| /* |
| * 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 com.android.server.connectivity; |
| |
| import static android.net.NetworkCapabilities.NET_CAPABILITY_VALIDATED; |
| |
| import android.content.Context; |
| import android.net.LinkProperties; |
| import android.net.Network; |
| import android.net.NetworkCapabilities; |
| import android.net.NetworkInfo; |
| import android.net.NetworkMisc; |
| import android.net.NetworkRequest; |
| import android.net.NetworkState; |
| import android.os.Handler; |
| import android.os.Messenger; |
| import android.util.SparseArray; |
| |
| import com.android.internal.util.AsyncChannel; |
| import com.android.server.ConnectivityService; |
| import com.android.server.connectivity.NetworkMonitor; |
| |
| import java.util.ArrayList; |
| import java.util.Comparator; |
| |
| /** |
| * A bag class used by ConnectivityService for holding a collection of most recent |
| * information published by a particular NetworkAgent as well as the |
| * AsyncChannel/messenger for reaching that NetworkAgent and lists of NetworkRequests |
| * interested in using it. Default sort order is descending by score. |
| */ |
| // States of a network: |
| // -------------------- |
| // 1. registered, uncreated, disconnected, unvalidated |
| // This state is entered when a NetworkFactory registers a NetworkAgent in any state except |
| // the CONNECTED state. |
| // 2. registered, uncreated, connecting, unvalidated |
| // This state is entered when a registered NetworkAgent for a VPN network transitions to the |
| // CONNECTING state (TODO: go through this state for every network, not just VPNs). |
| // ConnectivityService will tell netd to create the network early in order to add extra UID |
| // routing rules referencing the netID. These rules need to be in place before the network is |
| // connected to avoid racing against client apps trying to connect to a half-setup network. |
| // 3. registered, uncreated, connected, unvalidated |
| // This state is entered when a registered NetworkAgent transitions to the CONNECTED state. |
| // ConnectivityService will tell netd to create the network if it was not already created, and |
| // immediately transition to state #4. |
| // 4. registered, created, connected, unvalidated |
| // If this network can satisfy the default NetworkRequest, then NetworkMonitor will |
| // probe for Internet connectivity. |
| // If this network cannot satisfy the default NetworkRequest, it will immediately be |
| // transitioned to state #5. |
| // A network may remain in this state if NetworkMonitor fails to find Internet connectivity, |
| // for example: |
| // a. a captive portal is present, or |
| // b. a WiFi router whose Internet backhaul is down, or |
| // c. a wireless connection stops transfering packets temporarily (e.g. device is in elevator |
| // or tunnel) but does not disconnect from the AP/cell tower, or |
| // d. a stand-alone device offering a WiFi AP without an uplink for configuration purposes. |
| // 5. registered, created, connected, validated |
| // |
| // The device's default network connection: |
| // ---------------------------------------- |
| // Networks in states #4 and #5 may be used as a device's default network connection if they |
| // satisfy the default NetworkRequest. |
| // A network, that satisfies the default NetworkRequest, in state #5 should always be chosen |
| // in favor of a network, that satisfies the default NetworkRequest, in state #4. |
| // When deciding between two networks, that both satisfy the default NetworkRequest, to select |
| // for the default network connection, the one with the higher score should be chosen. |
| // |
| // When a network disconnects: |
| // --------------------------- |
| // If a network's transport disappears, for example: |
| // a. WiFi turned off, or |
| // b. cellular data turned off, or |
| // c. airplane mode is turned on, or |
| // d. a wireless connection disconnects from AP/cell tower entirely (e.g. device is out of range |
| // of AP for an extended period of time, or switches to another AP without roaming) |
| // then that network can transition from any state (#1-#5) to unregistered. This happens by |
| // the transport disconnecting their NetworkAgent's AsyncChannel with ConnectivityManager. |
| // ConnectivityService also tells netd to destroy the network. |
| // |
| // When ConnectivityService disconnects a network: |
| // ----------------------------------------------- |
| // If a network has no chance of satisfying any requests (even if it were to become validated |
| // and enter state #5), ConnectivityService will disconnect the NetworkAgent's AsyncChannel. |
| // If the network ever for any period of time had satisfied a NetworkRequest (i.e. had been |
| // the highest scoring that satisfied the NetworkRequest's constraints), but is no longer the |
| // highest scoring network for any NetworkRequest, then there will be a 30s pause before |
| // ConnectivityService disconnects the NetworkAgent's AsyncChannel. During this pause the |
| // network is considered "lingering". This pause exists to allow network communication to be |
| // wrapped up rather than abruptly terminated. During this pause if the network begins satisfying |
| // a NetworkRequest, ConnectivityService will cancel the future disconnection of the NetworkAgent's |
| // AsyncChannel, and the network is no longer considered "lingering". |
