1/*
2 * Copyright (C) 2014 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 com.android.captiveportallogin;
18
19import android.app.Activity;
20import android.app.LoadedApk;
21import android.content.Context;
22import android.content.Intent;
23import android.graphics.Bitmap;
24import android.net.CaptivePortal;
25import android.net.ConnectivityManager;
26import android.net.ConnectivityManager.NetworkCallback;
27import android.net.Network;
28import android.net.NetworkCapabilities;
29import android.net.NetworkRequest;
30import android.net.Proxy;
31import android.net.Uri;
32import android.net.http.SslError;
33import android.os.Bundle;
34import android.provider.Settings;
35import android.util.ArrayMap;
36import android.util.Log;
37import android.util.TypedValue;
38import android.view.Menu;
39import android.view.MenuItem;
40import android.webkit.SslErrorHandler;
41import android.webkit.WebChromeClient;
42import android.webkit.WebSettings;
43import android.webkit.WebView;
44import android.webkit.WebViewClient;
45import android.widget.ProgressBar;
46import android.widget.TextView;
47
48import java.io.IOException;
49import java.net.HttpURLConnection;
50import java.net.MalformedURLException;
51import java.net.URL;
52import java.lang.InterruptedException;
53import java.lang.reflect.Field;
54import java.lang.reflect.Method;
55import java.util.Random;
56
57public class CaptivePortalLoginActivity extends Activity {
58    private static final String TAG = "CaptivePortalLogin";
59    private static final String DEFAULT_SERVER = "connectivitycheck.gstatic.com";
60    private static final int SOCKET_TIMEOUT_MS = 10000;
61
62    private enum Result { DISMISSED, UNWANTED, WANTED_AS_IS };
63
64    private URL mURL;
65    private Network mNetwork;
66    private CaptivePortal mCaptivePortal;
67    private NetworkCallback mNetworkCallback;
68    private ConnectivityManager mCm;
69    private boolean mLaunchBrowser = false;
70    private MyWebViewClient mWebViewClient;
71
72    @Override
73    protected void onCreate(Bundle savedInstanceState) {
74        super.onCreate(savedInstanceState);
75
76        String server = Settings.Global.getString(getContentResolver(), "captive_portal_server");
77        if (server == null) server = DEFAULT_SERVER;
78        mCm = ConnectivityManager.from(this);
79        try {
80            mURL = new URL("http", server, "/generate_204");
81        } catch (MalformedURLException e) {
82            // System misconfigured, bail out in a way that at least provides network access.
83            Log.e(TAG, "Invalid captive portal URL, server=" + server);
84            done(Result.WANTED_AS_IS);
85        }
86        mNetwork = getIntent().getParcelableExtra(ConnectivityManager.EXTRA_NETWORK);
87        mCaptivePortal = getIntent().getParcelableExtra(ConnectivityManager.EXTRA_CAPTIVE_PORTAL);
88
89        // Also initializes proxy system properties.
90        mCm.bindProcessToNetwork(mNetwork);
91
92        // Proxy system properties must be initialized before setContentView is called because
93        // setContentView initializes the WebView logic which in turn reads the system properties.
94        setContentView(R.layout.activity_captive_portal_login);
95
96        getActionBar().setDisplayShowHomeEnabled(false);
97
98        // Exit app if Network disappears.
99        final NetworkCapabilities networkCapabilities = mCm.getNetworkCapabilities(mNetwork);
100        if (networkCapabilities == null) {
101            finish();
102            return;
103        }
104        mNetworkCallback = new NetworkCallback() {
105            @Override
106            public void onLost(Network lostNetwork) {
107                if (mNetwork.equals(lostNetwork)) done(Result.UNWANTED);
108            }
109        };
110        final NetworkRequest.Builder builder = new NetworkRequest.Builder();
111        for (int transportType : networkCapabilities.getTransportTypes()) {
112            builder.addTransportType(transportType);
113        }
114        mCm.registerNetworkCallback(builder.build(), mNetworkCallback);
115
116        final WebView myWebView = (WebView) findViewById(R.id.webview);
117        myWebView.clearCache(true);
118        WebSettings webSettings = myWebView.getSettings();
119        webSettings.setJavaScriptEnabled(true);
120        mWebViewClient = new MyWebViewClient();
121        myWebView.setWebViewClient(mWebViewClient);
122        myWebView.setWebChromeClient(new MyWebChromeClient());
123        // Start initial page load so WebView finishes loading proxy settings.
124        // Actual load of mUrl is initiated by MyWebViewClient.
125        myWebView.loadData("", "text/html", null);
126    }
127
128    // Find WebView's proxy BroadcastReceiver and prompt it to read proxy system properties.
