Merge "Add config_p2p_leases_subnet_prefix_length configuration"

Tethering/src/android/net/dhcp/DhcpServingParamsParcelExt.java

@@ -185,6 +185,16 @@ public class DhcpServingParamsParcelExt extends DhcpServingParamsParcel {
         return this;
     }
 
+    /** Set leases subnet prefix length. If the value is smaller than server address prefix length,
+     * this configuration will be ignored.
+     *
+     * <p>If not set, the default value is zero.
+     */
+    public DhcpServingParamsParcelExt setLeasesSubnetPrefixLength(int prefixLength) {
+        this.leasesSubnetPrefixLength = prefixLength;
+        return this;
+    }
+
     private static int[] toIntArray(@NonNull Collection<Inet4Address> addrs) {
         int[] res = new int[addrs.size()];
         int i = 0;

Tethering/src/android/net/ip/IpServer.java

@@ -241,6 +241,7 @@ public class IpServer extends StateMachine {
     private final LinkProperties mLinkProperties;
     private final boolean mUsingLegacyDhcp;
     private final boolean mUsingBpfOffload;
+    private final int mP2pLeasesSubnetPrefixLength;
 
     private final Dependencies mDeps;
 
@@ -299,6 +300,7 @@ public class IpServer extends StateMachine {
         mLinkProperties = new LinkProperties();
         mUsingLegacyDhcp = config.useLegacyDhcpServer();
         mUsingBpfOffload = config.isBpfOffloadEnabled();
+        mP2pLeasesSubnetPrefixLength = config.getP2pLeasesSubnetPrefixLength();
         mPrivateAddressCoordinator = addressCoordinator;
         mDeps = deps;
         resetLinkProperties();
@@ -527,6 +529,9 @@ public class IpServer extends StateMachine {
             @Nullable Inet4Address clientAddr) {
         final boolean changePrefixOnDecline =
                 (mInterfaceType == TetheringManager.TETHERING_NCM && clientAddr == null);
+        final int subnetPrefixLength = mInterfaceType == TetheringManager.TETHERING_WIFI_P2P
+                ? mP2pLeasesSubnetPrefixLength : 0 /* default value */;
+
         return new DhcpServingParamsParcelExt()
             .setDefaultRouters(defaultRouter)
             .setDhcpLeaseTimeSecs(DHCP_LEASE_TIME_SECS)
@@ -534,7 +539,8 @@ public class IpServer extends StateMachine {
             .setServerAddr(serverAddr)
             .setMetered(true)
             .setSingleClientAddr(clientAddr)
-            .setChangePrefixOnDecline(changePrefixOnDecline);
+            .setChangePrefixOnDecline(changePrefixOnDecline)
+            .setLeasesSubnetPrefixLength(subnetPrefixLength);
             // TODO: also advertise link MTU
     }
 

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

@@ -149,6 +149,7 @@ public class TetheringConfiguration {
     // TODO: Add to TetheringConfigurationParcel if required.
     private final boolean mEnableBpfOffload;
     private final boolean mEnableWifiP2pDedicatedIp;
+    private final int mP2pLeasesSubnetPrefixLength;
 
     private final int mUsbTetheringFunction;
     protected final ContentResolver mContentResolver;
@@ -214,9 +215,27 @@ public class TetheringConfiguration {
                 R.bool.config_tether_enable_legacy_wifi_p2p_dedicated_ip,
                 false /* defaultValue */);
 
+        mP2pLeasesSubnetPrefixLength = getP2pLeasesSubnetPrefixLengthFromRes(res, configLog);
+
         configLog.log(toString());
     }
 
+    private int getP2pLeasesSubnetPrefixLengthFromRes(final Resources res, final SharedLog log) {
+        if (!mEnableWifiP2pDedicatedIp) return 0;
+
+        int prefixLength = getResourceInteger(res,
+                R.integer.config_p2p_leases_subnet_prefix_length, 0 /* default value */);
+
+        // DhcpLeaseRepository ignores the first and last addresses of the range so the max prefix
+        // length is 30.
+        if (prefixLength < 0 || prefixLength > 30) {
+            log.e("Invalid p2p leases subnet prefix length configuration: " + prefixLength);
+            return 0;
+        }
+
+        return prefixLength;
+    }
+
     /** Check whether using legacy dhcp server. */
     public boolean useLegacyDhcpServer() {
         return mEnableLegacyDhcpServer;
@@ -272,6 +291,15 @@ public class TetheringConfiguration {
         return mEnableWifiP2pDedicatedIp;
     }
 
+    /**
+     * Get subnet prefix length of dhcp leases for wifi p2p.
+     * This feature only support when wifi p2p use dedicated address. If
+     * #shouldEnableWifiP2pDedicatedIp is false, this method would always return 0.
+     */
+    public int getP2pLeasesSubnetPrefixLength() {
+        return mP2pLeasesSubnetPrefixLength;
+    }
+
     /** Does the dumping.*/
     public void dump(PrintWriter pw) {
         pw.print("activeDataSubId: ");
@@ -310,6 +338,9 @@ public class TetheringConfiguration {
         pw.print("enableWifiP2pDedicatedIp: ");
         pw.println(mEnableWifiP2pDedicatedIp);
 
+        pw.print("p2pLeasesSubnetPrefixLength: ");
+        pw.println(mP2pLeasesSubnetPrefixLength);
+
         pw.print("mUsbTetheringFunction: ");
         pw.println(isUsingNcm() ? "NCM" : "RNDIS");
     }