implement wifi tethering

1 files changed, 89 insertions, 0 deletions

diff --git a/app/src/main/java/se/leap/bitmaskclient/firewall/ShutdownTetheringTask.java b/app/src/main/java/se/leap/bitmaskclient/firewall/ShutdownTetheringTask.java
new file mode 100644
index 00000000..6c15c3e3
--- /dev/null
+++ b/app/src/main/java/se/leap/bitmaskclient/firewall/ShutdownTetheringTask.java
@@ -0,0 +1,89 @@
+/**
+ * Copyright (c) 2020 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/>.
+ */
+package se.leap.bitmaskclient.firewall;
+
+import android.os.AsyncTask;
+import android.util.Log;
+
+import java.lang.ref.WeakReference;
+
+import se.leap.bitmaskclient.tethering.TetheringObservable;
+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 ShutdownTetheringTask extends AsyncTask<Void, Boolean, Boolean> {
+
+    private WeakReference<FirewallCallback> callbackWeakReference;
+
+    ShutdownTetheringTask(FirewallCallback callback) {
+        callbackWeakReference = new WeakReference<>(callback);
+    }
+
+    @Override
+    protected Boolean doInBackground(Void... args) {
+        TetheringState tetheringState = TetheringObservable.getInstance().getTetheringState();
+        StringBuilder log = new StringBuilder();
+
+        String[] bitmaskChain = new String[]{
+                "su",
+                "id",
+                "iptables -t filter --list " + BITMASK_FORWARD + " && iptables -t nat --list " + BITMASK_POSTROUTING };
+
+        try {
+            boolean hasBitmaskChain = runBlockingCmd(bitmaskChain, log) == 0;
+            boolean allowSu = log.toString().contains("uid=0");
+            callbackWeakReference.get().onSuRequested(allowSu);
+            if (!allowSu || !hasBitmaskChain) {
+                return false;
+            }
+
+            log = new StringBuilder();
+
+            String[] removeChains = new String[] {
+                    "su",
+                    "ip route flush table 61",
+                    "if [[ `ip rule show from " + tetheringState.wifiAddress+ " lookup 61` ]]; " +
+                            "then ip rule del from " + tetheringState.wifiAddress + " lookup 61; " +
+                            "fi",
+                    "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.onTetheringStarted(result);
+        }
+    }
+}