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 android.net; 18 19 import android.content.Context; 20 import android.os.Handler; 21 import android.os.Looper; 22 import android.os.Message; 23 import android.os.Messenger; 24 import android.util.Log; 25 26 import com.android.internal.util.AsyncChannel; 27 import com.android.internal.util.Protocol; 28 29 import java.util.ArrayList; 30 import java.util.concurrent.atomic.AtomicBoolean; 31 32 /** 33 * A Utility class for handling for communicating between bearer-specific 34 * code and ConnectivityService. 35 * 36 * A bearer may have more than one NetworkAgent if it can simultaneously 37 * support separate networks (IMS / Internet / MMS Apns on cellular, or 38 * perhaps connections with different SSID or P2P for Wi-Fi). 39 * 40 * @hide 41 */ 42 public abstract class NetworkAgent extends Handler { 43 // Guaranteed to be valid (not NETID_UNSET), otherwise registerNetworkAgent() would have thrown 44 // an exception. 45 public final int netId; 46 47 private volatile AsyncChannel mAsyncChannel; 48 private final String LOG_TAG; 49 private static final boolean DBG = true; 50 private static final boolean VDBG = false; 51 private final Context mContext; 52 private final ArrayList<Message>mPreConnectedQueue = new ArrayList<Message>(); 53 private volatile long mLastBwRefreshTime = 0; 54 private static final long BW_REFRESH_MIN_WIN_MS = 500; 55 private boolean mPollLceScheduled = false; 56 private AtomicBoolean mPollLcePending = new AtomicBoolean(false); 57 58 private static final int BASE = Protocol.BASE_NETWORK_AGENT; 59 60 /** 61 * Sent by ConnectivityService to the NetworkAgent to inform it of 62 * suspected connectivity problems on its network. The NetworkAgent 63 * should take steps to verify and correct connectivity. 64 */ 65 public static final int CMD_SUSPECT_BAD = BASE; 66 67 /** 68 * Sent by the NetworkAgent (note the EVENT vs CMD prefix) to 69 * ConnectivityService to pass the current NetworkInfo (connection state). 70 * Sent when the NetworkInfo changes, mainly due to change of state. 71 * obj = NetworkInfo 72 */ 73 public static final int EVENT_NETWORK_INFO_CHANGED = BASE + 1; 74 75 /** 76 * Sent by the NetworkAgent to ConnectivityService to pass the current 77 * NetworkCapabilties. 78 * obj = NetworkCapabilities 79 */ 80 public static final int EVENT_NETWORK_CAPABILITIES_CHANGED = BASE + 2; 81 82 /** 83 * Sent by the NetworkAgent to ConnectivityService to pass the current 84 * NetworkProperties. 85 * obj = NetworkProperties 86 */ 87 public static final int EVENT_NETWORK_PROPERTIES_CHANGED = BASE + 3; 88 89 /* centralize place where base network score, and network score scaling, will be 90 * stored, so as we can consistently compare apple and oranges, or wifi, ethernet and LTE 91 */ 92 public static final int WIFI_BASE_SCORE = 60; 93 94 /** 95 * Sent by the NetworkAgent to ConnectivityService to pass the current 96 * network score. 97 * obj = network score Integer 98 */ 99 public static final int EVENT_NETWORK_SCORE_CHANGED = BASE + 4; 100 101 /** 102 * Sent by the NetworkAgent to ConnectivityService to add new UID ranges 103 * to be forced into this Network. For VPNs only. 104 * obj = UidRange[] to forward 105 */ 106 public static final int EVENT_UID_RANGES_ADDED = BASE + 5; 107 108 /** 109 * Sent by the NetworkAgent to ConnectivityService to remove UID ranges 110 * from being forced into this Network. For VPNs only. 111 * obj = UidRange[] to stop forwarding 112 */ 113 public static final int EVENT_UID_RANGES_REMOVED = BASE + 6; 114 115 /** 116 * Sent by ConnectivityService to the NetworkAgent to inform the agent of the 117 * networks status - whether we could use the network or could not, due to 118 * either a bad network configuration (no internet link) or captive portal. 