Erik Kline | 9bba340 | 2017-01-13 16:46:52 +0900 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 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.tethering; |
| 18 | |
Erik Kline | dd8e891 | 2017-01-18 16:08:06 +0900 | [diff] [blame] | 19 | import static android.net.ConnectivityManager.TYPE_MOBILE_DUN; |
| 20 | import static android.net.ConnectivityManager.TYPE_MOBILE_HIPRI; |
| 21 | |
Erik Kline | 9bba340 | 2017-01-13 16:46:52 +0900 | [diff] [blame] | 22 | import android.content.Context; |
| 23 | import android.net.ConnectivityManager; |
| 24 | import android.net.ConnectivityManager.NetworkCallback; |
| 25 | import android.net.LinkProperties; |
| 26 | import android.net.Network; |
| 27 | import android.net.NetworkCapabilities; |
| 28 | import android.net.NetworkRequest; |
| 29 | import android.net.NetworkState; |
| 30 | import android.util.Log; |
| 31 | |
Erik Kline | 885a909 | 2017-01-16 16:27:22 +0900 | [diff] [blame] | 32 | import com.android.internal.annotations.VisibleForTesting; |
Erik Kline | 9bba340 | 2017-01-13 16:46:52 +0900 | [diff] [blame] | 33 | import com.android.internal.util.StateMachine; |
| 34 | |
| 35 | import java.util.HashMap; |
| 36 | |
| 37 | |
| 38 | /** |
| 39 | * A class to centralize all the network and link properties information |
| 40 | * pertaining to the current and any potential upstream network. |
| 41 | * |
| 42 | * Calling #start() registers two callbacks: one to track the system default |
| 43 | * network and a second to specifically observe TYPE_MOBILE_DUN networks. |
| 44 | * |
| 45 | * The methods and data members of this class are only to be accessed and |
| 46 | * modified from the tethering master state machine thread. Any other |
| 47 | * access semantics would necessitate the addition of locking. |
| 48 | * |
| 49 | * TODO: Move upstream selection logic here. |
| 50 | * |
| 51 | * @hide |
| 52 | */ |
| 53 | public class UpstreamNetworkMonitor { |
| 54 | private static final String TAG = UpstreamNetworkMonitor.class.getSimpleName(); |
| 55 | private static final boolean DBG = false; |
| 56 | private static final boolean VDBG = false; |
| 57 | |
| 58 | public static final int EVENT_ON_AVAILABLE = 1; |
| 59 | public static final int EVENT_ON_CAPABILITIES = 2; |
| 60 | public static final int EVENT_ON_LINKPROPERTIES = 3; |
| 61 | public static final int EVENT_ON_LOST = 4; |
| 62 | |
| 63 | private final Context mContext; |
| 64 | private final StateMachine mTarget; |
| 65 | private final int mWhat; |
| 66 | private final HashMap<Network, NetworkState> mNetworkMap = new HashMap<>(); |
| 67 | private ConnectivityManager mCM; |
| 68 | private NetworkCallback mDefaultNetworkCallback; |
| 69 | private NetworkCallback mDunTetheringCallback; |
| 70 | private NetworkCallback mMobileNetworkCallback; |
| 71 | private boolean mDunRequired; |
| 72 | |
| 73 | public UpstreamNetworkMonitor(Context ctx, StateMachine tgt, int what) { |
| 74 | mContext = ctx; |
| 75 | mTarget = tgt; |
| 76 | mWhat = what; |
| 77 | } |
| 78 | |
Erik Kline | 885a909 | 2017-01-16 16:27:22 +0900 | [diff] [blame] | 79 | @VisibleForTesting |
| 80 | public UpstreamNetworkMonitor(StateMachine tgt, int what, ConnectivityManager cm) { |
| 81 | this(null, tgt, what); |
| 82 | mCM = cm; |
| 83 | } |
| 84 | |
Erik Kline | 9bba340 | 2017-01-13 16:46:52 +0900 | [diff] [blame] | 85 | public void start() { |
| 86 | stop(); |
| 87 | |
| 88 | mDefaultNetworkCallback = new UpstreamNetworkCallback(); |
| 89 | cm().registerDefaultNetworkCallback(mDefaultNetworkCallback); |
| 90 | |
| 91 | final NetworkRequest dunTetheringRequest = new NetworkRequest.Builder() |
| 92 | .addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR) |
| 93 | .removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED) |
| 94 | .addCapability(NetworkCapabilities.NET_CAPABILITY_DUN) |
| 95 | .build(); |
| 96 | mDunTetheringCallback = new UpstreamNetworkCallback(); |
| 97 | cm().registerNetworkCallback(dunTetheringRequest, mDunTetheringCallback); |
| 98 | } |
| 99 | |
| 100 | public void stop() { |
| 101 | releaseMobileNetworkRequest(); |
| 102 | |
