Implement kernel_ipsec_t.bypass_socket() via JNI and VpnService.protect()

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

@@ -90,6 +90,34 @@ static void dbg_android(debug_t group, level_t level, char *fmt, ...)
 	}
 }
 
+METHOD(charonservice_t, bypass_socket, bool,
+	private_charonservice_t *this, int fd, int family)
+{
+	JNIEnv *env;
+	jmethodID method_id;
+
+	androidjni_attach_thread(&env);
+
+	method_id = (*env)->GetMethodID(env, android_charonvpnservice_class,
+									"protect", "(I)Z");
+	if (!method_id)
+	{
+		goto failed;
+	}
+	if (!(*env)->CallBooleanMethod(env, this->vpn_service, method_id, fd))
+	{
+		DBG1(DBG_CFG, "VpnService.protect() failed");
+		goto failed;
+	}
+	androidjni_detach_thread();
+	return TRUE;
+
+failed:
+	androidjni_exception_occurred(env);
+	androidjni_detach_thread();
+	return FALSE;
+}
+
 /**
  * Initialize the charonservice object
  */
@@ -105,6 +133,7 @@ static void charonservice_init(JNIEnv *env, jobject service)
 
 	INIT(this,
 		.public = {
+			.bypass_socket = _bypass_socket,
 		},
 		.vpn_service = (*env)->NewGlobalRef(env, service),
 	);

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

@@ -28,6 +28,8 @@
 #ifndef CHARONSERVICE_H_
 #define CHARONSERVICE_H_
 
+#include <library.h>
+
 typedef struct charonservice_t charonservice_t;
 
 /**
@@ -37,6 +39,16 @@ typedef struct charonservice_t charonservice_t;
  */
 struct charonservice_t {
 
+	/**
+	 * Install a bypass policy for the given socket using the protect() Method
+	 * of the Android VpnService interface
+	 *
+	 * @param fd			socket file descriptor
+	 * @param family		socket protocol family
+	 * @return				TRUE if operation successful
+	 */
+	bool (*bypass_socket)(charonservice_t *this, int fd, int family);
+
 };
 
 /**

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

@@ -15,6 +15,7 @@
  */
 
 #include "android_ipsec.h"
+#include "../charonservice.h"
 
 #include <debug.h>
 #include <library.h>
@@ -139,7 +140,7 @@ METHOD(kernel_ipsec_t, flush_policies, status_t,
 METHOD(kernel_ipsec_t, bypass_socket, bool,
 	private_kernel_android_ipsec_t *this, int fd, int family)
 {
-	return NOT_SUPPORTED;
+	return charonservice->bypass_socket(charonservice, fd, family);
 }
 
 METHOD(kernel_ipsec_t, enable_udp_decap, bool,