Re: [PATCH v4] net: netfilter: Fix rpfilter dropping vrf packets by mistake

[linmiaohe <linmiaohe@huawei.com>]

On 6/29/19 1:05 AM, David Ahern wrote:
> On 6/28/19 3:06 AM, Miaohe Lin wrote:
> > diff --git a/net/ipv6/netfilter/ip6t_rpfilter.c 
> > b/net/ipv6/netfilter/ip6t_rpfilter.c
> > index 6bcaf7357183..3c4a1772c15f 100644
> > --- a/net/ipv6/netfilter/ip6t_rpfilter.c
> > +++ b/net/ipv6/netfilter/ip6t_rpfilter.c
> > @@ -55,6 +55,10 @@ static bool rpfilter_lookup_reverse6(struct net *net, const struct sk_buff *skb,
> >  	if (rpfilter_addr_linklocal(&iph->saddr)) {
> >  		lookup_flags |= RT6_LOOKUP_F_IFACE;
> >  		fl6.flowi6_oif = dev->ifindex;
> > +	/* Set flowi6_oif for vrf devices to lookup route in l3mdev domain. */
> > +	} else if (netif_is_l3_master(dev) || netif_is_l3_slave(dev)) {
> > +		lookup_flags |= FLOWI_FLAG_SKIP_NH_OIF;
>
> you don't need to set that flag here. It is done by the fib_rules code as needed.
>
You're right. Fib rules code would set FLOWI_FLAG_SKIP_NH_OIF flag.  But I set
it here for distinguish with the flags & XT_RPFILTER_LOOSE branch. Without
this, they do the same work and maybe should be  combined. I don't want to
do that as that makes code confusing.
Is this code snipet below ok ? If so, I would delete this flag setting.
 
       } else if (netif_is_l3_master(dev) || netif_is_l3_slave(dev)) {
               fl6.flowi6_oif = dev->ifindex;
        } else if ((flags & XT_RPFILTER_LOOSE) == 0)
                fl6.flowi6_oif = dev->ifindex;