Merge "Allow wifi p2p to use legacy dedicated address" am: d2af4d9e2a

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1382398

Change-Id: I8977ef203c363d68c1c43ecd70f530a4924f01b9

Tethering/res/values/config.xml

@@ -71,6 +71,9 @@
     <!-- Use the old dnsmasq DHCP server for tethering instead of the framework implementation. -->
     <bool translatable="false" name="config_tether_enable_legacy_dhcp_server">false</bool>
 
+    <!-- Use legacy wifi p2p dedicated address instead of randomize address. -->
+    <bool translatable="false" name="config_tether_enable_legacy_wifi_p2p_dedicated_ip">false</bool>
+
     <!-- Dhcp range (min, max) to use for tethering purposes -->
     <string-array translatable="false" name="config_tether_dhcp_range">
     </string-array>

Tethering/res/values/overlayable.xml

@@ -30,6 +30,7 @@
             -->
             <item type="bool" name="config_tether_enable_bpf_offload"/>
             <item type="bool" name="config_tether_enable_legacy_dhcp_server"/>
+            <item type="bool" name="config_tether_enable_legacy_wifi_p2p_dedicated_ip"/>
             <item type="integer" name="config_tether_offload_poll_interval"/>
             <item type="array" name="config_tether_upstream_types"/>
             <item type="bool" name="config_tether_upstream_automatic"/>

Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java

@@ -15,6 +15,8 @@
  */
 package com.android.networkstack.tethering;
 
+import static android.net.TetheringManager.TETHERING_WIFI_P2P;
+
 import static java.util.Arrays.asList;
 
 import android.content.Context;
@@ -58,6 +60,7 @@ public class PrivateAddressCoordinator {
     private static final int BYTE_MASK = 0xff;
     // reserved for bluetooth tethering.
     private static final int BLUETOOTH_RESERVED = 44;
+    private static final int WIFI_P2P_RESERVED = 49;
     private static final byte DEFAULT_ID = (byte) 42;
 
     // Upstream monitor would be stopped when tethering is down. When tethering restart, downstream
@@ -71,15 +74,18 @@ public class PrivateAddressCoordinator {
     // 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16
     // Tethering use 192.168.0.0/16 that has 256 contiguous class C network numbers.
     private static final String DEFAULT_TETHERING_PREFIX = "192.168.0.0/16";
+    private static final String LEGACY_WIFI_P2P_IFACE_ADDRESS = "192.168.49.1/24";
     private final IpPrefix mTetheringPrefix;
     private final ConnectivityManager mConnectivityMgr;
+    private final TetheringConfiguration mConfig;
 
-    public PrivateAddressCoordinator(Context context) {
+    public PrivateAddressCoordinator(Context context, TetheringConfiguration config) {
         mDownstreams = new ArraySet<>();
         mUpstreamPrefixMap = new ArrayMap<>();
         mTetheringPrefix = new IpPrefix(DEFAULT_TETHERING_PREFIX);
         mConnectivityMgr = (ConnectivityManager) context.getSystemService(
                 Context.CONNECTIVITY_SERVICE);
+        mConfig = config;
     }
 
     /**
@@ -141,12 +147,21 @@ public class PrivateAddressCoordinator {
         mUpstreamPrefixMap.removeAll(toBeRemoved);
     }
 
+    private boolean isReservedSubnet(final int subnet) {
+        return subnet == BLUETOOTH_RESERVED || subnet == WIFI_P2P_RESERVED;
+    }
+
     /**
      * Pick a random available address and mark its prefix as in use for the provided IpServer,
      * returns null if there is no available address.
      */
     @Nullable
     public LinkAddress requestDownstreamAddress(final IpServer ipServer) {
+        if (mConfig.shouldEnableWifiP2pDedicatedIp()
+                && ipServer.interfaceType() == TETHERING_WIFI_P2P) {
+            return new LinkAddress(LEGACY_WIFI_P2P_IFACE_ADDRESS);
+        }
+
         // Address would be 192.168.[subAddress]/24.
         final byte[] bytes = mTetheringPrefix.getRawAddress();
         final int subAddress = getRandomSubAddr();
@@ -154,7 +169,7 @@ public class PrivateAddressCoordinator {
         bytes[3] = getSanitizedAddressSuffix(subAddress, (byte) 0, (byte) 1, (byte) 0xff);
         for (int i = 0; i < MAX_UBYTE; i++) {
             final int newSubNet = (subNet + i) & BYTE_MASK;
-            if (newSubNet == BLUETOOTH_RESERVED) continue;
+            if (isReservedSubnet(newSubNet)) continue;
 
             bytes[2] = (byte) newSubNet;
             final InetAddress addr;

