ipv6: flush nd cache on IFF_NOARP change
This patch is the IPv6 equivalent of commit
6c8b4e3ff81b ("arp: flush arp cache on IFF_NOARP change")
Without it, we keep buggy neighbours in the cache, with destination
MAC address equal to our own MAC address.
Tested:
tcpdump -i eth0 -s 0 ip6 -n -e &
ip link set dev eth0 arp off
ping6 remote // sends buggy frames
ip link set dev eth0 arp on
ping6 remote // should work once kernel is patched
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Mario Fanelli <mariofanelli@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 0a05b35..c53331c 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1650,6 +1650,7 @@
static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct netdev_notifier_change_info *change_info;
struct net *net = dev_net(dev);
struct inet6_dev *idev;
@@ -1664,6 +1665,11 @@
ndisc_send_unsol_na(dev);
in6_dev_put(idev);
break;
+ case NETDEV_CHANGE:
+ change_info = ptr;
+ if (change_info->flags_changed & IFF_NOARP)
+ neigh_changeaddr(&nd_tbl, dev);
+ break;
case NETDEV_DOWN:
neigh_ifdown(&nd_tbl, dev);
fib6_run_gc(0, net, false);