Added option to enable/disable domain blocking

Thanks @rgarza

Fixes #241
Closes #245

app/src/main/java/eu/faircode/netguard/ActivitySettings.java

@@ -179,9 +179,14 @@ public class ActivitySettings extends AppCompatActivity implements SharedPrefere
 
         // Handle hosts
         Preference pref_hosts = screen.findPreference("hosts");
+        Preference pref_block_domains = screen.findPreference("use_hosts");
+
         if (Util.isPlayStoreInstall(this)) {
             PreferenceCategory pref_backup = (PreferenceCategory) screen.findPreference("category_backup");
             pref_backup.removePreference(pref_hosts);
+            PreferenceCategory pref_category = (PreferenceCategory) screen.findPreference("category_options");
+            pref_category.removePreference(pref_block_domains);
+
         } else {
             pref_hosts.setEnabled(getIntentOpenHosts().resolveActivity(getPackageManager()) != null);
             pref_hosts.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
@@ -240,7 +245,7 @@ public class ActivitySettings extends AppCompatActivity implements SharedPrefere
             options.removePreference(screen.findPreference("national_roaming"));
         }
 
-        if (!Util.getSelfVersionName(this).endsWith("beta"))
+        if (!(Util.isDebuggable(this) || Util.getSelfVersionName(this).endsWith("beta")))
             screen.removePreference(screen.findPreference("category_development"));
     }
 
@@ -388,6 +393,9 @@ public class ActivitySettings extends AppCompatActivity implements SharedPrefere
                         .create().show();
             }
 
+        } else if ("use_hosts".equals(name)) {
+            SinkholeService.reload(null, "setting changed", this);
+
         } else if ("auto_enable".equals(name))
             getPreferenceScreen().findPreference(name).setTitle(getString(R.string.setting_auto, prefs.getString(name, "0")));
 

app/src/main/java/eu/faircode/netguard/SinkholeService.java

@@ -325,15 +325,7 @@ public class SinkholeService extends VpnService implements SharedPreferences.OnS
                 if (vpn == null)
                     throw new IllegalStateException("VPN start failed");
 
-                SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(SinkholeService.this);
-                boolean log = prefs.getBoolean("log", false);
-                boolean filter = prefs.getBoolean("filter", false);
-                if (log || filter) {
-                    int prio = Integer.parseInt(prefs.getString("loglevel", Integer.toString(Log.INFO)));
-                    File hosts = new File(getCacheDir(), "hosts.txt");
-                    String hname = (hosts.exists() ? hosts.getAbsolutePath() : null);
-                    jni_start(vpn.getFd(), getAllowedUids(listAllowed), hname, log, filter, prio);
-                }
+                startNative(listAllowed);
 
                 removeWarningNotifications();
                 updateEnforcingNotification(listAllowed.size(), listRule.size());
@@ -368,15 +360,7 @@ public class SinkholeService extends VpnService implements SharedPreferences.OnS
 
             // TODO drain old VPN
             jni_stop(vpn.getFd(), false);
-            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(SinkholeService.this);
-            boolean log = prefs.getBoolean("log", false);
-            boolean filter = prefs.getBoolean("filter", false);
-            if (log || filter) {
-                int prio = Integer.parseInt(prefs.getString("loglevel", Integer.toString(Log.INFO)));
-                File hosts = new File(getCacheDir(), "hosts.txt");
-                String hname = (hosts.exists() ? hosts.getAbsolutePath() : null);
-                jni_start(vpn.getFd(), getAllowedUids(listAllowed), hname, log, filter, prio);
-            }
+            startNative(listAllowed);
 
             if (prev != null)
                 stopVPN(prev);
@@ -717,6 +701,19 @@ public class SinkholeService extends VpnService implements SharedPreferences.OnS
         }
     }
 
+    private void startNative(List<Rule> listAllowed) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(SinkholeService.this);
+        boolean log = prefs.getBoolean("log", false);
+        boolean filter = prefs.getBoolean("filter", false);
+        boolean use_hosts = prefs.getBoolean("use_hosts", false);
+        if (log || filter) {
+            int prio = Integer.parseInt(prefs.getString("loglevel", Integer.toString(Log.INFO)));
+            File hosts = new File(getCacheDir(), "hosts.txt");
+            String hname = (use_hosts && hosts.exists() ? hosts.getAbsolutePath() : null);
+            jni_start(vpn.getFd(), getAllowedUids(listAllowed), hname, log, filter, prio);
+        }
+    }
+
     private List<Rule> getAllowedRules(List<Rule> listRule) {
         List<Rule> listAllowed = new ArrayList<>();
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);

app/src/main/jni/netguard/netguard.c

@@ -106,7 +106,7 @@ Java_eu_faircode_netguard_SinkholeService_jni_1start(
         jint loglevel_) {
 
     loglevel = loglevel_;
-    log_android(ANDROID_LOG_INFO, "Starting tun=%d log %d filter %d level %d",
+    log_android(ANDROID_LOG_WARN, "Starting tun=%d log %d filter %d level %d",
                 tun, log, filter, loglevel_);
 
