Paul Jensen | ca8f16a | 2014-05-09 12:47:55 -0400 | [diff] [blame] | 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 | |
| 17 | package com.android.server.connectivity; |
| 18 | |
| 19 | import android.content.Context; |
| 20 | import android.net.NetworkCapabilities; |
| 21 | import android.net.NetworkInfo; |
| 22 | import android.os.Handler; |
| 23 | import android.os.Message; |
| 24 | import android.os.SystemProperties; |
| 25 | import android.provider.Settings; |
| 26 | |
| 27 | import com.android.internal.util.Protocol; |
| 28 | import com.android.internal.util.State; |
| 29 | import com.android.internal.util.StateMachine; |
| 30 | import com.android.server.connectivity.NetworkAgentInfo; |
| 31 | |
| 32 | import java.io.BufferedReader; |
| 33 | import java.io.InputStreamReader; |
| 34 | import java.io.IOException; |
| 35 | import java.io.OutputStreamWriter; |
| 36 | import java.net.HttpURLConnection; |
| 37 | import java.net.InetSocketAddress; |
| 38 | import java.net.Socket; |
| 39 | import java.net.URL; |
| 40 | |
| 41 | /** |
| 42 | * {@hide} |
| 43 | */ |
| 44 | public class NetworkMonitor extends StateMachine { |
| 45 | private static final boolean DBG = true; |
| 46 | private static final String TAG = "NetworkMonitor"; |
| 47 | private static final String DEFAULT_SERVER = "clients3.google.com"; |
| 48 | private static final int SOCKET_TIMEOUT_MS = 10000; |
| 49 | |
| 50 | private static final int BASE = Protocol.BASE_NETWORK_MONITOR; |
| 51 | |
| 52 | /** |
| 53 | * Inform NetworkMonitor that their network is connected. |
| 54 | * Initiates Network Validation. |
| 55 | */ |
| 56 | public static final int CMD_NETWORK_CONNECTED = BASE + 1; |
| 57 | |
| 58 | /** |
| 59 | * Inform ConnectivityService that the network is validated. |
| 60 | * obj = NetworkAgentInfo |
| 61 | */ |
| 62 | public static final int EVENT_NETWORK_VALIDATED = BASE + 2; |
| 63 | |
| 64 | /** |
| 65 | * Inform NetworkMonitor to linger a network. The Monitor should |
| 66 | * start a timer and/or start watching for zero live connections while |
| 67 | * moving towards LINGER_COMPLETE. After the Linger period expires |
| 68 | * (or other events mark the end of the linger state) the LINGER_COMPLETE |
| 69 | * event should be sent and the network will be shut down. If a |
| 70 | * CMD_NETWORK_CONNECTED happens before the LINGER completes |
| 71 | * it indicates further desire to keep the network alive and so |
| 72 | * the LINGER is aborted. |
| 73 | */ |
| 74 | public static final int CMD_NETWORK_LINGER = BASE + 3; |
| 75 | |
| 76 | /** |
| 77 | * Message to self indicating linger delay has expired. |
| 78 | * arg1 = Token to ignore old messages. |
| 79 | */ |
| 80 | private static final int CMD_LINGER_EXPIRED = BASE + 4; |
| 81 | |
| 82 | /** |
| 83 | * Inform ConnectivityService that the network LINGER period has |
| 84 | * expired. |
| 85 | * obj = NetworkAgentInfo |
| 86 | */ |
| 87 | public static final int EVENT_NETWORK_LINGER_COMPLETE = BASE + 5; |
| 88 | |
| 89 | /** |
| 90 | * Message to self indicating it's time to check for a captive portal again. |
| 91 | * TODO - Remove this once broadcast intents are used to communicate with |
| 92 | * apps to log into captive portals. |
| 93 | * arg1 = Token to ignore old messages. |
| 94 | */ |
| 95 | private static final int CMD_CAPTIVE_PORTAL_REEVALUATE = BASE + 6; |
| 96 | |
| 97 | /** |
| 98 | * Message to self indicating it's time to evaluate a network's connectivity. |
| 99 | * arg1 = Token to ignore old messages. |
| 100 | */ |
| 101 | private static final int CMD_REEVALUATE = BASE + 7; |
| 102 | |
| 103 | /** |
| 104 | * Message to self indicating network evaluation is complete. |
| 105 | * arg1 = Token to ignore old messages. |
| 106 | * arg2 = HTTP response code of network evaluation. |
| 107 | */ |
