Add netlinkSocketForProto() without buffersize.

Test: atest NetworkStaticLibTests
atest FrameworksNetTests

Change-Id: I34a0a29eb7e78490701872229585e61f7a0c1dd3
diff --git a/staticlibs/device/com/android/net/module/util/netlink/NetlinkUtils.java b/staticlibs/device/com/android/net/module/util/netlink/NetlinkUtils.java
index 61d347c..541a375 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/NetlinkUtils.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/NetlinkUtils.java
@@ -225,7 +225,7 @@
     }
 
     /**
-     * Create netlink socket with the given netlink protocol type.
+     * Create netlink socket with the given netlink protocol type and buffersize.
      *
      * @param nlProto the netlink protocol
      * @param bufferSize the receive buffer size to set when the value is not 0
@@ -243,10 +243,23 @@
     }
 
     /**
+     * Create netlink socket with the given netlink protocol type. Receive buffer size is not set.
+     *
+     * @param nlProto the netlink protocol
+     *
+     * @return fd the fileDescriptor of the socket.
+     * @throws ErrnoException if the FileDescriptor not connect to be created successfully
+     */
+    public static FileDescriptor netlinkSocketForProto(int nlProto)
+            throws ErrnoException {
+        return netlinkSocketForProto(nlProto, 0);
+    }
+
+    /**
      * Construct a netlink inet_diag socket.
      */
     public static FileDescriptor createNetLinkInetDiagSocket() throws ErrnoException {
-        return netlinkSocketForProto(NETLINK_INET_DIAG, 0);
+        return netlinkSocketForProto(NETLINK_INET_DIAG);
     }
 
     /**
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/NetlinkUtilsTest.java b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/NetlinkUtilsTest.java
index b644a53..f64adb8 100644
--- a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/NetlinkUtilsTest.java
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/NetlinkUtilsTest.java
@@ -212,7 +212,7 @@
 
     @Test @IgnoreUpTo(Build.VERSION_CODES.R) // getsockoptInt requires > R
     public void testNetlinkSocketForProto_defaultBufferSize() throws Exception {
-        final FileDescriptor fd = NetlinkUtils.netlinkSocketForProto(NETLINK_ROUTE, 0);
+        final FileDescriptor fd = NetlinkUtils.netlinkSocketForProto(NETLINK_ROUTE);
         final int bufferSize = Os.getsockoptInt(fd, SOL_SOCKET, SO_RCVBUF) / 2;
 
         assertTrue("bufferSize: " + bufferSize, bufferSize > 0); // whatever the default value is
diff --git a/thread/service/java/com/android/server/thread/TunInterfaceController.java b/thread/service/java/com/android/server/thread/TunInterfaceController.java
index 619a510..7223b2a 100644
--- a/thread/service/java/com/android/server/thread/TunInterfaceController.java
+++ b/thread/service/java/com/android/server/thread/TunInterfaceController.java
@@ -60,8 +60,7 @@
     public void createTunInterface() throws IOException {
         mParcelTunFd = ParcelFileDescriptor.adoptFd(nativeCreateTunInterface(mIfName, MTU));
         try {
-            mNetlinkSocket =
-                    NetlinkUtils.netlinkSocketForProto(OsConstants.NETLINK_ROUTE, 0);
+            mNetlinkSocket = NetlinkUtils.netlinkSocketForProto(OsConstants.NETLINK_ROUTE);
         } catch (ErrnoException e) {
             throw new IOException("Failed to create netlink socket", e);
         }