Hello,
On Mon, 21 Oct 2013, Hannes Frederic Sowa wrote:
> Not related to the patch:
>
> That reminds me that Yoshifuji had the idea to cache the results for
> ipv6_addr_type in IP6CB to avoid calling this function over and over again.
> Maybe we can do the same for rt6_infos to save some cycles here and there.
Yes, ipv6_addr_type has little price. May be only
DNAT and IPSec can complicate such caching.
> Also, what do you think about this site:
>
> net/ipv6/ip6_output.c:
> 411
> 412 rt = (struct rt6_info *) dst;
> 413 if (rt->rt6i_flags & RTF_GATEWAY)
> 414 target = &rt->rt6i_gateway;
> 415 else
> 416 target = &hdr->daddr;
> 417
>
> Our provided skb_dst should come from ip6_route_input, thus ip6_pol_route. So
> I assume we have rt6i_gateway == hdr->daddr there, too. It is a bit more
> complicated because of possible routing extension headers. Maybe you already
> looked at this already?
Yes, I checked every site that uses rt6i_gateway but
not with the perspective to use rt6_nexthop(). It seems
this is a rt6_nexthop() candidate.
> I just found it while searching which other code paths do emit packets
> while xt_TEE is processing (generation of redirects) and could also lead
> to stack exhaustion. But the path in ip6_forward seems fine.
Yes. I found only one place more dangerous:
fib6_add_rt2node(). But I think its checks are still valid.
Regards
--
Julian Anastasov <ja@xxxxxx>
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