Merge changes I975a9439,Idec1fe8e into sc-dev
* changes:
[NS04.5] Have NetworkOffer embark a provider ID
[NS04] Introduce Network Offers and their callbacks
diff --git a/framework/src/android/net/ConnectivityManager.java b/framework/src/android/net/ConnectivityManager.java
index 20ff93f..8c93676 100644
--- a/framework/src/android/net/ConnectivityManager.java
+++ b/framework/src/android/net/ConnectivityManager.java
@@ -3234,7 +3234,60 @@
provider.setProviderId(NetworkProvider.ID_NONE);
}
+ /**
+ * Register or update a network offer with ConnectivityService.
+ *
+ * ConnectivityService keeps track of offers made by the various providers and matches
+ * them to networking requests made by apps or the system. The provider supplies a score
+ * and the capabilities of the network it might be able to bring up ; these act as filters
+ * used by ConnectivityService to only send those requests that can be fulfilled by the
+ * provider.
+ *
+ * The provider is under no obligation to be able to bring up the network it offers at any
+ * given time. Instead, this mechanism is meant to limit requests received by providers
+ * to those they actually have a chance to fulfill, as providers don't have a way to compare
+ * the quality of the network satisfying a given request to their own offer.
+ *
+ * An offer can be updated by calling this again with the same callback object. This is
+ * similar to calling unofferNetwork and offerNetwork again, but will only update the
+ * provider with the changes caused by the changes in the offer.
+ *
+ * @param provider The provider making this offer.
+ * @param score The prospective score of the network.
+ * @param caps The prospective capabilities of the network.
+ * @param callback The callback to call when this offer is needed or unneeded.
+ * @hide
+ */
+ @RequiresPermission(anyOf = {
+ NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
+ android.Manifest.permission.NETWORK_FACTORY})
+ public void offerNetwork(@NonNull final int providerId,
+ @NonNull final NetworkScore score, @NonNull final NetworkCapabilities caps,
+ @NonNull final INetworkOfferCallback callback) {
+ try {
+ mService.offerNetwork(providerId,
+ Objects.requireNonNull(score, "null score"),
+ Objects.requireNonNull(caps, "null caps"),
+ Objects.requireNonNull(callback, "null callback"));
+ } catch (RemoteException e) {
+ throw e.rethrowFromSystemServer();
+ }
+ }
+ /**
+ * Withdraw a network offer made with {@link #offerNetwork}.
+ *
+ * @param callback The callback passed at registration time. This must be the same object
+ * that was passed to {@link #offerNetwork}
+ * @hide
+ */
+ public void unofferNetwork(@NonNull final INetworkOfferCallback callback) {
+ try {
+ mService.unofferNetwork(Objects.requireNonNull(callback));
+ } catch (RemoteException e) {
+ throw e.rethrowFromSystemServer();
+ }
+ }
/** @hide exposed via the NetworkProvider class. */
@RequiresPermission(anyOf = {
NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
diff --git a/framework/src/android/net/IConnectivityManager.aidl b/framework/src/android/net/IConnectivityManager.aidl
index 0826922..728f375 100644
--- a/framework/src/android/net/IConnectivityManager.aidl
+++ b/framework/src/android/net/IConnectivityManager.aidl
@@ -23,6 +23,7 @@
import android.net.INetworkAgent;
import android.net.IOnCompleteListener;
import android.net.INetworkActivityListener;
+import android.net.INetworkOfferCallback;
import android.net.IQosCallback;
import android.net.ISocketKeepaliveCallback;
import android.net.LinkProperties;
@@ -221,4 +222,8 @@
in IOnCompleteListener listener);
int getRestrictBackgroundStatusByCaller();
+
+ void offerNetwork(int providerId, in NetworkScore score,
+ in NetworkCapabilities caps, in INetworkOfferCallback callback);
+ void unofferNetwork(in INetworkOfferCallback callback);
}
diff --git a/framework/src/android/net/INetworkOfferCallback.aidl b/framework/src/android/net/INetworkOfferCallback.aidl
new file mode 100644
index 0000000..67d2d40
--- /dev/null
+++ b/framework/src/android/net/INetworkOfferCallback.aidl
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2021 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.net.NetworkRequest;
+
+/**
+ * A callback registered with connectivity by network providers together with
+ * a NetworkOffer.
+ *
+ * When the offer is needed to satisfy some application or system component,
+ * connectivity will call onOfferNeeded on this callback. When this happens,
+ * the provider should try and bring up the network.
+ *
+ * When the offer is no longer needed, for example because the application has
+ * withdrawn the request or if the request is being satisfied by a network
+ * that this offer will never be able to beat, connectivity calls
+ * onOfferUnneeded. When this happens, the provider should stop trying to
+ * bring up the network, or tear it down if it has already been brought up.
