From: Benjamin Poirier bpoirier@cumulusnetworks.com
[ 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@cumulusnetworks.com Reviewed-by: Michal Kubecek mkubecek@suse.cz Reviewed-by: David Ahern dsahern@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/route.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -3283,6 +3283,7 @@ 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++; }