ipv6: update Destination Cache entries when gateway turn into host
RFC 4861 states in 7.2.5:
The IsRouter flag in the cache entry MUST be set based on the
Router flag in the received advertisement. In those cases
where the IsRouter flag changes from TRUE to FALSE as a result
of this update, the node MUST remove that router from the
Default Router List and update the Destination Cache entries
for all destinations using that neighbor as a router as
specified in Section 7.3.3. This is needed to detect when a
node that is used as a router stops forwarding packets due to
being configured as a host.
Currently, when dealing with NA Message which IsRouter flag changes from
TRUE to FALSE, the kernel only removes router from the Default Router List,
and don't update the Destination Cache entries.
Now in order to update those Destination Cache entries, i introduce
function rt6_clean_tohost().
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 09a22f4..ca8d4ea 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -851,7 +851,7 @@
static void ndisc_recv_na(struct sk_buff *skb)
{
struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
- const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
+ struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
u8 *lladdr = NULL;
u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
@@ -944,10 +944,7 @@
/*
* Change: router to host
*/
- struct rt6_info *rt;
- rt = rt6_get_dflt_router(saddr, dev);
- if (rt)
- ip6_del_rt(rt);
+ rt6_clean_tohost(dev_net(dev), saddr);
}
out: