[NS09] Implement the new ranking code
At this stage, this is turned off. Unit tests will be
in a followup change.
Test: In a followup
Bug: 167544279
Merged-In: I3c2563d4ae4e3715d0c6270344ba8f7ef067872f
Merged-In: I4448a3546fbc1a3dddf757982c031c5f39ba2889
Change-Id: I4448a3546fbc1a3dddf757982c031c5f39ba2889
(cherry-picked from ag/14010222 with fixes)
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 5af6d7c..a16db11 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -7901,7 +7901,7 @@
NetworkAgentInfo bestNetwork = null;
NetworkRequest bestRequest = null;
for (final NetworkRequest req : nri.mRequests) {
- bestNetwork = mNetworkRanker.getBestNetwork(req, nais);
+ bestNetwork = mNetworkRanker.getBestNetwork(req, nais, nri.getSatisfier());
// Stop evaluating as the highest possible priority request is satisfied.
if (null != bestNetwork) {
bestRequest = req;
@@ -8154,7 +8154,6 @@
@NonNull final NetworkOffer offer, @NonNull final NetworkRanker networkRanker) {
final NetworkRequest activeRequest = nri.isBeingSatisfied() ? nri.getActiveRequest() : null;
final NetworkAgentInfo satisfier = null != activeRequest ? nri.getSatisfier() : null;
- final FullScore satisfierScore = null != satisfier ? satisfier.getScore() : null;
// Multi-layer requests have a currently active request, the one being satisfied.
// Since the system will try to bring up a better network than is currently satisfying
@@ -8193,7 +8192,7 @@
&& satisfier.factorySerialNumber == offer.providerId;
final boolean newNeeded = (currentlyServing
|| (activeRequest.canBeSatisfiedBy(offer.caps)
- && networkRanker.mightBeat(activeRequest, satisfierScore, offer)));
+ && networkRanker.mightBeat(activeRequest, satisfier, offer)));
if (newNeeded != oldNeeded) {
if (newNeeded) {
offer.onNetworkNeeded(activeRequest);
diff --git a/service/src/com/android/server/connectivity/ConnectivityConstants.java b/service/src/com/android/server/connectivity/ConnectivityConstants.java
deleted file mode 100644
index 325a2cd..0000000
--- a/service/src/com/android/server/connectivity/ConnectivityConstants.java
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * Copyright (C) 2018 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;
-
-/**
- * A class encapsulating various constants used by Connectivity.
- * TODO : remove this class.
- * @hide
- */
-public class ConnectivityConstants {
- // VPNs typically have priority over other networks. Give them a score that will
- // let them win every single time.
- public static final int VPN_DEFAULT_SCORE = 101;
-}
diff --git a/service/src/com/android/server/connectivity/FullScore.java b/service/src/com/android/server/connectivity/FullScore.java
index 117253f..6e38e2d 100644
--- a/service/src/com/android/server/connectivity/FullScore.java
+++ b/service/src/com/android/server/connectivity/FullScore.java
@@ -193,14 +193,14 @@
// telephony factory, so that it depends on the carrier. For now this is handled by
// connectivity for backward compatibility.
public FullScore mixInScore(@NonNull final NetworkCapabilities caps,
- @NonNull final NetworkAgentConfig config, final boolean avoidBadWiFi) {
+ @NonNull final NetworkAgentConfig config, final boolean yieldToBadWifi) {
return withPolicies(mLegacyInt, mPolicies, mKeepConnectedReason,
caps.hasCapability(NET_CAPABILITY_VALIDATED),
caps.hasTransport(TRANSPORT_VPN),
caps.hasCapability(NET_CAPABILITY_NOT_METERED),
config.explicitlySelected,
config.acceptUnvalidated,
- avoidBadWiFi);
+ yieldToBadWifi);
}
// TODO : this shouldn't manage bad wifi avoidance – instead this should be done by the
diff --git a/service/src/com/android/server/connectivity/NetworkAgentInfo.java b/service/src/com/android/server/connectivity/NetworkAgentInfo.java
index 3902573..5d793fd 100644
--- a/service/src/com/android/server/connectivity/NetworkAgentInfo.java
+++ b/service/src/com/android/server/connectivity/NetworkAgentInfo.java
@@ -143,7 +143,7 @@
// the network is no longer considered "lingering". After the linger timer expires, if the network
// is satisfying one or more background NetworkRequests it is kept up in the background. If it is
// not, ConnectivityService disconnects the NetworkAgent's AsyncChannel.