+ *
+ * When NetworkProvider#offerNetwork is called, the provider can expect to
+ * immediately receive all requests that can be fulfilled by that offer and
+ * are not already satisfied by a better network. It is possible no such
+ * request is currently outstanding, because no requests have been made that
+ * can be satisfied by this offer, or because all such requests are already
+ * satisfied by a better network.
+ * onOfferNeeded can be called at any time after registration and until the
+ * offer is withdrawn with NetworkProvider#unofferNetwork is called. This
+ * typically happens when a new network request is filed by an application,
+ * or when the network satisfying a request disconnects and this offer now
+ * stands a chance to be the best network for it.
+ *
+ * @hide
+ */
+oneway interface INetworkOfferCallback {
+ /**
+ * Informs the registrant that the offer is needed to fulfill this request.
+ * @param networkRequest the request to satisfy
+ * @param providerId the ID of the provider currently satisfying
+ * this request, or NetworkProvider.ID_NONE if none.
+ */
+ void onOfferNeeded(in NetworkRequest networkRequest, int providerId);
+
+ /**
+ * Informs the registrant that the offer is no longer needed to fulfill this request.
+ */
+ void onOfferUnneeded(in NetworkRequest networkRequest);
+}
diff --git a/framework/src/android/net/NetworkProvider.java b/framework/src/android/net/NetworkProvider.java
index 14cb51c..d5b5c9b 100644
--- a/framework/src/android/net/NetworkProvider.java
+++ b/framework/src/android/net/NetworkProvider.java
@@ -28,6 +28,11 @@
import android.os.Messenger;
import android.util.Log;
+import com.android.internal.annotations.GuardedBy;
+
+import java.util.ArrayList;
+import java.util.concurrent.Executor;
+
/**
* Base class for network providers such as telephony or Wi-Fi. NetworkProviders connect the device
* to networks and makes them available to the core network stack by creating
@@ -78,7 +83,9 @@
*/
@SystemApi
public NetworkProvider(@NonNull Context context, @NonNull Looper looper, @NonNull String name) {
- Handler handler = new Handler(looper) {
+ // TODO (b/174636568) : this class should be able to cache an instance of
+ // ConnectivityManager so it doesn't have to fetch it again every time.
+ final Handler handler = new Handler(looper) {
@Override
public void handleMessage(Message m) {
switch (m.what) {
@@ -159,4 +166,152 @@
public void declareNetworkRequestUnfulfillable(@NonNull NetworkRequest request) {
ConnectivityManager.from(mContext).declareNetworkRequestUnfulfillable(request);
}
+
+ /** @hide */
+ // TODO : make @SystemApi when the impl is complete
+ public interface NetworkOfferCallback {
+ /** Called by the system when this offer is needed to satisfy some networking request. */
+ void onOfferNeeded(@NonNull NetworkRequest request, int providerId);
+ /** Called by the system when this offer is no longer needed. */
+ void onOfferUnneeded(@NonNull NetworkRequest request);
+ }
+
+ private class NetworkOfferCallbackProxy extends INetworkOfferCallback.Stub {
+ @NonNull public final NetworkOfferCallback callback;
+ @NonNull private final Executor mExecutor;
+
+ NetworkOfferCallbackProxy(@NonNull final NetworkOfferCallback callback,
+ @NonNull final Executor executor) {
+ this.callback = callback;
+ this.mExecutor = executor;
+ }
+
+ @Override
+ public void onOfferNeeded(final @NonNull NetworkRequest request,
+ final int providerId) {
+ mExecutor.execute(() -> callback.onOfferNeeded(request, providerId));
+ }
+
+ @Override
+ public void onOfferUnneeded(final @NonNull NetworkRequest request) {
+ mExecutor.execute(() -> callback.onOfferUnneeded(request));
+ }
+ }
+
+ @GuardedBy("mProxies")
+ @NonNull private final ArrayList<NetworkOfferCallbackProxy> mProxies = new ArrayList<>();
+
+ // Returns the proxy associated with this callback, or null if none.
+ @Nullable
+ private NetworkOfferCallbackProxy findProxyForCallback(@NonNull final NetworkOfferCallback cb) {
+ synchronized (mProxies) {
+ for (final NetworkOfferCallbackProxy p : mProxies) {
+ if (p.callback == cb) return p;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Register or update an offer for network with the passed caps and score.
+ *
+ * A NetworkProvider's job is to provide networks. This function is how a provider tells the
+ * connectivity stack what kind of network it may provide. The score and caps arguments act
+ * as filters that the connectivity stack uses to tell when the offer is necessary. When an
+ * offer might be advantageous over existing networks, the provider will receive a call to
+ * the associated callback's {@link NetworkOfferCallback#onOfferNeeded} method. The provider
+ * should then try to bring up this network. When an offer is no longer needed, the stack
+ * will inform the provider by calling {@link NetworkOfferCallback#onOfferUnneeded}. The
+ * provider should stop trying to bring up such a network, or disconnect it if it already has
+ * one.