119 * 120 * arg1 = either {@code VALID_NETWORK} or {@code INVALID_NETWORK} 121 */ 122 public static final int CMD_REPORT_NETWORK_STATUS = BASE + 7; 123 124 public static final int VALID_NETWORK = 1; 125 public static final int INVALID_NETWORK = 2; 126 127 /** 128 * Sent by the NetworkAgent to ConnectivityService to indicate this network was 129 * explicitly selected. This should be sent before the NetworkInfo is marked 130 * CONNECTED so it can be given special treatment at that time. 131 * 132 * obj = boolean indicating whether to use this network even if unvalidated 133 */ 134 public static final int EVENT_SET_EXPLICITLY_SELECTED = BASE + 8; 135 136 /** 137 * Sent by ConnectivityService to the NetworkAgent to inform the agent of 138 * whether the network should in the future be used even if not validated. 139 * This decision is made by the user, but it is the network transport's 140 * responsibility to remember it. 141 * 142 * arg1 = 1 if true, 0 if false 143 */ 144 public static final int CMD_SAVE_ACCEPT_UNVALIDATED = BASE + 9; 145 146 /** Sent by ConnectivityService to the NetworkAgent to inform the agent to pull 147 * the underlying network connection for updated bandwidth information. 148 */ 149 public static final int CMD_REQUEST_BANDWIDTH_UPDATE = BASE + 10; 150 151 /** 152 * Sent by ConnectivityService to the NeworkAgent to inform the agent to avoid 153 * automatically reconnecting to this network (e.g. via autojoin). Happens 154 * when user selects "No" option on the "Stay connected?" dialog box. 155 */ 156 public static final int CMD_PREVENT_AUTOMATIC_RECONNECT = BASE + 11; 157 158 public NetworkAgent(Looper looper, Context context, String logTag, NetworkInfo ni, 159 NetworkCapabilities nc, LinkProperties lp, int score) { 160 this(looper, context, logTag, ni, nc, lp, score, null); 161 } 162 163 public NetworkAgent(Looper looper, Context context, String logTag, NetworkInfo ni, 164 NetworkCapabilities nc, LinkProperties lp, int score, NetworkMisc misc) { 165 super(looper); 166 LOG_TAG = logTag; 167 mContext = context; 168 if (ni == null || nc == null || lp == null) { 169 throw new IllegalArgumentException(); 170 } 171 172 if (VDBG) log("Registering NetworkAgent"); 173 ConnectivityManager cm = (ConnectivityManager)mContext.getSystemService( 174 Context.CONNECTIVITY_SERVICE); 175 netId = cm.registerNetworkAgent(new Messenger(this), new NetworkInfo(ni), 176 new LinkProperties(lp), new NetworkCapabilities(nc), score, misc); 177 } 178 179 @Override 180 public void handleMessage(Message msg) { 181 switch (msg.what) { 182 case AsyncChannel.CMD_CHANNEL_FULL_CONNECTION: { 183 if (mAsyncChannel != null) { 184 log("Received new connection while already connected!"); 185 } else { 186 if (VDBG) log("NetworkAgent fully connected"); 187 AsyncChannel ac = new AsyncChannel(); 188 ac.connected(null, this, msg.replyTo); 189 ac.replyToMessage(msg, AsyncChannel.CMD_CHANNEL_FULLY_CONNECTED, 190 AsyncChannel.STATUS_SUCCESSFUL); 191 synchronized (mPreConnectedQueue) { 192 mAsyncChannel = ac; 193 for (Message m : mPreConnectedQueue) { 194 ac.sendMessage(m); 195 } 196 mPreConnectedQueue.clear(); 197 } 198 } 199 