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

[YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>]

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