rearrange firewalling code, move to separate package

4 files changed, 209 insertions, 0 deletions

diff --git a/app/src/main/java/se/leap/bitmaskclient/firewall/FirewallCallback.java b/app/src/main/java/se/leap/bitmaskclient/firewall/FirewallCallback.java
new file mode 100644
index 00000000..f6ccd227
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/firewall/FirewallCallback.java
@@ -0,0 +1,7 @@
+package se.leap.bitmaskclient.firewall;
+
+interface FirewallCallback {
+    void onFirewallStarted(boolean success);
+    void onFirewallStopped(boolean success);
+    void onSuRequested(boolean success);
+}
diff --git a/app/src/main/java/se/leap/bitmaskclient/firewall/FirewallManager.java b/app/src/main/java/se/leap/bitmaskclient/firewall/FirewallManager.java
new file mode 100644
index 00000000..a3be46e6
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/firewall/FirewallManager.java
@@ -0,0 +1,73 @@
+package se.leap.bitmaskclient.firewall;
+/**
+ * Copyright (c) 2019 LEAP Encryption Access Project and contributers
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import android.content.Context;
+
+import de.blinkt.openvpn.core.VpnStatus;
+import se.leap.bitmaskclient.utils.PreferenceHelper;
+
+
+public class FirewallManager implements FirewallCallback {
+    public static String BITMASK_CHAIN = "bitmask_fw";
+    static final String TAG = FirewallManager.class.getSimpleName();
+
+    private Context context;
+
+    public FirewallManager(Context context) {
+        this.context = context;
+    }
+
+
+    @Override
+    public void onFirewallStarted(boolean success) {
+        if (success) {
+            VpnStatus.logInfo("[FIREWALL] Custom rules established");
+        } else {
+            VpnStatus.logError("[FIREWALL] Could not establish custom rules.");
+        }
+    }
+
+    @Override
+    public void onFirewallStopped(boolean success) {
+        if (success) {
+            VpnStatus.logInfo("[FIREWALL] Custom rules deleted");
+        } else {
+            VpnStatus.logError("[FIREWALL] Could not delete custom rules");
+        }
+    }
+
+    @Override
+    public void onSuRequested(boolean success) {
+        PreferenceHelper.setSuPermission(context, success);
+        if (!success) {
+            VpnStatus.logError("[FIREWALL] Root permission needed to execute custom firewall rules.");
+        }
+    }
+
+
+    public void startFirewall() {
+        StartFirewallTask task = new StartFirewallTask(this);
+        task.execute();
+    }
+
+    public void shutdownFirewall() {
+        ShutdownFirewallTask task = new ShutdownFirewallTask(this);
+        task.execute();
+    }
+
+}
diff --git a/app/src/main/java/se/leap/bitmaskclient/firewall/ShutdownFirewallTask.java b/app/src/main/java/se/leap/bitmaskclient/firewall/ShutdownFirewallTask.java
new file mode 100644
index 00000000..50fa77cd
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/firewall/ShutdownFirewallTask.java
@@ -0,0 +1,55 @@
+package se.leap.bitmaskclient.firewall;
+
+import android.os.AsyncTask;
+import android.util.Log;
+
+import java.lang.ref.WeakReference;
+
+import static se.leap.bitmaskclient.firewall.FirewallManager.BITMASK_CHAIN;
+import static se.leap.bitmaskclient.utils.Cmd.runBlockingCmd;
+
+class ShutdownFirewallTask extends AsyncTask<Void, Boolean, Boolean> {
+
+    private WeakReference<FirewallCallback> callbackWeakReference;
+
+    ShutdownFirewallTask(FirewallCallback callback) {
+        callbackWeakReference = new WeakReference<>(callback);
+    }
+
+    @Override
+    protected Boolean doInBackground(Void... voids) {
+        boolean success;
+        StringBuilder log = new StringBuilder();
+        String[] deleteChain = new String[]{
+                "su",
+                "id",
+                "ip6tables --delete OUTPUT --jump " + BITMASK_CHAIN,
+                "ip6tables --flush " + BITMASK_CHAIN,
