CaptivePortalTracker.java revision 42d4f08db2c15e1829c1fc5d1942cf029ab0895b 
1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.net;
18
19import android.app.Activity;
20import android.app.Notification;
21import android.app.NotificationManager;
22import android.app.PendingIntent;
23import android.content.BroadcastReceiver;
24import android.content.Context;
25import android.content.Intent;
26import android.content.IntentFilter;
27import android.content.res.Resources;
28import android.database.ContentObserver;
29import android.net.ConnectivityManager;
30import android.net.IConnectivityManager;
31import android.os.Handler;
32import android.os.UserHandle;
33import android.os.Message;
34import android.os.RemoteException;
35import android.provider.Settings;
36import android.telephony.TelephonyManager;
37import android.text.TextUtils;
38
39import com.android.internal.util.State;
40import com.android.internal.util.StateMachine;
41
42import java.io.IOException;
43import java.net.HttpURLConnection;
44import java.net.InetAddress;
45import java.net.Inet4Address;
46import java.net.URL;
47import java.net.UnknownHostException;
48
49import com.android.internal.R;
50
51/**
52 * This class allows captive portal detection on a network.
53 * @hide
54 */
55public class CaptivePortalTracker extends StateMachine {
56    private static final boolean DBG = true;
57    private static final String TAG = "CaptivePortalTracker";
58
59    private static final String DEFAULT_SERVER = "clients3.google.com";
60    private static final String NOTIFICATION_ID = "CaptivePortal.Notification";
61
62    private static final int SOCKET_TIMEOUT_MS = 10000;
63
64    private String mServer;
65    private String mUrl;
66    private boolean mNotificationShown = false;
67    private boolean mIsCaptivePortalCheckEnabled = false;
68    private IConnectivityManager mConnService;
69    private TelephonyManager mTelephonyManager;
70    private Context mContext;
71    private NetworkInfo mNetworkInfo;
72
73    private static final int CMD_DETECT_PORTAL          = 0;
74    private static final int CMD_CONNECTIVITY_CHANGE    = 1;
75    private static final int CMD_DELAYED_CAPTIVE_CHECK  = 2;
76
77    /* This delay happens every time before we do a captive check on a network */
78    private static final int DELAYED_CHECK_INTERVAL_MS = 10000;
79    private int mDelayedCheckToken = 0;
80
81    private State mDefaultState = new DefaultState();
82    private State mNoActiveNetworkState = new NoActiveNetworkState();
83    private State mActiveNetworkState = new ActiveNetworkState();
84    private State mDelayedCaptiveCheckState = new DelayedCaptiveCheckState();
85
86    private static final String SETUP_WIZARD_PACKAGE = "com.google.android.setupwizard";
87    private boolean mDeviceProvisioned = false;
88    private ProvisioningObserver mProvisioningObserver;
89
90    private CaptivePortalTracker(Context context, IConnectivityManager cs) {
91        super(TAG);
92
93        mContext = context;
94        mConnService = cs;
95        mTelephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
96        mProvisioningObserver = new ProvisioningObserver();
97
98        IntentFilter filter = new IntentFilter();
99        filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
100        filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION_IMMEDIATE);
101        mContext.registerReceiver(mReceiver, filter);
102
103        mServer = Settings.Global.getString(mContext.getContentResolver(),
104                Settings.Global.CAPTIVE_PORTAL_SERVER);
105        if (mServer == null) mServer = DEFAULT_SERVER;
106
107        mIsCaptivePortalCheckEnabled = Settings.Global.getInt(mContext.getContentResolver(),
108                Settings.Global.CAPTIVE_PORTAL_DETECTION_ENABLED, 1) == 1;
109
110        addState(mDefaultState);
111            addState(mNoActiveNetworkState, mDefaultState);
112            addState(mActiveNetworkState, mDefaultState);
113                addState(mDelayedCaptiveCheckState, mActiveNetworkState);
114        setInitialState(mNoActiveNetworkState);
115    }
116
117    private class ProvisioningObserver extends ContentObserver {
118        ProvisioningObserver() {
119            super(new Handler());
120            mContext.getContentResolver().registerContentObserver(Settings.Global.getUriFor(
121                    Settings.Global.DEVICE_PROVISIONED), false, this);
122            onChange(false); // load initial value
123        }
124
125        @Override
126        public void onChange(boolean selfChange) {
127            mDeviceProvisioned = Settings.Global.getInt(mContext.getContentResolver(),
128                    Settings.Global.DEVICE_PROVISIONED, 0) != 0;
129        }
130    }
131
132    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
133        @Override
134        public void onReceive(Context context, Intent intent) {
135            String action = intent.getAction();
136            // Normally, we respond to CONNECTIVITY_ACTION, allowing time for the change in
137            // connectivity to stabilize, but if the device is not yet provisioned, respond
138            // immediately to speed up transit through the setup wizard.
