1 files changed, 95 insertions, 0 deletions
diff --git a/app/src/main/java/se/leap/bitmaskclient/firewall/ConfigureTetheringTask.java b/app/src/main/java/se/leap/bitmaskclient/firewall/ConfigureTetheringTask.java
new file mode 100644
index 00000000..29e9542d
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/firewall/ConfigureTetheringTask.java
@@ -0,0 +1,95 @@
+package se.leap.bitmaskclient.firewall;
+
+import android.os.AsyncTask;
+import android.util.Log;
+
+import java.lang.ref.WeakReference;
+
+import se.leap.bitmaskclient.tethering.TetheringState;
+
+import static se.leap.bitmaskclient.firewall.FirewallManager.BITMASK_FORWARD;
+import static se.leap.bitmaskclient.firewall.FirewallManager.BITMASK_POSTROUTING;
+import static se.leap.bitmaskclient.utils.Cmd.runBlockingCmd;
+
+public class ConfigureTetheringTask extends AsyncTask<TetheringState, Boolean, Boolean> {
+
+    private WeakReference<FirewallCallback> callbackWeakReference;
+
+    ConfigureTetheringTask(FirewallCallback callback) {
+        callbackWeakReference = new WeakReference<>(callback);
+    }
+
+    @Override
+    protected Boolean doInBackground(TetheringState... tetheringStates) {
+        TetheringState tetheringState = tetheringStates[0];
+        StringBuilder log = new StringBuilder();
+
+        String[] bitmaskChain = new String[]{
+                "su",
+                "id",
+                "iptables --list " + BITMASK_FORWARD + " && iptables --list " + BITMASK_POSTROUTING };
+
+        try {
+            boolean hasBitmaskChain = runBlockingCmd(bitmaskChain, log) == 0;
+            boolean allowSu = log.toString().contains("uid=0");
+            callbackWeakReference.get().onSuRequested(allowSu);
+            if (!allowSu) {
+                return false;
+            }
+
+            boolean success;
+            log = new StringBuilder();
+            if (hasAnyTetheringEnabled(tetheringState)) {
+                if (!hasBitmaskChain) {
+                    String[] createChains = new String[]{
+                            "su",
+                            "iptables -t filter --new-chain " + BITMASK_FORWARD,
+                            "iptables -t nat --new-chain " + BITMASK_POSTROUTING,
+                            "iptables -t filter --insert FORWARD --jump " + BITMASK_FORWARD,
+                            "iptables -t nat --insert POSTROUTING --jump " + BITMASK_POSTROUTING,
+                    };
+                    success = runBlockingCmd(createChains, log) == 0;
+                    Log.d(FirewallManager.TAG, "added " + BITMASK_FORWARD + " and " + BITMASK_POSTROUTING+" to iptables: " + success);
+                    Log.d(FirewallManager.TAG, log.toString());
+                }
+
+                String[] addRules = new String[] {
+                        "su",
+                        "iptables -t filter --flush " + BITMASK_FORWARD,
+                        "iptables -t nat --flush " + BITMASK_POSTROUTING,
+                        "iptables -t filter --append " + BITMASK_FORWARD + " --jump ACCEPT",
+                        "iptables -t nat --append " + BITMASK_POSTROUTING + " --jump MASQUERADE" };
+                return runBlockingCmd(addRules, log) == 0;
+            } else {
+                if (!hasBitmaskChain) return true;
+                String[] removeChains = new String[] {
+                        "su",
+                        "iptables -t filter --delete FORWARD --jump " + BITMASK_FORWARD,
+                        "iptables -t nat --delete POSTROUTING --jump " + BITMASK_POSTROUTING,
+                        "iptables -t filter --flush " + BITMASK_FORWARD,
+                        "iptables -t nat --flush " + BITMASK_POSTROUTING,
+                        "iptables -t filter --delete-chain " + BITMASK_FORWARD,
+                        "iptables -t nat --delete-chain " + BITMASK_POSTROUTING
+                };
+                return runBlockingCmd(removeChains, 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.onTetheringConfigured(result);
+        }
+    }
+
+    private boolean hasAnyTetheringEnabled(TetheringState state) {
+        return state.isBluetoothTetheringEnabled || state.isUsbTetheringEnabled || state.isWifiTetheringEnabled;
+    }
+}