the port used for RADIUS accounting. For each RADIUS server a
-	priority can be specified using the **preference** [0] option.
+	priority can be specified using the **preference** [0] option. The
+	retransmission time for each server can set set using **retransmit_base**,
+	**retransmit_timeout** and **retransmit_tries**.
 
 charon.plugins.eap-radius.sockets = 1
 	Number of sockets (ports) to use, increase for high load.

src/libcharon/plugins/eap_radius/eap_radius_plugin.c

@@ -14,6 +14,28 @@
  * for more details.
  */
 
+/*
+ * Copyright (C) 2015 Thom Troy
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
 #include "eap_radius_plugin.h"
 
 #include "eap_radius.h"
@@ -98,6 +120,8 @@ static void load_configs(private_eap_radius_plugin_t *this)
 	radius_config_t *config;
 	char *nas_identifier, *secret, *address, *section;
 	int auth_port, acct_port, sockets, preference;
+	u_int retransmit_tries;
+	double retransmit_timeout, retransmit_base;
 
 	address = lib->settings->get_str(lib->settings,
 								"%s.plugins.eap-radius.server", NULL, lib->ns);
@@ -117,8 +141,18 @@ static void load_configs(private_eap_radius_plugin_t *this)
 						"%s.plugins.eap-radius.port", AUTH_PORT, lib->ns);
 		sockets = lib->settings->get_int(lib->settings,
 						"%s.plugins.eap-radius.sockets", 1, lib->ns);
+
+		retransmit_tries = lib->settings->get_int(lib->settings,
+						"%s.plugins.eap-radius.retransmit_tries", 4, lib->ns);
+		retransmit_timeout = lib->settings->get_double(lib->settings,
+						"%s.plugins.eap-radius.retransmit_timeout", 2, lib->ns);
+		retransmit_base = lib->settings->get_double(lib->settings,
+						"%s.plugins.eap-radius.retransmit_base", 1.4, lib->ns);
+
 		config = radius_config_create(address, address, auth_port, ACCT_PORT,
-									  nas_identifier, secret, sockets, 0);
+									  nas_identifier, secret, sockets, 0,
+									  retransmit_tries, retransmit_timeout,
+									  retransmit_base);
 		if (!config)
 		{
 			DBG1(DBG_CFG, "no RADUIS server defined");
@@ -170,11 +204,33 @@ static void load_configs(private_eap_radius_plugin_t *this)
 					lib->settings->get_int(lib->settings,
 						"%s.plugins.eap-radius.sockets", 1, lib->ns),
 				lib->ns, section);
+
+		retransmit_tries = lib->settings->get_int(lib->settings,
+				"%s.plugins.eap-radius.servers.%s.retransmit_tries",
+					lib->settings->get_int(lib->settings,
+						"%s.plugins.eap-radius.retransmit_tries", 4, lib->ns),
+				lib->ns, section);
+
+		retransmit_timeout = lib->settings->get_double(lib->settings,
+				"%s.plugins.eap-radius.servers.%s.retransmit_timeout",
+					lib->settings->get_double(lib->settings,
+						"%s.plugins.eap-radius.retransmit_timeout", 2, lib->ns),
+				lib->ns, section);
+
+		retransmit_base = lib->settings->get_double(lib->settings,
+				"%s.plugins.eap-radius.servers.%s.retransmit_base",
+					lib->settings->get_double(lib->settings,
+						"%s.plugins.eap-radius.retransmit_base", 1.4, lib->ns),
+				lib->ns, section);
+
 		preference = lib->settings->get_int(lib->settings,
 				"%s.plugins.eap-radius.servers.%s.preference", 0,
 				lib->ns, section);
+
 		config = radius_config_create(section, address, auth_port, acct_port,
-								nas_identifier, secret, sockets, preference);
+								nas_identifier, secret, sockets, preference,
+								retransmit_tries, retransmit_timeout,
+								retransmit_base);
 		if (!config)
 		{
 			DBG1(DBG_CFG, "loading RADIUS server '%s' failed, skipped", section);

src/libradius/Makefile.am

@@ -7,7 +7,7 @@ AM_LDFLAGS = \
 ipseclib_LTLIBRARIES = libradius.la
 
 libradius_la_LIBADD = \
-	$(top_builddir)/src/libstrongswan/libstrongswan.la
+	$(top_builddir)/src/libstrongswan/libstrongswan.la -lm
 
 libradius_la_SOURCES = \
 	radius_message.h radius_message.c \

src/libradius/radius_config.c

@@ -13,6 +13,28 @@
  * for more details.
  */
 
+/*
+ * Copyright (C) 2015 Thom Troy
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
 #include "radius_config.h"
 
 #include <threading/mutex.h>
@@ -180,7 +202,8 @@ METHOD(radius_config_t, destroy, void,
 radius_config_t *radius_config_create(char *name, char *address,
 									  u_int16_t auth_port, u_int16_t acct_port,
 									  char *nas_identifier, char *secret,
-									  int sockets, int preference)
+									  int sockets, int preference,
+									  u_int tries, double timeout, double base)
 {
 	private_radius_config_t *this;
 	radius_socket_t *socket;
@@ -209,7 +232,8 @@ radius_config_t *radius_config_create(char *name, char *address,
 	while (sockets--)
 	{
 		socket = radius_socket_create(address, auth_port, acct_port,
-									  chunk_create(secret, strlen(secret)));
+									  chunk_create(secret, strlen(secret)),
+									  tries, timeout, base);
 		if (!socket)
 		{
 			destroy(this);

src/libradius/radius_config.h

@@ -13,6 +13,28 @@
  * for more details.
  */
 
+/*
+ * Copyright (C) 2015 Thom Troy
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
 /**
  * @defgroup radius_config radius_config
  * @{ @ingroup libradius
@@ -91,10 +113,14 @@ struct radius_config_t {
  * @param secret			secret to use with this server
  * @param sockets			number of sockets to create in pool
  * @param preference		preference boost for this server
+ * @param tries				number of times we retransmit messages
+ * @param timeout			retransmission timeout
+ * @param base				base to calculate retransmission timeout
  */
 radius_config_t *radius_config_create(char *name, char *address,
 									  u_int16_t auth_port, u_int16_t acct_port,
 									  char *nas_identifier, char *secret,
-									  int sockets, int preference);
+									  int sockets, int preference,
+									  u_int tries, double timeout, double base);
 
