Merge changes from topic "fix_master_build"

* changes:
  Revert "Cherry-pick the relevant parts of master change"
  Revert "Remove providesRoutesToMostDestinations."

core/java/android/net/NetworkUtils.java

@@ -16,19 +16,15 @@
 
 package android.net;
 
-import static android.system.OsConstants.AF_INET;
-import static android.system.OsConstants.AF_INET6;
-
-import android.annotation.NonNull;
 import android.annotation.UnsupportedAppUsage;
 import android.net.shared.Inet4AddressUtils;
 import android.os.Build;
 import android.system.ErrnoException;
-import android.system.Os;
 import android.util.Log;
 import android.util.Pair;
 
 import java.io.FileDescriptor;
+import java.math.BigInteger;
 import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.InetAddress;
@@ -36,6 +32,7 @@ import java.net.SocketException;
 import java.net.UnknownHostException;
 import java.util.Collection;
 import java.util.Locale;
+import java.util.TreeSet;
 
 /**
  * Native methods for managing network interfaces.
@@ -390,29 +387,71 @@ public class NetworkUtils {
         return result;
     }
 
-    private static final int[] ADDRESS_FAMILIES = new int[] {AF_INET, AF_INET6};
+    /**
+     * Returns a prefix set without overlaps.
+     *
+     * This expects the src set to be sorted from shorter to longer. Results are undefined
+     * failing this condition. The returned prefix set is sorted in the same order as the
+     * passed set, with the same comparator.
+     */
+    private static TreeSet<IpPrefix> deduplicatePrefixSet(final TreeSet<IpPrefix> src) {
+        final TreeSet<IpPrefix> dst = new TreeSet<>(src.comparator());
+        // Prefixes match addresses that share their upper part up to their length, therefore
+        // the only kind of possible overlap in two prefixes is strict inclusion of the longer
+        // (more restrictive) in the shorter (including equivalence if they have the same
+        // length).
+        // Because prefixes in the src set are sorted from shorter to longer, deduplicating
+        // is done by simply iterating in order, and not adding any longer prefix that is
+        // already covered by a shorter one.
+        newPrefixes:
+        for (IpPrefix newPrefix : src) {
+            for (IpPrefix existingPrefix : dst) {
+                if (existingPrefix.containsPrefix(newPrefix)) {
+                    continue newPrefixes;
+                }
+            }
+            dst.add(newPrefix);
+        }
+        return dst;
+    }
 
     /**
-     * Returns true if the hostname is weakly validated.
+     * Returns how many IPv4 addresses match any of the prefixes in the passed ordered set.
-     * @param hostname Name of host to validate.
-     * @return True if it's a valid-ish hostname.
      *
-     * @hide
+     * Obviously this returns an integral value between 0 and 2**32.
+     * The behavior is undefined if any of the prefixes is not an IPv4 prefix or if the
+     * set is not ordered smallest prefix to longer prefix.
+     *
+     * @param prefixes the set of prefixes, ordered by length
      */
-    public static boolean isWeaklyValidatedHostname(@NonNull String hostname) {
+    public static long routedIPv4AddressCount(final TreeSet<IpPrefix> prefixes) {
-        // TODO(b/34953048): Use a validation method that permits more accurate,
+        long routedIPCount = 0;
-        // but still inexpensive, checking of likely valid DNS hostnames.
+        for (final IpPrefix prefix : deduplicatePrefixSet(prefixes)) {
-        final String weakHostnameRegex = "^[a-zA-Z0-9_.-]+$";
+            if (!prefix.isIPv4()) {
-        if (!hostname.matches(weakHostnameRegex)) {
+                Log.wtf(TAG, "Non-IPv4 prefix in routedIPv4AddressCount");
-            return false;
-        }
-
-        for (int address_family : ADDRESS_FAMILIES) {
-            if (Os.inet_pton(address_family, hostname) != null) {
-                return false;
             }
+            int rank = 32 - prefix.getPrefixLength();
+            routedIPCount += 1L << rank;
         }
+        return routedIPCount;
+    }
 
-        return true;
+    /**
+     * Returns how many IPv6 addresses match any of the prefixes in the passed ordered set.
+     *
+     * This returns a BigInteger between 0 and 2**128.
+     * The behavior is undefined if any of the prefixes is not an IPv6 prefix or if the
+     * set is not ordered smallest prefix to longer prefix.
+     */
+    public static BigInteger routedIPv6AddressCount(final TreeSet<IpPrefix> prefixes) {
+        BigInteger routedIPCount = BigInteger.ZERO;
+        for (final IpPrefix prefix : deduplicatePrefixSet(prefixes)) {
+            if (!prefix.isIPv6()) {
+                Log.wtf(TAG, "Non-IPv6 prefix in routedIPv6AddressCount");
+            }
+            int rank = 128 - prefix.getPrefixLength();
+            routedIPCount = routedIPCount.add(BigInteger.ONE.shiftLeft(rank));
+        }
+        return routedIPCount;
     }
 }

