Use reflection instead of parcel magic to get around networkName check

README.md

@@ -167,6 +167,7 @@ Greylisted/blacklisted APIs or internal constants: (some constants are hardcoded
 * (since API 26) `Landroid/net/wifi/WifiManager;->cancelLocalOnlyHotspotRequest()V,unsupported`
 * (prior to API 26) `Landroid/net/wifi/WifiManager;->setWifiApEnabled(Landroid/net/wifi/WifiConfiguration;Z)Z`
 * `Landroid/net/wifi/p2p/WifiP2pConfig$Builder;->MAC_ANY_ADDRESS:Landroid/net/MacAddress;,blocked`
+* (since API 29) `Landroid/net/wifi/p2p/WifiP2pConfig$Builder;->mNetworkName:Ljava/lang/String;,blocked`
 * `Landroid/net/wifi/p2p/WifiP2pManager;->startWps(Landroid/net/wifi/p2p/WifiP2pManager$Channel;Landroid/net/wifi/WpsInfo;Landroid/net/wifi/p2p/WifiP2pManager$ActionListener;)V,max-target-r`
 * (since API 28, prior to API 30) `Landroid/provider/Settings$Global;->SOFT_AP_TIMEOUT_ENABLED:Ljava/lang/String;,lo-prio,max-target-o`
 * (prior to API 30) `Lcom/android/internal/R$array;->config_tether_bluetooth_regexs:I,max-target-q`
@@ -300,10 +301,7 @@ Nonexported system resources:
 * (since API 30) `@com.android.networkstack.tethering:array/config_tether_wigig_regexs`
 * (since API 30) `@com.android.wifi.resources:integer/config_wifiFrameworkSoftApShutDownTimeoutMilliseconds`
 
-Other:
+Other: Activity `com.android.settings/.Settings$TetherSettingsActivity` is assumed to be exported.
-
-* (since API 29) `android.net.wifi.p2p.WifiP2pConfig` needs to be parcelized in a very specific order, except for possible extra fields at the end. (used only for safe mode)
-* Activity `com.android.settings/.Settings$TetherSettingsActivity` is assumed to be exported.
 
 For `ip rule` priorities, `RULE_PRIORITY_SECURE_VPN` and `RULE_PRIORITY_TETHERING` is assumed to be 12000 and 18000 respectively;
 (prior to API 24) `RULE_PRIORITY_DEFAULT_NETWORK` is assumed to be 22000 (or at least > 18000).

mobile/src/main/java/be/mygod/vpnhotspot/RepeaterService.kt

@@ -13,7 +13,6 @@ import android.os.Looper
 import android.provider.Settings
 import androidx.annotation.StringRes
 import androidx.core.content.edit
-import be.mygod.librootkotlinx.useParcel
 import be.mygod.vpnhotspot.App.Companion.app
 import be.mygod.vpnhotspot.net.MacAddressCompat
 import be.mygod.vpnhotspot.net.monitor.TetherTimeoutMonitor
@@ -48,10 +47,6 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
         private const val KEY_AUTO_SHUTDOWN = "service.repeater.autoShutdown"
         private const val KEY_SHUTDOWN_TIMEOUT = "service.repeater.shutdownTimeout"
         private const val KEY_DEVICE_ADDRESS = "service.repeater.mac"
-        /**
-         * Placeholder for bypassing networkName check.
-         */
-        private const val PLACEHOLDER_NETWORK_NAME = "DIRECT-00-VPNHotspot"
 
         var persistentSupported = false
 
@@ -65,6 +60,7 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
         val safeModeConfigurable get() = Build.VERSION.SDK_INT >= 29 && hasP2pValidateName
         val safeMode get() = Build.VERSION.SDK_INT >= 29 &&
                 (!hasP2pValidateName || app.pref.getBoolean(KEY_SAFE_MODE, true))
+        private val mNetworkName by lazy { UnblockCentral.WifiP2pConfig_Builder_mNetworkName }
 
         var networkName: String?
             get() = app.pref.getString(KEY_NETWORK_NAME, null)
@@ -372,7 +368,12 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
                 p2pManager.createGroup(channel, listener)
             } else @TargetApi(29) {
                 p2pManager.createGroup(channel, WifiP2pConfig.Builder().apply {
-                    setNetworkName(PLACEHOLDER_NETWORK_NAME)
+                    try {
+                        mNetworkName.set(this, networkName) // bypass networkName check
+                    } catch (e: ReflectiveOperationException) {
+                        Timber.w(e)
+                        setNetworkName(networkName)
+                    }
                     setPassphrase(passphrase)
                     when (val oc = operatingChannel) {
                         0 -> setGroupOperatingBand(when (val band = operatingBand) {
@@ -386,37 +387,9 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
                         }
                     }
                     setDeviceAddress(deviceAddress?.toPlatform())
-                }.build().run {
+                }.build(), listener)
-                    useParcel { p ->
-                        p.writeParcelable(this, 0)
-                        val end = p.dataPosition()
-                        p.setDataPosition(0)
-                        val creator = p.readString()
-                        val deviceAddress = p.readString()
-                        val wps = p.readParcelable<WpsInfo>(javaClass.classLoader)
-                        val long = p.readLong()
-                        check(p.readString() == PLACEHOLDER_NETWORK_NAME)
-                        check(p.readString() == passphrase)
-                        val extrasLength = end - p.dataPosition()
-                        check(extrasLength and 3 == 0)  // parcel should be padded
-                        if (extrasLength != 4) app.logEvent("p2p_config_extras_unexpected_length") {
-                            param("length", extrasLength.toLong())
             }
-                        val extras = (0 until extrasLength / 4).map { p.readInt() }
+        } catch (e: RuntimeException) {
-                        p.setDataPosition(0)
-                        p.writeString(creator)
-                        p.writeString(deviceAddress)
-                        p.writeParcelable(wps, 0)
-                        p.writeLong(long)
-                        p.writeString(networkName)
-                        p.writeString(passphrase)
-                        extras.forEach(p::writeInt)
-                        p.setDataPosition(0)
-                        p.readParcelable(javaClass.classLoader)
-                    }
-                }, listener)
-            }
-        } catch (e: SecurityException) {
             Timber.w(e)
             startFailure(e.readableMessage)
         }

mobile/src/main/java/be/mygod/vpnhotspot/util/UnblockCentral.kt

@@ -1,13 +1,16 @@
 package be.mygod.vpnhotspot.util
 
 import android.annotation.SuppressLint
+import android.net.wifi.p2p.WifiP2pConfig
 import androidx.annotation.RequiresApi
 import timber.log.Timber
 
 /**
  * The central object for accessing all the useful blocked APIs. Thanks Google!
+ *
+ * Lazy cannot be used directly as it will create inner classes.
  */
-@SuppressLint("DiscouragedPrivateApi")
+@SuppressLint("BlockedPrivateApi", "DiscouragedPrivateApi")
 @Suppress("FunctionName")
 object UnblockCentral {
     /**
@@ -27,4 +30,9 @@ object UnblockCentral {
 
     @RequiresApi(31)
     fun getApInstanceIdentifier(clazz: Class<*>) = init.let { clazz.getDeclaredMethod("getApInstanceIdentifier") }
+
+    @get:RequiresApi(29)
+    val WifiP2pConfig_Builder_mNetworkName get() = init.let {
+        WifiP2pConfig.Builder::class.java.getDeclaredField("mNetworkName").apply { isAccessible = true }
+    }
 }