 #endif /** RADIUS_CONFIG_H_ @}*/

src/libradius/radius_socket.c

@@ -13,11 +13,34 @@
  * for more details.
  */
 
+/*
+ * Copyright (C) 2015 Thom Troy
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
 #include "radius_socket.h"
 #include "radius_mppe.h"
 
 #include <errno.h>
 #include <unistd.h>
+#include <math.h>
 
 #include <pen/pen.h>
 #include <utils/debug.h>
@@ -83,6 +106,21 @@ struct private_radius_socket_t {
 	 * RADIUS secret
 	 */
 	chunk_t secret;
+
+	/**
+	 * Number of times we retransmit messages before giving up
+	 */
+	u_int retransmit_tries;
+
+	/**
+	 * Retransmission timeout
+	 */
+	double retransmit_timeout;
+
+	/**
+	 * Base to calculate retransmission timeout
+	 */
+	double retransmit_base;
 };
 
 /**
@@ -185,7 +223,7 @@ METHOD(radius_socket_t, request, radius_message_t*,
 {
 	radius_message_t *response;
 	chunk_t data;
-	int i, *fd, retransmit = 0;
+	int *fd, retransmit = 0, timeout;
 	u_int16_t port;
 	rng_t *rng = NULL;
 
@@ -218,21 +256,22 @@ METHOD(radius_socket_t, request, radius_message_t*,
 	data = request->get_encoding(request);
 	DBG3(DBG_CFG, "%B", &data);
 
-	/* timeout after 2, 3, 4, 5 seconds */
+	while (retransmit < this->retransmit_tries)
-	for (i = 2; i <= 5; i++)
 	{
+		timeout = (int)(this->retransmit_timeout * 1000.0 *
+						pow(this->retransmit_base, retransmit));
 		if (retransmit)
 		{
-			DBG1(DBG_CFG, "retransmitting RADIUS %N (attempt %d)",
+			DBG1(DBG_CFG, "retransmit %d of RADIUS %N (timeout: %.1fs)",
-				 radius_message_code_names, request->get_code(request),
+				 retransmit, radius_message_code_names,
-				 retransmit);
+				 request->get_code(request), timeout/1000.0);
 		}
 		if (send(*fd, data.ptr, data.len, 0) != data.len)
 		{
 			DBG1(DBG_CFG, "sending RADIUS message failed: %s", strerror(errno));
 			return NULL;
 		}
-		switch (receive_response(*fd, i*1000, request->get_identifier(request),
+		switch (receive_response(*fd, timeout, request->get_identifier(request),
 								 &response))
 		{
 			case SUCCESS:
@@ -251,8 +290,9 @@ METHOD(radius_socket_t, request, radius_message_t*,
 		response->destroy(response);
 		return NULL;
 	}
-	DBG1(DBG_CFG, "RADIUS %N timed out after %d retransmits",
+
-		 radius_message_code_names, request->get_code(request), retransmit - 1);
+	DBG1(DBG_CFG, "RADIUS %N timed out after %d attempts",
+		 radius_message_code_names, request->get_code(request), retransmit);
 	return NULL;
 }
 
@@ -336,7 +376,8 @@ METHOD(radius_socket_t, destroy, void,
  * See header
  */
 radius_socket_t *radius_socket_create(char *address, u_int16_t auth_port,
-									  u_int16_t acct_port, chunk_t secret)
+									  u_int16_t acct_port, chunk_t secret,
+									  u_int tries, double timeout, double base)
 {
 	private_radius_socket_t *this;
 
@@ -354,6 +395,9 @@ radius_socket_t *radius_socket_create(char *address, u_int16_t auth_port,
 		.hasher = lib->crypto->create_hasher(lib->crypto, HASH_MD5),
 		.signer = lib->crypto->create_signer(lib->crypto, AUTH_HMAC_MD5_128),
 		.rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK),
+		.retransmit_tries = tries,
+		.retransmit_timeout = timeout,
+		.retransmit_base = base,
 	);
 
 	if (!this->hasher || !this->signer || !this->rng ||

src/libradius/radius_socket.h

@@ -13,6 +13,28 @@
  * for more details.
  */
 
+/*
+ * Copyright (C) 2015 Thom Troy
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
 /**
  * @defgroup radius_socket radius_socket
  * @{ @ingroup libradius
@@ -70,8 +92,12 @@ struct radius_socket_t {
  * @param auth_port	server port for authentication
  * @param acct_port	server port for accounting
  * @param secret	RADIUS secret
+ * @param tries		number of times we retransmit messages
+ * @param timeout	retransmission timeout
+ * @param base		base to calculate retransmission timeout
  */
 radius_socket_t *radius_socket_create(char *address, u_int16_t auth_port,
-									  u_int16_t acct_port, chunk_t secret);
+									  u_int16_t acct_port, chunk_t secret,
+									  u_int tries, double timeout, double base);
 
 #endif /** RADIUS_SOCKET_H_ @}*/