129    private void setWebViewProxy() {
130        LoadedApk loadedApk = getApplication().mLoadedApk;
131        try {
132            Field receiversField = LoadedApk.class.getDeclaredField("mReceivers");
133            receiversField.setAccessible(true);
134            ArrayMap receivers = (ArrayMap) receiversField.get(loadedApk);
135            for (Object receiverMap : receivers.values()) {
136                for (Object rec : ((ArrayMap) receiverMap).keySet()) {
137                    Class clazz = rec.getClass();
138                    if (clazz.getName().contains("ProxyChangeListener")) {
139                        Method onReceiveMethod = clazz.getDeclaredMethod("onReceive", Context.class,
140                                Intent.class);
141                        Intent intent = new Intent(Proxy.PROXY_CHANGE_ACTION);
142                        onReceiveMethod.invoke(rec, getApplicationContext(), intent);
143                        Log.v(TAG, "Prompting WebView proxy reload.");
144                    }
145                }
146            }
147        } catch (Exception e) {
148            Log.e(TAG, "Exception while setting WebView proxy: " + e);
149        }
150    }
151
152    private void done(Result result) {
153        if (mNetworkCallback != null) {
154            mCm.unregisterNetworkCallback(mNetworkCallback);
155            mNetworkCallback = null;
156        }
157        switch (result) {
158            case DISMISSED:
159                mCaptivePortal.reportCaptivePortalDismissed();
160                break;
161            case UNWANTED:
162                mCaptivePortal.ignoreNetwork();
163                break;
164            case WANTED_AS_IS:
165                mCaptivePortal.useNetwork();
166                break;
167        }
168        finish();
169    }
170
171    @Override
172    public boolean onCreateOptionsMenu(Menu menu) {
173        getMenuInflater().inflate(R.menu.captive_portal_login, menu);
174        return true;
175    }
176
177    @Override
178    public void onBackPressed() {
179        WebView myWebView = (WebView) findViewById(R.id.webview);
180        if (myWebView.canGoBack() && mWebViewClient.allowBack()) {
181            myWebView.goBack();
182        } else {
183            super.onBackPressed();
184        }
185    }
186
187    @Override
188    public boolean onOptionsItemSelected(MenuItem item) {
189        int id = item.getItemId();
190        if (id == R.id.action_use_network) {
191            done(Result.WANTED_AS_IS);
192            return true;
193        }
194        if (id == R.id.action_do_not_use_network) {
195            done(Result.UNWANTED);
196            return true;
197        }
198        return super.onOptionsItemSelected(item);
199    }
200
201    @Override
202    public void onDestroy() {
203        super.onDestroy();
204
205        if (mNetworkCallback != null) {
206            mCm.unregisterNetworkCallback(mNetworkCallback);
207            mNetworkCallback = null;
208        }
209        if (mLaunchBrowser) {
210            // Give time for this network to become default. After 500ms just proceed.
211            for (int i = 0; i < 5; i++) {
212                // TODO: This misses when mNetwork underlies a VPN.
213                if (mNetwork.equals(mCm.getActiveNetwork())) break;
214                try {
215                    Thread.sleep(100);
216                } catch (InterruptedException e) {
217                }
218            }
219            startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(mURL.toString())));
220        }
221    }
222
223    private void testForCaptivePortal() {
224        new Thread(new Runnable() {
225            public void run() {
226                // Give time for captive portal to open.
227                try {
228                    Thread.sleep(1000);
229                } catch (InterruptedException e) {
230                }
231                HttpURLConnection urlConnection = null;
232                int httpResponseCode = 500;
233                try {
234                    urlConnection = (HttpURLConnection) mURL.openConnection();
235                    urlConnection.setInstanceFollowRedirects(false);
236                    urlConnection.setConnectTimeout(SOCKET_TIMEOUT_MS);
237                    urlConnection.setReadTimeout(SOCKET_TIMEOUT_MS);
238                    urlConnection.setUseCaches(false);
239                    urlConnection.getInputStream();
240                    httpResponseCode = urlConnection.getResponseCode();
241                } catch (IOException e) {
242                } finally {
243                    if (urlConnection != null) urlConnection.disconnect();
244                }
245                if (httpResponseCode == 204) {
246                    done(Result.DISMISSED);
247                }
248            }
249        }).start();
250    }
251
252    private class MyWebViewClient extends WebViewClient {
253        private static final String INTERNAL_ASSETS = "file:///android_asset/";
254        private final String mBrowserBailOutToken = Long.toString(new Random().nextLong());
255        // How many Android device-independent-pixels per scaled-pixel
256        // dp/sp = (px/sp) / (px/dp) = (1/sp) / (1/dp)
257        private final float mDpPerSp = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 1,
258                    getResources().getDisplayMetrics()) /
259                    TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 1,
260                    getResources().getDisplayMetrics());
261        private int mPagesLoaded;
262
263        // If we haven't finished cleaning up the history, don't allow going back.
