implement wgOnEvent

3 files changed, 63 insertions, 12 deletions

diff --git a/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java b/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
index 3d0886cf..b7e55465 100644
--- a/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
+++ b/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
@@ -40,7 +40,7 @@ import androidx.collection.ArraySet;
  * WireGuard tunnels.
  */
 @NonNullForAll
-public final class GoBackend implements Backend {
+public final class GoBackend implements Backend, EventHandler {
     private static final int DNS_RESOLUTION_RETRIES = 10;
     private static final String TAG = "WireGuard/GoBackend";
     @Nullable private static AlwaysOnCallback alwaysOnCallback;
@@ -78,7 +78,7 @@ public final class GoBackend implements Backend {
 
     private static native void wgTurnOff(int handle);
 
-    private static native int wgTurnOn(String ifName, int tunFd, String settings);
+    private static native int wgTurnOn(String ifName, int tunFd, String settings, EventHandler handler);
 
     private static native String wgVersion();
 
@@ -304,7 +304,7 @@ public final class GoBackend implements Backend {
                 if (tun == null)
                     throw new BackendException(Reason.TUN_CREATION_ERROR);
                 Log.d(TAG, "Go backend " + wgVersion());
-                currentTunnelHandle = wgTurnOn(tunnel.getName(), tun.detachFd(), goConfig);
+                currentTunnelHandle = wgTurnOn(tunnel.getName(), tun.detachFd(), goConfig, this);
             }
             if (currentTunnelHandle < 0)
                 throw new BackendException(Reason.GO_ACTIVATION_ERROR_CODE, currentTunnelHandle);
@@ -329,6 +329,9 @@ public final class GoBackend implements Backend {
         tunnel.onStateChange(state);
     }
 
+    public void onEvent(String event) {
+    }
+
     /**
      * Callback for {@link GoBackend} that is invoked when {@link VpnService} is started by the
      * system's Always-On VPN mode.
@@ -415,3 +418,7 @@ public final class GoBackend implements Backend {
         }
     }
 }
+
+interface EventHandler {
+    public void onEvent(String event);
+}
diff --git a/tunnel/tools/libwg-go/api-android.go b/tunnel/tools/libwg-go/api-android.go
index d47c5d76..e3e97c67 100644
--- a/tunnel/tools/libwg-go/api-android.go
+++ b/tunnel/tools/libwg-go/api-android.go
@@ -7,6 +7,7 @@ package main
 
 // #cgo LDFLAGS: -llog
 // #include <android/log.h>
+// extern void wgOnEvent(void *eventHandler, const char *event);
 import "C"
 
 import (
@@ -48,6 +49,7 @@ func (l AndroidLogger) Printf(format string, args ...interface{}) {
 type TunnelHandle struct {
 	device *device.Device
 	uapi   net.Listener
+	eventHandler unsafe.Pointer
 }
 
 var tunnelHandles map[int32]TunnelHandle
@@ -73,7 +75,7 @@ func init() {
 }
 
 //export wgTurnOn
-func wgTurnOn(interfaceName string, tunFd int32, settings string) int32 {
+func wgTurnOn(interfaceName string, tunFd int32, settings string, eventHandler unsafe.Pointer) int32 {
 	tag := cstring("WireGuard/GoBackend/" + interfaceName)
 	logger := &device.Logger{
 		Verbosef: AndroidLogger{level: C.ANDROID_LOG_DEBUG, tag: tag}.Printf,
@@ -142,21 +144,23 @@ func wgTurnOn(interfaceName string, tunFd int32, settings string) int32 {
 		device.Close()
 		return -1
 	}
-	tunnelHandles[i] = TunnelHandle{device: device, uapi: uapi}
+	tunnelHandles[i] = TunnelHandle{device: device, uapi: uapi, eventHandler: eventHandler}
 	return i
 }
 
 //export wgTurnOff
-func wgTurnOff(tunnelHandle int32) {
+func wgTurnOff(tunnelHandle int32) unsafe.Pointer {
 	handle, ok := tunnelHandles[tunnelHandle]
 	if !ok {
-		return
+		return nil
 	}
+	eventHandler := handle.eventHandler
 	delete(tunnelHandles, tunnelHandle)
 	if handle.uapi != nil {
 		handle.uapi.Close()
 	}
 	handle.device.Close()
+	return eventHandler
 }
 
