Setting MTU size for specific network.

Able to config network specific MTU size. Normally, the default size of MTU is 1500.
 US - ATT 1410, TMUS 1440, SPRINT 1422
 KR - SKT 1440, KT 1450, LGU+ 1428
 JP - KDDI 1420, SoftBank 1340
 CA - RGS 1430, FIDO 1430, MTS 1430, BELL 1358, SaskTel 1358
 AU - TEL 1400

Bug: 10195070
Change-Id: Ie18650b37a3d44af944f2dae4aa97c04fb12cd5e

core/java/android/net/LinkProperties.java

@@ -66,6 +66,7 @@ public class LinkProperties implements Parcelable {
     private String mDomains;
     private Collection<RouteInfo> mRoutes = new ArrayList<RouteInfo>();
     private ProxyProperties mHttpProxy;
+    private int mMtu;
 
     // Stores the properties of links that are "stacked" above this link.
     // Indexed by interface name to allow modification and to prevent duplicates being added.
@@ -104,6 +105,7 @@ public class LinkProperties implements Parcelable {
             for (LinkProperties l: source.mStackedLinks.values()) {
                 addStackedLink(l);
             }
+            setMtu(source.getMtu());
         }
     }
 
@@ -223,6 +225,14 @@ public class LinkProperties implements Parcelable {
         mDomains = domains;
     }
 
+    public void setMtu(int mtu) {
+        mMtu = mtu;
+    }
+
+    public int getMtu() {
+        return mMtu;
+    }
+
     private RouteInfo routeWithInterface(RouteInfo route) {
         return new RouteInfo(
             route.getDestination(),
@@ -322,6 +332,7 @@ public class LinkProperties implements Parcelable {
         mRoutes.clear();
         mHttpProxy = null;
         mStackedLinks.clear();
+        mMtu = 0;
     }
 
     /**
@@ -346,6 +357,8 @@ public class LinkProperties implements Parcelable {
 
         String domainName = "Domains: " + mDomains;
 
+        String mtu = "MTU: " + mMtu;
+
         String routes = " Routes: [";
         for (RouteInfo route : mRoutes) routes += route.toString() + ",";
         routes += "] ";
@@ -359,7 +372,8 @@ public class LinkProperties implements Parcelable {
             }
             stacked += "] ";
         }
-        return "{" + ifaceName + linkAddresses + routes + dns + domainName + proxy + stacked + "}";
+        return "{" + ifaceName + linkAddresses + routes + dns + domainName + mtu
+            + proxy + stacked + "}";
     }
 
     /**
@@ -474,6 +488,16 @@ public class LinkProperties implements Parcelable {
         return true;
     }
 
+    /**
+     * Compares this {@code LinkProperties} MTU against the target
+     *
+     * @@param target LinkProperties to compare.
+     * @return {@code true} if both are identical, {@code false} otherwise.
+     */
+    public boolean isIdenticalMtu(LinkProperties target) {
+        return getMtu() == target.getMtu();
+    }
+
     @Override
     /**
      * Compares this {@code LinkProperties} instance against the target
@@ -505,7 +529,8 @@ public class LinkProperties implements Parcelable {
                 isIdenticalDnses(target) &&
                 isIdenticalRoutes(target) &&
                 isIdenticalHttpProxy(target) &&
-                isIdenticalStackedLinks(target);
+                isIdenticalStackedLinks(target) &&
+                isIdenticalMtu(target);
     }
 
     /**
@@ -607,7 +632,8 @@ public class LinkProperties implements Parcelable {
                 + ((null == mDomains) ? 0 : mDomains.hashCode())
                 + mRoutes.size() * 41
                 + ((null == mHttpProxy) ? 0 : mHttpProxy.hashCode())
-                + mStackedLinks.hashCode() * 47);
+                + mStackedLinks.hashCode() * 47)
+                + mMtu * 51;
     }
 
     /**
@@ -625,7 +651,7 @@ public class LinkProperties implements Parcelable {
             dest.writeByteArray(d.getAddress());
         }
         dest.writeString(mDomains);
-
+        dest.writeInt(mMtu);
         dest.writeInt(mRoutes.size());
         for(RouteInfo route : mRoutes) {
             dest.writeParcelable(route, flags);
@@ -664,6 +690,7 @@ public class LinkProperties implements Parcelable {
                     } catch (UnknownHostException e) { }
                 }
                 netProp.setDomains(in.readString());
+                netProp.setMtu(in.readInt());
                 addressCount = in.readInt();
                 for (int i=0; i<addressCount; i++) {
                     netProp.addRoute((RouteInfo)in.readParcelable(null));

core/tests/coretests/src/android/net/LinkPropertiesTest.java

@@ -33,6 +33,7 @@ public class LinkPropertiesTest extends TestCase {
     private static InetAddress GATEWAY1 = NetworkUtils.numericToInetAddress("75.208.8.1");
     private static InetAddress GATEWAY2 = NetworkUtils.numericToInetAddress("69.78.8.1");
     private static String NAME = "qmi0";
+    private static int MTU = 1500;
 
     private static LinkAddress LINKADDRV4 = new LinkAddress(ADDRV4, 32);
     private static LinkAddress LINKADDRV6 = new LinkAddress(ADDRV6, 128);
@@ -57,6 +58,9 @@ public class LinkPropertiesTest extends TestCase {
         assertTrue(source.isIdenticalStackedLinks(target));
         assertTrue(target.isIdenticalStackedLinks(source));
 
