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-rw-r--r--core/java/android/net/NetworkUtils.java81
-rw-r--r--services/core/java/com/android/server/connectivity/Vpn.java80
-rw-r--r--tests/net/java/android/net/NetworkUtilsTest.java128
3 files changed, 259 insertions, 30 deletions
diff --git a/core/java/android/net/NetworkUtils.java b/core/java/android/net/NetworkUtils.java
index d045549bd8c7..e6472e9c1d5f 100644
--- a/core/java/android/net/NetworkUtils.java
+++ b/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.
@@ -390,30 +387,72 @@ 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.
- * @param hostname Name of host to validate.
- * @return True if it's a valid-ish hostname.
+ * Returns how many IPv4 addresses match any of the prefixes in the passed ordered set.
*
- * @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) {
- // TODO(b/34953048): Use a validation method that permits more accurate,
- // but still inexpensive, checking of likely valid DNS hostnames.
- final String weakHostnameRegex = "^[a-zA-Z0-9_.-]+$";
- if (!hostname.matches(weakHostnameRegex)) {
- return false;
+ public static long routedIPv4AddressCount(final TreeSet<IpPrefix> prefixes) {
+ long routedIPCount = 0;
+ for (final IpPrefix prefix : deduplicatePrefixSet(prefixes)) {
+ if (!prefix.isIPv4()) {
+ Log.wtf(TAG, "Non-IPv4 prefix in routedIPv4AddressCount");
+ }
+ int rank = 32 - prefix.getPrefixLength();
+ routedIPCount += 1L << rank;
}
+ return routedIPCount;
+ }
- for (int address_family : ADDRESS_FAMILIES) {
- if (Os.inet_pton(address_family, hostname) != null) {
- return false;
+ /**
+ * 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 true;
+ return routedIPCount;
}
private static final int[] ADDRESS_FAMILIES = new int[] {AF_INET, AF_INET6};
diff --git a/services/core/java/com/android/server/connectivity/Vpn.java b/services/core/java/com/android/server/connectivity/Vpn.java
index 1240a002936d..e7a8b132d850 100644
--- a/services/core/java/com/android/server/connectivity/Vpn.java
+++ b/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 + "\"");
@@ -874,6 +902,38 @@ public class Vpn {
}
/**
+ * 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
* has certain changes, in which case this method would just return {@code false}.
@@ -1598,8 +1658,8 @@ public class Vpn {
*/
public PendingIntent pendingIntentGetActivityAsUser(
Intent intent, int flags, UserHandle user) {
- return PendingIntent.getActivityAsUser(mContext, 0 /* request */, intent, flags,
- null /* options */, user);
+ return PendingIntent.getActivityAsUser(mContext, 0 /*request*/, intent, flags,
+ 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;
diff --git a/tests/net/java/android/net/NetworkUtilsTest.java b/tests/net/java/android/net/NetworkUtilsTest.java
new file mode 100644
index 000000000000..7748288aeb05
--- /dev/null
+++ b/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));
+ }
+}
generated by cgit v1.2.3-59-g8ed1b (git 2.39.0) at 2025-10-23 00:39:15 +0000