 //export wgGetSocketV4
diff --git a/tunnel/tools/libwg-go/jni.c b/tunnel/tools/libwg-go/jni.c
index 7ad94d35..353cb474 100644
--- a/tunnel/tools/libwg-go/jni.c
+++ b/tunnel/tools/libwg-go/jni.c
@@ -3,31 +3,58 @@
  * Copyright © 2017-2021 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
  */
 
+#include <assert.h>
 #include <jni.h>
 #include <stdlib.h>
 #include <string.h>
+#include <android/log.h>
+
+#define TAG "WireGuard/GoBackend"
 
 struct go_string { const char *str; long n; };
-extern int wgTurnOn(struct go_string ifname, int tun_fd, struct go_string settings);
-extern void wgTurnOff(int handle);
+extern int wgTurnOn(struct go_string ifname, int tun_fd, struct go_string settings, void *eventHandler);
+extern void *wgTurnOff(int handle);
 extern int wgGetSocketV4(int handle);
 extern int wgGetSocketV6(int handle);
 extern char *wgGetConfig(int handle);
 extern char *wgVersion();
+extern void wgOnEvent(void *eventHandler, const char *event);
+
+static JavaVM *gVm;
+static jclass gEventHandlerClass;
+static jmethodID gOnEventMethod;
+
+JNIEXPORT jint JNI_OnLoad(JavaVM *vm, void *reserved)
+{
+	JNIEnv* env;
+	char buf[128];
+
+	gVm = vm;
+	if ((*vm)->GetEnv(vm, (void**)&env, JNI_VERSION_1_6) != JNI_OK) {
+		return JNI_ERR;
+	}
+
+	gEventHandlerClass = (*env)->FindClass(env, "com/wireguard/android/backend/EventHandler");
 
-JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOn(JNIEnv *env, jclass c, jstring ifname, jint tun_fd, jstring settings)
+	gOnEventMethod = (*env)->GetMethodID(env, gEventHandlerClass, "onEvent", "(Ljava/lang/String;)V");
+
+	return JNI_VERSION_1_6;
+}
+
+JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOn(JNIEnv *env, jclass c, jstring ifname, jint tun_fd, jstring settings, jobject eventHandler)
 {
 	const char *ifname_str = (*env)->GetStringUTFChars(env, ifname, 0);
 	size_t ifname_len = (*env)->GetStringUTFLength(env, ifname);
 	const char *settings_str = (*env)->GetStringUTFChars(env, settings, 0);
 	size_t settings_len = (*env)->GetStringUTFLength(env, settings);
+	jobject event_handler = (*env)->NewGlobalRef(env, eventHandler);
 	int ret = wgTurnOn((struct go_string){
 		.str = ifname_str,
 		.n = ifname_len
 	}, tun_fd, (struct go_string){
 		.str = settings_str,
 		.n = settings_len
-	});
+	}, event_handler);
 	(*env)->ReleaseStringUTFChars(env, ifname, ifname_str);
 	(*env)->ReleaseStringUTFChars(env, settings, settings_str);
 	return ret;
@@ -35,7 +62,9 @@ JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOn(JNI
 
 JNIEXPORT void JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOff(JNIEnv *env, jclass c, jint handle)
 {
-	wgTurnOff(handle);
+	jobject event_handler = wgTurnOff(handle);
+	if (event_handler)
+		(*env)->DeleteGlobalRef(env, event_handler);
 }
 
 JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgGetSocketV4(JNIEnv *env, jclass c, jint handle)
@@ -69,3 +98,14 @@ JNIEXPORT jstring JNICALL Java_com_wireguard_android_backend_GoBackend_wgVersion
 	free(version);
 	return ret;
 }
+
+void wgOnEvent(void *eventHandler, const char *event)
+{
+	JavaVMAttachArgs attachArgs = { JNI_VERSION_1_6, NULL, NULL };
+	jobject jEventHandler = eventHandler;
+	JNIEnv *env;
+	jint rs = (*gVm)->AttachCurrentThread(gVm, &env, &attachArgs);
+	assert (rs == JNI_OK);
+	jstring jevent = (*env)->NewStringUTF(env, event);
+	(*env)->CallVoidMethod(env, jEventHandler, gOnEventMethod, jevent);
+}