1 files changed, 167 insertions, 0 deletions
diff --git a/app/src/main/java/se/leap/bitmaskclient/utils/FirewallHelper.java b/app/src/main/java/se/leap/bitmaskclient/utils/FirewallHelper.java
new file mode 100644
index 00000000..43a5296f
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/utils/FirewallHelper.java
@@ -0,0 +1,167 @@
+package se.leap.bitmaskclient.utils;
+/**
+ * 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.os.AsyncTask;
+import android.text.TextUtils;
+import android.util.Log;
+
+import java.lang.ref.WeakReference;
+
+import static se.leap.bitmaskclient.utils.Cmd.runBlockingCmd;
+
+interface FirewallCallback {
+    void onFirewallStarted(boolean success);
+    void onFirewallStopped(boolean success);
+}
+
+
+public class FirewallHelper implements FirewallCallback {
+    private static String BITMASK_CHAIN = "bitmask_fw";
+    private static final String TAG = FirewallHelper.class.getSimpleName();
+
+
+    @Override
+    public void onFirewallStarted(boolean success) {
+        Log.d(TAG, "Firewall started " + success);
+    }
+
+    @Override
+    public void onFirewallStopped(boolean success) {
+        Log.d(TAG, "Firewall stopped " + success);
+    }
+
+
+    static class StartFirewallTask extends  AsyncTask<Void, Boolean, Boolean> {
+
+       WeakReference<FirewallCallback> callbackWeakReference;
+
+        public StartFirewallTask(FirewallCallback callback) {
+            callbackWeakReference = new WeakReference<>(callback);
+        }
+
+        @Override
+        protected Boolean doInBackground(Void... voids) {
+            if (requestSU()) {
+                Log.d(TAG, "su acquired");
+                StringBuilder log = new StringBuilder();
+                String[] bitmaskChain = new String[]{
+                        "su",
+                        "ip6tables --list " + BITMASK_CHAIN };
+                try {
+                    boolean hasBitmaskChain = runBlockingCmd(bitmaskChain, log) == 0;
+                    Log.d(TAG, log.toString());
+                    if (!hasBitmaskChain) {
+                        String[] createChain = new String[]{
+                                "su",
+                                "ip6tables --new-chain " + BITMASK_CHAIN,
+                                "ip6tables --insert OUTPUT --jump " + BITMASK_CHAIN };
+                        log = new StringBuilder();
+                        int success = runBlockingCmd(createChain, log);
+                        Log.d(TAG, "added " + BITMASK_CHAIN + " to ip6tables: " + success);
+                        Log.d(TAG, log.toString());
+                        if (success != 0) {
+                            return false;
+                        }
+                    }
+
+                    log = new StringBuilder();
+                    String[] addRules = new String[] {
+                            "su",
+                            "ip6tables --append " + BITMASK_CHAIN + " -p tcp --jump REJECT",
+                            "ip6tables --append " + BITMASK_CHAIN + " -p udp --jump REJECT" };
+                    boolean successResult = runBlockingCmd(addRules, log) == 0;
+                    Log.d(TAG, log.toString());
+                    return successResult;
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    Log.e(TAG, log.toString());
+                }
+            };
+            return false;
+        }
+
+        @Override
+        protected void onPostExecute(Boolean result) {
+            super.onPostExecute(result);
+            FirewallCallback callback = callbackWeakReference.get();
+            if (callback != null) {
+                callback.onFirewallStarted(result);
+            }
+        }
+    }
+
+    static class ShutdownFirewallTask extends AsyncTask<Void, Boolean, Boolean> {
+
+        @Override
+        protected Boolean doInBackground(Void... voids) {
+
+            if (requestSU()) {
+                StringBuilder log = new StringBuilder();
+                String[] deleteChain = new String[]{
+                        "su",
+                        "ip6tables --delete OUTPUT --jump " + BITMASK_CHAIN,
+                        "ip6tables --flush " + BITMASK_CHAIN,
+                        "ip6tables --delete-chain " + BITMASK_CHAIN
+                };
+                try {
+                    runBlockingCmd(deleteChain, log);
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    Log.e(TAG, log.toString());
+                }
+
+            }
+
+            return null;
+        }
+    }
+
+
+    public void startFirewall() {
+        StartFirewallTask task = new StartFirewallTask(this);
+        task.execute();
+    }
+
+    public void shutdownFirewall() {
+        ShutdownFirewallTask task = new ShutdownFirewallTask();
+        task.execute();
+    }
+
+    public static boolean hasSU() {
+        StringBuilder log = new StringBuilder();
+
+        try {
+            String suCommand = "su -v";
+            runBlockingCmd(new String[]{suCommand}, log);
+        } catch (Exception e) {
+            return false;
+        }
+
+        return !TextUtils.isEmpty(log) && !log.toString().contains("su: not found");
+    }
+
+    public static boolean requestSU() {
+        try {
+            String suCommand = "su";
+            return  runBlockingCmd(new String[]{suCommand}, null) == 0;
+        } catch (Exception e) {
+            return false;
+        }
+    }
+
+}