break; 200 } 201 case AsyncChannel.CMD_CHANNEL_DISCONNECT: { 202 if (VDBG) log("CMD_CHANNEL_DISCONNECT"); 203 if (mAsyncChannel != null) mAsyncChannel.disconnect(); 204 break; 205 } 206 case AsyncChannel.CMD_CHANNEL_DISCONNECTED: { 207 if (DBG) log("NetworkAgent channel lost"); 208 // let the client know CS is done with us. 209 unwanted(); 210 synchronized (mPreConnectedQueue) { 211 mAsyncChannel = null; 212 } 213 break; 214 } 215 case CMD_SUSPECT_BAD: { 216 log("Unhandled Message " + msg); 217 break; 218 } 219 case CMD_REQUEST_BANDWIDTH_UPDATE: { 220 long currentTimeMs = System.currentTimeMillis(); 221 if (VDBG) { 222 log("CMD_REQUEST_BANDWIDTH_UPDATE request received."); 223 } 224 if (currentTimeMs >= (mLastBwRefreshTime + BW_REFRESH_MIN_WIN_MS)) { 225 mPollLceScheduled = false; 226 if (mPollLcePending.getAndSet(true) == false) { 227 pollLceData(); 228 } 229 } else { 230 // deliver the request at a later time rather than discard it completely. 231 if (!mPollLceScheduled) { 232 long waitTime = mLastBwRefreshTime + BW_REFRESH_MIN_WIN_MS - 233 currentTimeMs + 1; 234 mPollLceScheduled = sendEmptyMessageDelayed( 235 CMD_REQUEST_BANDWIDTH_UPDATE, waitTime); 236 } 237 } 238 break; 239 } 240 case CMD_REPORT_NETWORK_STATUS: { 241 if (VDBG) { 242 log("CMD_REPORT_NETWORK_STATUS(" + 243 (msg.arg1 == VALID_NETWORK ? "VALID)" : "INVALID)")); 244 } 245 networkStatus(msg.arg1); 246 break; 247 } 248 case CMD_SAVE_ACCEPT_UNVALIDATED: { 249 saveAcceptUnvalidated(msg.arg1 != 0); 250 break; 251 } 252 case CMD_PREVENT_AUTOMATIC_RECONNECT: { 253 preventAutomaticReconnect(); 254 break; 255 } 256 } 257 } 258 259 private void queueOrSendMessage(int what, Object obj) { 260 synchronized (mPreConnectedQueue) { 261 if (mAsyncChannel != null) { 262 mAsyncChannel.sendMessage(what, obj); 263 } else { 264 Message msg = Message.obtain(); 265 msg.what = what; 266 msg.obj = obj; 267 mPreConnectedQueue.add(msg); 268 } 269 } 270 } 271 272 /** 273 * Called by the bearer code when it has new LinkProperties data. 274 */ 275 public void sendLinkProperties(LinkProperties linkProperties) { 276 queueOrSendMessage(EVENT_NETWORK_PROPERTIES_CHANGED, new LinkProperties(linkProperties)); 277 } 278 279 /** 280 * Called by the bearer code when it has new NetworkInfo data. 281 */ 282 public void sendNetworkInfo(NetworkInfo networkInfo) { 283 queueOrSendMessage(EVENT_NETWORK_INFO_CHANGED, new NetworkInfo(networkInfo)); 284 } 285 286 /** 287 * Called by the bearer code when it has new NetworkCapabilities data. 288 */ 289 public void sendNetworkCapabilities(NetworkCapabilities networkCapabilities) { 290 mPollLcePending.set(false); 291 mLastBwRefreshTime = System.currentTimeMillis(); 292 queueOrSendMessage(EVENT_NETWORK_CAPABILITIES_CHANGED, 293 new NetworkCapabilities(networkCapabilities)); 294 } 295 296 /** 297 * Called by the bearer code when it has a new score for this network. 298 */ 299 public void sendNetworkScore(int score) { 300 if (score < 0) { 301 throw new IllegalArgumentException("Score must be >= 0"); 302 } 303 queueOrSendMessage(EVENT_NETWORK_SCORE_CHANGED, new Integer(score)); 304 } 305 306 /** 307 * Called by the VPN code when it wants to add ranges of UIDs to be routed 308 * through the VPN network. 309 */ 310 public void addUidRanges(UidRange[] ranges) { 311 queueOrSendMessage(EVENT_UID_RANGES_ADDED, ranges); 312 } 313 314 /** 315 * Called by the VPN code when it wants to remove ranges of UIDs from being routed 316 * through the VPN network. 