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

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

[Lorenzo Colitti]

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@google.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 9282665..e5fe004 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1915,7 +1915,8 @@ 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);
-- 
1.8.1.3

Re: [PATCH] net: ipv6: Don't purge default router if accept_ra=2

[YOSHIFUJI Hideaki]

Lorenzo Colitti wrote:
> 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@google.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 9282665..e5fe004 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -1915,7 +1915,8 @@ 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);
> 

Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

--yoshfuji

Re: [PATCH] net: ipv6: Don't purge default router if accept_ra=2

[Eric Dumazet]

On Mon, 2013-03-04 at 15:46 +0900, Lorenzo Colitti wrote:
> 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@google.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 9282665..e5fe004 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -1915,7 +1915,8 @@ 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);

Acked-by: Eric Dumazet <edumazet@google.com>

Re: [PATCH] net: ipv6: Don't purge default router if accept_ra=2

[David Miller]

From: Lorenzo Colitti <lorenzo@google.com>
Date: Mon, 4 Mar 2013 15:46:46 +0900

> 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@google.com>

Applied and queued up for -stable.