On 17 February 2016 at 17:55, Felix Fietkau <n...@openwrt.org> wrote:
> On 2016-02-17 12:55, Grzegorz Bajorski wrote:
>> Client interface briding was only possible when 4addr frames were used with
>> a 4addr/WDS aware AP. It was not possible to do it otherwise due to 3addr
>> frame limitation.
>>
>> The extap logic introduces a smart MAC address masking/translation
>> (including modyfing packets beyond SA/DA, e.g. DHCP broadcast flag is set).
>>
>> There are still some unsolved problems and bugs:
>>  - due to bridge port routing and sk_buff payload sharing skb_copy() is
>>    performed; this ideally should be reworked
>>  - ipv6 support is still not finished
>>  - extap is enabled by default currently; it should be configurable via
>>    nl80211 the same way 4addr is
>>
>> There's also an idea to move this as a generic link driver (just like
>> macvlan, et al) which would allow unmodified cfg80211 drivers to enjoy the
>> extap functionality. Thoughts?
>>
>> Note: This changes cfg80211 file in this single patch only for reviewing
>> convienence.
>>
>> This is an early draft to solicit comments on the design.
>>
>> Signed-off-by: Grzegorz Bajorski <grzegorz.bajor...@tieto.com>
> You can get a lot of the same effect (sharing the same subnet between
> hosts behind multiple interfaces and having forwarding between them)
> without any changes to mac80211.
>
> OpenWrt uses a daemon called 'relayd' which I wrote some years ago. It
> does ARP translation, DHCP packet mangling and sets up policy routing to
> forward packets between multiple interfaces.
>
> You can find it here:
> http://git.openwrt.org/?p=project/relayd.git;a=summary
> git://git.openwrt.org/project/relayd.git
>
> Since you can cover the same use cases with user space code, I don't
> think it's a good idea to put bridge emulation hacks in the kernel's
> wireless stack.

You can't really implement complete IPv6 support in relayd though.
Link-local routing is forbidden by the spec explicitly and a patch
I've cooked up was rejected[1].

I guess this leaves either the kernel's wireless stack to take up the
task or a special link device (for which I'm soliciting feedback now
[2]).

Thoughts?


[1]: http://marc.info/?l=linux-netdev&m=146084698311664&w=2
[2]: http://marc.info/?l=linux-netdev&m=146097234002385&w=2


Michal
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to