+        assertTrue(source.isIdenticalMtu(target));
+        assertTrue(target.isIdenticalMtu(source));
+
         // Check result of equals().
         assertTrue(source.equals(target));
         assertTrue(target.equals(source));
@@ -88,6 +92,7 @@ public class LinkPropertiesTest extends TestCase {
             // set 2 gateways
             source.addRoute(new RouteInfo(GATEWAY1));
             source.addRoute(new RouteInfo(GATEWAY2));
+            source.setMtu(MTU);
 
             LinkProperties target = new LinkProperties();
 
@@ -99,6 +104,7 @@ public class LinkPropertiesTest extends TestCase {
             target.addDns(DNS2);
             target.addRoute(new RouteInfo(GATEWAY1));
             target.addRoute(new RouteInfo(GATEWAY2));
+            target.setMtu(MTU);
 
             assertLinkPropertiesEqual(source, target);
 
@@ -111,6 +117,7 @@ public class LinkPropertiesTest extends TestCase {
             target.addDns(DNS2);
             target.addRoute(new RouteInfo(GATEWAY1));
             target.addRoute(new RouteInfo(GATEWAY2));
+            target.setMtu(MTU);
             assertFalse(source.equals(target));
 
             target.clear();
@@ -123,6 +130,7 @@ public class LinkPropertiesTest extends TestCase {
             target.addDns(DNS2);
             target.addRoute(new RouteInfo(GATEWAY1));
             target.addRoute(new RouteInfo(GATEWAY2));
+            target.setMtu(MTU);
             assertFalse(source.equals(target));
 
             target.clear();
@@ -134,6 +142,7 @@ public class LinkPropertiesTest extends TestCase {
             target.addDns(DNS2);
             target.addRoute(new RouteInfo(GATEWAY1));
             target.addRoute(new RouteInfo(GATEWAY2));
+            target.setMtu(MTU);
             assertFalse(source.equals(target));
 
             target.clear();
@@ -145,6 +154,19 @@ public class LinkPropertiesTest extends TestCase {
             // change gateway
             target.addRoute(new RouteInfo(NetworkUtils.numericToInetAddress("75.208.8.2")));
             target.addRoute(new RouteInfo(GATEWAY2));
+            target.setMtu(MTU);
+            assertFalse(source.equals(target));
+
+            target.clear();
+            target.setInterfaceName(NAME);
+            target.addLinkAddress(LINKADDRV4);
+            target.addLinkAddress(LINKADDRV6);
+            target.addDns(DNS1);
+            target.addDns(DNS2);
+            target.addRoute(GATEWAY1);
+            target.addRoute(GATEWAY2);
+            // change mtu
+            target.setMtu(1440);
             assertFalse(source.equals(target));
 
         } catch (Exception e) {
@@ -167,6 +189,7 @@ public class LinkPropertiesTest extends TestCase {
             // set 2 gateways
             source.addRoute(new RouteInfo(GATEWAY1));
             source.addRoute(new RouteInfo(GATEWAY2));
+            source.setMtu(MTU);
 
             LinkProperties target = new LinkProperties();
             // Exchange order
@@ -177,6 +200,7 @@ public class LinkPropertiesTest extends TestCase {
             target.addDns(DNS1);
             target.addRoute(new RouteInfo(GATEWAY2));
             target.addRoute(new RouteInfo(GATEWAY1));
+            target.setMtu(MTU);
 
             assertLinkPropertiesEqual(source, target);
         } catch (Exception e) {

services/java/com/android/server/ConnectivityService.java

@@ -2299,6 +2299,7 @@ public class ConnectivityService extends IConnectivityManager.Stub {
         }
         thisNet.setTeardownRequested(false);
         updateNetworkSettings(thisNet);
+        updateMtuSizeSettings(thisNet);
         handleConnectivityChange(newNetType, false);
         sendConnectedBroadcastDelayed(info, getConnectivityChangeDelay());
 
@@ -2636,6 +2637,26 @@ public class ConnectivityService extends IConnectivityManager.Stub {
         return routesChanged;
     }
 
+   /**
+     * Reads the network specific MTU size from reources.
+     * and set it on it's iface.
+     */
+   private void updateMtuSizeSettings(NetworkStateTracker nt) {
+       final String iface = nt.getLinkProperties().getInterfaceName();
+       final int mtu = nt.getLinkProperties().getMtu();
+
+       if (mtu < 68 || mtu > 10000) {
+           loge("Unexpected mtu value: " + nt);
+           return;
+       }
+
+       try {
+           if (VDBG) log("Setting MTU size: " + iface + ", " + mtu);
+           mNetd.setMtu(iface, mtu);
+       } catch (Exception e) {
+           Slog.e(TAG, "exception in setMtu()" + e);
+       }
+   }
 
     /**
      * Reads the network specific TCP buffer sizes from SystemProperties
@@ -4774,4 +4795,3 @@ public class ConnectivityService extends IConnectivityManager.Stub {
         mAlarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, wakeupTime, intent);
     }
 }
-