Merge changes I7ad55374,I4a0c7f6e into main

* changes:
  Add test to verify callbacks for enable/disableInterface APIs
  Fix enable/disableInterface APIs to properly affect administrative state
diff --git a/service-t/src/com/android/server/ethernet/EthernetTracker.java b/service-t/src/com/android/server/ethernet/EthernetTracker.java
index 8fb632e..bfcc171 100644
--- a/service-t/src/com/android/server/ethernet/EthernetTracker.java
+++ b/service-t/src/com/android/server/ethernet/EthernetTracker.java
@@ -384,7 +384,7 @@
 
     /** Configure the administrative state of ethernet interface by toggling IFF_UP. */
     public void setInterfaceEnabled(String iface, boolean enabled, EthernetCallback cb) {
-        mHandler.post(() -> updateInterfaceState(iface, enabled, cb));
+        mHandler.post(() -> setInterfaceAdministrativeState(iface, enabled, cb));
     }
 
     IpConfiguration getIpConfiguration(String iface) {
@@ -642,25 +642,40 @@
         }
     }
 
-    private void updateInterfaceState(String iface, boolean up) {
-        updateInterfaceState(iface, up, new EthernetCallback(null /* cb */));
-    }
-
-    // TODO(b/225315248): enable/disableInterface() should not affect link state.
-    private void updateInterfaceState(String iface, boolean up, EthernetCallback cb) {
-        final int mode = getInterfaceMode(iface);
-        if (mode == INTERFACE_MODE_SERVER || !mFactory.hasInterface(iface)) {
-            // The interface is in server mode or is not tracked.
-            cb.onError("Failed to set link state " + (up ? "up" : "down") + " for " + iface);
+    private void setInterfaceAdministrativeState(String iface, boolean up, EthernetCallback cb) {
+        if (getInterfaceState(iface) == EthernetManager.STATE_ABSENT) {
+            cb.onError("Failed to enable/disable absent interface: " + iface);
+            return;
+        }
+        if (getInterfaceRole(iface) == EthernetManager.ROLE_SERVER) {
+            // TODO: support setEthernetState for server mode interfaces.
+            cb.onError("Failed to enable/disable interface in server mode: " + iface);
             return;
         }
 
+        if (up) {
+            // WARNING! setInterfaceUp() clears the IPv4 address and readds it. Calling
+            // enableInterface() on an active interface can lead to a provisioning failure which
+            // will cause IpClient to be restarted.
+            // TODO: use netlink directly rather than calling into netd.
+            NetdUtils.setInterfaceUp(mNetd, iface);
+        } else {
+            NetdUtils.setInterfaceDown(mNetd, iface);
+        }
+        cb.onResult(iface);
+    }
+
+    private void updateInterfaceState(String iface, boolean up) {
+        final int mode = getInterfaceMode(iface);
+        if (mode == INTERFACE_MODE_SERVER) {
+            // TODO: support tracking link state for interfaces in server mode.
+            return;
+        }
+
+        // If updateInterfaceLinkState returns false, the interface is already in the correct state.
         if (mFactory.updateInterfaceLinkState(iface, up)) {
             broadcastInterfaceStateChange(iface);
         }
-        // If updateInterfaceLinkState returns false, the interface is already in the correct state.
-        // Always return success.
-        cb.onResult(iface);
     }
 
     private void maybeUpdateServerModeInterfaceState(String iface, boolean available) {
diff --git a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
index b7e5205..7af3c83 100644
--- a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
+++ b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
@@ -899,6 +899,20 @@
     }
 
     @Test
+    fun testEnableDisableInterface_callbacks() {
+        val iface = createInterface()
+        val listener = EthernetStateListener()
+        addInterfaceStateListener(listener)
+        listener.expectCallback(iface, STATE_LINK_UP, ROLE_CLIENT)
+
+        disableInterface(iface).expectResult(iface.name)
+        listener.expectCallback(iface, STATE_LINK_DOWN, ROLE_CLIENT)
+
+        enableInterface(iface).expectResult(iface.name)
+        listener.expectCallback(iface, STATE_LINK_UP, ROLE_CLIENT)
+    }
+
+    @Test
     fun testUpdateConfiguration_forBothIpConfigAndCapabilities() {
         val iface = createInterface()
         val cb = requestNetwork(ETH_REQUEST.copyWithEthernetSpecifier(iface.name))