android: Determine source address dynamically

src/frontends/android/jni/libandroidbridge/backend/android_service.c

@@ -58,11 +58,6 @@ struct private_android_service_t {
 	 */
 	char *type;
 
-	/**
-	 * local ipv4 address
-	 */
-	char *local_address;
-
 	/**
 	 * gateway
 	 */
@@ -480,7 +475,7 @@ static job_requeue_t initiate(private_android_service_t *this)
 		}
 	};
 
-	ike_cfg = ike_cfg_create(TRUE, TRUE, this->local_address, FALSE,
+	ike_cfg = ike_cfg_create(TRUE, TRUE, "0.0.0.0", FALSE,
 							 charon->socket->get_port(charon->socket, FALSE),
 							 this->gateway, FALSE, IKEV2_UDP_PORT);
 	ike_cfg->add_proposal(ike_cfg, proposal_create_default(PROTO_IKE));
@@ -591,7 +586,6 @@ METHOD(android_service_t, destroy, void,
 	close_tun_device(this);
 	this->lock->destroy(this->lock);
 	free(this->type);
-	free(this->local_address);
 	free(this->gateway);
 	free(this->username);
 	if (this->password)
@@ -606,8 +600,8 @@ METHOD(android_service_t, destroy, void,
  * See header
  */
 android_service_t *android_service_create(android_creds_t *creds, char *type,
-										  char *local_address, char *gateway,
+										  char *gateway, char *username,
-										  char *username, char *password)
+										  char *password)
 {
 	private_android_service_t *this;
 
@@ -624,7 +618,6 @@ android_service_t *android_service_create(android_creds_t *creds, char *type,
 			.destroy = _destroy,
 		},
 		.lock = rwlock_create(RWLOCK_TYPE_DEFAULT),
-		.local_address = local_address,
 		.username = username,
 		.password = password,
 		.gateway = gateway,

src/frontends/android/jni/libandroidbridge/backend/android_service.h

@@ -53,13 +53,12 @@ struct android_service_t {
  *
  * @param creds					Android specific credential set
  * @param type					VPN type (see VpnType.java)
- * @param local_address			local ip address
  * @param gateway				gateway address
  * @param username				user name (local identity)
  * @param password				password (if any)
  */
 android_service_t *android_service_create(android_creds_t *creds, char *type,
-										  char *local_address, char *gateway,
+										  char *gateway, char *username,
-										  char *username, char *password);
+										  char *password);
 
 #endif /** ANDROID_SERVICE_H_ @}*/

src/frontends/android/jni/libandroidbridge/charonservice.c

@@ -73,6 +73,11 @@ struct private_charonservice_t {
 	 */
 	vpnservice_builder_t *builder;
 
+	/**
+	 * NetworkManager instance (accessed via JNI)
+	 */
+	network_manager_t *network_manager;
+
 	/**
 	 * CharonVpnService reference
 	 */
@@ -330,22 +335,26 @@ METHOD(charonservice_t, get_vpnservice_builder, vpnservice_builder_t*,
 	return this->builder;
 }
 
+METHOD(charonservice_t, get_network_manager, network_manager_t*,
+	private_charonservice_t *this)
+{
+	return this->network_manager;
+}
+
 /**
  * Initiate a new connection
  *
- * @param local				local ip address (gets owned)
  * @param gateway			gateway address (gets owned)
  * @param username			username (gets owned)
  * @param password			password (gets owned)
  */
-static void initiate(char *type, char *local, char *gateway,
+static void initiate(char *type, char *gateway, char *username, char *password)
-					 char *username, char *password)
 {
 	private_charonservice_t *this = (private_charonservice_t*)charonservice;
 
 	this->creds->clear(this->creds);
 	DESTROY_IF(this->service);
-	this->service = android_service_create(this->creds, type, local, gateway,
+	this->service = android_service_create(this->creds, type, gateway,
 										   username, password);
 }
 
@@ -400,10 +409,12 @@ static void charonservice_init(JNIEnv *env, jobject service, jobject builder)
 			.get_user_certificate = _get_user_certificate,
 			.get_user_key = _get_user_key,
 			.get_vpnservice_builder = _get_vpnservice_builder,
+			.get_network_manager = _get_network_manager,
 		},
 		.attr = android_attr_create(),
 		.creds = android_creds_create(),
 		.builder = vpnservice_builder_create(builder),
+		.network_manager = network_manager_create(),
 		.vpn_service = (*env)->NewGlobalRef(env, service),
 	);
 	charonservice = &this->public;
@@ -439,6 +450,7 @@ static void charonservice_deinit(JNIEnv *env)
 {
 	private_charonservice_t *this = (private_charonservice_t*)charonservice;
 
+	this->network_manager->destroy(this->network_manager);
 	this->builder->destroy(this->builder);
 	this->creds->destroy(this->creds);
 	this->attr->destroy(this->attr);
@@ -555,16 +567,14 @@ JNI_METHOD(CharonVpnService, deinitializeCharon, void)
  * Initiate SA
  */
 JNI_METHOD(CharonVpnService, initiate, void,
-	jstring jtype, jstring jlocal_address, jstring jgateway, jstring jusername,
+	jstring jtype, jstring jgateway, jstring jusername, jstring jpassword)
-	jstring jpassword)
 {
-	char *type, *local_address, *gateway, *username, *password;
+	char *type, *gateway, *username, *password;
 
 	type = androidjni_convert_jstring(env, jtype);
-	local_address = androidjni_convert_jstring(env, jlocal_address);
 	gateway = androidjni_convert_jstring(env, jgateway);
 	username = androidjni_convert_jstring(env, jusername);
 	password = androidjni_convert_jstring(env, jpassword);
 