| 108 | private static final int EVENT_REEVALUATION_COMPLETE = BASE + 8; |
| 109 | |
| 110 | /** |
| 111 | * Inform NetworkMonitor that the network has disconnected. |
| 112 | */ |
| 113 | public static final int CMD_NETWORK_DISCONNECTED = BASE + 9; |
| 114 | |
| 115 | /** |
| 116 | * Force evaluation even if it has succeeded in the past. |
| 117 | */ |
| 118 | public static final int CMD_FORCE_REEVALUATION = BASE + 10; |
| 119 | |
| 120 | private static final String LINGER_DELAY_PROPERTY = "persist.netmon.linger"; |
| 121 | // Default to 30s linger time-out. |
| 122 | private static final int DEFAULT_LINGER_DELAY_MS = 30000; |
| 123 | private final int mLingerDelayMs; |
| 124 | private int mLingerToken = 0; |
| 125 | |
| 126 | private static final int CAPTIVE_PORTAL_REEVALUATE_DELAY_MS = 5000; |
| 127 | private int mCaptivePortalReevaluateToken = 0; |
| 128 | |
| 129 | // Negative values disable reevaluation. |
| 130 | private static final String REEVALUATE_DELAY_PROPERTY = "persist.netmon.reeval_delay"; |
| 131 | // Default to 5s reevaluation delay. |
| 132 | private static final int DEFAULT_REEVALUATE_DELAY_MS = 5000; |
| 133 | private final int mReevaluateDelayMs; |
| 134 | private int mReevaluateToken = 0; |
| 135 | |
| 136 | private final Context mContext; |
| 137 | private final Handler mConnectivityServiceHandler; |
| 138 | private final NetworkAgentInfo mNetworkAgentInfo; |
| 139 | |
| 140 | private String mServer; |
| 141 | private boolean mIsCaptivePortalCheckEnabled = false; |
| 142 | |
| 143 | private State mDefaultState = new DefaultState(); |
| 144 | private State mOfflineState = new OfflineState(); |
| 145 | private State mValidatedState = new ValidatedState(); |
| 146 | private State mEvaluatingState = new EvaluatingState(); |
| 147 | private State mCaptivePortalState = new CaptivePortalState(); |
| 148 | private State mLingeringState = new LingeringState(); |
| 149 | |
| 150 | public NetworkMonitor(Context context, Handler handler, NetworkAgentInfo networkAgentInfo) { |
| 151 | // Add suffix indicating which NetworkMonitor we're talking about. |
| 152 | super(TAG + networkAgentInfo.name()); |
| 153 | |
| 154 | mContext = context; |
| 155 | mConnectivityServiceHandler = handler; |
| 156 | mNetworkAgentInfo = networkAgentInfo; |
| 157 | |
| 158 | addState(mDefaultState); |
| 159 | addState(mOfflineState, mDefaultState); |
| 160 | addState(mValidatedState, mDefaultState); |
| 161 | addState(mEvaluatingState, mDefaultState); |
| 162 | addState(mCaptivePortalState, mDefaultState); |
| 163 | addState(mLingeringState, mDefaultState); |
| 164 | setInitialState(mOfflineState); |
| 165 | |
| 166 | mServer = Settings.Global.getString(mContext.getContentResolver(), |
| 167 | Settings.Global.CAPTIVE_PORTAL_SERVER); |
| 168 | if (mServer == null) mServer = DEFAULT_SERVER; |
| 169 | |
| 170 | mLingerDelayMs = SystemProperties.getInt(LINGER_DELAY_PROPERTY, DEFAULT_LINGER_DELAY_MS); |
| 171 | mReevaluateDelayMs = SystemProperties.getInt(REEVALUATE_DELAY_PROPERTY, |
| 172 | DEFAULT_REEVALUATE_DELAY_MS); |
| 173 | |
| 174 | // TODO: Enable this when we're ready. |
| 175 | // mIsCaptivePortalCheckEnabled = Settings.Global.getInt(mContext.getContentResolver(), |
| 176 | // Settings.Global.CAPTIVE_PORTAL_DETECTION_ENABLED, 1) == 1; |
| 177 | |
| 178 | start(); |
| 179 | } |
| 180 | |
| 181 | private class DefaultState extends State { |
| 182 | @Override |
| 183 | public boolean processMessage(Message message) { |
| 184 | if (DBG) log(getName() + message.toString()); |
| 185 | switch (message.what) { |
| 186 | case CMD_NETWORK_LINGER: |
| 187 | if (DBG) log("Lingering"); |
| 188 | transitionTo(mLingeringState); |
| 189 | break; |
| 190 | case CMD_NETWORK_CONNECTED: |
| 191 | if (DBG) log("Connected"); |
| 192 | transitionTo(mEvaluatingState); |
| 193 | break; |
| 194 | case CMD_NETWORK_DISCONNECTED: |