| 103 | releaseCallback(mDefaultNetworkCallback); |
| 104 | mDefaultNetworkCallback = null; |
| 105 | |
| 106 | releaseCallback(mDunTetheringCallback); |
| 107 | mDunTetheringCallback = null; |
| 108 | |
| 109 | mNetworkMap.clear(); |
| 110 | } |
| 111 | |
| 112 | public void mobileUpstreamRequiresDun(boolean dunRequired) { |
| 113 | final boolean valueChanged = (mDunRequired != dunRequired); |
| 114 | mDunRequired = dunRequired; |
| 115 | if (valueChanged && mobileNetworkRequested()) { |
| 116 | releaseMobileNetworkRequest(); |
| 117 | registerMobileNetworkRequest(); |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | public boolean mobileNetworkRequested() { |
| 122 | return (mMobileNetworkCallback != null); |
| 123 | } |
| 124 | |
| 125 | public void registerMobileNetworkRequest() { |
| 126 | if (mMobileNetworkCallback != null) return; |
| 127 | |
| 128 | final NetworkRequest.Builder builder = new NetworkRequest.Builder() |
| 129 | .addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR); |
| 130 | if (mDunRequired) { |
| 131 | builder.removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED) |
| 132 | .addCapability(NetworkCapabilities.NET_CAPABILITY_DUN); |
| 133 | } else { |
| 134 | builder.addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET); |
| 135 | } |
| 136 | final NetworkRequest mobileUpstreamRequest = builder.build(); |
| 137 | |
| 138 | // The existing default network and DUN callbacks will be notified. |
| 139 | // Therefore, to avoid duplicate notifications, we only register a no-op. |
| 140 | mMobileNetworkCallback = new NetworkCallback(); |
| 141 | |
| 142 | // TODO: Change the timeout from 0 (no onUnavailable callback) to use some |
| 143 | // moderate callback time (once timeout callbacks are implemented). This might |
| 144 | // be useful for updating some UI. Additionally, we should definitely log a |
| 145 | // message to aid in any subsequent debugging |
| 146 | if (DBG) Log.d(TAG, "requesting mobile upstream network: " + mobileUpstreamRequest); |
| 147 | |
Erik Kline | dd8e891 | 2017-01-18 16:08:06 +0900 | [diff] [blame] | 148 | // The following use of the legacy type system cannot be removed until |
| 149 | // after upstream selection no longer finds networks by legacy type. |
| 150 | // See also b/34364553. |
| 151 | final int apnType = mDunRequired ? TYPE_MOBILE_DUN : TYPE_MOBILE_HIPRI; |
| 152 | cm().requestNetwork(mobileUpstreamRequest, mMobileNetworkCallback, 0, apnType); |
Erik Kline | 9bba340 | 2017-01-13 16:46:52 +0900 | [diff] [blame] | 153 | } |
| 154 | |
| 155 | public void releaseMobileNetworkRequest() { |
| 156 | if (mMobileNetworkCallback == null) return; |
| 157 | |
| 158 | cm().unregisterNetworkCallback(mMobileNetworkCallback); |
| 159 | mMobileNetworkCallback = null; |
| 160 | } |
| 161 | |
| 162 | public NetworkState lookup(Network network) { |
| 163 | return (network != null) ? mNetworkMap.get(network) : null; |
| 164 | } |
| 165 | |
| 166 | private void handleAvailable(Network network) { |
| 167 | if (VDBG) { |
| 168 | Log.d(TAG, "EVENT_ON_AVAILABLE for " + network); |
| 169 | } |
| 170 | if (!mNetworkMap.containsKey(network)) { |
| 171 | mNetworkMap.put(network, |
| 172 | new NetworkState(null, null, null, network, null, null)); |
| 173 | } |
| 174 | |
| 175 | final ConnectivityManager cm = cm(); |
| 176 | |
| 177 | if (mDefaultNetworkCallback != null) { |
| 178 | cm.requestNetworkCapabilities(mDefaultNetworkCallback); |
| 179 | cm.requestLinkProperties(mDefaultNetworkCallback); |
| 180 | } |
| 181 | |
| 182 | // Requesting updates for mDunTetheringCallback is not |
| 183 | // necessary. Because it's a listen, it will already have |
| 184 | // heard all NetworkCapabilities and LinkProperties updates |
| 185 | // since UpstreamNetworkMonitor was started. Because we |
| 186 | // start UpstreamNetworkMonitor before chooseUpstreamType() |
| 187 | // is ever invoked (it can register a DUN request) this is |
| 188 | // mostly safe. However, if a DUN network is already up for |
| 189 | // some reason (unlikely, because DUN is restricted and, |
