[BOT.5] Move class Ipv6ForwardingRule from IpServer to the coordinator

This is a preparation for moving adding/removing forwarding rules from
IpServer to BpfCoordinator.

Bug: 150736748
Test: atest IpServerTest
Change-Id: I85316ef09ff3c9389ded11dcc384493d699da48e
diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index 4d02877..088b88c 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -33,7 +33,6 @@
 import android.net.LinkProperties;
 import android.net.MacAddress;
 import android.net.RouteInfo;
-import android.net.TetherOffloadRuleParcel;
 import android.net.TetheredClient;
 import android.net.TetheringManager;
 import android.net.TetheringRequestParcel;
@@ -66,6 +65,7 @@
 import com.android.internal.util.State;
 import com.android.internal.util.StateMachine;
 import com.android.networkstack.tethering.BpfCoordinator;
+import com.android.networkstack.tethering.BpfCoordinator.Ipv6ForwardingRule;
 import com.android.networkstack.tethering.PrivateAddressCoordinator;
 
 import java.io.IOException;
@@ -272,40 +272,6 @@
         }
     }
 
-    static class Ipv6ForwardingRule {
-        public final int upstreamIfindex;
-        public final int downstreamIfindex;
-        public final Inet6Address address;
-        public final MacAddress srcMac;
-        public final MacAddress dstMac;
-
-        Ipv6ForwardingRule(int upstreamIfindex, int downstreamIfIndex, Inet6Address address,
-                MacAddress srcMac, MacAddress dstMac) {
-            this.upstreamIfindex = upstreamIfindex;
-            this.downstreamIfindex = downstreamIfIndex;
-            this.address = address;
-            this.srcMac = srcMac;
-            this.dstMac = dstMac;
-        }
-
-        public Ipv6ForwardingRule onNewUpstream(int newUpstreamIfindex) {
-            return new Ipv6ForwardingRule(newUpstreamIfindex, downstreamIfindex, address, srcMac,
-                    dstMac);
-        }
-
-        // Don't manipulate TetherOffloadRuleParcel directly because implementing onNewUpstream()
-        // would be error-prone due to generated stable AIDL classes not having a copy constructor.
-        public TetherOffloadRuleParcel toTetherOffloadRuleParcel() {
-            final TetherOffloadRuleParcel parcel = new TetherOffloadRuleParcel();
-            parcel.inputInterfaceIndex = upstreamIfindex;
-            parcel.outputInterfaceIndex = downstreamIfindex;
-            parcel.destination = address.getAddress();
-            parcel.prefixLength = 128;
-            parcel.srcL2Address = srcMac.toByteArray();
-            parcel.dstL2Address = dstMac.toByteArray();
-            return parcel;
-        }
-    }
     private final LinkedHashMap<Inet6Address, Ipv6ForwardingRule> mIpv6ForwardingRules =
             new LinkedHashMap<>();
 
diff --git a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
index aded6cf..6b854f2 100644
--- a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
+++ b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
@@ -26,8 +26,10 @@
 
 import android.app.usage.NetworkStatsManager;
 import android.net.INetd;
+import android.net.MacAddress;
 import android.net.NetworkStats;
 import android.net.NetworkStats.Entry;
+import android.net.TetherOffloadRuleParcel;
 import android.net.TetherStatsParcel;
 import android.net.netstats.provider.NetworkStatsProvider;
 import android.net.util.SharedLog;
@@ -43,6 +45,8 @@
 
 import com.android.internal.annotations.VisibleForTesting;
 
+import java.net.Inet6Address;
+
 /**
  *  This coordinator is responsible for providing BPF offload relevant functionality.
  *  - Get tethering stats.
@@ -169,6 +173,45 @@
         }
     }
 
+    /** IPv6 forwarding rule class. */
+    public static class Ipv6ForwardingRule {
+        public final int upstreamIfindex;
+        public final int downstreamIfindex;
+        public final Inet6Address address;
+        public final MacAddress srcMac;
+        public final MacAddress dstMac;
+
+        public Ipv6ForwardingRule(int upstreamIfindex, int downstreamIfIndex, Inet6Address address,
+                MacAddress srcMac, MacAddress dstMac) {
+            this.upstreamIfindex = upstreamIfindex;
+            this.downstreamIfindex = downstreamIfIndex;
+            this.address = address;
+            this.srcMac = srcMac;
+            this.dstMac = dstMac;
+        }
+
+        /** Return a new rule object which updates with new upstream index. */
+        public Ipv6ForwardingRule onNewUpstream(int newUpstreamIfindex) {
+            return new Ipv6ForwardingRule(newUpstreamIfindex, downstreamIfindex, address, srcMac,
+                    dstMac);
+        }
+
+        /**
+         * Don't manipulate TetherOffloadRuleParcel directly because implementing onNewUpstream()
+         * would be error-prone due to generated stable AIDL classes not having a copy constructor.
+         */
+        public TetherOffloadRuleParcel toTetherOffloadRuleParcel() {
+            final TetherOffloadRuleParcel parcel = new TetherOffloadRuleParcel();
+            parcel.inputInterfaceIndex = upstreamIfindex;
+            parcel.outputInterfaceIndex = downstreamIfindex;
+            parcel.destination = address.getAddress();
+            parcel.prefixLength = 128;
+            parcel.srcL2Address = srcMac.toByteArray();
+            parcel.dstL2Address = dstMac.toByteArray();
+            return parcel;
+        }
+    }
+
     /**
      * A BPF tethering stats provider to provide network statistics to the system.
      * Note that this class's data may only be accessed on the handler thread.