| Message ID | 20171121075012.11077-1-idosch@mellanox.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] ipv6: Do not consider linkdown nexthops during multipath | expand |
On 11/21/17 12:50 AM, Ido Schimmel wrote: > When the 'ignore_routes_with_linkdown' sysctl is set, we should not > consider linkdown nexthops during route lookup. > > While the code correctly verifies that the initially selected route > ('match') has a carrier, it does not perform the same check in the > subsequent multipath selection, resulting in a potential packet loss. > > In case the chosen route does not have a carrier and the sysctl is set, > choose the initially selected route. > > Fixes: 35103d11173b ("net: ipv6 sysctl option to ignore routes when nexthop link is down") > Signed-off-by: Ido Schimmel <idosch@mellanox.com> > --- > net/ipv6/route.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/net/ipv6/route.c b/net/ipv6/route.c > index 05eb7bc36156..0363db914c7a 100644 > --- a/net/ipv6/route.c > +++ b/net/ipv6/route.c > @@ -472,6 +472,11 @@ static struct rt6_info *rt6_multipath_select(struct rt6_info *match, > &match->rt6i_siblings, rt6i_siblings) { > route_choosen--; > if (route_choosen == 0) { > + struct inet6_dev *idev = sibling->rt6i_idev; > + > + if (!netif_carrier_ok(sibling->dst.dev) && > + idev->cnf.ignore_routes_with_linkdown) > + break; > if (rt6_score_route(sibling, oif, strict) < 0) > break; > match = sibling; > Looks right to me. Acked-by: David Ahern <dsahern@gmail.com>
On Tue, Nov 21, 2017 at 09:50:12AM +0200, Ido Schimmel wrote: > When the 'ignore_routes_with_linkdown' sysctl is set, we should not > consider linkdown nexthops during route lookup. > > While the code correctly verifies that the initially selected route > ('match') has a carrier, it does not perform the same check in the > subsequent multipath selection, resulting in a potential packet loss. > > In case the chosen route does not have a carrier and the sysctl is set, > choose the initially selected route. > > Fixes: 35103d11173b ("net: ipv6 sysctl option to ignore routes when nexthop link is down") > Signed-off-by: Ido Schimmel <idosch@mellanox.com> Nice find. Looks good to me, as well. Acked-by: Andy Gospodarek <andy@greyhouse.net> > --- > net/ipv6/route.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/net/ipv6/route.c b/net/ipv6/route.c > index 05eb7bc36156..0363db914c7a 100644 > --- a/net/ipv6/route.c > +++ b/net/ipv6/route.c > @@ -472,6 +472,11 @@ static struct rt6_info *rt6_multipath_select(struct rt6_info *match, > &match->rt6i_siblings, rt6i_siblings) { > route_choosen--; > if (route_choosen == 0) { > + struct inet6_dev *idev = sibling->rt6i_idev; > + > + if (!netif_carrier_ok(sibling->dst.dev) && > + idev->cnf.ignore_routes_with_linkdown) > + break; > if (rt6_score_route(sibling, oif, strict) < 0) > break; > match = sibling; > -- > 2.14.3 >
From: Ido Schimmel <idosch@mellanox.com> Date: Tue, 21 Nov 2017 09:50:12 +0200 > When the 'ignore_routes_with_linkdown' sysctl is set, we should not > consider linkdown nexthops during route lookup. > > While the code correctly verifies that the initially selected route > ('match') has a carrier, it does not perform the same check in the > subsequent multipath selection, resulting in a potential packet loss. > > In case the chosen route does not have a carrier and the sysctl is set, > choose the initially selected route. > > Fixes: 35103d11173b ("net: ipv6 sysctl option to ignore routes when nexthop link is down") > Signed-off-by: Ido Schimmel <idosch@mellanox.com> Applied.
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 05eb7bc36156..0363db914c7a 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -472,6 +472,11 @@ static struct rt6_info *rt6_multipath_select(struct rt6_info *match, &match->rt6i_siblings, rt6i_siblings) { route_choosen--; if (route_choosen == 0) { + struct inet6_dev *idev = sibling->rt6i_idev; + + if (!netif_carrier_ok(sibling->dst.dev) && + idev->cnf.ignore_routes_with_linkdown) + break; if (rt6_score_route(sibling, oif, strict) < 0) break; match = sibling;
When the 'ignore_routes_with_linkdown' sysctl is set, we should not consider linkdown nexthops during route lookup. While the code correctly verifies that the initially selected route ('match') has a carrier, it does not perform the same check in the subsequent multipath selection, resulting in a potential packet loss. In case the chosen route does not have a carrier and the sysctl is set, choose the initially selected route. Fixes: 35103d11173b ("net: ipv6 sysctl option to ignore routes when nexthop link is down") Signed-off-by: Ido Schimmel <idosch@mellanox.com> --- net/ipv6/route.c | 5 +++++ 1 file changed, 5 insertions(+)