Support toggling hotspots in app

This is a just-for-fun feature. It probably doesn't work.
2018-04-21 13:02:52 -07:00
parent 0355dae65e
commit 958b1ec350
15 changed files with 440 additions and 50 deletions
--- a/mobile/src/main/java/be/mygod/vpnhotspot/net/TetheringManager.kt
+++ b/mobile/src/main/java/be/mygod/vpnhotspot/net/TetheringManager.kt
@@ -0,0 +1,131 @@
+package be.mygod.vpnhotspot.net
+
+import android.annotation.SuppressLint
+import android.net.ConnectivityManager
+import android.os.Build
+import android.os.Bundle
+import android.os.Handler
+import android.support.annotation.RequiresApi
+import android.util.Log
+import be.mygod.vpnhotspot.App.Companion.app
+import com.android.dx.stock.ProxyBuilder
+
+/**
+ * Heavily based on:
+ * https://github.com/aegis1980/WifiHotSpot
+ * https://android.googlesource.com/platform/frameworks/base.git/+/android-7.0.0_r1/core/java/android/net/ConnectivityManager.java
+ */
+object TetheringManager {
+    /**
+     * Callback for use with [.startTethering] to find out whether tethering succeeded.
+     */
+    interface OnStartTetheringCallback {
+        /**
+         * Called when tethering has been successfully started.
+         */
+        fun onTetheringStarted() { }
+
+        /**
+         * Called when starting tethering failed.
+         */
+        fun onTetheringFailed() { }
+    }
+
+    private const val TAG = "TetheringManager"
+
+    /**
+     * This is a sticky broadcast since almost forever.
+     *
+     * https://android.googlesource.com/platform/frameworks/base.git/+/2a091d7aa0c174986387e5d56bf97a87fe075bdb%5E%21/services/java/com/android/server/connectivity/Tethering.java
+     */
+    const val ACTION_TETHER_STATE_CHANGED = "android.net.conn.TETHER_STATE_CHANGED"
+    private const val EXTRA_ACTIVE_TETHER_LEGACY = "activeArray"
+    @RequiresApi(26)
+    private const val EXTRA_ACTIVE_LOCAL_ONLY = "localOnlyArray"
+    @RequiresApi(26)
+    private const val EXTRA_ACTIVE_TETHER = "tetherArray"
+
+    const val TETHERING_WIFI = 0
+    /**
+     * Requires MANAGE_USB permission, unfortunately.
+     *
+     * Source: https://android.googlesource.com/platform/frameworks/base/+/7ca5d3a/services/usb/java/com/android/server/usb/UsbService.java#389
+     */
+    const val TETHERING_USB = 1
+    /**
+     * Requires BLUETOOTH permission.
+     */
+    const val TETHERING_BLUETOOTH = 2
+
+    private val classOnStartTetheringCallback by lazy @SuppressLint("PrivateApi") {
+        Class.forName("android.net.ConnectivityManager\$OnStartTetheringCallback")
+    }
+    private val startTethering by lazy {
+        ConnectivityManager::class.java.getDeclaredMethod("startTethering",
+                Int::class.java, Boolean::class.java, classOnStartTetheringCallback, Handler::class.java)
+    }
+    private val stopTethering by lazy {
+        ConnectivityManager::class.java.getDeclaredMethod("stopTethering", Int::class.java)
+    }
+
+    /**
+     * Runs tether provisioning for the given type if needed and then starts tethering if
+     * the check succeeds. If no carrier provisioning is required for tethering, tethering is
+     * enabled immediately. If provisioning fails, tethering will not be enabled. It also
+     * schedules tether provisioning re-checks if appropriate.
+     *
+     * @param type The type of tethering to start. Must be one of
+     *         {@link ConnectivityManager.TETHERING_WIFI},
+     *         {@link ConnectivityManager.TETHERING_USB}, or
+     *         {@link ConnectivityManager.TETHERING_BLUETOOTH}.
+     * @param showProvisioningUi a boolean indicating to show the provisioning app UI if there
+     *         is one. This should be true the first time this function is called and also any time
+     *         the user can see this UI. It gives users information from their carrier about the
+     *         check failing and how they can sign up for tethering if possible.
+     * @param callback an {@link OnStartTetheringCallback} which will be called to notify the caller
+     *         of the result of trying to tether.
+     * @param handler {@link Handler} to specify the thread upon which the callback will be invoked.
+     */
+    @RequiresApi(24)
+    fun start(type: Int, showProvisioningUi: Boolean, callback: OnStartTetheringCallback, handler: Handler? = null) {
+        val proxy = ProxyBuilder.forClass(classOnStartTetheringCallback)
+                .dexCache(app.cacheDir)
+                .handler { proxy, method, args ->
+                    if (args.isNotEmpty()) Log.w(TAG, "Unexpected args for ${method.name}: $args")
+                    when (method.name) {
+                        "onTetheringStarted" -> {
+                            callback.onTetheringStarted()
+                            null
+                        }
+                        "onTetheringFailed" -> {
+                            callback.onTetheringFailed()
+                            null
+                        }
+                        else -> {
+                            Log.w(TAG, "Unexpected method, calling super: $method")
+                            ProxyBuilder.callSuper(proxy, method, args)
+                        }
+                    }
+                }
+                .build()
+        startTethering.invoke(app.connectivity, type, showProvisioningUi, proxy, handler)
+    }
+
+    /**
+     * Stops tethering for the given type. Also cancels any provisioning rechecks for that type if
+     * applicable.
+     *
+     * @param type The type of tethering to stop. Must be one of
+     *         {@link ConnectivityManager.TETHERING_WIFI},
+     *         {@link ConnectivityManager.TETHERING_USB}, or
+     *         {@link ConnectivityManager.TETHERING_BLUETOOTH}.
+     */
+    @RequiresApi(24)
+    fun stop(type: Int) {
+        stopTethering.invoke(app.connectivity, type)
+    }
+
+    fun getTetheredIfaces(extras: Bundle) = if (Build.VERSION.SDK_INT >= 26)
+        extras.getStringArrayList(EXTRA_ACTIVE_TETHER).toSet() + extras.getStringArrayList(EXTRA_ACTIVE_LOCAL_ONLY)
+    else extras.getStringArrayList(EXTRA_ACTIVE_TETHER_LEGACY).toSet()
+}