+ *
+ * The stack determines what offers are needed according to what networks are currently
+ * available to the system, and what networking requests are made by applications. If an
+ * offer looks like it could be a better choice than any existing network for any particular
+ * request, that's when the stack decides the offer is needed. If the current networking
+ * requests are all satisfied by networks that this offer can't possibly be a better match
+ * for, that's when the offer is unneeded. An offer starts off as unneeded ; the provider
+ * should not try to bring up the network until {@link NetworkOfferCallback#onOfferNeeded}
+ * is called.
+ *
+ * Note that the offers are non-binding to the providers, in particular because providers
+ * often don't know if they will be able to bring up such a network at any given time. For
+ * example, no wireless network may be in range when the offer is needed. This is fine and
+ * expected ; the provider should simply continue to try to bring up the network and do so
+ * if/when it becomes possible. In the mean time, the stack will continue to satisfy requests
+ * with the best network currently available, or if none, keep the apps informed that no
+ * network can currently satisfy this request. When/if the provider can bring up the network,
+ * the connectivity stack will match it against requests, and inform interested apps of the
+ * availability of this network. This may, in turn, render the offer of some other provider
+ * unneeded if all requests it used to satisfy are now better served by this network.
+ *
+ * A network can become unneeded for a reason like the above : whether the provider managed
+ * to bring up the offered network after it became needed or not, some other provider may
+ * bring up a better network than this one, making this offer unneeded. A network may also
+ * become unneeded if the application making the request withdrew it (for example, after it
+ * is done transferring data, or if the user canceled an operation).
+ *
+ * The capabilities and score act as filters as to what requests the provider will see.
+ * They are not promises, but for best performance, the providers should strive to put
+ * as much known information as possible in the offer. For capabilities in particular, it
+ * should put all NetworkAgent-managed capabilities a network may have, even if it doesn't
+ * have them at first. This applies to INTERNET, for example ; if a provider thinks the
+ * network it can bring up for this offer may offer Internet access it should include the
+ * INTERNET bit. It's fine if the brought up network ends up not actually having INTERNET.
+ *
+ * TODO : in the future, to avoid possible infinite loops, there should be constraints on
+ * what can be put in capabilities of networks brought up for an offer. If a provider might
+ * bring up a network with or without INTERNET, then it should file two offers : this will
+ * let it know precisely what networks are needed, so it can avoid bringing up networks that
+ * won't actually satisfy requests and remove the risk for bring-up-bring-down loops.
+ *
+ * @hide
+ */
+ // TODO : make @SystemApi when the impl is complete
+ @RequiresPermission(android.Manifest.permission.NETWORK_FACTORY)
+ public void offerNetwork(@NonNull final NetworkScore score,
+ @NonNull final NetworkCapabilities caps, @NonNull final Executor executor,
+ @NonNull final NetworkOfferCallback callback) {
+ // Can't offer a network with a provider that is not yet registered or already unregistered.
+ final int providerId = mProviderId;
+ if (providerId == ID_NONE) return;
+ NetworkOfferCallbackProxy proxy = null;
+ synchronized (mProxies) {
+ for (final NetworkOfferCallbackProxy existingProxy : mProxies) {
+ if (existingProxy.callback == callback) {
+ proxy = existingProxy;
+ break;
+ }
+ }
+ if (null == proxy) {
+ proxy = new NetworkOfferCallbackProxy(callback, executor);
+ mProxies.add(proxy);
+ }
+ }
+ mContext.getSystemService(ConnectivityManager.class)
+ .offerNetwork(providerId, score, caps, proxy);
+ }
+
+ /**
+ * Withdraw a network offer previously made to the networking stack.
+ *
+ * If a provider can no longer provide a network they offered, it should call this method.
+ * An example of usage could be if the hardware necessary to bring up the network was turned
+ * off in UI by the user. Note that because offers are never binding, the provider might
+ * alternatively decide not to withdraw this offer and simply refuse to bring up the network
+ * even when it's needed. However, withdrawing the request is slightly more resource-efficient
+ * because the networking stack won't have to compare this offer to exiting networks to see
+ * if it could beat any of them, and may be advantageous to the provider's implementation that
+ * can rely on no longer receiving callbacks for a network that they can't bring up anyways.
+ *
+ * @hide
+ */
+ // TODO : make @SystemApi when the impl is complete
+ @RequiresPermission(android.Manifest.permission.NETWORK_FACTORY)
+ public void unofferNetwork(final @NonNull NetworkOfferCallback callback) {
+ final NetworkOfferCallbackProxy proxy = findProxyForCallback(callback);
+ if (null == proxy) return;
+ mProxies.remove(proxy);
+ mContext.getSystemService(ConnectivityManager.class).unofferNetwork(proxy);
+ }
}