+                "ip6tables --delete-chain " + BITMASK_CHAIN
+        };
+        try {
+            success = runBlockingCmd(deleteChain, log) == 0;
+        } catch (Exception e) {
+            e.printStackTrace();
+            Log.e(FirewallManager.TAG, log.toString());
+            return false;
+        }
+
+        try {
+            boolean allowSu = log.toString().contains("uid=0");
+            callbackWeakReference.get().onSuRequested(allowSu);
+        } catch (Exception e) {
+            //ignore
+        }
+        return success;
+    }
+
+    @Override
+    protected void onPostExecute(Boolean result) {
+        super.onPostExecute(result);
+        FirewallCallback callback = callbackWeakReference.get();
+        if (callback != null) {
+            callback.onFirewallStopped(result);
+        }
+    }
+}
diff --git a/app/src/main/java/se/leap/bitmaskclient/firewall/StartFirewallTask.java b/app/src/main/java/se/leap/bitmaskclient/firewall/StartFirewallTask.java
new file mode 100644
index 00000000..9b3a125f
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/firewall/StartFirewallTask.java
@@ -0,0 +1,74 @@
+package se.leap.bitmaskclient.firewall;
+
+import android.os.AsyncTask;
+import android.util.Log;
+
+import java.lang.ref.WeakReference;
+
+import static se.leap.bitmaskclient.firewall.FirewallManager.BITMASK_CHAIN;
+import static se.leap.bitmaskclient.utils.Cmd.runBlockingCmd;
+
+class StartFirewallTask extends AsyncTask<Void, Boolean, Boolean> {
+
+   private WeakReference<FirewallCallback> callbackWeakReference;
+
+    StartFirewallTask(FirewallCallback callback) {
+        callbackWeakReference = new WeakReference<>(callback);
+    }
+
+    @Override
+    protected Boolean doInBackground(Void... voids) {
+        StringBuilder log = new StringBuilder();
+        String[] bitmaskChain = new String[]{
+                "su",
+                "id",
+                "ip6tables --list " + BITMASK_CHAIN };
+
+
+        try {
+            boolean hasBitmaskChain = runBlockingCmd(bitmaskChain, log) == 0;
+            boolean allowSu = log.toString().contains("uid=0");
+            try {
+                callbackWeakReference.get().onSuRequested(allowSu);
+                Thread.sleep(1000);
+            } catch (Exception e) {
+                //ignore
+            }
+
+            boolean success;
+            log = new StringBuilder();
+            if (!hasBitmaskChain) {
+                String[] createChainAndRules = new String[]{
+                        "su",
+                        "ip6tables --new-chain " + BITMASK_CHAIN,
+                        "ip6tables --insert OUTPUT --jump " + BITMASK_CHAIN,
+                        "ip6tables --append " + BITMASK_CHAIN + " -p tcp --jump REJECT",
+                        "ip6tables --append " + BITMASK_CHAIN + " -p udp --jump REJECT"
+                };
+                success = runBlockingCmd(createChainAndRules, log) == 0;
+                Log.d(FirewallManager.TAG, "added " + BITMASK_CHAIN + " to ip6tables: " + success);
+                Log.d(FirewallManager.TAG, log.toString());
+                return success;
+            } else {
+                String[] addRules = new String[] {
+                        "su",
+                        "ip6tables --append " + BITMASK_CHAIN + " -p tcp --jump REJECT",
+                        "ip6tables --append " + BITMASK_CHAIN + " -p udp --jump REJECT" };
+                return runBlockingCmd(addRules, log) == 0;
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+            Log.e(FirewallManager.TAG, log.toString());
+        }
+        return false;
+    }
+
+    @Override
+    protected void onPostExecute(Boolean result) {
+        super.onPostExecute(result);
+        FirewallCallback callback = callbackWeakReference.get();
+        if (callback != null) {
+            callback.onFirewallStarted(result);
+        }
+    }
+}