[FIX][PATCH] ipv6 addrconf.c : wrong handling of non-ipv6 hardware since 2.6.21

[Oliver Hartkopp <socketcan@hartkopp.net>]

Hello Hideaki, hello David,

since 2.6.21 the new case NETDEV_REGISTER has been added to the big 
'switch' in addrconf_notify().

But within this "case NETDEV_REGISTER"-code no check about valid ipv6 
networking hardware is done, as it is done in NETDEV_UP, NETDEV_CHANGE 
and others.

Please apply the following patch to handle only valid ipv6 networking 
hardware inside the addrconf-notifier. This omits the invocation of 
ipv6_add_dev(dev) for non ipv6 capable hardware (e.g. with MTUs < 
IPV6_MIN_MTU) which leads to an ugly //"IPv6: add_dev failed for %s\n" 
kernel warning.//

The patch applies since 2.6.21 and also to the latest 2.6.22-rc1-git5 
(with an offset of 78 lines).

Best regards,
Oliver

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>

---
*--- linux-2.6.21/net/ipv6/addrconf.c.orig    2007-05-16 
01:43:30.000000000 +0200
+++ linux-2.6.21/net/ipv6/addrconf.c    2007-05-16 02:01:18.000000000 +0200
@@ -2076,15 +2076,6 @@ static void addrconf_dev_config(struct n
 
     ASSERT_RTNL();
 
-    if ((dev->type != ARPHRD_ETHER) &&
-        (dev->type != ARPHRD_FDDI) &&
-        (dev->type != ARPHRD_IEEE802_TR) &&
-        (dev->type != ARPHRD_ARCNET) &&
-        (dev->type != ARPHRD_INFINIBAND)) {
-        /* Alas, we support only Ethernet autoconfiguration. */
-        return;
-    }
-
     idev = addrconf_add_dev(dev);
     if (idev == NULL)
         return;
@@ -2172,13 +2163,35 @@ static void addrconf_ip6_tnl_config(stru
     ip6_tnl_add_linklocal(idev);
 }
 
+static int ipv6_hwtype(struct net_device *dev)
+{
+    if ((dev->type == ARPHRD_ETHER) ||
+        (dev->type == ARPHRD_LOOPBACK) ||
+#if defined(CONFIG_IPV6_SIT) || defined(CONFIG_IPV6_SIT_MODULE)
+        (dev->type == ARPHRD_SIT) ||
+#endif
+        (dev->type == ARPHRD_TUNNEL6) ||
+        (dev->type == ARPHRD_FDDI) ||
+        (dev->type == ARPHRD_IEEE802_TR) ||
+        (dev->type == ARPHRD_ARCNET) ||
+        (dev->type == ARPHRD_INFINIBAND))
+        return 1;
+
+    return 0;
+}
+
 static int addrconf_notify(struct notifier_block *this, unsigned long 
event,
                void * data)
 {
     struct net_device *dev = (struct net_device *) data;
-    struct inet6_dev *idev = __in6_dev_get(dev);
+    struct inet6_dev *idev;
     int run_pending = 0;
 
+    if (!ipv6_hwtype(dev))
+        return NOTIFY_OK;
+
+    idev = __in6_dev_get(dev);
+
     switch(event) {
     case NETDEV_REGISTER:
         if (!idev) {
*