139            if ((mDeviceProvisioned && action.equals(ConnectivityManager.CONNECTIVITY_ACTION))
140                    || (!mDeviceProvisioned
141                            && action.equals(ConnectivityManager.CONNECTIVITY_ACTION_IMMEDIATE))) {
142                NetworkInfo info = intent.getParcelableExtra(
143                        ConnectivityManager.EXTRA_NETWORK_INFO);
144                sendMessage(obtainMessage(CMD_CONNECTIVITY_CHANGE, info));
145            }
146        }
147    };
148
149    public static CaptivePortalTracker makeCaptivePortalTracker(Context context,
150            IConnectivityManager cs) {
151        CaptivePortalTracker captivePortal = new CaptivePortalTracker(context, cs);
152        captivePortal.start();
153        return captivePortal;
154    }
155
156    public void detectCaptivePortal(NetworkInfo info) {
157        sendMessage(obtainMessage(CMD_DETECT_PORTAL, info));
158    }
159
160    private class DefaultState extends State {
161        @Override
162        public void enter() {
163            if (DBG) log(getName() + "\n");
164        }
165
166        @Override
167        public boolean processMessage(Message message) {
168            if (DBG) log(getName() + message.toString() + "\n");
169            switch (message.what) {
170                case CMD_DETECT_PORTAL:
171                    NetworkInfo info = (NetworkInfo) message.obj;
172                    // Checking on a secondary connection is not supported
173                    // yet
174                    notifyPortalCheckComplete(info);
175                    break;
176                case CMD_CONNECTIVITY_CHANGE:
177                case CMD_DELAYED_CAPTIVE_CHECK:
178                    break;
179                default:
180                    loge("Ignoring " + message);
181                    break;
182            }
183            return HANDLED;
184        }
185    }
186
187    private class NoActiveNetworkState extends State {
188        @Override
189        public void enter() {
190            if (DBG) log(getName() + "\n");
191            mNetworkInfo = null;
192            /* Clear any previous notification */
193            setNotificationVisible(false);
194        }
195
196        @Override
197        public boolean processMessage(Message message) {
198            if (DBG) log(getName() + message.toString() + "\n");
199            InetAddress server;
200            NetworkInfo info;
201            switch (message.what) {
202                case CMD_CONNECTIVITY_CHANGE:
203                    info = (NetworkInfo) message.obj;
204                    if (info.isConnected() && isActiveNetwork(info)) {
205                        mNetworkInfo = info;
206                        transitionTo(mDelayedCaptiveCheckState);
207                    }
208                    break;
209                default:
210                    return NOT_HANDLED;
211            }
212            return HANDLED;
213        }
214    }
215
216    private class ActiveNetworkState extends State {
217        @Override
218        public void enter() {
219            if (DBG) log(getName() + "\n");
220        }
221
222        @Override
223        public boolean processMessage(Message message) {
224            NetworkInfo info;
225            switch (message.what) {
226               case CMD_CONNECTIVITY_CHANGE:
227                    info = (NetworkInfo) message.obj;
228                    if (!info.isConnected()
229                            && info.getType() == mNetworkInfo.getType()) {
230                        if (DBG) log("Disconnected from active network " + info);
231                        transitionTo(mNoActiveNetworkState);
232                    } else if (info.getType() != mNetworkInfo.getType() &&
233                            info.isConnected() &&
234                            isActiveNetwork(info)) {
235                        if (DBG) log("Active network switched " + info);
236                        deferMessage(message);
237                        transitionTo(mNoActiveNetworkState);
238                    }
239                    break;
240                default:
241                    return NOT_HANDLED;
242            }
