On Tue, Sep 1, 2020 at 8:58 AM Brian Vazquez <bria...@google.com> wrote:
>
> The problem is exposed when the system has multiple ifaces and
> forwarding is enabled on a subset of them, __rt6_purge_dflt_routers will
> clean the default route on all the ifaces which is not desired.
>
> This patches fixes that by cleaning only the routes where the iface has
> forwarding enabled.
>
> Fixes: 830218c1add1 ("net: ipv6: Fix processing of RAs in presence of VRF")
> Cc: David Ahern <d...@cumulusnetworks.com>
> Signed-off-by: Brian Vazquez <bria...@google.com>
> ---
> net/ipv6/route.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 5e7e25e2523a..41181cd489ea 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -4283,6 +4283,7 @@ static void __rt6_purge_dflt_routers(struct net *net,
> struct fib6_table *table)
> {
> struct fib6_info *rt;
> + bool deleted = false;
>
> restart:
> rcu_read_lock();
> @@ -4291,16 +4292,19 @@ static void __rt6_purge_dflt_routers(struct net *net,
> struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
>
> if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
> - (!idev || idev->cnf.accept_ra != 2) &&
> + (!idev || (idev->cnf.forwarding == 1 &&
> + idev->cnf.accept_ra != 2)) &&
> fib6_info_hold_safe(rt)) {
> rcu_read_unlock();
> ip6_del_rt(net, rt, false);
> + deleted = true;
> goto restart;
> }
> }
> rcu_read_unlock();
>
> - table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
> + if (deleted)
> + table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
This seems wrong : We want to keep the flag set if at least one
candidate route has not been deleted,
so that next time rt6_purge_dflt_routers() is called, we can call
__rt6_purge_dflt_routers() ?