-public class NetworkAgentInfo implements Comparable<NetworkAgentInfo> {
+public class NetworkAgentInfo implements Comparable<NetworkAgentInfo>, NetworkRanker.Scoreable {
@NonNull public NetworkInfo networkInfo;
// This Network object should always be used if possible, so as to encourage reuse of the
@@ -890,7 +890,15 @@
return isVPN();
}
- public FullScore getScore() {
+ // Caller must not mutate. This method is called frequently and making a defensive copy
+ // would be too expensive. This is used by NetworkRanker.Scoreable, so it can be compared
+ // against other scoreables.
+ @Override public NetworkCapabilities getCaps() {
+ return networkCapabilities;
+ }
+
+ // NetworkRanker.Scoreable
+ @Override public FullScore getScore() {
return mScore;
}
diff --git a/service/src/com/android/server/connectivity/NetworkOffer.java b/service/src/com/android/server/connectivity/NetworkOffer.java
index a0d3924..5336593 100644
--- a/service/src/com/android/server/connectivity/NetworkOffer.java
+++ b/service/src/com/android/server/connectivity/NetworkOffer.java
@@ -40,7 +40,7 @@
*
* @hide
*/
-public class NetworkOffer {
+public class NetworkOffer implements NetworkRanker.Scoreable {
@NonNull public final FullScore score;
@NonNull public final NetworkCapabilities caps;
@NonNull public final INetworkOfferCallback callback;
@@ -67,6 +67,20 @@
}
/**
+ * Get the score filter of this offer
+ */
+ @Override @NonNull public FullScore getScore() {
+ return score;
+ }
+
+ /**
+ * Get the capabilities filter of this offer
+ */
+ @Override @NonNull public NetworkCapabilities getCaps() {
+ return caps;
+ }
+
+ /**
* Tell the provider for this offer that the network is needed for a request.
* @param request the request for which the offer is needed
*/
diff --git a/service/src/com/android/server/connectivity/NetworkRanker.java b/service/src/com/android/server/connectivity/NetworkRanker.java
index 0e4dda2..698744a 100644
--- a/service/src/com/android/server/connectivity/NetworkRanker.java
+++ b/service/src/com/android/server/connectivity/NetworkRanker.java
@@ -16,31 +16,223 @@
package com.android.server.connectivity;
+import static android.net.NetworkCapabilities.TRANSPORT_BLUETOOTH;
+import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
+import static android.net.NetworkCapabilities.TRANSPORT_ETHERNET;
+import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
+import static android.net.NetworkScore.POLICY_EXITING;
+import static android.net.NetworkScore.POLICY_TRANSPORT_PRIMARY;
+import static android.net.NetworkScore.POLICY_YIELD_TO_BAD_WIFI;
+
+import static com.android.server.connectivity.FullScore.POLICY_ACCEPT_UNVALIDATED;
+import static com.android.server.connectivity.FullScore.POLICY_EVER_USER_SELECTED;
+import static com.android.server.connectivity.FullScore.POLICY_IS_VALIDATED;
+import static com.android.server.connectivity.FullScore.POLICY_IS_VPN;
+
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.net.NetworkCapabilities;
import android.net.NetworkRequest;
+import com.android.net.module.util.CollectionUtils;
+
+import java.util.ArrayList;
+import java.util.Arrays;
import java.util.Collection;
+import java.util.List;
+import java.util.function.Predicate;
/**
* A class that knows how to find the best network matching a request out of a list of networks.
