Re: broadcast buffer / TIM map in mesh mode

[Johannes Berg <johannes@sipsolutions.net>]

Hi Marco,

> I am working on a mesh powersave implementation. One requirement for 
> that is to buffer broadcasts, set the TIM map and count powersave 
> neighbors. All of these routines are currently bound to the AP-specific 
> ieee80211_if_ap structure.
> Do you have any recommendations how to properly implement this for mesh 
> interfaces?
> 
> a) allocate/free ieee80211_if_ap in 
> iface.c:ieee80211_do_open/ieee80211_do_stop and bind to sdata->bss pointer?
> b) include ieee80211_if_ap into ieee80211_if_mesh structure and use 
> sdata->bss?
> c) completely different?

I don't think a) or b) are appropriate since the if_ap structure
contains a number of fields that you won't use or need. I would
therefore suggest to split out the PS related fields of that structure
into a substructure that you embed in both if_ap and if_mesh, and in the
code you could then pass a pointer to that structure to the powersave
handling functions.

Please do a separate patch to separate it out though, not just one huge
patch to do both mesh & the splitting up :)


> Also, what is the purpose of the sdata->bss pointer? It seems to be used 
> at times and not at others.

The sdata->bss pointer should be used in *most* cases, it's a link to
the "AP data" for the AP interface (where it just points to itself) and
any AP_VLAN interface (where it points to the master AP interface)