-	initiate(type, local_address, gateway, username, password);
+	initiate(type, gateway, username, password);
 }

src/frontends/android/jni/libandroidbridge/charonservice.h

@@ -32,6 +32,7 @@
 #define CHARONSERVICE_H_
 
 #include "vpnservice_builder.h"
+#include "kernel/network_manager.h"
 
 #include <library.h>
 #include <utils/linked_list.h>
@@ -111,6 +112,12 @@ struct charonservice_t {
 	 */
 	vpnservice_builder_t *(*get_vpnservice_builder)(charonservice_t *this);
 
+	/**
+	 * Get the current network_manager_t object
+	 *
+	 * @return				NetworkManager instance
+	 */
+	network_manager_t *(*get_network_manager)(charonservice_t *this);
 };
 
 /**

src/frontends/android/jni/libandroidbridge/kernel/android_net.c

@@ -14,6 +14,8 @@
 
 #include "android_net.h"
 
+#include "../charonservice.h"
+
 typedef struct private_kernel_android_net_t private_kernel_android_net_t;
 
 struct private_kernel_android_net_t {
@@ -22,8 +24,20 @@ struct private_kernel_android_net_t {
 	 * Public kernel interface
 	 */
 	kernel_android_net_t public;
+
+	/**
+	 * Reference to NetworkManager object
+	 */
+	network_manager_t *network_manager;
 };
 
+METHOD(kernel_net_t, get_source_addr, host_t*,
+	private_kernel_android_net_t *this, host_t *dest, host_t *src)
+{
+	return this->network_manager->get_local_address(this->network_manager,
+											dest->get_family(dest) == AF_INET);
+}
+
 METHOD(kernel_net_t, add_ip, status_t,
 	private_kernel_android_net_t *this, host_t *virtual_ip, host_t *iface_ip)
 {
@@ -47,7 +61,7 @@ kernel_android_net_t *kernel_android_net_create()
 	INIT(this,
 		.public = {
 			.interface = {
-				.get_source_addr = (void*)return_null,
+				.get_source_addr = _get_source_addr,
 				.get_nexthop = (void*)return_null,
 				.get_interface = (void*)return_null,
 				.create_address_enumerator = (void*)enumerator_create_empty,
@@ -58,6 +72,7 @@ kernel_android_net_t *kernel_android_net_create()
 				.destroy = _destroy,
 			},
 		},
+		.network_manager = charonservice->get_network_manager(charonservice),
 	);
 
 	return &this->public;

src/frontends/android/src/org/strongswan/android/logic/CharonVpnService.java

@@ -18,14 +18,10 @@
 package org.strongswan.android.logic;
 
 import java.io.File;
-import java.net.InetAddress;
-import java.net.NetworkInterface;
-import java.net.SocketException;
 import java.security.PrivateKey;
 import java.security.cert.CertificateEncodingException;
 import java.security.cert.X509Certificate;
 import java.util.ArrayList;
-import java.util.Enumeration;
 
 import org.strongswan.android.data.VpnProfile;
 import org.strongswan.android.data.VpnProfileDataSource;
@@ -218,9 +214,7 @@ public class CharonVpnService extends VpnService implements Runnable
 						initializeCharon(builder, mLogFile);
 						Log.i(TAG, "charon started");
 
-						String local_address = getLocalIPv4Address();
 						initiate(mCurrentProfile.getVpnType().getIdentifier(),
-								 local_address != null ? local_address : "0.0.0.0",
 								 mCurrentProfile.getGateway(), mCurrentProfile.getUsername(),
 								 mCurrentProfile.getPassword());
 					}
@@ -486,41 +480,7 @@ public class CharonVpnService extends VpnService implements Runnable
 	/**
 	 * Initiate VPN, provided by libandroidbridge.so
 	 */
-	public native void initiate(String type, String local_address, String gateway,
+	public native void initiate(String type, String gateway, String username, String password);
-								String username, String password);
-
-	/**
-	 * Helper function that retrieves a local IPv4 address.
-	 *
-	 * @return string representation of an IPv4 address, or null if none found
-	 */
-	private static String getLocalIPv4Address()
-	{
-		try
-		{
-			Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces();
-			while (en.hasMoreElements())
-			{
-				NetworkInterface intf = en.nextElement();
-
-				Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses();
-				while (enumIpAddr.hasMoreElements())
-				{
-					InetAddress inetAddress = enumIpAddr.nextElement();
-					if (!inetAddress.isLoopbackAddress() && inetAddress.getAddress().length == 4)
-					{
-						return inetAddress.getHostAddress().toString();
-					}
-				}
-			}
-		}
-		catch (SocketException ex)
-		{
-			ex.printStackTrace();
-			return null;
-		}
-		return null;
-	}
 
 	/**
 	 * Adapter for VpnService.Builder which is used to access it safely via JNI.