*/
public class NetworkRanker {
+ /**
+ * A class that can be scored against other scoreables.
+ */
+ public interface Scoreable {
+ /** Get score of this scoreable */
+ FullScore getScore();
+ /** Get capabilities of this scoreable */
+ NetworkCapabilities getCaps();
+ }
+
+ private static final boolean USE_POLICY_RANKING = false;
+
public NetworkRanker() { }
+ // TODO : move to module utils CollectionUtils.
+ @NonNull private static <T> ArrayList<T> filter(@NonNull final Collection<T> source,
+ @NonNull final Predicate<T> test) {
+ final ArrayList<T> matches = new ArrayList<>();
+ for (final T e : source) {
+ if (test.test(e)) {
+ matches.add(e);
+ }
+ }
+ return matches;
+ }
+
+
/**
* Find the best network satisfying this request among the list of passed networks.
*/
- // Almost equivalent to Collections.max(nais), but allows returning null if no network
- // satisfies the request.
@Nullable
public NetworkAgentInfo getBestNetwork(@NonNull final NetworkRequest request,
+ @NonNull final Collection<NetworkAgentInfo> nais,
+ @Nullable final NetworkAgentInfo currentSatisfier) {
+ final ArrayList<NetworkAgentInfo> candidates = filter(nais, nai -> nai.satisfies(request));
+ if (candidates.size() == 1) return candidates.get(0); // Only one potential satisfier
+ if (candidates.size() <= 0) return null; // No network can satisfy this request
+ if (USE_POLICY_RANKING) {
+ return getBestNetworkByPolicy(candidates, currentSatisfier);
+ } else {
+ return getBestNetworkByLegacyInt(candidates);
+ }
+ }
+
+ // Transport preference order, if it comes down to that.
+ private static final int[] PREFERRED_TRANSPORTS_ORDER = { TRANSPORT_ETHERNET, TRANSPORT_WIFI,
+ TRANSPORT_BLUETOOTH, TRANSPORT_CELLULAR };
+
+ // Function used to partition a list into two working areas depending on whether they
+ // satisfy a predicate. All items satisfying the predicate will be put in |positive|, all
+ // items that don't will be put in |negative|.
+ // This is useful in this file because many of the ranking checks will retain only networks that
+ // satisfy a predicate if any of them do, but keep them all if all of them do. Having working
+ // areas is uncustomary in Java, but this function is called in a fairly intensive manner
+ // and doing allocation quite that often might affect performance quite badly.
+ private static <T> void partitionInto(@NonNull final List<T> source, @NonNull Predicate<T> test,
+ @NonNull final List<T> positive, @NonNull final List<T> negative) {
+ positive.clear();
+ negative.clear();
+ for (final T item : source) {
+ if (test.test(item)) {
+ positive.add(item);
+ } else {
+ negative.add(item);
+ }
+ }
+ }
+
+ @Nullable private <T extends Scoreable> T getBestNetworkByPolicy(
+ @NonNull List<T> candidates,
+ @Nullable final T currentSatisfier) {
+ // Used as working areas.
+ final ArrayList<T> accepted =
+ new ArrayList<>(candidates.size() /* initialCapacity */);
+ final ArrayList<T> rejected =
+ new ArrayList<>(candidates.size() /* initialCapacity */);
+
+ // The following tests will search for a network matching a given criterion. They all
+ // function the same way : if any network matches the criterion, drop from consideration
+ // all networks that don't. To achieve this, the tests below :
+ // 1. partition the list of remaining candidates into accepted and rejected networks.
+ // 2. if only one candidate remains, that's the winner : if accepted.size == 1 return [0]
+ // 3. if multiple remain, keep only the accepted networks and go on to the next criterion.
