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 NetworkAgent(Looper looper, Context context, String logTag, NetworkInfo ni, NetworkCapabilities nc, LinkProperties lp, int score)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 NetworkAgent(Looper looper, Context context, String logTag, NetworkInfo ni, NetworkCapabilities nc, LinkProperties lp, int score, NetworkMisc misc)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 handleMessage(Message msg)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 queueOrSendMessage(int what, Object obj)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 */ sendLinkProperties(LinkProperties linkProperties)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 */ sendNetworkInfo(NetworkInfo networkInfo)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 */ sendNetworkCapabilities(NetworkCapabilities networkCapabilities)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 */ sendNetworkScore(int score)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 */ addUidRanges(UidRange[] ranges)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 */ removeUidRanges(UidRange[] ranges)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 */ explicitlySelected(boolean acceptUnvalidated)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 */ unwanted()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 */ pollLceData()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 */ networkStatus(int status)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 */ saveAcceptUnvalidated(boolean accept)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 */ preventAutomaticReconnect()386 protected void preventAutomaticReconnect() { 387 } 388 log(String s)389 protected void log(String s) { 390 Log.d(LOG_TAG, "NetworkAgent: " + s); 391 } 392 } 393