| 195 | if (DBG) log("Disconnected"); |
| 196 | transitionTo(mOfflineState); |
| 197 | break; |
| 198 | case CMD_FORCE_REEVALUATION: |
| 199 | if (DBG) log("Forcing reevaluation"); |
| 200 | transitionTo(mEvaluatingState); |
| 201 | break; |
| 202 | default: |
| 203 | break; |
| 204 | } |
| 205 | return HANDLED; |
| 206 | } |
| 207 | } |
| 208 | |
| 209 | private class OfflineState extends State { |
| 210 | @Override |
| 211 | public boolean processMessage(Message message) { |
| 212 | if (DBG) log(getName() + message.toString()); |
| 213 | return NOT_HANDLED; |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | private class ValidatedState extends State { |
| 218 | @Override |
| 219 | public void enter() { |
| 220 | if (DBG) log("Validated"); |
| 221 | mConnectivityServiceHandler.sendMessage( |
| 222 | obtainMessage(EVENT_NETWORK_VALIDATED, mNetworkAgentInfo)); |
| 223 | } |
| 224 | |
| 225 | @Override |
| 226 | public boolean processMessage(Message message) { |
| 227 | if (DBG) log(getName() + message.toString()); |
| 228 | switch (message.what) { |
| 229 | case CMD_NETWORK_CONNECTED: |
| 230 | transitionTo(mValidatedState); |
| 231 | break; |
| 232 | default: |
| 233 | return NOT_HANDLED; |
| 234 | } |
| 235 | return HANDLED; |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | private class EvaluatingState extends State { |
| 240 | private class EvaluateInternetConnectivity extends Thread { |
| 241 | private int mToken; |
| 242 | EvaluateInternetConnectivity(int token) { |
| 243 | mToken = token; |
| 244 | } |
| 245 | public void run() { |
| 246 | sendMessage(EVENT_REEVALUATION_COMPLETE, mToken, isCaptivePortal()); |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | @Override |
| 251 | public void enter() { |
| 252 | sendMessage(CMD_REEVALUATE, ++mReevaluateToken, 0); |
| 253 | } |
| 254 | |
| 255 | @Override |
| 256 | public boolean processMessage(Message message) { |
| 257 | if (DBG) log(getName() + message.toString()); |
| 258 | switch (message.what) { |
| 259 | case CMD_REEVALUATE: |
| 260 | if (message.arg1 != mReevaluateToken) |
| 261 | break; |
| 262 | // If network provides no internet connectivity adjust evaluation. |
| 263 | if (mNetworkAgentInfo.networkCapabilities.hasCapability( |
| 264 | NetworkCapabilities.NET_CAPABILITY_INTERNET)) { |
| 265 | // TODO: Try to verify something works. Do all gateways respond to pings? |
| 266 | transitionTo(mValidatedState); |
| 267 | } |
| 268 | // Kick off a thread to perform internet connectivity evaluation. |
| 269 | Thread thread = new EvaluateInternetConnectivity(mReevaluateToken); |
| 270 | thread.run(); |
| 271 | break; |
| 272 | case EVENT_REEVALUATION_COMPLETE: |
| 273 | if (message.arg1 != mReevaluateToken) |
| 274 | break; |
| 275 | int httpResponseCode = message.arg2; |
| 276 | if (httpResponseCode == 204) { |
| 277 | transitionTo(mValidatedState); |
| 278 | } else if (httpResponseCode >= 200 && httpResponseCode <= 399) { |
| 279 | transitionTo(mCaptivePortalState); |
| 280 | } else { |
| 281 | if (mReevaluateDelayMs >= 0) { |
| 282 | Message msg = obtainMessage(CMD_REEVALUATE, ++mReevaluateToken, 0); |
| 283 | sendMessageDelayed(msg, mReevaluateDelayMs); |
| 284 | } |
| 285 | } |
| 286 | break; |
| 287 | default: |
| 288 | return NOT_HANDLED; |
| 289 | } |
| 290 | return HANDLED; |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | // TODO: Until we add an intent from the app handling captive portal |
| 295 | // login we'll just re-evaluate after a delay. |
| 296 | private class CaptivePortalState extends State { |
| 297 | @Override |
| 298 | public void enter() { |
| 299 | Message message = obtainMessage(CMD_CAPTIVE_PORTAL_REEVALUATE, |
| 300 | ++mCaptivePortalReevaluateToken, 0); |
| 301 | sendMessageDelayed(message, CAPTIVE_PORTAL_REEVALUATE_DELAY_MS); |
| 302 | } |
| 303 | |
| 304 | @Override |
