diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 2d4ac192..5e6a899a 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -8,7 +8,7 @@
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
     <uses-permission android:name="com.android.vending.BILLING" />
-    <!--uses-permission android:name="android.permission.INTERNET" /-->
+    <uses-permission android:name="android.permission.INTERNET" />
     <!-- http://developer.android.com/guide/topics/security/permissions.html#normal-dangerous -->
 
     <uses-feature
diff --git a/app/src/main/java/eu/faircode/netguard/ActivitySettings.java b/app/src/main/java/eu/faircode/netguard/ActivitySettings.java
index 71d8d6b2..162cc4c5 100644
--- a/app/src/main/java/eu/faircode/netguard/ActivitySettings.java
+++ b/app/src/main/java/eu/faircode/netguard/ActivitySettings.java
@@ -230,11 +230,11 @@ public class ActivitySettings extends AppCompatActivity implements SharedPrefere
             options.removePreference(screen.findPreference("national_roaming"));
         }
 
-
-        //if (!Util.isDebuggable(this)) {
-        PreferenceCategory backup = (PreferenceCategory) screen.findPreference("category_backup");
-        backup.removePreference(screen.findPreference("pcap"));
-        //}
+        // Development
+        if (!Util.isDebuggable(this)) {
+            PreferenceCategory development = (PreferenceCategory) screen.findPreference("category_development");
+            screen.removePreference(development);
+        }
     }
 
     @Override
@@ -410,7 +410,9 @@ public class ActivitySettings extends AppCompatActivity implements SharedPrefere
 
         } else if ("stats_samples".equals(name)) {
             getPreferenceScreen().findPreference(name).setTitle(getString(R.string.setting_stats_samples, prefs.getString(name, "90")));
-        }
+
+        } else if ("native".equals(name))
+            SinkholeService.reload(null, "setting changed", this);
     }
 
     @Override
diff --git a/app/src/main/java/eu/faircode/netguard/SinkholeService.java b/app/src/main/java/eu/faircode/netguard/SinkholeService.java
index 1bd2ddbb..b12ef0b2 100644
--- a/app/src/main/java/eu/faircode/netguard/SinkholeService.java
+++ b/app/src/main/java/eu/faircode/netguard/SinkholeService.java
@@ -112,9 +112,9 @@ public class SinkholeService extends VpnService implements SharedPreferences.OnS
 
     private static final String ACTION_SCREEN_OFF_DELAYED = "eu.faircode.netguard.SCREEN_OFF_DELAYED";
 
-    private native void jni_init(int loglevel, String pcap);
+    private native void jni_init(String pcap);
 
-    private native void jni_start(int tun);
+    private native void jni_start(int tun, int loglevel, boolean native_);
 
     private native void jni_stop(int tun, boolean clear);
 
@@ -247,7 +247,7 @@ public class SinkholeService extends VpnService implements SharedPreferences.OnS
                             if (vpn == null)
                                 throw new IllegalStateException("VPN start failed");
                             if (prefs.getBoolean("log", false))
-                                jni_start(vpn.getFd());
+                                jni_start(vpn.getFd(), Log.INFO, prefs.getBoolean("native", false));
                             removeDisabledNotification();
                         }
                         break;
@@ -276,7 +276,7 @@ public class SinkholeService extends VpnService implements SharedPreferences.OnS
                         }
                         jni_stop(vpn.getFd(), false);
                         if (prefs.getBoolean("log", false))
-                            jni_start(vpn.getFd());
+                            jni_start(vpn.getFd(), Log.INFO, prefs.getBoolean("native", false));
                         if (prev != null)
                             stopVPN(prev);
                         break;
@@ -858,8 +858,7 @@ public class SinkholeService extends VpnService implements SharedPreferences.OnS
         File pcap = new File(getCacheDir(), "netguard.pcap");
         if (pcap.exists())
             pcap.delete();
-        //jni_init(Log.INFO, pcap.getAbsolutePath());
-        jni_init(Log.INFO, null);
+        jni_init(pcap.getAbsolutePath());
 
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
         prefs.registerOnSharedPreferenceChangeListener(this);
diff --git a/app/src/main/jni/netguard/netguard.c b/app/src/main/jni/netguard/netguard.c
index d63a5679..6b2c1290 100644
--- a/app/src/main/jni/netguard/netguard.c
+++ b/app/src/main/jni/netguard/netguard.c
@@ -34,15 +34,14 @@ pthread_t thread_id;
 int signaled = 0;
 struct session *session = NULL;
 
