Change tetheroffloadjni to tetheringutilsjni

Rename tetheroffloadjni to tetheringutilsjni and move setupRaSocket
jni method from NetUtils into tetheringutilsjni.

Bug: 143195885
Test: -build, flash, boot
      -atest TetheringTests
      -Off/On hotspot with ipv6 upstream

Change-Id: Ib68eb6999bbe2d3ca97e68712f22b105311ef800
diff --git a/Tethering/src/android/net/ip/RouterAdvertisementDaemon.java b/Tethering/src/android/net/ip/RouterAdvertisementDaemon.java
index 4147413..4396cdb 100644
--- a/Tethering/src/android/net/ip/RouterAdvertisementDaemon.java
+++ b/Tethering/src/android/net/ip/RouterAdvertisementDaemon.java
@@ -30,6 +30,7 @@
 import android.net.NetworkUtils;
 import android.net.TrafficStats;
 import android.net.util.InterfaceParams;
+import android.net.util.TetheringUtils;
 import android.system.ErrnoException;
 import android.system.Os;
 import android.system.StructTimeval;
@@ -613,7 +614,7 @@
                     mSocket, SOL_SOCKET, SO_SNDTIMEO, StructTimeval.fromMillis(send_timout_ms));
             Os.setsockoptIfreq(mSocket, SOL_SOCKET, SO_BINDTODEVICE, mInterface.name);
             NetworkUtils.protectFromVpn(mSocket);
-            NetworkUtils.setupRaSocket(mSocket, mInterface.index);
+            TetheringUtils.setupRaSocket(mSocket, mInterface.index);
         } catch (ErrnoException | IOException e) {
             Log.e(TAG, "Failed to create RA daemon socket: " + e);
             return false;
diff --git a/Tethering/src/android/net/util/TetheringUtils.java b/Tethering/src/android/net/util/TetheringUtils.java
new file mode 100644
index 0000000..2fb73ce
--- /dev/null
+++ b/Tethering/src/android/net/util/TetheringUtils.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.net.util;
+
+import java.io.FileDescriptor;
+import java.net.SocketException;
+
+/**
+ * Native methods for tethering utilization.
+ *
+ * {@hide}
+ */
+public class TetheringUtils {
+
+    /**
+     * Offload management process need to know conntrack rules to support NAT, but it may not have
+     * permission to create netlink netfilter sockets. Create two netlink netfilter sockets and
+     * share them with offload management process.
+     */
+    public static native boolean configOffload();
+
+    /**
+     * Configures a socket for receiving ICMPv6 router solicitations and sending advertisements.
+     * @param fd the socket's {@link FileDescriptor}.
+     * @param ifIndex the interface index.
+     */
+    public static native void setupRaSocket(FileDescriptor fd, int ifIndex)
+            throws SocketException;
+}