     // Set blocking
@@ -139,9 +139,10 @@ Java_eu_faircode_netguard_SinkholeService_jni_1start(
         if (hosts_ == NULL) {
             args->hcount = 0;
             args->hosts = NULL;
+            log_android(ANDROID_LOG_WARN, "No hosts file");
         } else {
             const char *hosts = (*env)->GetStringUTFChars(env, hosts_, 0);
-            log_android(ANDROID_LOG_INFO, "hosts file %s", hosts);
+            log_android(ANDROID_LOG_WARN, "hosts file %s", hosts);
             read_hosts(hosts, args);
             (*env)->ReleaseStringUTFChars(env, hosts_, hosts);
         }
@@ -161,7 +162,7 @@ Java_eu_faircode_netguard_SinkholeService_jni_1start(
 JNIEXPORT void JNICALL
 Java_eu_faircode_netguard_SinkholeService_jni_1stop(JNIEnv *env, jobject instance,
                                                     jint tun, jboolean clear) {
-    log_android(ANDROID_LOG_INFO, "Stop tun %d clear %d", tun, (int) clear);
+    log_android(ANDROID_LOG_WARN, "Stop tun %d clear %d", tun, (int) clear);
     if (pthread_kill(thread_id, 0) == 0) {
         stopping = 1;
         log_android(ANDROID_LOG_DEBUG, "Kill thread %lu", thread_id);
@@ -302,7 +303,7 @@ void *handle_events(void *a) {
                     log_android(ANDROID_LOG_WARN, "pselect signaled");
                     break;
                 } else {
-                    log_android(ANDROID_LOG_WARN, "pselect interrupted");
+                    log_android(ANDROID_LOG_DEBUG, "pselect interrupted");
                     continue;
                 }
             } else {
@@ -384,7 +385,7 @@ void *handle_events(void *a) {
     free(args->hosts);
     free(args);
 
-    log_android(ANDROID_LOG_INFO, "Stopped events tun=%d thread %lu", args->tun, thread_id);
+    log_android(ANDROID_LOG_WARN, "Stopped events tun=%d thread %lu", args->tun, thread_id);
     return NULL;
 }
 
@@ -2062,7 +2063,7 @@ char *trim(char *str) {
 }
 
 void read_hosts(const char *name, struct arguments *args) {
-    log_android(ANDROID_LOG_WARN, "Reading %s", name);
+    log_android(ANDROID_LOG_INFO, "Reading %s", name);
 
     args->hcount = 0;
     args->hosts = NULL;

app/src/main/res/values/strings.xml

@@ -43,6 +43,8 @@ These issues are caused by bugs in Android, or in the software provided by the m
     <string name="setting_tethering">Allow tethering</string>
     <string name="setting_log">Log traffic</string>
     <string name="setting_filter">Filter traffic</string>
+    <string name="setting_block_domains">Block domain names</string>
+
     <string name="setting_auto">Auto enable after %1$s minutes</string>
     <string name="setting_delay">Delay screen off %1$s minutes</string>
     <string name="setting_theme">Theme: %1$s</string>
@@ -71,6 +73,7 @@ These issues are caused by bugs in Android, or in the software provided by the m
     <string name="summary_system">Define rules for system applications (for experts)</string>
     <string name="summary_log">Log addresses of IP packets going into the VPN sinkhole. This might result in extra battery usage.</string>
     <string name="summary_filter">Filter IP packets going out of the VPN sinkhole. This might result in extra battery usage.</string>
+    <string name="summary_block_domains">Redirect blocked domain names to local device</string>
     <string name="summary_stats">Show network speed graph in status bar notification</string>
     <string name="summary_auto">After disabling using the widget, automatically enable NetGuard again after the selected number of minutes (enter zero to disable this option)</string>
     <string name="summary_delay">After turning the screen off, keep screen on rules active for the selected number of minutes (enter zero to disable this option)</string>

app/src/main/res/xml/preferences.xml

@@ -46,6 +46,12 @@
             android:key="filter"
             android:summary="@string/summary_filter"
             android:title="@string/setting_filter" />
+        <SwitchPreference
+            android:defaultValue="true"
+            android:dependency="filter"
+            android:key="use_hosts"
+            android:summary="@string/summary_block_domains"
+            android:title="@string/setting_block_domains" />
         <EditTextPreference
             android:defaultValue="0"
             android:inputType="number"