Re: [Cake] cake and nat in openwrt... on by default?

[Dave Taht <dave.taht@gmail.com>]

On Sun, Apr 5, 2020 at 12:57 AM Kevin Darbyshire-Bryant
<kevin@darbyshire-bryant.me.uk> wrote:
>
>
>
> > On 5 Apr 2020, at 05:17, Dave Taht <dave.taht@gmail.com> wrote:
> >
> > I see cake is moving to the upstreamed version. As best as I recall,
> > nat mode was on by default in the openwrt code, but not the upstreamed
> > code.
> >
> > People not setting nat mode on would explain a few things i've seen
> > 'round the intertubes this week.
>
> From sch_cake repo and hence ‘out of tree’ cake
>
>         if (tb[TCA_CAKE_NAT]) {
> #if IS_REACHABLE(CONFIG_NF_CONNTRACK)
>                 q->flow_mode &= ~CAKE_FLOW_NAT_FLAG;
>                 q->flow_mode |= CAKE_FLOW_NAT_FLAG *
>                         !!nla_get_u32(tb[TCA_CAKE_NAT]);
> #else
> #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 16, 0)
>                 NL_SET_ERR_MSG_ATTR(extack, tb[TCA_CAKE_NAT],
>                                     "No conntrack support in kernel");
> #endif
>                 return -EOPNOTSUPP;
> #endif
>         }
>
>
> From kernel 5.4 as found in openwrt build dir
>
>         if (tb[TCA_CAKE_NAT]) {
> #if IS_ENABLED(CONFIG_NF_CONNTRACK)
>                 q->flow_mode &= ~CAKE_FLOW_NAT_FLAG;
>                 q->flow_mode |= CAKE_FLOW_NAT_FLAG *
>                         !!nla_get_u32(tb[TCA_CAKE_NAT]);
> #else
>                 NL_SET_ERR_MSG_ATTR(extack, tb[TCA_CAKE_NAT],
>                                     "No conntrack support in kernel");
>                 return -EOPNOTSUPP;
> #endif
>
>
>
> cake_init(…) in both does:
>
> q->flow_mode  = CAKE_FLOW_TRIPLE;
>
>
> So openwrt doesn’t, by default, enable NAT mode in cake.
>
> I honestly don’t think that there are enough instances of cake out there, let alone instances of cake from openwrt, let alone instances of cake from master which switched to upstream cake 2-3 days ago, to make any sort of difference anyway.

I'd still be willing to bet, then, that the majority of instances were
not turning nat mode on, when
they should have been.

>
> >
> > --
> > Make Music, Not War
> >
> > Dave Täht
> > CTO, TekLibre, LLC
> > http://www.teklibre.com
> > Tel: 1-831-435-0729
> > _______________________________________________
> > Cake mailing list
> > Cake@lists.bufferbloat.net
> > https://lists.bufferbloat.net/listinfo/cake
>
>
> Cheers,
>
> Kevin D-B
>
> gpg: 012C ACB2 28C6 C53E 9775  9123 B3A2 389B 9DE2 334A
>


-- 
Make Music, Not War

Dave Täht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-435-0729