Re: batman-adv: design suggestions
From: Sven Eckelmann
Date: Fri Aug 13 2010 - 19:25:52 EST
Vasiliy Kulikov wrote:
> On Tue, Aug 10, 2010 at 00:34 +0400, Vasiliy Kulikov wrote:
> > 2) It seems to me that NF_HOOK() at hard-interface.c:458 is misused:
> > ...
> >
> > ret = NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, dev, NULL,
> >
> > batman_skb_recv_finish);
> >
> > if (ret != 1)
> >
> > goto err_out;
> >
> > /* packet should hold at least type and version */
> > if (unlikely(skb_headlen(skb) < 2))
> >
> > goto err_free;
> >
> > /* expect a valid ethernet header here. */
> > if (unlikely(skb->mac_len != sizeof(struct ethhdr)
> >
> > || !skb_mac_header(skb)))
> >
> > goto err_free;
> >
> > ...
> >
> > static int batman_skb_recv_finish(struct sk_buff *skb)
> > {
> >
> > return NF_ACCEPT;
> >
> > }
> >
> > As I understand, if there is any hook that returns NF_STOLEN, then skb
> > is leaked.
>
[...]
> b) Why do you use bridge tables at all? This layer does not know
> anything about batman layer, only ethernet that is only a tunnel for
> batman. So, it is able to hook traffic from concrete prev-hop routers,
> but not from original sources of packets. I think it is not enough for
> network filter.
> Also if you want to process [*] cases you have to append fake
> ethernet headers before network header as NF_HOOK() would use ethernet
> header.
Because a different person (no one from the actual development team) wanted to
have it for testing purposes. Maybe we just drop it again.
thanks,
Sven
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