services/core/java/com/android/server/connectivity/Vpn.java

@@ -58,6 +58,7 @@ import android.net.NetworkFactory;
 import android.net.NetworkInfo;
 import android.net.NetworkInfo.DetailedState;
 import android.net.NetworkMisc;
+import android.net.NetworkUtils;
 import android.net.RouteInfo;
 import android.net.UidRange;
 import android.net.VpnService;
@@ -104,6 +105,7 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.math.BigInteger;
 import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.InetAddress;
@@ -112,6 +114,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Objects;
 import java.util.Set;
@@ -131,6 +134,31 @@ public class Vpn {
     // the device idle whitelist during service launch and VPN bootstrap.
     private static final long VPN_LAUNCH_IDLE_WHITELIST_DURATION_MS = 60 * 1000;
 
+    // Settings for how much of the address space should be routed so that Vpn considers
+    // "most" of the address space is routed. This is used to determine whether this Vpn
+    // should be marked with the INTERNET capability.
+    private static final long MOST_IPV4_ADDRESSES_COUNT;
+    private static final BigInteger MOST_IPV6_ADDRESSES_COUNT;
+    static {
+        // 85% of the address space must be routed for Vpn to consider this VPN to provide
+        // INTERNET access.
+        final int howManyPercentIsMost = 85;
+
+        final long twoPower32 = 1L << 32;
+        MOST_IPV4_ADDRESSES_COUNT = twoPower32 * howManyPercentIsMost / 100;
+        final BigInteger twoPower128 = BigInteger.ONE.shiftLeft(128);
+        MOST_IPV6_ADDRESSES_COUNT = twoPower128
+                .multiply(BigInteger.valueOf(howManyPercentIsMost))
+                .divide(BigInteger.valueOf(100));
+    }
+    // How many routes to evaluate before bailing and declaring this Vpn should provide
+    // the INTERNET capability. This is necessary because computing the address space is
+    // O(n²) and this is running in the system service, so a limit is needed to alleviate
+    // the risk of attack.
+    // This is taken as a total of IPv4 + IPV6 routes for simplicity, but the algorithm
+    // is actually O(n²)+O(n²).
+    private static final int MAX_ROUTES_TO_EVALUATE = 150;
+
     // TODO: create separate trackers for each unique VPN to support
     // automated reconnection
 
@@ -228,7 +256,7 @@ public class Vpn {
     }
 
     /**
-     * Update current state, dispatching event to listeners.
+     * Update current state, dispaching event to listeners.
      */
     @VisibleForTesting
     protected void updateState(DetailedState detailedState, String reason) {
@@ -273,7 +301,7 @@ public class Vpn {
     }
 
     @VisibleForTesting
-    static void applyUnderlyingCapabilities(
+    public static void applyUnderlyingCapabilities(
             ConnectivityManager cm,
             Network[] underlyingNetworks,
             NetworkCapabilities caps,
@@ -387,7 +415,7 @@ public class Vpn {
         PackageManager pm = mContext.getPackageManager();
         ApplicationInfo appInfo = null;
         try {
-            appInfo = pm.getApplicationInfoAsUser(packageName, 0 /* flags */, mUserHandle);
+            appInfo = pm.getApplicationInfoAsUser(packageName, 0 /*flags*/, mUserHandle);
         } catch (NameNotFoundException unused) {
             Log.w(TAG, "Can't find \"" + packageName + "\" when checking always-on support");
         }
@@ -548,7 +576,7 @@ public class Vpn {
             final String alwaysOnPackage = mSystemServices.settingsSecureGetStringForUser(
                     Settings.Secure.ALWAYS_ON_VPN_APP, mUserHandle);
             final boolean alwaysOnLockdown = mSystemServices.settingsSecureGetIntForUser(
-                    Settings.Secure.ALWAYS_ON_VPN_LOCKDOWN, 0 /* default */, mUserHandle) != 0;
+                    Settings.Secure.ALWAYS_ON_VPN_LOCKDOWN, 0 /*default*/, mUserHandle) != 0;
             final String whitelistString = mSystemServices.settingsSecureGetStringForUser(
                     Settings.Secure.ALWAYS_ON_VPN_LOCKDOWN_WHITELIST, mUserHandle);
             final List<String> whitelistedPackages = TextUtils.isEmpty(whitelistString)
@@ -800,7 +828,7 @@ public class Vpn {
         PackageManager pm = mContext.getPackageManager();
         try {
             ApplicationInfo appInfo =
-                    pm.getApplicationInfoAsUser(packageName, 0 /* flags */, mUserHandle);
+                    pm.getApplicationInfoAsUser(packageName, 0 /*flags*/, mUserHandle);
             return appInfo.targetSdkVersion >= VERSION_CODES.Q;
         } catch (NameNotFoundException unused) {
             Log.w(TAG, "Can't find \"" + packageName + "\"");
@@ -873,6 +901,38 @@ public class Vpn {
         return lp;
     }
 
