From 1da35f71d2889699864d0cd8f76a6ee8caacfb5b Mon Sep 17 00:00:00 2001
From: jiaguo <jiaguo@marvell.com>
Date: Thu, 9 Jan 2014 16:39:59 +0800
Subject: [PATCH] Tethering: Skip link local addresses when enabling NAT

Only one entry is allowed to be added to route table 60 for all
interface ipv6 link local addresses, so skip ipv6 link local
addresses on all interfaces when enabling NAT

Change-Id: Ibbe6c2bdae83586cdd38287089715f3433bbb91f
Signed-off-by: jiaguo <jiaguo@marvell.com>
---
 .../android/server/NetworkManagementService.java | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/services/java/com/android/server/NetworkManagementService.java b/services/java/com/android/server/NetworkManagementService.java
index ad7ec99775a31..e6c5422a8fc11 100644
--- a/services/java/com/android/server/NetworkManagementService.java
+++ b/services/java/com/android/server/NetworkManagementService.java
@@ -82,6 +82,7 @@ import java.net.SocketException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.StringTokenizer;
@@ -1022,6 +1023,15 @@ public class NetworkManagementService extends INetworkManagementService.Stub
         }
     }
 
+    private List<InterfaceAddress> excludeLinkLocal(List<InterfaceAddress> addresses) {
+        ArrayList<InterfaceAddress> filtered = new ArrayList<InterfaceAddress>(addresses.size());
+        for (InterfaceAddress ia : addresses) {
+            if (!ia.getAddress().isLinkLocalAddress())
+                filtered.add(ia);
+        }
+        return filtered;
+    }
+
     private void modifyNat(String action, String internalInterface, String externalInterface)
             throws SocketException {
         final Command cmd = new Command("nat", action, internalInterface, externalInterface);
@@ -1031,8 +1041,10 @@ public class NetworkManagementService extends INetworkManagementService.Stub
         if (internalNetworkInterface == null) {
             cmd.appendArg("0");
         } else {
-            Collection<InterfaceAddress> interfaceAddresses = internalNetworkInterface
-                    .getInterfaceAddresses();
+            // Don't touch link-local routes, as link-local addresses aren't routable,
+            // kernel creates link-local routes on all interfaces automatically
+            List<InterfaceAddress> interfaceAddresses = excludeLinkLocal(
+                    internalNetworkInterface.getInterfaceAddresses());
             cmd.appendArg(interfaceAddresses.size());
             for (InterfaceAddress ia : interfaceAddresses) {
                 InetAddress addr = NetworkUtils.getNetworkPart(