Tethering/src/com/android/networkstack/tethering/Tethering.java

@@ -320,10 +320,13 @@ public class Tethering {
         mExecutor = new TetheringThreadExecutor(mHandler);
         mActiveDataSubIdListener = new ActiveDataSubIdListener(mExecutor);
         mNetdCallback = new NetdCallback();
-        mPrivateAddressCoordinator = new PrivateAddressCoordinator(mContext);
 
         // Load tethering configuration.
         updateConfiguration();
+        // It is OK for the configuration to be passed to the PrivateAddressCoordinator at
+        // construction time because the only part of the configuration it uses is
+        // shouldEnableWifiP2pDedicatedIp(), and currently do not support changing that.
+        mPrivateAddressCoordinator = new PrivateAddressCoordinator(mContext, mConfig);
 
         // Must be initialized after tethering configuration is loaded because BpfCoordinator
         // constructor needs to use the configuration.

Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java

@@ -84,6 +84,9 @@ public class TetheringConfiguration {
     public static final String TETHER_ENABLE_LEGACY_DHCP_SERVER =
             "tether_enable_legacy_dhcp_server";
 
+    public static final String USE_LEGACY_WIFI_P2P_DEDICATED_IP =
+            "use_legacy_wifi_p2p_dedicated_ip";
+
     /**
      * Default value that used to periodic polls tether offload stats from tethering offload HAL
      * to make the data warnings work.
@@ -113,6 +116,7 @@ public class TetheringConfiguration {
     private final int mOffloadPollInterval;
     // TODO: Add to TetheringConfigurationParcel if required.
     private final boolean mEnableBpfOffload;
+    private final boolean mEnableWifiP2pDedicatedIp;
 
     public TetheringConfiguration(Context ctx, SharedLog log, int id) {
         final SharedLog configLog = log.forSubComponent("config");
@@ -156,6 +160,10 @@ public class TetheringConfiguration {
                 R.integer.config_tether_offload_poll_interval,
                 DEFAULT_TETHER_OFFLOAD_POLL_INTERVAL_MS);
 
+        mEnableWifiP2pDedicatedIp = getResourceBoolean(res,
+                R.bool.config_tether_enable_legacy_wifi_p2p_dedicated_ip,
+                false /* defaultValue */);
+
         configLog.log(toString());
     }
 
@@ -199,6 +207,11 @@ public class TetheringConfiguration {
         return !TextUtils.isEmpty(provisioningAppNoUi);
     }
 
+    /** Check whether dedicated wifi p2p address is enabled. */
+    public boolean shouldEnableWifiP2pDedicatedIp() {
+        return mEnableWifiP2pDedicatedIp;
+    }
+
     /** Does the dumping.*/
     public void dump(PrintWriter pw) {
         pw.print("activeDataSubId: ");
@@ -233,6 +246,9 @@ public class TetheringConfiguration {
 
         pw.print("enableLegacyDhcpServer: ");
         pw.println(enableLegacyDhcpServer);
+
+        pw.print("enableWifiP2pDedicatedIp: ");
+        pw.println(mEnableWifiP2pDedicatedIp);
     }
 
     /** Returns the string representation of this object.*/

Tethering/tests/unit/src/com/android/networkstack/tethering/PrivateAddressCoordinatorTest.java

@@ -15,6 +15,11 @@
  */
 package com.android.networkstack.tethering;
 
+import static android.net.TetheringManager.TETHERING_ETHERNET;
+import static android.net.TetheringManager.TETHERING_USB;
+import static android.net.TetheringManager.TETHERING_WIFI;
+import static android.net.TetheringManager.TETHERING_WIFI_P2P;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
 import static org.mockito.Mockito.never;
@@ -54,22 +59,34 @@ public final class PrivateAddressCoordinatorTest {
     @Mock private IpServer mHotspotIpServer;
     @Mock private IpServer mUsbIpServer;
     @Mock private IpServer mEthernetIpServer;
+    @Mock private IpServer mWifiP2pIpServer;
     @Mock private Context mContext;
     @Mock private ConnectivityManager mConnectivityMgr;
+    @Mock private TetheringConfiguration mConfig;
 
     private PrivateAddressCoordinator mPrivateAddressCoordinator;
     private final IpPrefix mBluetoothPrefix = new IpPrefix("192.168.44.0/24");
+    private final LinkAddress mLegacyWifiP2pAddress = new LinkAddress("192.168.49.1/24");
     private final Network mWifiNetwork = new Network(1);
     private final Network mMobileNetwork = new Network(2);
     private final Network[] mAllNetworks = {mMobileNetwork, mWifiNetwork};
 
