ipv6: generate link local address for GRE tunnel

Use same logic as SIT tunnel to handle link local address
for GRE tunnel. OSPFv3 requires link-local address to function.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 35 insertions, 0 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 498b927f68be..3e369425df58 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1559,6 +1559,11 @@ static int addrconf_ifid_sit(u8 *eui, struct net_device *dev)
         return -1;
 }
 
+static int addrconf_ifid_gre(u8 *eui, struct net_device *dev)
+{
+        return __ipv6_isatap_ifid(eui, *(__be32 *)dev->dev_addr);
+}
+
 static int ipv6_generate_eui64(u8 *eui, struct net_device *dev)
 {
         switch (dev->type) {
@@ -1572,6 +1577,8 @@ static int ipv6_generate_eui64(u8 *eui, struct net_device *dev)
                 return addrconf_ifid_infiniband(eui, dev);
         case ARPHRD_SIT:
                 return addrconf_ifid_sit(eui, dev);
+        case ARPHRD_IPGRE:
+                return addrconf_ifid_gre(eui, dev);
         }
         return -1;
 }
@@ -2423,6 +2430,29 @@ static void addrconf_sit_config(struct net_device *dev)
 }
 #endif
 
+#if defined(CONFIG_NET_IPGRE) || defined(CONFIG_NET_IPGRE_MODULE)
+static void addrconf_gre_config(struct net_device *dev)
+{
+        struct inet6_dev *idev;
+        struct in6_addr addr;
+
+        pr_info("ipv6: addrconf_gre_config(%s)\n", dev->name);
+
+        ASSERT_RTNL();
+
+        if ((idev = ipv6_find_idev(dev)) == NULL) {
+                printk(KERN_DEBUG "init gre: add_dev failed\n");
+                return;
+        }
+
+        ipv6_addr_set(&addr,  htonl(0xFE800000), 0, 0, 0);
+        addrconf_prefix_route(&addr, 64, dev, 0, 0);
+
+        if (!ipv6_generate_eui64(addr.s6_addr + 8, dev))
+                addrconf_add_linklocal(idev, &addr);
+}
+#endif
+
 static inline int
 ipv6_inherit_linklocal(struct inet6_dev *idev, struct net_device *link_dev)
 {
@@ -2539,6 +2569,11 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event,
                         addrconf_sit_config(dev);
                         break;
 #endif
+#if defined(CONFIG_NET_IPGRE) || defined(CONFIG_NET_IPGRE_MODULE)
+                case ARPHRD_IPGRE:
+                        addrconf_gre_config(dev);
+                        break;
+#endif
                 case ARPHRD_TUNNEL6:
                         addrconf_ip6_tnl_config(dev);
                         break;