IPv4 and IPv6 react differently to a netdev being unregistered. In IPv4,
in case the netdev is used as a nexthop device in a multipath route, the
entire route is flushed.
However, IPv6 only removes the nexthops associated with the unregistered
netdev.
Align IPv4 and IPv6 and flush all the sibling routes when a nexthop
device is unregistered.
Signed-off-by: Ido Schimmel <ido...@mellanox.com>
---
net/ipv6/route.c | 44 +++++++++++++++++++++++++++++++++++++++-----
1 file changed, 39 insertions(+), 5 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 4d0d32309bcc..cf895989f2bb 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3503,6 +3503,29 @@ void rt6_sync_up(struct net_device *dev, unsigned int
nh_flags)
fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
}
+static bool rt6_multipath_uses_dev(const struct rt6_info *rt,
+ const struct net_device *dev)
+{
+ struct rt6_info *iter;
+
+ if (rt->dst.dev == dev)
+ return true;
+ list_for_each_entry(iter, &rt->rt6i_siblings, rt6i_siblings)
+ if (iter->dst.dev == dev)
+ return true;
+
+ return false;
+}
+
+static void rt6_multipath_flush(struct rt6_info *rt)
+{
+ struct rt6_info *iter;
+
+ rt->should_flush = 1;
+ list_for_each_entry(iter, &rt->rt6i_siblings, rt6i_siblings)
+ iter->should_flush = 1;
+}
+
/* called with write lock held for table with rt */
static int fib6_ifdown(struct rt6_info *rt, void *p_arg)
{
@@ -3510,20 +3533,31 @@ static int fib6_ifdown(struct rt6_info *rt, void *p_arg)
const struct net_device *dev = arg->dev;
const struct net *net = dev_net(dev);
- if (rt->dst.dev != dev || rt == net->ipv6.ip6_null_entry)
+ if (rt == net->ipv6.ip6_null_entry)
return 0;
switch (arg->event) {
case NETDEV_UNREGISTER:
- return -1;
+ if (rt->should_flush)
+ return -1;
+ if (!rt->rt6i_nsiblings)
+ return rt->dst.dev == dev ? -1 : 0;
+ if (rt6_multipath_uses_dev(rt, dev)) {
+ rt6_multipath_flush(rt);
+ return -1;
+ }
+ return -2;
case NETDEV_DOWN:
+ if (rt->dst.dev != dev)
+ break;
if (rt->rt6i_nsiblings == 0 ||
!rt->rt6i_idev->cnf.ignore_routes_with_linkdown)
return -1;
- rt->rt6i_nh_flags |= RTNH_F_DEAD;
- /* fall through */
+ rt->rt6i_nh_flags |= (RTNH_F_DEAD | RTNH_F_LINKDOWN);
+ break;
case NETDEV_CHANGE:
- if (rt->rt6i_flags & (RTF_LOCAL | RTF_ANYCAST))
+ if (rt->dst.dev != dev ||
+ rt->rt6i_flags & (RTF_LOCAL | RTF_ANYCAST))
break;
rt->rt6i_nh_flags |= RTNH_F_LINKDOWN;
break;
--
2.14.3