| 190 | // unless the DUN network is shared with another APN, only |
| 191 | // the system can request it and this is the only part of |
| 192 | // the system that requests it) we won't know its |
| 193 | // LinkProperties or NetworkCapabilities. |
| 194 | |
| 195 | notifyTarget(EVENT_ON_AVAILABLE, network); |
| 196 | } |
| 197 | |
| 198 | private void handleNetCap(Network network, NetworkCapabilities newNc) { |
| 199 | if (!mNetworkMap.containsKey(network)) { |
| 200 | // Ignore updates for networks for which we have not yet |
| 201 | // received onAvailable() - which should never happen - |
| 202 | // or for which we have already received onLost(). |
| 203 | return; |
| 204 | } |
| 205 | if (VDBG) { |
| 206 | Log.d(TAG, String.format("EVENT_ON_CAPABILITIES for %s: %s", |
| 207 | network, newNc)); |
| 208 | } |
| 209 | |
| 210 | final NetworkState prev = mNetworkMap.get(network); |
| 211 | mNetworkMap.put(network, |
| 212 | new NetworkState(null, prev.linkProperties, newNc, |
| 213 | network, null, null)); |
| 214 | notifyTarget(EVENT_ON_CAPABILITIES, network); |
| 215 | } |
| 216 | |
| 217 | private void handleLinkProp(Network network, LinkProperties newLp) { |
| 218 | if (!mNetworkMap.containsKey(network)) { |
| 219 | // Ignore updates for networks for which we have not yet |
| 220 | // received onAvailable() - which should never happen - |
| 221 | // or for which we have already received onLost(). |
| 222 | return; |
| 223 | } |
| 224 | if (VDBG) { |
| 225 | Log.d(TAG, String.format("EVENT_ON_LINKPROPERTIES for %s: %s", |
| 226 | network, newLp)); |
| 227 | } |
| 228 | |
| 229 | final NetworkState prev = mNetworkMap.get(network); |
| 230 | mNetworkMap.put(network, |
| 231 | new NetworkState(null, newLp, prev.networkCapabilities, |
| 232 | network, null, null)); |
| 233 | notifyTarget(EVENT_ON_LINKPROPERTIES, network); |
| 234 | } |
| 235 | |
| 236 | private void handleLost(Network network) { |
| 237 | if (!mNetworkMap.containsKey(network)) { |
| 238 | // Ignore updates for networks for which we have not yet |
| 239 | // received onAvailable() - which should never happen - |
| 240 | // or for which we have already received onLost(). |
| 241 | return; |
| 242 | } |
| 243 | if (VDBG) { |
| 244 | Log.d(TAG, "EVENT_ON_LOST for " + network); |
| 245 | } |
| 246 | notifyTarget(EVENT_ON_LOST, mNetworkMap.remove(network)); |
| 247 | } |
| 248 | |
| 249 | // Fetch (and cache) a ConnectivityManager only if and when we need one. |
| 250 | private ConnectivityManager cm() { |
| 251 | if (mCM == null) { |
| 252 | mCM = mContext.getSystemService(ConnectivityManager.class); |
| 253 | } |
| 254 | return mCM; |
| 255 | } |
| 256 | |
| 257 | /** |
| 258 | * A NetworkCallback class that relays information of interest to the |
| 259 | * tethering master state machine thread for subsequent processing. |
| 260 | */ |
| 261 | private class UpstreamNetworkCallback extends NetworkCallback { |
| 262 | @Override |
| 263 | public void onAvailable(Network network) { |
| 264 | mTarget.getHandler().post(() -> handleAvailable(network)); |
| 265 | } |
| 266 | |
| 267 | @Override |
| 268 | public void onCapabilitiesChanged(Network network, NetworkCapabilities newNc) { |
| 269 | mTarget.getHandler().post(() -> handleNetCap(network, newNc)); |
| 270 | } |
| 271 | |
| 272 | @Override |
| 273 | public void onLinkPropertiesChanged(Network network, LinkProperties newLp) { |
| 274 | mTarget.getHandler().post(() -> handleLinkProp(network, newLp)); |
| 275 | } |
| 276 | |
| 277 | @Override |
| 278 | public void onLost(Network network) { |
| 279 | mTarget.getHandler().post(() -> handleLost(network)); |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | private void releaseCallback(NetworkCallback cb) { |
| 284 | if (cb != null) cm().unregisterNetworkCallback(cb); |
| 285 | } |
| 286 | |
| 287 | private void notifyTarget(int which, Network network) { |
| 288 | notifyTarget(which, mNetworkMap.get(network)); |
| 289 | } |
| 290 | |
| 291 | private void notifyTarget(int which, NetworkState netstate) { |
| 292 | mTarget.sendMessage(mWhat, which, 0, netstate); |
| 293 | } |
| 294 | } |