264        public boolean allowBack() {
265            return mPagesLoaded > 1;
266        }
267
268        @Override
269        public void onPageStarted(WebView view, String url, Bitmap favicon) {
270            if (url.contains(mBrowserBailOutToken)) {
271                mLaunchBrowser = true;
272                done(Result.WANTED_AS_IS);
273                return;
274            }
275            // The first page load is used only to cause the WebView to
276            // fetch the proxy settings.  Don't update the URL bar, and
277            // don't check if the captive portal is still there.
278            if (mPagesLoaded == 0) return;
279            // For internally generated pages, leave URL bar listing prior URL as this is the URL
280            // the page refers to.
281            if (!url.startsWith(INTERNAL_ASSETS)) {
282                final TextView myUrlBar = (TextView) findViewById(R.id.url_bar);
283                myUrlBar.setText(url);
284            }
285            testForCaptivePortal();
286        }
287
288        @Override
289        public void onPageFinished(WebView view, String url) {
290            mPagesLoaded++;
291            if (mPagesLoaded == 1) {
292                // Now that WebView has loaded at least one page we know it has read in the proxy
293                // settings.  Now prompt the WebView read the Network-specific proxy settings.
294                setWebViewProxy();
295                // Load the real page.
296                view.loadUrl(mURL.toString());
297                return;
298            } else if (mPagesLoaded == 2) {
299                // Prevent going back to empty first page.
300                view.clearHistory();
301            }
302            testForCaptivePortal();
303        }
304
305        // Convert Android device-independent-pixels (dp) to HTML size.
306        private String dp(int dp) {
307            // HTML px's are scaled just like dp's, so just add "px" suffix.
308            return Integer.toString(dp) + "px";
309        }
310
311        // Convert Android scaled-pixels (sp) to HTML size.
312        private String sp(int sp) {
313            // Convert sp to dp's.
314            float dp = sp * mDpPerSp;
315            // Apply a scale factor to make things look right.
316            dp *= 1.3;
317            // Convert dp's to HTML size.
318            return dp((int)dp);
319        }
320
321        // A web page consisting of a large broken lock icon to indicate SSL failure.
322        private final String SSL_ERROR_HTML = "<html><head><style>" +
323                "body { margin-left:" + dp(48) + "; margin-right:" + dp(48) + "; " +
324                        "margin-top:" + dp(96) + "; background-color:#fafafa; }" +
325                "img { width:" + dp(48) + "; height:" + dp(48) + "; }" +
326                "div.warn { font-size:" + sp(16) + "; margin-top:" + dp(16) + "; " +
327                "           opacity:0.87; line-height:1.28; }" +
328                "div.example { font-size:" + sp(14) + "; margin-top:" + dp(16) + "; " +
329                "              opacity:0.54; line-height:1.21905; }" +
330                "a { font-size:" + sp(14) + "; text-decoration:none; text-transform:uppercase; " +
331                "    margin-top:" + dp(24) + "; display:inline-block; color:#4285F4; " +
332                "    height:" + dp(48) + "; font-weight:bold; }" +
333                "</style></head><body><p><img src=quantum_ic_warning_amber_96.png><br>" +
334                "<div class=warn>%s</div>" +
335                "<div class=example>%s</div>" +
336                "<a href=%s>%s</a></body></html>";
337
338        @Override
339        public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
340            Log.w(TAG, "SSL error (error: " + error.getPrimaryError() + " host: " +
341                    // Only show host to avoid leaking private info.
342                    Uri.parse(error.getUrl()).getHost() + " certificate: " +
343                    error.getCertificate() + "); displaying SSL warning.");
344            final String html = String.format(SSL_ERROR_HTML, getString(R.string.ssl_error_warning),
345                    getString(R.string.ssl_error_example), mBrowserBailOutToken,
346                    getString(R.string.ssl_error_continue));
347            view.loadDataWithBaseURL(INTERNAL_ASSETS, html, "text/HTML", "UTF-8", null);
348        }
349
350        @Override
351        public boolean shouldOverrideUrlLoading (WebView view, String url) {
352            if (url.startsWith("tel:")) {
353                startActivity(new Intent(Intent.ACTION_DIAL, Uri.parse(url)));
354                return true;
355            }
356            return false;
357        }
358    }
359
360    private class MyWebChromeClient extends WebChromeClient {
361        @Override
362        public void onProgressChanged(WebView view, int newProgress) {
363            final ProgressBar myProgressBar = (ProgressBar) findViewById(R.id.progress_bar);
364            myProgressBar.setProgress(newProgress);
365        }
366    }
367}
368