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

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

[linmiaohe]

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;

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

[David Ahern]

On 6/28/19 8:13 PM, linmiaohe wrote:
> 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;

that looks fine to me, but it is up to Pablo.

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

[linmiaohe]

On 6/29/19 20:20 PM, David Ahern wrote:
> On 6/28/19 8:13 PM, linmiaohe wrote:
> > 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;

> that looks fine to me, but it is up to Pablo.

@David Ahern  Many thanks for your valuable advice.

@ Pablo Hi, could you please tell me if this code snipet is ok?
If not, which code would you prefer? It's very nice of you to
figure it out for me. Thanks a lot.

Have a nice day.
Best wishes.

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

[Pablo Neira Ayuso]

On Sat, Jun 29, 2019 at 02:13:59PM +0000, linmiaohe wrote:
> On 6/29/19 20:20 PM, David Ahern wrote:
> > On 6/28/19 8:13 PM, linmiaohe wrote:
> > > 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;
> 
> > that looks fine to me, but it is up to Pablo.
> 
> @David Ahern  Many thanks for your valuable advice.
> 
> @ Pablo Hi, could you please tell me if this code snipet is ok?
> If not, which code would you prefer? It's very nice of you to
> figure it out for me. Thanks a lot.

Probably this?

        } else if (netif_is_l3_master(dev) || netif_is_l3_slave(dev) ||
                   (flags & XT_RPFILTER_LOOSE) == 0) {
                fl6.flowi6_oif = dev->ifindex;
        }

Thanks.