+ // Because the working areas will be wiped, a copy of the accepted networks needs to be
+ // made.
+ // 4. if none remain, the criterion did not help discriminate so keep them all. As an
+ // optimization, skip creating a new array and go on to the next criterion.
+
+ // If there is a connected VPN, use it.
+ partitionInto(candidates, nai -> nai.getScore().hasPolicy(POLICY_IS_VPN),
+ accepted, rejected);
+ if (accepted.size() == 1) return accepted.get(0);
+ if (accepted.size() > 0 && rejected.size() > 0) candidates = new ArrayList<>(accepted);
+
+ // Selected & Accept-unvalidated policy : if any network has both of these, then don't
+ // choose one that doesn't.
+ partitionInto(candidates, nai -> nai.getScore().hasPolicy(POLICY_EVER_USER_SELECTED)
+ && nai.getScore().hasPolicy(POLICY_ACCEPT_UNVALIDATED),
+ accepted, rejected);
+ if (accepted.size() == 1) return accepted.get(0);
+ if (accepted.size() > 0 && rejected.size() > 0) candidates = new ArrayList<>(accepted);
+
+ // Yield to bad wifi policy : if any wifi has ever been validated, keep only networks
+ // that don't yield to such a wifi network.
+ final boolean anyWiFiEverValidated = CollectionUtils.any(candidates,
+ nai -> nai.getScore().hasPolicy(POLICY_EVER_USER_SELECTED)
+ && nai.getCaps().hasTransport(TRANSPORT_WIFI));
+ if (anyWiFiEverValidated) {
+ partitionInto(candidates, nai -> !nai.getScore().hasPolicy(POLICY_YIELD_TO_BAD_WIFI),
+ accepted, rejected);
+ if (accepted.size() == 1) return accepted.get(0);
+ if (accepted.size() > 0 && rejected.size() > 0) candidates = new ArrayList<>(accepted);
+ }
+
+ // If any network is validated (or should be accepted even if it's not validated), then
+ // don't choose one that isn't.
+ partitionInto(candidates, nai -> nai.getScore().hasPolicy(POLICY_IS_VALIDATED)
+ || nai.getScore().hasPolicy(POLICY_ACCEPT_UNVALIDATED),
+ accepted, rejected);
+ if (accepted.size() == 1) return accepted.get(0);
+ if (accepted.size() > 0 && rejected.size() > 0) candidates = new ArrayList<>(accepted);
+
+ // If any network is not exiting, don't choose one that is.
+ partitionInto(candidates, nai -> !nai.getScore().hasPolicy(POLICY_EXITING),
+ accepted, rejected);
+ if (accepted.size() == 1) return accepted.get(0);
+ if (accepted.size() > 0 && rejected.size() > 0) candidates = new ArrayList<>(accepted);
+
+ // TODO : If any network is unmetered, don't choose a metered network.
+ // This can't be implemented immediately because prospective networks are always
+ // considered unmetered because factories don't know if the network will be metered.
+ // Saying an unmetered network always beats a metered one would mean that when metered wifi
+ // is connected, the offer for telephony would beat WiFi but the actual metered network
+ // would lose, so we'd have an infinite loop where telephony would continually bring up
+ // a network that is immediately torn down.
+ // Fix this by getting the agent to tell connectivity whether the network they will
+ // bring up is metered. Cell knows that in advance, while WiFi has a good estimate and
+ // can revise it if the network later turns out to be metered.
+ // partitionInto(candidates, nai -> nai.getScore().hasPolicy(POLICY_IS_UNMETERED),
+ // accepted, rejected);
+ // if (accepted.size() == 1) return accepted.get(0);
+ // if (accepted.size() > 0 && rejected.size() > 0) candidates = new ArrayList<>(accepted);
+
+ // If any network is for the default subscription, don't choose a network for another
+ // subscription with the same transport.
