| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.net; |
| |
| import android.annotation.UnsupportedAppUsage; |
| import android.content.Context; |
| import android.os.Build; |
| import android.os.Handler; |
| import android.os.Looper; |
| import android.os.Message; |
| import android.os.Messenger; |
| import android.util.Log; |
| import android.util.SparseArray; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| import com.android.internal.util.IndentingPrintWriter; |
| import com.android.internal.util.Protocol; |
| |
| import java.io.FileDescriptor; |
| import java.io.PrintWriter; |
| |
| /** |
| * A NetworkFactory is an entity that creates NetworkAgent objects. |
| * The bearers register with ConnectivityService using {@link #register} and |
| * their factory will start receiving scored NetworkRequests. NetworkRequests |
| * can be filtered 3 ways: by NetworkCapabilities, by score and more complexly by |
| * overridden function. All of these can be dynamic - changing NetworkCapabilities |
| * or score forces re-evaluation of all current requests. |
| * |
| * If any requests pass the filter some overrideable functions will be called. |
| * If the bearer only cares about very simple start/stopNetwork callbacks, those |
| * functions can be overridden. If the bearer needs more interaction, it can |
| * override addNetworkRequest and removeNetworkRequest which will give it each |
| * request that passes their current filters. |
| * @hide |
| **/ |
| public class NetworkFactory extends Handler { |
| private static final boolean DBG = true; |
| private static final boolean VDBG = false; |
| |
| private static final int BASE = Protocol.BASE_NETWORK_FACTORY; |
| /** |
| * Pass a network request to the bearer. If the bearer believes it can |
| * satisfy the request it should connect to the network and create a |
| * NetworkAgent. Once the NetworkAgent is fully functional it will |
| * register itself with ConnectivityService using registerNetworkAgent. |
| * If the bearer cannot immediately satisfy the request (no network, |
| * user disabled the radio, lower-scored network) it should remember |
| * any NetworkRequests it may be able to satisfy in the future. It may |
| * disregard any that it will never be able to service, for example |
| * those requiring a different bearer. |
| * msg.obj = NetworkRequest |
| * msg.arg1 = score - the score of the any network currently satisfying this |
| * request. If this bearer knows in advance it cannot |
| * exceed this score it should not try to connect, holding the request |
| * for the future. |
| * Note that subsequent events may give a different (lower |
| * or higher) score for this request, transmitted to each |
| * NetworkFactory through additional CMD_REQUEST_NETWORK msgs |
| * with the same NetworkRequest but an updated score. |
| * Also, network conditions may change for this bearer |
| * allowing for a better score in the future. |
| */ |
| public static final int CMD_REQUEST_NETWORK = BASE; |
| |
| /** |
| * Cancel a network request |
| * msg.obj = NetworkRequest |
| */ |
| public static final int CMD_CANCEL_REQUEST = BASE + 1; |
| |
| /** |
| * Internally used to set our best-guess score. |
| * msg.arg1 = new score |
| */ |
| private static final int CMD_SET_SCORE = BASE + 2; |
| |
| /** |
| * Internally used to set our current filter for coarse bandwidth changes with |
| * technology changes. |
| * msg.obj = new filter |
| */ |
| private static final int CMD_SET_FILTER = BASE + 3; |
| |
| private final Context mContext; |
| private final String LOG_TAG; |
| |
| private final SparseArray<NetworkRequestInfo> mNetworkRequests = |
| new SparseArray<NetworkRequestInfo>(); |
| |
| private int mScore; |
| private NetworkCapabilities mCapabilityFilter; |
| |
| private int mRefCount = 0; |
| private Messenger mMessenger = null; |
| |
| @UnsupportedAppUsage |
| public NetworkFactory(Looper looper, Context context, String logTag, |
| NetworkCapabilities filter) { |
| super(looper); |
| LOG_TAG = logTag; |
| mContext = context; |
| mCapabilityFilter = filter; |
| } |
| |
| public void register() { |
| if (DBG) log("Registering NetworkFactory"); |
| if (mMessenger == null) { |
| mMessenger = new Messenger(this); |
| ConnectivityManager.from(mContext).registerNetworkFactory(mMessenger, LOG_TAG); |
| } |
| } |
| |
| public void unregister() { |
| if (DBG) log("Unregistering NetworkFactory"); |
| if (mMessenger != null) { |
| ConnectivityManager.from(mContext).unregisterNetworkFactory(mMessenger); |
| mMessenger = null; |
| } |
| } |
| |
| @Override |
| public void handleMessage(Message msg) { |
| switch (msg.what) { |
| case CMD_REQUEST_NETWORK: { |
| handleAddRequest((NetworkRequest)msg.obj, msg.arg1); |
| break; |
| } |
| case CMD_CANCEL_REQUEST: { |
| handleRemoveRequest((NetworkRequest) msg.obj); |
| break; |
| } |
| case CMD_SET_SCORE: { |
| handleSetScore(msg.arg1); |
| break; |
| } |
| case CMD_SET_FILTER: { |
| handleSetFilter((NetworkCapabilities) msg.obj); |
| break; |
| } |
| } |
| } |
| |
| private class NetworkRequestInfo { |
| public final NetworkRequest request; |
| public int score; |
| public boolean requested; // do we have a request outstanding, limited by score |
| |
| public NetworkRequestInfo(NetworkRequest request, int score) { |
| this.request = request; |
| this.score = score; |
| this.requested = false; |
| } |
| |
| @Override |
