From ae3ace443379046b2fefaeb477fbf51bdd162ce1 Mon Sep 17 00:00:00 2001
From: Patrick Rohr <prohr@google.com>
Date: Wed, 5 Oct 2022 09:27:55 -0700
Subject: [PATCH] ethernet: fix IpClient restart when link is down

Do not restart IpClient when link is down after calling
updateConfiguration().

Test: atest EthernetManagerTest
Bug: 249897651

Change-Id: Ia0f6b67cde63747a608d35b8bec6ad37bcabb110
---
 .../ethernet/EthernetNetworkFactory.java      |  4 +++-
 .../android/net/cts/EthernetManagerTest.kt    | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java b/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
index 48d68d7894..00f6c56849 100644
--- a/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
+++ b/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
@@ -469,7 +469,9 @@ public class EthernetNetworkFactory {
             // TODO: Update this logic to only do a restart if required. Although a restart may
             //  be required due to the capabilities or ipConfiguration values, not all
             //  capabilities changes require a restart.
-            restart();
+            if (mIpClient != null) {
+                restart();
+            }
         }
 
         boolean isRestricted() {
diff --git a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
index 3635b7ba89..1e44440b8a 100644
--- a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
+++ b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
@@ -979,4 +979,23 @@ class EthernetManagerTest {
         cb.eventuallyExpectCapabilities(TEST_CAPS)
         cb.eventuallyExpectLpForStaticConfig(STATIC_IP_CONFIGURATION.staticIpConfiguration)
     }
+
+    @Test
+    fun testUpdateConfiguration_withLinkDown() {
+        assumeChangingCarrierSupported()
+        // createInterface without carrier is racy, so create it and then remove carrier.
+        val iface = createInterface()
+        val cb = requestNetwork(ETH_REQUEST)
+        cb.expectAvailable()
+
+        iface.setCarrierEnabled(false)
+        cb.eventuallyExpectLost()
+
+        updateConfiguration(iface, STATIC_IP_CONFIGURATION, TEST_CAPS).expectResult(iface.name)
+        cb.assertNoCallback()
+
+        iface.setCarrierEnabled(true)
+        cb.eventuallyExpectCapabilities(TEST_CAPS)
+        cb.eventuallyExpectLpForStaticConfig(STATIC_IP_CONFIGURATION.staticIpConfiguration)
+    }
 }