| public class NetworkAgentInfo implements Comparable<NetworkAgentInfo> { |
| public NetworkInfo networkInfo; |
| // This Network object should always be used if possible, so as to encourage reuse of the |
| // enclosed socket factory and connection pool. Avoid creating other Network objects. |
| // This Network object is always valid. |
| public final Network network; |
| public LinkProperties linkProperties; |
| // This should only be modified via ConnectivityService.updateCapabilities(). |
| public NetworkCapabilities networkCapabilities; |
| public final NetworkMonitor networkMonitor; |
| public final NetworkMisc networkMisc; |
| // Indicates if netd has been told to create this Network. From this point on the appropriate |
| // routing rules are setup and routes are added so packets can begin flowing over the Network. |
| // This is a sticky bit; once set it is never cleared. |
| public boolean created; |
| // Set to true after the first time this network is marked as CONNECTED. Once set, the network |
| // shows up in API calls, is able to satisfy NetworkRequests and can become the default network. |
| // This is a sticky bit; once set it is never cleared. |
| public boolean everConnected; |
| // Set to true if this Network successfully passed validation or if it did not satisfy the |
| // default NetworkRequest in which case validation will not be attempted. |
| // This is a sticky bit; once set it is never cleared even if future validation attempts fail. |
| public boolean everValidated; |
| |
| // The result of the last validation attempt on this network (true if validated, false if not). |
| // This bit exists only because we never unvalidate a network once it's been validated, and that |
| // is because the network scoring and revalidation code does not (may not?) deal properly with |
| // networks becoming unvalidated. |
| // TODO: Fix the network scoring code, remove this, and rename everValidated to validated. |
| public boolean lastValidated; |
| |
| // Whether a captive portal was ever detected on this network. |
| // This is a sticky bit; once set it is never cleared. |
| public boolean everCaptivePortalDetected; |
| |
| // Whether a captive portal was found during the last network validation attempt. |
| public boolean lastCaptivePortalDetected; |
| |
| // Indicates whether the network is lingering. Networks are lingered when they become unneeded |
| // as a result of their NetworkRequests being satisfied by a different network, so as to allow |
| // communication to wrap up before the network is taken down. This usually only happens to the |
| // default network. Lingering ends with either the linger timeout expiring and the network |
| // being taken down, or the network satisfying a request again. |
| public boolean lingering; |
| |
| // This represents the last score received from the NetworkAgent. |
| private int currentScore; |
| // Penalty applied to scores of Networks that have not been validated. |
| private static final int UNVALIDATED_SCORE_PENALTY = 40; |
| |
| // Score for explicitly connected network. |
| // |
| // This ensures that a) the explicitly selected network is never trumped by anything else, and |
| // b) the explicitly selected network is never torn down. |
| private static final int MAXIMUM_NETWORK_SCORE = 100; |
| |
| // The list of NetworkRequests being satisfied by this Network. |
| private final SparseArray<NetworkRequest> mNetworkRequests = new SparseArray<>(); |
| // The list of NetworkRequests that this Network previously satisfied with the highest |
| // score. A non-empty list indicates that if this Network was validated it is lingered. |
| // NOTE: This list is only used for debugging. |
| public final ArrayList<NetworkRequest> networkLingered = new ArrayList<NetworkRequest>(); |
| // How many of the satisfied requests are actual requests and not listens. |
| private int mNumRequestNetworkRequests = 0; |
| |
| public final Messenger messenger; |
| public final AsyncChannel asyncChannel; |
| |
| // Used by ConnectivityService to keep track of 464xlat. |
| public Nat464Xlat clatd; |
| |
| public NetworkAgentInfo(Messenger messenger, AsyncChannel ac, Network net, NetworkInfo info, |
| LinkProperties lp, NetworkCapabilities nc, int score, Context context, Handler handler, |
| NetworkMisc misc, NetworkRequest defaultRequest, ConnectivityService connService) { |
| this.messenger = messenger; |
| asyncChannel = ac; |
| network = net; |
| networkInfo = info; |
| linkProperties = lp; |
| networkCapabilities = nc; |
| currentScore = score; |
| networkMonitor = connService.createNetworkMonitor(context, handler, this, defaultRequest); |
| networkMisc = misc; |
| } |
| |
| // Functions for manipulating the requests satisfied by this network. |
| // |
| // These functions must only called on ConnectivityService's main thread. |
| |
| /** |
| * Add {@code networkRequest} to this network as it's satisfied by this network. |
| * @return true if {@code networkRequest} was added or false if {@code networkRequest} was |
| * already present. |
| */ |
| public boolean addRequest(NetworkRequest networkRequest) { |
| NetworkRequest existing = mNetworkRequests.get(networkRequest.requestId); |
| if (existing == networkRequest) return false; |
| if (existing != null && existing.isRequest()) mNumRequestNetworkRequests--; |
| mNetworkRequests.put(networkRequest.requestId, networkRequest); |
| if (networkRequest.isRequest()) mNumRequestNetworkRequests++; |