+    /**
+     * Analyzes the passed LinkedProperties to figure out whether it routes to most of the IP space.
+     *
+     * This returns true if the passed LinkedProperties contains routes to either most of the IPv4
+     * space or to most of the IPv6 address space, where "most" is defined by the value of the
+     * MOST_IPV{4,6}_ADDRESSES_COUNT constants : if more than this number of addresses are matched
+     * by any of the routes, then it's decided that most of the space is routed.
+     * @hide
+     */
+    @VisibleForTesting
+    static boolean providesRoutesToMostDestinations(LinkProperties lp) {
+        final List<RouteInfo> routes = lp.getAllRoutes();
+        if (routes.size() > MAX_ROUTES_TO_EVALUATE) return true;
+        final Comparator<IpPrefix> prefixLengthComparator = IpPrefix.lengthComparator();
+        TreeSet<IpPrefix> ipv4Prefixes = new TreeSet<>(prefixLengthComparator);
+        TreeSet<IpPrefix> ipv6Prefixes = new TreeSet<>(prefixLengthComparator);
+        for (final RouteInfo route : routes) {
+            if (route.getType() == RouteInfo.RTN_UNREACHABLE) continue;
+            IpPrefix destination = route.getDestination();
+            if (destination.isIPv4()) {
+                ipv4Prefixes.add(destination);
+            } else {
+                ipv6Prefixes.add(destination);
+            }
+        }
+        if (NetworkUtils.routedIPv4AddressCount(ipv4Prefixes) > MOST_IPV4_ADDRESSES_COUNT) {
+            return true;
+        }
+        return NetworkUtils.routedIPv6AddressCount(ipv6Prefixes)
+                .compareTo(MOST_IPV6_ADDRESSES_COUNT) >= 0;
+    }
+
     /**
      * Attempt to perform a seamless handover of VPNs by only updating LinkProperties without
      * registering a new NetworkAgent. This is not always possible if the new VPN configuration
@@ -1598,8 +1658,8 @@ public class Vpn {
          */
         public PendingIntent pendingIntentGetActivityAsUser(
                 Intent intent, int flags, UserHandle user) {
-            return PendingIntent.getActivityAsUser(mContext, 0 /* request */, intent, flags,
+            return PendingIntent.getActivityAsUser(mContext, 0 /*request*/, intent, flags,
-                    null /* options */, user);
+                    null /*options*/, user);
         }
 
         /**
@@ -1705,7 +1765,7 @@ public class Vpn {
             byte[] value = keyStore.get(Credentials.USER_CERTIFICATE + profile.ipsecServerCert);
             serverCert = (value == null) ? null : new String(value, StandardCharsets.UTF_8);
         }
-        if (userCert == null || caCert == null || serverCert == null) {
+        if (privateKey == null || userCert == null || caCert == null || serverCert == null) {
             throw new IllegalStateException("Cannot load credentials");
         }
 
@@ -1824,7 +1884,7 @@ public class Vpn {
      * Return the information of the current ongoing legacy VPN.
      * Callers are responsible for checking permissions if needed.
      */
-    private synchronized LegacyVpnInfo getLegacyVpnInfoPrivileged() {
+    public synchronized LegacyVpnInfo getLegacyVpnInfoPrivileged() {
         if (mLegacyVpnRunner == null) return null;
 
         final LegacyVpnInfo info = new LegacyVpnInfo();
@@ -1978,6 +2038,7 @@ public class Vpn {
 
         private void bringup() {
             // Catch all exceptions so we can clean up a few things.
+            boolean initFinished = false;
             try {
                 // Initialize the timer.
                 mBringupStartTime = SystemClock.elapsedRealtime();
@@ -1996,6 +2057,7 @@ public class Vpn {
                     throw new IllegalStateException("Cannot delete the state");
                 }
                 new File("/data/misc/vpn/abort").delete();
+                initFinished = true;
 