+ partitionInto(candidates, nai -> nai.getScore().hasPolicy(POLICY_TRANSPORT_PRIMARY),
+ accepted, rejected);
+ for (final Scoreable defaultSubNai : accepted) {
+ // Remove all networks without the DEFAULT_SUBSCRIPTION policy and the same transports
+ // as a network that has it.
+ final int[] transports = defaultSubNai.getCaps().getTransportTypes();
+ candidates.removeIf(nai -> !nai.getScore().hasPolicy(POLICY_TRANSPORT_PRIMARY)
+ && Arrays.equals(transports, nai.getCaps().getTransportTypes()));
+ }
+ if (1 == candidates.size()) return candidates.get(0);
+ // It's guaranteed candidates.size() > 0 because there is at least one with DEFAULT_SUB
+ // policy and only those without it were removed.
+
+ // If some of the networks have a better transport than others, keep only the ones with
+ // the best transports.
+ for (final int transport : PREFERRED_TRANSPORTS_ORDER) {
+ partitionInto(candidates, nai -> nai.getCaps().hasTransport(transport),
+ accepted, rejected);
+ if (accepted.size() == 1) return accepted.get(0);
+ if (accepted.size() > 0 && rejected.size() > 0) {
+ candidates = new ArrayList<>(accepted);
+ break;
+ }
+ }
+
+ // At this point there are still multiple networks passing all the tests above. If any
+ // of them is the previous satisfier, keep it.
+ if (candidates.contains(currentSatisfier)) return currentSatisfier;
+
+ // If there are still multiple options at this point but none of them is any of the
+ // transports above, it doesn't matter which is returned. They are all the same.
+ return candidates.get(0);
+ }
+
+ // TODO : switch to the policy implementation and remove
+ // Almost equivalent to Collections.max(nais), but allows returning null if no network
+ // satisfies the request.
+ private NetworkAgentInfo getBestNetworkByLegacyInt(
@NonNull final Collection<NetworkAgentInfo> nais) {
NetworkAgentInfo bestNetwork = null;
int bestScore = Integer.MIN_VALUE;
for (final NetworkAgentInfo nai : nais) {
- if (!nai.satisfies(request)) continue;
if (nai.getCurrentScore() > bestScore) {
bestNetwork = nai;
bestScore = nai.getCurrentScore();
@@ -63,19 +255,37 @@
* beat a current champion.
*
* @param request The request to evaluate against.
- * @param championScore The currently best network for this request.
+ * @param champion The currently best network for this request.
* @param offer The offer.
* @return Whether the offer stands a chance to beat the champion.
*/
public boolean mightBeat(@NonNull final NetworkRequest request,
- @Nullable final FullScore championScore,
+ @Nullable final NetworkAgentInfo champion,
@NonNull final NetworkOffer offer) {
// If this network can't even satisfy the request then it can't beat anything, not
// even an absence of network. It can't satisfy it anyway.
if (!request.canBeSatisfiedBy(offer.caps)) return false;
// If there is no satisfying network, then this network can beat, because some network
// is always better than no network.
- if (null == championScore) return true;
+ if (null == champion) return true;
+ if (USE_POLICY_RANKING) {
+ // If there is no champion, the offer can always beat.
+ // Otherwise rank them.
+ final ArrayList<Scoreable> candidates = new ArrayList<>();
+ candidates.add(champion);
+ candidates.add(offer);
+ return offer == getBestNetworkByPolicy(candidates, champion);
+ } else {
+ return mightBeatByLegacyInt(request, champion.getScore(), offer);
+ }
+ }
+
+ /**
+ * Returns whether an offer might beat a champion according to the legacy int.
+ */
+ public boolean mightBeatByLegacyInt(@NonNull final NetworkRequest request,
+ @Nullable final FullScore championScore,
+ @NonNull final NetworkOffer offer) {
final int offerIntScore;
if (offer.caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)) {
// If the offer might have Internet access, then it might validate.