[RFC PATCH net-next 09/19] ipv6: Ignore dead routes during lookup
From: Ido Schimmel <hidden>
Date: 2017-12-31 16:16:42
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Currently, dead routes are only present in the routing tables in case the 'ignore_routes_with_linkdown' sysctl is set. Otherwise, they are flushed. Subsequent patches are going to remove the reliance on this sysctl and make IPv6 more consistent with IPv4. Before this is done, we need to make sure dead routes are skipped during route lookup, so as to not cause packet loss. Signed-off-by: Ido Schimmel <redacted> --- net/ipv6/route.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 2bef8d1f279d..0927b02b2819 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c@@ -474,6 +474,8 @@ static struct rt6_info *rt6_multipath_select(struct rt6_info *match, if (route_choosen == 0) { struct inet6_dev *idev = sibling->rt6i_idev; + if (sibling->rt6i_nh_flags & RTNH_F_DEAD) + break; if (sibling->rt6i_nh_flags & RTNH_F_LINKDOWN && idev->cnf.ignore_routes_with_linkdown) break;
@@ -499,12 +501,15 @@ static inline struct rt6_info *rt6_device_match(struct net *net, struct rt6_info *local = NULL; struct rt6_info *sprt; - if (!oif && ipv6_addr_any(saddr)) - goto out; + if (!oif && ipv6_addr_any(saddr) && !(rt->rt6i_nh_flags & RTNH_F_DEAD)) + return rt; for (sprt = rt; sprt; sprt = rcu_dereference(sprt->rt6_next)) { struct net_device *dev = sprt->dst.dev; + if (sprt->rt6i_nh_flags & RTNH_F_DEAD) + continue; + if (oif) { if (dev->ifindex == oif) return sprt;
@@ -533,8 +538,8 @@ static inline struct rt6_info *rt6_device_match(struct net *net, if (flags & RT6_LOOKUP_F_IFACE) return net->ipv6.ip6_null_entry; } -out: - return rt; + + return rt->rt6i_nh_flags & RTNH_F_DEAD ? net->ipv6.ip6_null_entry : rt; } #ifdef CONFIG_IPV6_ROUTER_PREF
@@ -680,6 +685,9 @@ static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict, bool match_do_rr = false; struct inet6_dev *idev = rt->rt6i_idev; + if (rt->rt6i_nh_flags & RTNH_F_DEAD) + goto out; + if (idev->cnf.ignore_routes_with_linkdown && rt->rt6i_nh_flags & RTNH_F_LINKDOWN && !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
@@ -2153,6 +2161,8 @@ static struct rt6_info *__ip6_route_redirect(struct net *net, fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); restart: for_each_fib6_node_rt_rcu(fn) { + if (rt->rt6i_nh_flags & RTNH_F_DEAD) + continue; if (rt6_check_expired(rt)) continue; if (rt->dst.error)
--
2.14.3