-int loglevel = ANDROID_LOG_WARN;
 char *pcap_fn = NULL;
+int loglevel = ANDROID_LOG_WARN;
+int native = 0;
 
 // JNI
 
 JNIEXPORT void JNICALL
-Java_eu_faircode_netguard_SinkholeService_jni_1init(JNIEnv *env, jobject instance,
-                                                    jint loglevel_, jstring pcap_) {
-    loglevel = loglevel_;
+Java_eu_faircode_netguard_SinkholeService_jni_1init(JNIEnv *env, jobject instance, jstring pcap_) {
     if (pcap_ == NULL)
         pcap_fn = NULL;
     else {
@@ -65,14 +64,19 @@ Java_eu_faircode_netguard_SinkholeService_jni_1init(JNIEnv *env, jobject instanc
         pcap_hdr.network = LINKTYPE_RAW;
         pcap_write(&pcap_hdr, sizeof(struct pcap_hdr_s));
 
+        // TODO limit pcap file size
+
         (*env)->ReleaseStringUTFChars(env, pcap_, pcap);
     }
 }
 
 JNIEXPORT void JNICALL
 Java_eu_faircode_netguard_SinkholeService_jni_1start(JNIEnv *env, jobject instance,
-                                                     jint tun) {
-    ng_log(ANDROID_LOG_INFO, "Starting tun=%d", tun);
+                                                     jint tun, jint loglevel_, jboolean native_) {
+    loglevel = loglevel_;
+    native = native_;
+
+    ng_log(ANDROID_LOG_INFO, "Starting tun=%d level %d native %d", tun, loglevel, native);
 
     if (pthread_kill(thread_id, 0) == 0)
         ng_log(ANDROID_LOG_WARN, "Already running thread %ld", thread_id);
@@ -340,7 +344,7 @@ int check_tun(const struct arguments *args, fd_set *rfds, fd_set *wfds, fd_set *
         }
         else if (length > 0) {
             // Write pcap record
-            if (pcap_fn != NULL) {
+            if (native && pcap_fn != NULL) {
                 struct timespec ts;
                 if (clock_gettime(CLOCK_REALTIME, &ts))
                     ng_log(ANDROID_LOG_ERROR, "clock_gettime error %d: %s",
@@ -603,14 +607,13 @@ void handle_ip(const struct arguments *args, const uint8_t *buffer, const uint16
            "Packet v%d %s/%u -> %s/%u proto %d flags %s uid %d",
            version, source, sport, dest, dport, protocol, flags, uid);
 
-    //if (protocol == IPPROTO_TCP)
-    //    handle_tcp(env, instance, args, buffer, length, uid);
+    if (protocol == IPPROTO_TCP && native)
+        handle_tcp(args, buffer, length, uid);
 
     // Call back
-    //if ((protocol == IPPROTO_TCP && syn) || protocol == IPPROTO_UDP) {
     JNIEnv *env = args->env;
     jobject instance = args->instance;
-    if (protocol == IPPROTO_TCP || protocol == IPPROTO_UDP) {
+    if ((protocol == IPPROTO_TCP && (syn || !native)) || protocol == IPPROTO_UDP) {
         jclass cls = (*env)->GetObjectClass(env, instance);
         jmethodID mid = (*env)->GetMethodID(
                 env, cls, "logPacket",
@@ -1063,7 +1066,7 @@ int write_tcp(const struct session *cur,
     int res = write(tun, buffer, len);
 
     // Write pcap record
-    if (pcap_fn != NULL) {
+    if (native && pcap_fn != NULL) {
         struct timespec ts;
         if (clock_gettime(CLOCK_REALTIME, &ts))
             ng_log(ANDROID_LOG_ERROR, "clock_gettime error %d: %s", errno, strerror(errno));
diff --git a/app/src/main/res/xml/preferences.xml b/app/src/main/res/xml/preferences.xml
index ae8463b8..bc00e1a5 100644
--- a/app/src/main/res/xml/preferences.xml
+++ b/app/src/main/res/xml/preferences.xml
@@ -124,8 +124,18 @@
         <Preference
             android:key="import"
             android:title="@string/setting_import" />
+    </PreferenceCategory>
+    <PreferenceCategory
+        android:key="category_development"
+        android:title="Development">
+        <SwitchPreference
+            android:defaultValue="false"
+            android:dependency="log"
+            android:key="native"
+            android:title="Native code" />
         <Preference
             android:key="pcap"
+            android:dependency="native"
             android:title="Export PCAP" />
     </PreferenceCategory>
     <PreferenceCategory