243            return HANDLED;
244        }
245    }
246
247
248
249    private class DelayedCaptiveCheckState extends State {
250        @Override
251        public void enter() {
252            if (DBG) log(getName() + "\n");
253            Message message = obtainMessage(CMD_DELAYED_CAPTIVE_CHECK, ++mDelayedCheckToken, 0);
254            if (mDeviceProvisioned) {
255                sendMessageDelayed(message, DELAYED_CHECK_INTERVAL_MS);
256            } else {
257                sendMessage(message);
258            }
259        }
260
261        @Override
262        public boolean processMessage(Message message) {
263            if (DBG) log(getName() + message.toString() + "\n");
264            switch (message.what) {
265                case CMD_DELAYED_CAPTIVE_CHECK:
266                    if (message.arg1 == mDelayedCheckToken) {
267                        InetAddress server = lookupHost(mServer);
268                        boolean captive = server != null && isCaptivePortal(server);
269                        if (captive) {
270                            if (DBG) log("Captive network " + mNetworkInfo);
271                        } else {
272                            if (DBG) log("Not captive network " + mNetworkInfo);
273                        }
274                        if (mDeviceProvisioned) {
275                            if (captive) {
276                                // Setup Wizard will assist the user in connecting to a captive
277                                // portal, so make the notification visible unless during setup
278                                setNotificationVisible(true);
279                            }
280                        } else {
281                            Intent intent = new Intent(
282                                    ConnectivityManager.ACTION_CAPTIVE_PORTAL_TEST_COMPLETED);
283                            intent.putExtra(ConnectivityManager.EXTRA_IS_CAPTIVE_PORTAL, captive);
284                            intent.setPackage(SETUP_WIZARD_PACKAGE);
285                            mContext.sendBroadcast(intent);
286                        }
287
288                        transitionTo(mActiveNetworkState);
289                    }
290                    break;
291                default:
292                    return NOT_HANDLED;
293            }
294            return HANDLED;
295        }
296    }
297
298    private void notifyPortalCheckComplete(NetworkInfo info) {
299        if (info == null) {
300            loge("notifyPortalCheckComplete on null");
301            return;
302        }
303        try {
304            mConnService.captivePortalCheckComplete(info);
305        } catch(RemoteException e) {
306            e.printStackTrace();
307        }
308    }
309
310    private boolean isActiveNetwork(NetworkInfo info) {
311        try {
312            NetworkInfo active = mConnService.getActiveNetworkInfo();
313            if (active != null && active.getType() == info.getType()) {
314                return true;
315            }
316        } catch (RemoteException e) {
317            e.printStackTrace();
318        }
319        return false;
320    }
321
322    /**
323     * Do a URL fetch on a known server to see if we get the data we expect
324     */
325    private boolean isCaptivePortal(InetAddress server) {
326        HttpURLConnection urlConnection = null;
327        if (!mIsCaptivePortalCheckEnabled) return false;
328
329        mUrl = "http://" + server.getHostAddress() + "/generate_204";
330        if (DBG) log("Checking " + mUrl);
331        try {
332            URL url = new URL(mUrl);
333            urlConnection = (HttpURLConnection) url.openConnection();
334            urlConnection.setInstanceFollowRedirects(false);
335            urlConnection.setConnectTimeout(SOCKET_TIMEOUT_MS);
336            urlConnection.setReadTimeout(SOCKET_TIMEOUT_MS);
337            urlConnection.setUseCaches(false);
338            urlConnection.getInputStream();
339            // we got a valid response, but not from the real google
340            return urlConnection.getResponseCode() != 204;
341        } catch (IOException e) {
342            if (DBG) log("Probably not a portal: exception " + e);
