Add a method to create a TAP interface without bringing it up. am: 333d5e52f5

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1987455

Change-Id: I38b1ab96f413ead1938631cce25814dceaa2ef07
diff --git a/framework/src/android/net/ITestNetworkManager.aidl b/framework/src/android/net/ITestNetworkManager.aidl
index 2a863ad..847f14e 100644
--- a/framework/src/android/net/ITestNetworkManager.aidl
+++ b/framework/src/android/net/ITestNetworkManager.aidl
@@ -29,8 +29,7 @@
  */
 interface ITestNetworkManager
 {
-    TestNetworkInterface createTunInterface(in LinkAddress[] linkAddrs);
-    TestNetworkInterface createTapInterface();
+    TestNetworkInterface createInterface(boolean isTun, boolean bringUp, in LinkAddress[] addrs);
 
     void setupTestNetwork(in String iface, in LinkProperties lp, in boolean isMetered,
             in int[] administratorUids, in IBinder binder);
diff --git a/framework/src/android/net/TestNetworkManager.java b/framework/src/android/net/TestNetworkManager.java
index 9ddd2f5..280e497 100644
--- a/framework/src/android/net/TestNetworkManager.java
+++ b/framework/src/android/net/TestNetworkManager.java
@@ -49,6 +49,11 @@
 
     @NonNull private final ITestNetworkManager mService;
 
+    private static final boolean TAP = false;
+    private static final boolean TUN = true;
+    private static final boolean BRING_UP = true;
+    private static final LinkAddress[] NO_ADDRS = new LinkAddress[0];
+
     /** @hide */
     public TestNetworkManager(@NonNull ITestNetworkManager service) {
         mService = Objects.requireNonNull(service, "missing ITestNetworkManager");
@@ -155,7 +160,7 @@
     public TestNetworkInterface createTunInterface(@NonNull Collection<LinkAddress> linkAddrs) {
         try {
             final LinkAddress[] arr = new LinkAddress[linkAddrs.size()];
-            return mService.createTunInterface(linkAddrs.toArray(arr));
+            return mService.createInterface(TUN, BRING_UP, linkAddrs.toArray(arr));
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
@@ -173,10 +178,28 @@
     @NonNull
     public TestNetworkInterface createTapInterface() {
         try {
-            return mService.createTapInterface();
+            return mService.createInterface(TAP, BRING_UP, NO_ADDRS);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
     }
 
+    /**
+     * Create a tap interface for testing purposes
+     *
+     * @param bringUp whether to bring up the interface before returning it.
+     *
+     * @return A ParcelFileDescriptor of the underlying TAP interface. Close this to tear down the
+     *     TAP interface.
+     * @hide
+     */
+    @RequiresPermission(Manifest.permission.MANAGE_TEST_NETWORKS)
+    @NonNull
+    public TestNetworkInterface createTapInterface(boolean bringUp) {
+        try {
+            return mService.createInterface(TAP, bringUp, NO_ADDRS);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
 }
diff --git a/service/src/com/android/server/TestNetworkService.java b/service/src/com/android/server/TestNetworkService.java
index fffd2be..a0bfb4a 100644
--- a/service/src/com/android/server/TestNetworkService.java
+++ b/service/src/com/android/server/TestNetworkService.java
@@ -99,12 +99,14 @@
     }
 
     /**
-     * Create a TUN or TAP interface with the given interface name and link addresses
+     * Create a TUN or TAP interface with the specified parameters.
      *
      * <p>This method will return the FileDescriptor to the interface. Close it to tear down the
      * interface.
      */
-    private TestNetworkInterface createInterface(boolean isTun, LinkAddress[] linkAddrs) {
+    @Override
+    public TestNetworkInterface createInterface(boolean isTun, boolean bringUp,
+            LinkAddress[] linkAddrs) {
         enforceTestNetworkPermissions(mContext);
 
         Objects.requireNonNull(linkAddrs, "missing linkAddrs");
@@ -122,7 +124,9 @@
                         addr.getPrefixLength());
             }
 
-            NetdUtils.setInterfaceUp(mNetd, iface);
+            if (bringUp) {
+                NetdUtils.setInterfaceUp(mNetd, iface);
+            }
 
             return new TestNetworkInterface(tunIntf, iface);
         } catch (RemoteException e) {
@@ -132,28 +136,6 @@
         }
     }
 
-    /**
-     * Create a TUN interface with the given interface name and link addresses
-     *
-     * <p>This method will return the FileDescriptor to the TUN interface. Close it to tear down the
-     * TUN interface.
-     */
-    @Override
-    public TestNetworkInterface createTunInterface(@NonNull LinkAddress[] linkAddrs) {
-        return createInterface(true, linkAddrs);
-    }
-
-    /**
-     * Create a TAP interface with the given interface name
-     *
-     * <p>This method will return the FileDescriptor to the TAP interface. Close it to tear down the
-     * TAP interface.
-     */
-    @Override
-    public TestNetworkInterface createTapInterface() {
-        return createInterface(false, new LinkAddress[0]);
-    }
-
     // Tracker for TestNetworkAgents
     @GuardedBy("mTestNetworkTracker")
     @NonNull