| From foo@baz Mon 02 Mar 2020 05:10:46 PM CET |
| From: Benjamin Poirier <bpoirier@cumulusnetworks.com> |
| Date: Wed, 12 Feb 2020 10:41:07 +0900 |
| Subject: ipv6: Fix nlmsg_flags when splitting a multipath route |
| |
| 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 |
| @@ -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++; |
| } |
| |