diff mbox series

[net-next,09/18] ipv6: Ignore dead routes during lookup

Message ID 20180107104518.31693-10-idosch@mellanox.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series ipv6: Align nexthop behaviour with IPv4 | expand

Commit Message

Ido Schimmel Jan. 7, 2018, 10:45 a.m. UTC 
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 <idosch@mellanox.com>
---
 net/ipv6/route.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

Comments

David Ahern Jan. 7, 2018, 5:02 p.m. UTC | #1 
On 1/7/18 3:45 AM, Ido Schimmel wrote:
> 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 <idosch@mellanox.com>
> ---
>  net/ipv6/route.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)

Acked-by: David Ahern <dsahern@gmail.com>
diff mbox series

Patch

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index f980f904d6ea..c00156805bf0 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)