* ebtables on mac80211
@ 2012-04-11 22:34 ` Wilco Baan Hofman
0 siblings, 0 replies; 4+ messages in thread
From: Wilco Baan Hofman @ 2012-04-11 22:34 UTC (permalink / raw)
To: bridge; +Cc: linux-wireless
Hi,
I'm looking to implement hooks to ebtables in the mac80211 wireless
stack.
I'm trying to find the best approach for doing this.. basically what I
want to be able to have is clients being able to communicate, but not
ARP spoofing the gateway or setting up a rogue DHCP.
As it's currently implemented, there's some sort of internal bridge
functionality within the wireless stack in net/mac80211/rx.c at around
ieee802_deliver_skb(), where every ethernet packet essentially gets
routed among wireless clients.
If I understand ebtables correctly, an forward event is triggered for
every packet to every interface, right? So essentially, this should do
the same, except that for every wireless client would be a forward from
the wireless interface to the wireless interface.
What would be the best way to implement this and in what way would it be
acceptable upstream?
Best regards,
Wilco Baan Hofman
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bridge] ebtables on mac80211
@ 2012-04-11 22:34 ` Wilco Baan Hofman
0 siblings, 0 replies; 4+ messages in thread
From: Wilco Baan Hofman @ 2012-04-11 22:34 UTC (permalink / raw)
To: bridge; +Cc: linux-wireless
Hi,
I'm looking to implement hooks to ebtables in the mac80211 wireless
stack.
I'm trying to find the best approach for doing this.. basically what I
want to be able to have is clients being able to communicate, but not
ARP spoofing the gateway or setting up a rogue DHCP.
As it's currently implemented, there's some sort of internal bridge
functionality within the wireless stack in net/mac80211/rx.c at around
ieee802_deliver_skb(), where every ethernet packet essentially gets
routed among wireless clients.
If I understand ebtables correctly, an forward event is triggered for
every packet to every interface, right? So essentially, this should do
the same, except that for every wireless client would be a forward from
the wireless interface to the wireless interface.
What would be the best way to implement this and in what way would it be
acceptable upstream?
Best regards,
Wilco Baan Hofman
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Bridge] ebtables on mac80211
2012-04-11 22:34 ` [Bridge] " Wilco Baan Hofman
@ 2012-04-12 18:45 ` Bart De Schuymer
-1 siblings, 0 replies; 4+ messages in thread
From: Bart De Schuymer @ 2012-04-12 18:45 UTC (permalink / raw)
To: Wilco Baan Hofman; +Cc: bridge, linux-wireless
Op 12/04/2012 0:34, Wilco Baan Hofman schreef:
> Hi,
>
> I'm looking to implement hooks to ebtables in the mac80211 wireless
> stack.
>
> I'm trying to find the best approach for doing this.. basically what I
> want to be able to have is clients being able to communicate, but not
> ARP spoofing the gateway or setting up a rogue DHCP.
>
> As it's currently implemented, there's some sort of internal bridge
> functionality within the wireless stack in net/mac80211/rx.c at around
> ieee802_deliver_skb(), where every ethernet packet essentially gets
> routed among wireless clients.
>
> If I understand ebtables correctly, an forward event is triggered for
> every packet to every interface, right? So essentially, this should do
> the same, except that for every wireless client would be a forward from
> the wireless interface to the wireless interface.
>
> What would be the best way to implement this and in what way would it be
> acceptable upstream?
You can add a new ebtables table, requiring minimal changes to the
userland tool. You can start by adding a table called something like
"filter-wireless" with a built-in chain on NF_BR_FORWARD. See
net/bridge/netfilter/ebtable_broute.c: it contains the code that adds
the broute table with a built-in chain on NF_BR_BROUTING. This approach
has minimal impact since it doesn't use netfilter hooks (no call to
nf_register_hooks) and uses a built-in chain that ebtables understands.
If you want to use the netfilter infrastructure, you'll probably need a
new protocol family. See net/bridge/netfilter/ebtable_filter.c in that case.
cheers,
Bart
--
Bart De Schuymer
www.artinalgorithms.be
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Bridge] ebtables on mac80211
@ 2012-04-12 18:45 ` Bart De Schuymer
0 siblings, 0 replies; 4+ messages in thread
From: Bart De Schuymer @ 2012-04-12 18:45 UTC (permalink / raw)
To: Wilco Baan Hofman; +Cc: linux-wireless, bridge
Op 12/04/2012 0:34, Wilco Baan Hofman schreef:
> Hi,
>
> I'm looking to implement hooks to ebtables in the mac80211 wireless
> stack.
>
> I'm trying to find the best approach for doing this.. basically what I
> want to be able to have is clients being able to communicate, but not
> ARP spoofing the gateway or setting up a rogue DHCP.
>
> As it's currently implemented, there's some sort of internal bridge
> functionality within the wireless stack in net/mac80211/rx.c at around
> ieee802_deliver_skb(), where every ethernet packet essentially gets
> routed among wireless clients.
>
> If I understand ebtables correctly, an forward event is triggered for
> every packet to every interface, right? So essentially, this should do
> the same, except that for every wireless client would be a forward from
> the wireless interface to the wireless interface.
>
> What would be the best way to implement this and in what way would it be
> acceptable upstream?
You can add a new ebtables table, requiring minimal changes to the
userland tool. You can start by adding a table called something like
"filter-wireless" with a built-in chain on NF_BR_FORWARD. See
net/bridge/netfilter/ebtable_broute.c: it contains the code that adds
the broute table with a built-in chain on NF_BR_BROUTING. This approach
has minimal impact since it doesn't use netfilter hooks (no call to
nf_register_hooks) and uses a built-in chain that ebtables understands.
If you want to use the netfilter infrastructure, you'll probably need a
new protocol family. See net/bridge/netfilter/ebtable_filter.c in that case.
cheers,
Bart
--
Bart De Schuymer
www.artinalgorithms.be
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-04-12 18:45 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-04-11 22:34 ebtables on mac80211 Wilco Baan Hofman
2012-04-11 22:34 ` [Bridge] " Wilco Baan Hofman
2012-04-12 18:45 ` Bart De Schuymer
2012-04-12 18:45 ` Bart De Schuymer
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.