[ 3.5.y.z extended stable ] Patch "net: ipv6: Don't purge default router if accept_ra=2" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    net: ipv6: Don't purge default router if accept_ra=2

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 04ad8706dda6b719b961bcba7bd324b95516f0fd Mon Sep 17 00:00:00 2001
From: Lorenzo Colitti <lorenzo at google.com>
Date: Sun, 3 Mar 2013 20:46:46 +0000
Subject: [PATCH] net: ipv6: Don't purge default router if accept_ra=2

commit 3e8b0ac3e41e3c882222a5522d5df7212438ab51 upstream.

Setting net.ipv6.conf.<interface>.accept_ra=2 causes the kernel
to accept RAs even when forwarding is enabled. However, enabling
forwarding purges all default routes on the system, breaking
connectivity until the next RA is received. Fix this by not
purging default routes on interfaces that have accept_ra=2.

Signed-off-by: Lorenzo Colitti <lorenzo at google.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji at linux-ipv6.org>
Acked-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ipv6/route.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 08c149c..577bb2f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1971,7 +1971,8 @@ void rt6_purge_dflt_routers(struct net *net)
 restart:
 	read_lock_bh(&table->tb6_lock);
 	for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
-		if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) {
+		if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
+		    (!rt->rt6i_idev || rt->rt6i_idev->cnf.accept_ra != 2)) {
 			dst_hold(&rt->dst);
 			read_unlock_bh(&table->tb6_lock);
 			ip6_del_rt(rt);
--
1.8.1.2