Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5ea65d60 authored by Irfan Sheriff's avatar Irfan Sheriff
Browse files

Update walled garden detection logic 

DNS based techniques dont always work. Some hotspots
redirect on data fetch on IP. Use a known pattern match
on URL to detect a walled garden instead.

Also, added gservices capability to turn off the feature
or change the URL & the pattern to match

Bug: 4378442
Change-Id: I78b4208d3ea3ace20069169e7c01ed769892d94d
parent 40f4efe7

core/java/android/provider/Settings.java

+24 −0
Original line number Diff line number Diff line
@@ -2923,6 +2923,30 @@ public final class Settings { 
         */

        public static final String WIFI_WATCHDOG_PING_TIMEOUT_MS = "wifi_watchdog_ping_timeout_ms";



        /**

         * Setting to turn off walled garden test on Wi-Fi. Feature is enabled by default and

         * the setting needs to be set to 0 to disable it.

         * @hide

         */

        public static final String WIFI_WATCHDOG_WALLED_GARDEN_TEST_ENABLED =

                "wifi_watchdog_walled_garden_test_enabled";



        /**

         * The URL used for walled garden check upon a new conection. WifiWatchdogService

         * fetches the URL and checks to see if {@link #WIFI_WATCHDOG_WALLED_GARDEN_PATTERN}

         * is not part of the title string to notify the user on the presence of a walled garden.

         * @hide

         */

        public static final String WIFI_WATCHDOG_WALLED_GARDEN_URL =

                "wifi_watchdog_walled_garden_url";



        /**

         * The pattern string in the fetched URL used to detect a walled garden

         * @hide

         */

        public static final String WIFI_WATCHDOG_WALLED_GARDEN_PATTERN =

                "wifi_watchdog_walled_garden_pattern";



        /**

         * The maximum number of times we will retry a connection to an access

         * point for which we have failed in acquiring an IP address from DHCP.

services/java/com/android/server/WifiWatchdogService.java

+59 −10
Original line number Diff line number Diff line
@@ -36,16 +36,21 @@ import android.provider.Settings; 
import android.text.TextUtils;

import android.util.Slog;



import java.io.BufferedInputStream;

import java.io.InputStream;

import java.io.IOException;

import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.HttpURLConnection;

import java.net.InetAddress;

import java.net.SocketException;

import java.net.SocketTimeoutException;

import java.net.UnknownHostException;

import java.net.URL;

import java.util.Collection;

import java.util.List;

import java.util.Random;

import java.util.Scanner;



/**

 * {@link WifiWatchdogService} monitors the initial connection to a Wi-Fi
@@ -196,6 +201,34 @@ public class WifiWatchdogService { 
            Settings.Secure.WIFI_WATCHDOG_PING_DELAY_MS, 250);

    }



    /**

     * @see android.provider.Settings.Secure#WIFI_WATCHDOG_WALLED_GARDEN_TEST_ENABLED

     */

     private Boolean isWalledGardenTestEnabled() {

        return Settings.Secure.getInt(mContentResolver,

                 Settings.Secure.WIFI_WATCHDOG_WALLED_GARDEN_TEST_ENABLED, 1) == 1;

     }



    /**

     * @see android.provider.Settings.Secure#WIFI_WATCHDOG_WALLED_GARDEN_URL

     */

     private String getWalledGardenUrl() {

        String url = Settings.Secure.getString(mContentResolver,

                 Settings.Secure.WIFI_WATCHDOG_WALLED_GARDEN_URL);

        if (TextUtils.isEmpty(url)) return "http://www.google.com/";

        return url;

     }



    /**

     * @see android.provider.Settings.Secure#WIFI_WATCHDOG_WALLED_GARDEN_PATTERN

     */

     private String getWalledGardenPattern() {

        String pattern = Settings.Secure.getString(mContentResolver,

                 Settings.Secure.WIFI_WATCHDOG_WALLED_GARDEN_PATTERN);

        if (TextUtils.isEmpty(pattern)) return "<title>.*Google.*</title>";

        return pattern;

     }

    

    /**

     * @see android.provider.Settings.Secure#WIFI_WATCHDOG_ACCEPTABLE_PACKET_LOSS_PERCENTAGE

     */
@@ -509,7 +542,7 @@ public class WifiWatchdogService { 
            // This access point does not require a watchdog, so queue idle on the main thread

            mHandler.idle();

        }

        mHandler.checkWalledGarden(ssid);

        if (isWalledGardenTestEnabled()) mHandler.checkWalledGarden(ssid);

    }

    

    /**
@@ -1118,19 +1151,35 @@ public class WifiWatchdogService { 
            }

        }



        /**

         * DNS based detection techniques do not work at all hotspots. The one sure way to check

         * a walled garden is to see if a URL fetch on a known address fetches the data we

         * expect

         */

        private boolean isWalledGardenConnection() {

            //One way to detect a walled garden is to see if multiple DNS queries

            //resolve to the same IP address

            InputStream in = null;

            HttpURLConnection  urlConnection = null;

            try {

                String host1 = "www.google.com";

                String host2 = "www.android.com";

                String address1 = InetAddress.getByName(host1).getHostAddress();

                String address2 = InetAddress.getByName(host2).getHostAddress();

                if (address1.equals(address2)) return true;

            } catch (UnknownHostException e) {

                URL url = new URL(getWalledGardenUrl());

                urlConnection = (HttpURLConnection) url.openConnection();

                in = new BufferedInputStream(urlConnection.getInputStream());

                Scanner scanner = new Scanner(in);

                if (scanner.findInLine(getWalledGardenPattern()) != null) {

                    return false;

                } else {

                    return true;

                }

            } catch (IOException e) {

                return false;

            } finally {

                if (in != null) {

                    try {

                        in.close();

                    } catch (IOException e) {

                    }

                }

                if (urlConnection != null) urlConnection.disconnect();

            }

        }



        private void handleWalledGardenCheck(String ssid) {