| return true; |
| } |
| |
| /** |
| * Remove the specified request from this network. |
| */ |
| public void removeRequest(int requestId) { |
| NetworkRequest existing = mNetworkRequests.get(requestId); |
| if (existing != null && existing.isRequest()) mNumRequestNetworkRequests--; |
| mNetworkRequests.remove(requestId); |
| } |
| |
| /** |
| * Returns whether this network is currently satisfying the request with the specified ID. |
| */ |
| public boolean isSatisfyingRequest(int id) { |
| return mNetworkRequests.get(id) != null; |
| } |
| |
| /** |
| * Returns the request at the specified position in the list of requests satisfied by this |
| * network. |
| */ |
| public NetworkRequest requestAt(int index) { |
| return mNetworkRequests.valueAt(index); |
| } |
| |
| /** |
| * Returns the number of requests currently satisfied by this network for which |
| * {@link android.net.NetworkRequest#isRequest} returns {@code true}. |
| */ |
| public int numRequestNetworkRequests() { |
| return mNumRequestNetworkRequests; |
| } |
| |
| /** |
| * Returns the number of requests of any type currently satisfied by this network. |
| */ |
| public int numNetworkRequests() { |
| return mNetworkRequests.size(); |
| } |
| |
| // Does this network satisfy request? |
| public boolean satisfies(NetworkRequest request) { |
| return created && |
| request.networkCapabilities.satisfiedByNetworkCapabilities(networkCapabilities); |
| } |
| |
| public boolean satisfiesImmutableCapabilitiesOf(NetworkRequest request) { |
| return created && |
| request.networkCapabilities.satisfiedByImmutableNetworkCapabilities( |
| networkCapabilities); |
| } |
| |
| public boolean isVPN() { |
| return networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_VPN); |
| } |
| |
| private int getCurrentScore(boolean pretendValidated) { |
| // TODO: We may want to refactor this into a NetworkScore class that takes a base score from |
| // the NetworkAgent and signals from the NetworkAgent and uses those signals to modify the |
| // score. The NetworkScore class would provide a nice place to centralize score constants |
| // so they are not scattered about the transports. |
| |
| // If this network is explicitly selected and the user has decided to use it even if it's |
| // unvalidated, give it the maximum score. Also give it the maximum score if it's explicitly |
| // selected and we're trying to see what its score could be. This ensures that we don't tear |
| // down an explicitly selected network before the user gets a chance to prefer it when |
| // a higher-scoring network (e.g., Ethernet) is available. |
| if (networkMisc.explicitlySelected && (networkMisc.acceptUnvalidated || pretendValidated)) { |
| return MAXIMUM_NETWORK_SCORE; |
| } |
| |
| int score = currentScore; |
| // Use NET_CAPABILITY_VALIDATED here instead of lastValidated, this allows |
| // ConnectivityService.updateCapabilities() to compute the old score prior to updating |
| // networkCapabilities (with a potentially different validated state). |
| if (!networkCapabilities.hasCapability(NET_CAPABILITY_VALIDATED) && !pretendValidated) { |
| score -= UNVALIDATED_SCORE_PENALTY; |
| } |
| if (score < 0) score = 0; |
| return score; |
| } |
| |
| // Get the current score for this Network. This may be modified from what the |
| // NetworkAgent sent, as it has modifiers applied to it. |
| public int getCurrentScore() { |
| return getCurrentScore(false); |
| } |
| |
| // Get the current score for this Network as if it was validated. This may be modified from |
| // what the NetworkAgent sent, as it has modifiers applied to it. |
| public int getCurrentScoreAsValidated() { |
| return getCurrentScore(true); |
| } |
| |
| public void setCurrentScore(int newScore) { |
| currentScore = newScore; |
| } |
| |
| public NetworkState getNetworkState() { |
| synchronized (this) { |
| // Network objects are outwardly immutable so there is no point to duplicating. |
| // Duplicating also precludes sharing socket factories and connection pools. |
| final String subscriberId = (networkMisc != null) ? networkMisc.subscriberId : null; |
| return new NetworkState(new NetworkInfo(networkInfo), |
| new LinkProperties(linkProperties), |
| new NetworkCapabilities(networkCapabilities), network, subscriberId, null); |
| } |
| } |
| |
| public String toString() { |
| return "NetworkAgentInfo{ ni{" + networkInfo + "} " + |
| "network{" + network + "} nethandle{" + network.getNetworkHandle() + "} " + |
| "lp{" + linkProperties + "} " + |
| "nc{" + networkCapabilities + "} Score{" + getCurrentScore() + "} " + |
| "everValidated{" + everValidated + "} lastValidated{" + lastValidated + "} " + |
| "created{" + created + "} lingering{" + lingering + "} " + |
| "explicitlySelected{" + networkMisc.explicitlySelected + "} " + |
| "acceptUnvalidated{" + networkMisc.acceptUnvalidated + "} " + |
| "everCaptivePortalDetected{" + everCaptivePortalDetected + "} " + |
| "lastCaptivePortalDetected{" + lastCaptivePortalDetected + "} " + |
| "}"; |
| } |
| |
| public String name() { |
| return "NetworkAgentInfo [" + networkInfo.getTypeName() + " (" + |
| networkInfo.getSubtypeName() + ") - " + |
| (network == null ? "null" : network.toString()) + "]"; |
| } |
| |
| // Enables sorting in descending order of score. |
| @Override |
| public int compareTo(NetworkAgentInfo other) { |
| return other.getCurrentScore() - getCurrentScore(); |
| } |
| } |