| public String toString() { |
| return "{" + request + ", score=" + score + ", requested=" + requested + "}"; |
| } |
| } |
| |
| @VisibleForTesting |
| protected void handleAddRequest(NetworkRequest request, int score) { |
| NetworkRequestInfo n = mNetworkRequests.get(request.requestId); |
| if (n == null) { |
| if (DBG) log("got request " + request + " with score " + score); |
| n = new NetworkRequestInfo(request, score); |
| mNetworkRequests.put(n.request.requestId, n); |
| } else { |
| if (VDBG) log("new score " + score + " for exisiting request " + request); |
| n.score = score; |
| } |
| if (VDBG) log(" my score=" + mScore + ", my filter=" + mCapabilityFilter); |
| |
| evalRequest(n); |
| } |
| |
| @VisibleForTesting |
| protected void handleRemoveRequest(NetworkRequest request) { |
| NetworkRequestInfo n = mNetworkRequests.get(request.requestId); |
| if (n != null) { |
| mNetworkRequests.remove(request.requestId); |
| if (n.requested) releaseNetworkFor(n.request); |
| } |
| } |
| |
| private void handleSetScore(int score) { |
| mScore = score; |
| evalRequests(); |
| } |
| |
| private void handleSetFilter(NetworkCapabilities netCap) { |
| mCapabilityFilter = netCap; |
| evalRequests(); |
| } |
| |
| /** |
| * Overridable function to provide complex filtering. |
| * Called for every request every time a new NetworkRequest is seen |
| * and whenever the filterScore or filterNetworkCapabilities change. |
| * |
| * acceptRequest can be overridden to provide complex filter behavior |
| * for the incoming requests |
| * |
| * For output, this class will call {@link #needNetworkFor} and |
| * {@link #releaseNetworkFor} for every request that passes the filters. |
| * If you don't need to see every request, you can leave the base |
| * implementations of those two functions and instead override |
| * {@link #startNetwork} and {@link #stopNetwork}. |
| * |
| * If you want to see every score fluctuation on every request, set |
| * your score filter to a very high number and watch {@link #needNetworkFor}. |
| * |
| * @return {@code true} to accept the request. |
| */ |
| public boolean acceptRequest(NetworkRequest request, int score) { |
| return true; |
| } |
| |
| private void evalRequest(NetworkRequestInfo n) { |
| if (VDBG) log("evalRequest"); |
| if (n.requested == false && n.score < mScore && |
| n.request.networkCapabilities.satisfiedByNetworkCapabilities( |
| mCapabilityFilter) && acceptRequest(n.request, n.score)) { |
| if (VDBG) log(" needNetworkFor"); |
| needNetworkFor(n.request, n.score); |
| n.requested = true; |
| } else if (n.requested == true && |
| (n.score > mScore || n.request.networkCapabilities.satisfiedByNetworkCapabilities( |
| mCapabilityFilter) == false || acceptRequest(n.request, n.score) == false)) { |
| if (VDBG) log(" releaseNetworkFor"); |
| releaseNetworkFor(n.request); |
| n.requested = false; |
| } else { |
| if (VDBG) log(" done"); |
| } |
| } |
| |
| private void evalRequests() { |
| for (int i = 0; i < mNetworkRequests.size(); i++) { |
| NetworkRequestInfo n = mNetworkRequests.valueAt(i); |
| |
| evalRequest(n); |
| } |
| } |
| |
| /** |
| * Post a command, on this NetworkFactory Handler, to re-evaluate all |
| * oustanding requests. Can be called from a factory implementation. |
| */ |
| protected void reevaluateAllRequests() { |
| post(() -> { |
| evalRequests(); |
| }); |
| } |
| |
| // override to do simple mode (request independent) |
| protected void startNetwork() { } |
| protected void stopNetwork() { } |
| |
| // override to do fancier stuff |
| protected void needNetworkFor(NetworkRequest networkRequest, int score) { |
| if (++mRefCount == 1) startNetwork(); |
| } |
| |
| protected void releaseNetworkFor(NetworkRequest networkRequest) { |
| if (--mRefCount == 0) stopNetwork(); |
| } |
| |
| |
| public void addNetworkRequest(NetworkRequest networkRequest, int score) { |
| sendMessage(obtainMessage(CMD_REQUEST_NETWORK, |
| new NetworkRequestInfo(networkRequest, score))); |
| } |
| |
| public void removeNetworkRequest(NetworkRequest networkRequest) { |
| sendMessage(obtainMessage(CMD_CANCEL_REQUEST, networkRequest)); |
| } |
| |
| @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023) |
| public void setScoreFilter(int score) { |
| sendMessage(obtainMessage(CMD_SET_SCORE, score, 0)); |
| } |
| |
| public void setCapabilityFilter(NetworkCapabilities netCap) { |
| sendMessage(obtainMessage(CMD_SET_FILTER, new NetworkCapabilities(netCap))); |
| } |
| |
| @VisibleForTesting |
| protected int getRequestCount() { |
| return mNetworkRequests.size(); |
| } |
| |
| protected void log(String s) { |
| Log.d(LOG_TAG, s); |
| } |
| |
| @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023) |
| public void dump(FileDescriptor fd, PrintWriter writer, String[] args) { |
| final IndentingPrintWriter pw = new IndentingPrintWriter(writer, " "); |
| pw.println(toString()); |
| pw.increaseIndent(); |
| for (int i = 0; i < mNetworkRequests.size(); i++) { |
| pw.println(mNetworkRequests.valueAt(i)); |
| } |
| pw.decreaseIndent(); |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder sb = new StringBuilder("{").append(LOG_TAG).append(" - ScoreFilter="). |
| append(mScore).append(", Filter=").append(mCapabilityFilter).append(", requests="). |
| append(mNetworkRequests.size()).append(", refCount=").append(mRefCount). |
| append("}"); |
| return sb.toString(); |
| } |
| } |