317 */ 318 public void removeUidRanges(UidRange[] ranges) { 319 queueOrSendMessage(EVENT_UID_RANGES_REMOVED, ranges); 320 } 321 322 /** 323 * Called by the bearer to indicate this network was manually selected by the user. 324 * This should be called before the NetworkInfo is marked CONNECTED so that this 325 * Network can be given special treatment at that time. If {@code acceptUnvalidated} is 326 * {@code true}, then the system will switch to this network. If it is {@code false} and the 327 * network cannot be validated, the system will ask the user whether to switch to this network. 328 * If the user confirms and selects "don't ask again", then the system will call 329 * {@link #saveAcceptUnvalidated} to persist the user's choice. Thus, if the transport ever 330 * calls this method with {@code acceptUnvalidated} set to {@code false}, it must also implement 331 * {@link #saveAcceptUnvalidated} to respect the user's choice. 332 */ 333 public void explicitlySelected(boolean acceptUnvalidated) { 334 queueOrSendMessage(EVENT_SET_EXPLICITLY_SELECTED, acceptUnvalidated); 335 } 336 337 /** 338 * Called when ConnectivityService has indicated they no longer want this network. 339 * The parent factory should (previously) have received indication of the change 340 * as well, either canceling NetworkRequests or altering their score such that this 341 * network won't be immediately requested again. 342 */ 343 abstract protected void unwanted(); 344 345 /** 346 * Called when ConnectivityService request a bandwidth update. The parent factory 347 * shall try to overwrite this method and produce a bandwidth update if capable. 348 */ 349 protected void pollLceData() { 350 } 351 352 /** 353 * Called when the system determines the usefulness of this network. 354 * 355 * Networks claiming internet connectivity will have their internet 356 * connectivity verified. 357 * 358 * Currently there are two possible values: 359 * {@code VALID_NETWORK} if the system is happy with the connection, 360 * {@code INVALID_NETWORK} if the system is not happy. 361 * TODO - add indications of captive portal-ness and related success/failure, 362 * ie, CAPTIVE_SUCCESS_NETWORK, CAPTIVE_NETWORK for successful login and detection 363 * 364 * This may be called multiple times as the network status changes and may 365 * generate false negatives if we lose ip connectivity before the link is torn down. 366 */ 367 protected void networkStatus(int status) { 368 } 369 370 /** 371 * Called when the user asks to remember the choice to use this network even if unvalidated. 372 * The transport is responsible for remembering the choice, and the next time the user connects 373 * to the network, should explicitlySelected with {@code acceptUnvalidated} set to {@code true}. 374 * This method will only be called if {@link #explicitlySelected} was called with 375 * {@code acceptUnvalidated} set to {@code false}. 376 */ 377 protected void saveAcceptUnvalidated(boolean accept) { 378 } 379 380 /** 381 * Called when the user asks to not stay connected to this network because it was found to not 382 * provide Internet access. Usually followed by call to {@code unwanted}. The transport is 383 * responsible for making sure the device does not automatically reconnect to the same network 384 * after the {@code unwanted} call. 385 */ 386 protected void preventAutomaticReconnect() { 387 } 388 389 protected void log(String s) { 390 Log.d(LOG_TAG, "NetworkAgent: " + s); 391 } 392 } 393
