From: Benjamin Poirier <bpoirier@xxxxxxxxxxxxxxxxxxx>
[ Upstream commit afecdb376bd81d7e16578f0cfe82a1aec7ae18f3 ]
When splitting an RTA_MULTIPATH request into multiple routes and adding the
second and later components, we must not simply remove NLM_F_REPLACE but
instead replace it by NLM_F_CREATE. Otherwise, it may look like the netlink
message was malformed.
For example,
ip route add 2001:db8::1/128 dev dummy0
ip route change 2001:db8::1/128 nexthop via fe80::30:1 dev dummy0 \
nexthop via fe80::30:2 dev dummy0
results in the following warnings:
[ 1035.057019] IPv6: RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE
[ 1035.057517] IPv6: NLM_F_CREATE should be set when creating new route
This patch makes the nlmsg sequence look equivalent for __ip6_ins_rt() to
what it would get if the multipath route had been added in multiple netlink
operations:
ip route add 2001:db8::1/128 dev dummy0
ip route change 2001:db8::1/128 nexthop via fe80::30:1 dev dummy0
ip route append 2001:db8::1/128 nexthop via fe80::30:2 dev dummy0
Fixes: 27596472473a ("ipv6: fix ECMP route replacement")
Signed-off-by: Benjamin Poirier <bpoirier@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Michal Kubecek <mkubecek@xxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/route.c | 1 +
1 file changed, 1 insertion(+)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3069,6 +3069,7 @@ static int ip6_route_multipath_add(struc
*/
cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
NLM_F_REPLACE);
+ cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
nhn++;
}