+    private void setUpIpServers() throws Exception {
+        when(mUsbIpServer.interfaceType()).thenReturn(TETHERING_USB);
+        when(mEthernetIpServer.interfaceType()).thenReturn(TETHERING_ETHERNET);
+        when(mHotspotIpServer.interfaceType()).thenReturn(TETHERING_WIFI);
+        when(mWifiP2pIpServer.interfaceType()).thenReturn(TETHERING_WIFI_P2P);
+    }
+
     @Before
     public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);
 
         when(mContext.getSystemService(Context.CONNECTIVITY_SERVICE)).thenReturn(mConnectivityMgr);
         when(mConnectivityMgr.getAllNetworks()).thenReturn(mAllNetworks);
-        mPrivateAddressCoordinator = spy(new PrivateAddressCoordinator(mContext));
+        when(mConfig.shouldEnableWifiP2pDedicatedIp()).thenReturn(false);
+        setUpIpServers();
+        mPrivateAddressCoordinator = spy(new PrivateAddressCoordinator(mContext, mConfig));
     }
 
     @Test
@@ -256,4 +273,38 @@ public final class PrivateAddressCoordinatorTest {
         final IpPrefix ethPrefix = PrefixUtils.asIpPrefix(ethAddr);
         assertEquals(predefinedPrefix, ethPrefix);
     }
+
+    private int getSubAddress(final byte... ipv4Address) {
+        assertEquals(4, ipv4Address.length);
+
+        int subnet = Byte.toUnsignedInt(ipv4Address[2]);
+        return (subnet << 8) + ipv4Address[3];
+    }
+
+    private void assertReseveredWifiP2pPrefix() throws Exception {
+        LinkAddress address = mPrivateAddressCoordinator.requestDownstreamAddress(
+                mHotspotIpServer);
+        final IpPrefix hotspotPrefix = PrefixUtils.asIpPrefix(address);
+        final IpPrefix legacyWifiP2pPrefix = PrefixUtils.asIpPrefix(mLegacyWifiP2pAddress);
+        assertNotEquals(legacyWifiP2pPrefix, hotspotPrefix);
+        mPrivateAddressCoordinator.releaseDownstream(mHotspotIpServer);
+    }
+
+    @Test
+    public void testEnableLegacyWifiP2PAddress() throws Exception {
+        when(mPrivateAddressCoordinator.getRandomSubAddr()).thenReturn(
+                getSubAddress(mLegacyWifiP2pAddress.getAddress().getAddress()));
+        // No matter #shouldEnableWifiP2pDedicatedIp() is enabled or not, legacy wifi p2p prefix
+        // is resevered.
+        assertReseveredWifiP2pPrefix();
+
+        when(mConfig.shouldEnableWifiP2pDedicatedIp()).thenReturn(true);
+        assertReseveredWifiP2pPrefix();
+
+        // If #shouldEnableWifiP2pDedicatedIp() is enabled, wifi P2P gets the configured address.
+        LinkAddress address = mPrivateAddressCoordinator.requestDownstreamAddress(
+                mWifiP2pIpServer);
+        assertEquals(mLegacyWifiP2pAddress, address);
+        mPrivateAddressCoordinator.releaseDownstream(mWifiP2pIpServer);
+    }
 }

Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java

@@ -128,6 +128,8 @@ public class TetheringConfigurationTest {
                 .thenReturn(new String[0]);
         when(mResources.getBoolean(R.bool.config_tether_enable_legacy_dhcp_server)).thenReturn(
                 false);
+        when(mResources.getBoolean(R.bool.config_tether_enable_legacy_wifi_p2p_dedicated_ip))
+                .thenReturn(false);
         initializeBpfOffloadConfiguration(true, null /* unset */);
 
         mHasTelephonyManager = true;
@@ -413,4 +415,17 @@ public class TetheringConfigurationTest {
                 R.string.config_mobile_hotspot_provision_response)).thenReturn(
                 PROVISIONING_APP_RESPONSE);
     }
+
+    @Test
+    public void testEnableLegacyWifiP2PAddress() throws Exception {
+        final TetheringConfiguration defaultCfg = new TetheringConfiguration(
+                mMockContext, mLog, INVALID_SUBSCRIPTION_ID);
+        assertFalse(defaultCfg.shouldEnableWifiP2pDedicatedIp());
+
+        when(mResources.getBoolean(R.bool.config_tether_enable_legacy_wifi_p2p_dedicated_ip))
+                .thenReturn(true);
+        final TetheringConfiguration testCfg = new TetheringConfiguration(
+                mMockContext, mLog, INVALID_SUBSCRIPTION_ID);
+        assertTrue(testCfg.shouldEnableWifiP2pDedicatedIp());
+    }
 }