                 // Check if we need to restart any of the daemons.
                 boolean restart = false;

tests/net/java/android/net/NetworkUtilsTest.java

@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2015 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 static junit.framework.Assert.assertEquals;
+
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.math.BigInteger;
+import java.util.TreeSet;
+
+@RunWith(AndroidJUnit4.class)
+@androidx.test.filters.SmallTest
+public class NetworkUtilsTest {
+    @Test
+    public void testRoutedIPv4AddressCount() {
+        final TreeSet<IpPrefix> set = new TreeSet<>(IpPrefix.lengthComparator());
+        // No routes routes to no addresses.
+        assertEquals(0, NetworkUtils.routedIPv4AddressCount(set));
+
+        set.add(new IpPrefix("0.0.0.0/0"));
+        assertEquals(1l << 32, NetworkUtils.routedIPv4AddressCount(set));
+
+        set.add(new IpPrefix("20.18.0.0/16"));
+        set.add(new IpPrefix("20.18.0.0/24"));
+        set.add(new IpPrefix("20.18.0.0/8"));
+        // There is a default route, still covers everything
+        assertEquals(1l << 32, NetworkUtils.routedIPv4AddressCount(set));
+
+        set.clear();
+        set.add(new IpPrefix("20.18.0.0/24"));
+        set.add(new IpPrefix("20.18.0.0/8"));
+        // The 8-length includes the 24-length prefix
+        assertEquals(1l << 24, NetworkUtils.routedIPv4AddressCount(set));
+
+        set.add(new IpPrefix("10.10.10.126/25"));
+        // The 8-length does not include this 25-length prefix
+        assertEquals((1l << 24) + (1 << 7), NetworkUtils.routedIPv4AddressCount(set));
+
+        set.clear();
+        set.add(new IpPrefix("1.2.3.4/32"));
+        set.add(new IpPrefix("1.2.3.4/32"));
+        set.add(new IpPrefix("1.2.3.4/32"));
+        set.add(new IpPrefix("1.2.3.4/32"));
+        assertEquals(1l, NetworkUtils.routedIPv4AddressCount(set));
+
+        set.add(new IpPrefix("1.2.3.5/32"));
+        set.add(new IpPrefix("1.2.3.6/32"));
+
+        set.add(new IpPrefix("1.2.3.7/32"));
+        set.add(new IpPrefix("1.2.3.8/32"));
+        set.add(new IpPrefix("1.2.3.9/32"));
+        set.add(new IpPrefix("1.2.3.0/32"));
+        assertEquals(7l, NetworkUtils.routedIPv4AddressCount(set));
+
+        // 1.2.3.4/30 eats 1.2.3.{4-7}/32
+        set.add(new IpPrefix("1.2.3.4/30"));
+        set.add(new IpPrefix("6.2.3.4/28"));
+        set.add(new IpPrefix("120.2.3.4/16"));
+        assertEquals(7l - 4 + 4 + 16 + 65536, NetworkUtils.routedIPv4AddressCount(set));
+    }
+
+    @Test
+    public void testRoutedIPv6AddressCount() {
+        final TreeSet<IpPrefix> set = new TreeSet<>(IpPrefix.lengthComparator());
+        // No routes routes to no addresses.
+        assertEquals(BigInteger.ZERO, NetworkUtils.routedIPv6AddressCount(set));
+
+        set.add(new IpPrefix("::/0"));
+        assertEquals(BigInteger.ONE.shiftLeft(128), NetworkUtils.routedIPv6AddressCount(set));
+
+        set.add(new IpPrefix("1234:622a::18/64"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6adb/96"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6adb/8"));
+        // There is a default route, still covers everything
+        assertEquals(BigInteger.ONE.shiftLeft(128), NetworkUtils.routedIPv6AddressCount(set));
+
+        set.clear();
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6adb/96"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6adb/8"));
+        // The 8-length includes the 96-length prefix
+        assertEquals(BigInteger.ONE.shiftLeft(120), NetworkUtils.routedIPv6AddressCount(set));
+
+        set.add(new IpPrefix("10::26/64"));
+        // The 8-length does not include this 64-length prefix
+        assertEquals(BigInteger.ONE.shiftLeft(120).add(BigInteger.ONE.shiftLeft(64)),
+                NetworkUtils.routedIPv6AddressCount(set));
+
+        set.clear();
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad4/128"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad4/128"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad4/128"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad4/128"));
+        assertEquals(BigInteger.ONE, NetworkUtils.routedIPv6AddressCount(set));
+
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad5/128"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad6/128"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad7/128"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad8/128"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad9/128"));
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad0/128"));
+        assertEquals(BigInteger.valueOf(7), NetworkUtils.routedIPv6AddressCount(set));
+
+        // add4:f00:80:f7:1111::6ad4/126 eats add4:f00:8[:f7:1111::6ad{4-7}/128
+        set.add(new IpPrefix("add4:f00:80:f7:1111::6ad4/126"));
+        set.add(new IpPrefix("d00d:f00:80:f7:1111::6ade/124"));
+        set.add(new IpPrefix("f00b:a33::/112"));
+        assertEquals(BigInteger.valueOf(7l - 4 + 4 + 16 + 65536),
+                NetworkUtils.routedIPv6AddressCount(set));
+    }
+}