* Missing INET6_PROTO_FINAL in l2tp_ip6_protocol?
@ 2016-05-21 12:50 Shmulik Ladkani
2016-05-21 15:55 ` Hannes Frederic Sowa
0 siblings, 1 reply; 5+ messages in thread
From: Shmulik Ladkani @ 2016-05-21 12:50 UTC (permalink / raw)
To: netdev
Hi,
inet6_protocol's INET6_PROTO_FINAL flag denotes handler is expected not
to request resubmission for local delivery.
For an INET6_PROTO_FINAL handler, the following actions gets executed
prior delivery, in ip6_input_finish:
nf_reset(skb);
skb_postpull_rcsum(skb, skb_network_header(skb),
skb_network_header_len(skb));
For some reason, l2tp_ip6_protocol handler is NOT marked as
INET6_PROTO_FINAL. Probably an oversight.
Since 'l2tp_ip6_recv' never results in a resubmission, the above actions
are not applied to skbs passed to l2tp_ip6.
Any reason why l2tp_ip6_protocol should NOT be marked INET6_PROTO_FINAL?
What's the consequences not executing the above actions for l2tp_ip6
packets?
Thanks,
Shmulik
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Missing INET6_PROTO_FINAL in l2tp_ip6_protocol?
2016-05-21 12:50 Missing INET6_PROTO_FINAL in l2tp_ip6_protocol? Shmulik Ladkani
@ 2016-05-21 15:55 ` Hannes Frederic Sowa
2016-05-21 20:02 ` Shmulik Ladkani
0 siblings, 1 reply; 5+ messages in thread
From: Hannes Frederic Sowa @ 2016-05-21 15:55 UTC (permalink / raw)
To: Shmulik Ladkani, netdev
On 21.05.2016 14:50, Shmulik Ladkani wrote:
> Hi,
>
> inet6_protocol's INET6_PROTO_FINAL flag denotes handler is expected not
> to request resubmission for local delivery.
>
> For an INET6_PROTO_FINAL handler, the following actions gets executed
> prior delivery, in ip6_input_finish:
>
> nf_reset(skb);
>
> skb_postpull_rcsum(skb, skb_network_header(skb),
> skb_network_header_len(skb));
>
> For some reason, l2tp_ip6_protocol handler is NOT marked as
> INET6_PROTO_FINAL. Probably an oversight.
>
> Since 'l2tp_ip6_recv' never results in a resubmission, the above actions
> are not applied to skbs passed to l2tp_ip6.
>
> Any reason why l2tp_ip6_protocol should NOT be marked INET6_PROTO_FINAL?
I don't see any specific reason why it shouldn't be a INET6_PROTO_FINAL.
Anyway, receive path of L2TPv3 without UDP encapsulation doesn't deal
with checksums anyway, as far as I know.
> What's the consequences not executing the above actions for l2tp_ip6
> packets?
Probably not a whole lot in this case.
Bye,
Hannes
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Missing INET6_PROTO_FINAL in l2tp_ip6_protocol?
2016-05-21 15:55 ` Hannes Frederic Sowa
@ 2016-05-21 20:02 ` Shmulik Ladkani
2016-05-23 11:05 ` Hannes Frederic Sowa
0 siblings, 1 reply; 5+ messages in thread
From: Shmulik Ladkani @ 2016-05-21 20:02 UTC (permalink / raw)
To: Hannes Frederic Sowa; +Cc: netdev
On Sat, 21 May 2016 17:55:59 +0200 Hannes Frederic Sowa <hannes@stressinduktion.org> wrote:
> On 21.05.2016 14:50, Shmulik Ladkani wrote:
> > Hi,
> >
> > inet6_protocol's INET6_PROTO_FINAL flag denotes handler is expected not
> > to request resubmission for local delivery.
> >
> > For an INET6_PROTO_FINAL handler, the following actions gets executed
> > prior delivery, in ip6_input_finish:
> >
> > nf_reset(skb);
> >
> > skb_postpull_rcsum(skb, skb_network_header(skb),
> > skb_network_header_len(skb));
> >
> > For some reason, l2tp_ip6_protocol handler is NOT marked as
> > INET6_PROTO_FINAL. Probably an oversight.
> >
> > Since 'l2tp_ip6_recv' never results in a resubmission, the above actions
> > are not applied to skbs passed to l2tp_ip6.
> >
> > Any reason why l2tp_ip6_protocol should NOT be marked INET6_PROTO_FINAL?
>
> I don't see any specific reason why it shouldn't be a INET6_PROTO_FINAL.
> Anyway, receive path of L2TPv3 without UDP encapsulation doesn't deal
> with checksums anyway, as far as I know.
>
> > What's the consequences not executing the above actions for l2tp_ip6
> > packets?
>
> Probably not a whole lot in this case.
