Patch "net: ipv6: Do not consider link state for nexthop validation" has been added to the 4.8-stable tree

This is a note to let you know that I've just added the patch titled

net: ipv6: Do not consider link state for nexthop validation

to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
net-ipv6-do-not-consider-link-state-for-nexthop-validation.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: David Ahern <[email protected]>
Date: Mon, 24 Oct 2016 12:27:23 -0700
Subject: net: ipv6: Do not consider link state for nexthop validation

From: David Ahern <[email protected]>

[ Upstream commit d5d32e4b76687f4df9ad3ba8d3702b7347f51fa6 ]

Similar to IPv4, do not consider link state when validating next hops.

Currently, if the link is down default routes can fail to insert:

 $ ip -6 ro add vrf blue default via 2100:2::64 dev eth2
 RTNETLINK answers: No route to host

With this patch the command succeeds.

---
 include/net/ip6_route.h |    1 +
 net/ipv6/route.c        |    6 ++++--
 2 files changed, 5 insertions(+), 2 deletions(-)

@@ -32,6 +32,7 @@ struct route_info {
 #define RT6_LOOKUP_F_SRCPREF_TMP	0x00000008
 #define RT6_LOOKUP_F_SRCPREF_PUBLIC	0x00000010
 #define RT6_LOOKUP_F_SRCPREF_COA	0x00000020
+#define RT6_LOOKUP_F_IGNORE_LINKSTATE	0x00000040
 
 /* We do not (yet ?) support IPv6 jumbograms (RFC 2675)
  * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header

@@ -656,7 +656,8 @@ static struct rt6_info *find_match(struc
 	struct net_device *dev = rt->dst.dev;
 
 	if (dev && !netif_carrier_ok(dev) &&
-	    idev->cnf.ignore_routes_with_linkdown)
+	    idev->cnf.ignore_routes_with_linkdown &&
+	    !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
 		goto out;
 
 	if (rt6_check_expired(rt))

@@ -1050,6 +1051,7 @@ struct rt6_info *ip6_pol_route(struct ne
 	int strict = 0;
 
 	strict |= flags & RT6_LOOKUP_F_IFACE;
+	strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
 	if (net->ipv6.devconf_all->forwarding == 0)
 		strict |= RT6_LOOKUP_F_REACHABLE;
 

@@ -1783,7 +1785,7 @@ static struct rt6_info *ip6_nh_lookup_ta
 	};
 	struct fib6_table *table;
 	struct rt6_info *rt;
-	int flags = RT6_LOOKUP_F_IFACE;
+	int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_IGNORE_LINKSTATE;
 
 	table = fib6_get_table(net, cfg->fc_table);
 	if (!table)

Patches currently in stable-queue which might be from [email protected] are

queue-4.8/net-ipv6-do-not-consider-link-state-for-nexthop-validation.patch queue-4.8/net-core-correctly-iterate-over-lower-adjacency-list.patch