| 305 | public boolean processMessage(Message message) { |
| 306 | if (DBG) log(getName() + message.toString()); |
| 307 | switch (message.what) { |
| 308 | case CMD_CAPTIVE_PORTAL_REEVALUATE: |
| 309 | if (message.arg1 != mCaptivePortalReevaluateToken) |
| 310 | break; |
| 311 | transitionTo(mEvaluatingState); |
| 312 | break; |
| 313 | default: |
| 314 | return NOT_HANDLED; |
| 315 | } |
| 316 | return HANDLED; |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | private class LingeringState extends State { |
| 321 | @Override |
| 322 | public void enter() { |
| 323 | Message message = obtainMessage(CMD_LINGER_EXPIRED, ++mLingerToken, 0); |
| 324 | sendMessageDelayed(message, mLingerDelayMs); |
| 325 | } |
| 326 | |
| 327 | @Override |
| 328 | public boolean processMessage(Message message) { |
| 329 | if (DBG) log(getName() + message.toString()); |
| 330 | switch (message.what) { |
| 331 | case CMD_NETWORK_CONNECTED: |
| 332 | // Go straight to active as we've already evaluated. |
| 333 | transitionTo(mValidatedState); |
| 334 | break; |
| 335 | case CMD_LINGER_EXPIRED: |
| 336 | if (message.arg1 != mLingerToken) |
| 337 | break; |
| 338 | mConnectivityServiceHandler.sendMessage( |
| 339 | obtainMessage(EVENT_NETWORK_LINGER_COMPLETE, mNetworkAgentInfo)); |
| 340 | break; |
| 341 | default: |
| 342 | return NOT_HANDLED; |
| 343 | } |
| 344 | return HANDLED; |
| 345 | } |
| 346 | } |
| 347 | |
| 348 | /** |
| 349 | * Do a URL fetch on a known server to see if we get the data we expect. |
| 350 | * Returns HTTP response code. |
| 351 | */ |
| 352 | private int isCaptivePortal() { |
| 353 | if (!mIsCaptivePortalCheckEnabled) return 204; |
| 354 | |
| 355 | String urlString = "http://" + mServer + "/generate_204"; |
| 356 | if (DBG) log("Checking " + urlString); |
| 357 | HttpURLConnection urlConnection = null; |
| 358 | Socket socket = null; |
| 359 | int httpResponseCode = 500; |
| 360 | try { |
| 361 | URL url = new URL(urlString); |
| 362 | if (false) { |
| 363 | // TODO: Need to add URLConnection.setNetwork() before we can enable. |
| 364 | urlConnection = (HttpURLConnection) url.openConnection(); |
| 365 | urlConnection.setInstanceFollowRedirects(false); |
| 366 | urlConnection.setConnectTimeout(SOCKET_TIMEOUT_MS); |
| 367 | urlConnection.setReadTimeout(SOCKET_TIMEOUT_MS); |
| 368 | urlConnection.setUseCaches(false); |
| 369 | urlConnection.getInputStream(); |
| 370 | httpResponseCode = urlConnection.getResponseCode(); |
| 371 | } else { |
| 372 | socket = new Socket(); |
| 373 | // TODO: setNetworkForSocket(socket, mNetworkAgentInfo.network.netId); |
| 374 | InetSocketAddress address = new InetSocketAddress(url.getHost(), 80); |
| 375 | // TODO: address = new InetSocketAddress( |
| 376 | // getByNameOnNetwork(mNetworkAgentInfo.network, url.getHost()), 80); |
| 377 | socket.connect(address); |
| 378 | BufferedReader reader = new BufferedReader( |
| 379 | new InputStreamReader(socket.getInputStream())); |
| 380 | OutputStreamWriter writer = new OutputStreamWriter(socket.getOutputStream()); |
| 381 | writer.write("GET " + url.getFile() + " HTTP/1.1\r\n\n"); |
| 382 | writer.flush(); |
| 383 | String response = reader.readLine(); |
| 384 | if (response.startsWith("HTTP/1.1 ")) { |
| 385 | httpResponseCode = Integer.parseInt(response.substring(9, 12)); |
| 386 | } |
| 387 | } |
| 388 | if (DBG) log("isCaptivePortal: ret=" + httpResponseCode); |
| 389 | } catch (IOException e) { |
| 390 | if (DBG) log("Probably not a portal: exception " + e); |
| 391 | } finally { |
| 392 | if (urlConnection != null) { |
| 393 | urlConnection.disconnect(); |
| 394 | } |
| 395 | if (socket != null) { |
| 396 | try { |
| 397 | socket.close(); |
| 398 | } catch (IOException e) { |
| 399 | // Ignore |
| 400 | } |
| 401 | } |
| 402 | } |
| 403 | return httpResponseCode; |
| 404 | } |
| 405 | } |