343            return false;
344        } finally {
345            if (urlConnection != null) {
346                urlConnection.disconnect();
347            }
348        }
349    }
350
351    private InetAddress lookupHost(String hostname) {
352        InetAddress inetAddress[];
353        try {
354            inetAddress = InetAddress.getAllByName(hostname);
355        } catch (UnknownHostException e) {
356            return null;
357        }
358
359        for (InetAddress a : inetAddress) {
360            if (a instanceof Inet4Address) return a;
361        }
362        return null;
363    }
364
365    private void setNotificationVisible(boolean visible) {
366        // if it should be hidden and it is already hidden, then noop
367        if (!visible && !mNotificationShown) {
368            if (DBG) log("setNotivicationVisible: false and not shown, so noop");
369            return;
370        }
371
372        Resources r = Resources.getSystem();
373        NotificationManager notificationManager = (NotificationManager) mContext
374            .getSystemService(Context.NOTIFICATION_SERVICE);
375
376        if (visible) {
377            CharSequence title;
378            CharSequence details;
379            int icon;
380            String url = null;
381            switch (mNetworkInfo.getType()) {
382                case ConnectivityManager.TYPE_WIFI:
383                    title = r.getString(R.string.wifi_available_sign_in, 0);
384                    details = r.getString(R.string.network_available_sign_in_detailed,
385                            mNetworkInfo.getExtraInfo());
386                    icon = R.drawable.stat_notify_wifi_in_range;
387                    url = mUrl;
388                    break;
389                case ConnectivityManager.TYPE_MOBILE:
390                    title = r.getString(R.string.network_available_sign_in, 0);
391                    // TODO: Change this to pull from NetworkInfo once a printable
392                    // name has been added to it
393                    details = mTelephonyManager.getNetworkOperatorName();
394                    icon = R.drawable.stat_notify_rssi_in_range;
395                    try {
396                        url = mConnService.getMobileProvisioningUrl();
397                        if (TextUtils.isEmpty(url)) {
398                            url = mConnService.getMobileRedirectedProvisioningUrl();
399                        }
400                    } catch(RemoteException e) {
401                        e.printStackTrace();
402                    }
403                    if (TextUtils.isEmpty(url)) {
404                        url = mUrl;
405                    }
406                    break;
407                default:
408                    title = r.getString(R.string.network_available_sign_in, 0);
409                    details = r.getString(R.string.network_available_sign_in_detailed,
410                            mNetworkInfo.getExtraInfo());
411                    icon = R.drawable.stat_notify_rssi_in_range;
412                    url = mUrl;
413                    break;
414            }
415
416            Notification notification = new Notification();
417            notification.when = 0;
418            notification.icon = icon;
419            notification.flags = Notification.FLAG_AUTO_CANCEL;
420            Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
421            intent.setFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT |
422                    Intent.FLAG_ACTIVITY_NEW_TASK);
423            notification.contentIntent = PendingIntent.getActivity(mContext, 0, intent, 0);
424            notification.tickerText = title;
425            notification.setLatestEventInfo(mContext, title, details, notification.contentIntent);
426
427            if (DBG) log("setNotivicationVisible: make visible");
428            notificationManager.notify(NOTIFICATION_ID, 1, notification);
429        } else {
430            if (DBG) log("setNotivicationVisible: cancel notification");
431            notificationManager.cancel(NOTIFICATION_ID, 1);
432        }
433        mNotificationShown = visible;
434    }
435}
436