On 17 February 2016 at 17:55, Felix Fietkau <nbd@xxxxxxxxxxx> 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.bajorski@xxxxxxxxx> > 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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