OK, so the skb_postpull_rcsum is irrelevant for IPPROTO_L2TP over ipv6.
However, one more thing WRT to INET6_PROTO_FINAL not being set - we're
also missing the multicast filtering of 'ip6_input_finish':
if (ipv6_addr_is_multicast(&hdr->daddr) &&
!ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
&hdr->saddr) &&
!ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
goto discard;
I assume no reason to allow multicast daddr which aren't in the mc_list
(or saddr excluded) to pass up into 'l2tp_ip6_recv'?
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Missing INET6_PROTO_FINAL in l2tp_ip6_protocol?
2016-05-21 20:02 ` Shmulik Ladkani
@ 2016-05-23 11:05 ` Hannes Frederic Sowa
2016-05-23 11:25 ` Shmulik Ladkani
0 siblings, 1 reply; 5+ messages in thread
From: Hannes Frederic Sowa @ 2016-05-23 11:05 UTC (permalink / raw)
To: Shmulik Ladkani; +Cc: netdev
On 21.05.2016 22:02, Shmulik Ladkani wrote:
> On Sat, 21 May 2016 17:55:59 +0200 Hannes Frederic Sowa <hannes@stressinduktion.org> wrote:
>> On 21.05.2016 14:50, Shmulik Ladkani wrote:
>>> Hi,
>>>
>>> inet6_protocol's INET6_PROTO_FINAL flag denotes handler is expected not
>>> to request resubmission for local delivery.
>>>
>>> For an INET6_PROTO_FINAL handler, the following actions gets executed
>>> prior delivery, in ip6_input_finish:
>>>
>>> nf_reset(skb);
>>>
>>> skb_postpull_rcsum(skb, skb_network_header(skb),
>>> skb_network_header_len(skb));
>>>
>>> For some reason, l2tp_ip6_protocol handler is NOT marked as
>>> INET6_PROTO_FINAL. Probably an oversight.
>>>
>>> Since 'l2tp_ip6_recv' never results in a resubmission, the above actions
>>> are not applied to skbs passed to l2tp_ip6.
>>>
>>> Any reason why l2tp_ip6_protocol should NOT be marked INET6_PROTO_FINAL?
>>
>> I don't see any specific reason why it shouldn't be a INET6_PROTO_FINAL.
>> Anyway, receive path of L2TPv3 without UDP encapsulation doesn't deal
>> with checksums anyway, as far as I know.
>>
>>> What's the consequences not executing the above actions for l2tp_ip6
>>> packets?
>>
>> Probably not a whole lot in this case.
>
> OK, so the skb_postpull_rcsum is irrelevant for IPPROTO_L2TP over ipv6.
>
> However, one more thing WRT to INET6_PROTO_FINAL not being set - we're
> also missing the multicast filtering of 'ip6_input_finish':
>
> if (ipv6_addr_is_multicast(&hdr->daddr) &&
> !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
> &hdr->saddr) &&
> !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
> goto discard;
>
> I assume no reason to allow multicast daddr which aren't in the mc_list
> (or saddr excluded) to pass up into 'l2tp_ip6_recv'?
>
Good point, seems we would benefit of the addition of the PROTO_FINAL
flag. Could you test and send a patch?
Thanks,
Hannes
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Missing INET6_PROTO_FINAL in l2tp_ip6_protocol?
2016-05-23 11:05 ` Hannes Frederic Sowa
@ 2016-05-23 11:25 ` Shmulik Ladkani
0 siblings, 0 replies; 5+ messages in thread
From: Shmulik Ladkani @ 2016-05-23 11:25 UTC (permalink / raw)
To: Hannes Frederic Sowa; +Cc: netdev
Hi,
On Mon, 23 May 2016 13:05:50 +0200, hannes@stressinduktion.org wrote:
> > However, one more thing WRT to INET6_PROTO_FINAL not being set - we're
> > also missing the multicast filtering of 'ip6_input_finish':
> >
> > if (ipv6_addr_is_multicast(&hdr->daddr) &&
> > !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
> > &hdr->saddr) &&
> > !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
> > goto discard;
> >
> > I assume no reason to allow multicast daddr which aren't in the mc_list
> > (or saddr excluded) to pass up into 'l2tp_ip6_recv'?
> >
>
> Good point, seems we would benefit of the addition of the PROTO_FINAL
> flag. Could you test and send a patch?
Will do.
Regards,
Shmulik
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-05-23 11:25 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-05-21 12:50 Missing INET6_PROTO_FINAL in l2tp_ip6_protocol? Shmulik Ladkani
2016-05-21 15:55 ` Hannes Frederic Sowa
2016-05-21 20:02 ` Shmulik Ladkani
2016-05-23 11:05 ` Hannes Frederic Sowa
2016-05-23 11:25 ` Shmulik Ladkani
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