On Thursday 07 May 2015 13:00:52 Joseph Zimmer wrote:
Is there a way to adjust BATMAN using batctl to select routes basedon the RSSI value?
No
Does the algorithm for route selection use RSSI in the calculationand if so can we modify the algorithm to increase the importance of RSSI in the selection?
No.
How do we gain access to the code to make these modifications?a. Can you give me a little guidance on how to modify BATMAN-adv to suite my situation?
But you could patch your wifi driver/framework (for example mac80211) to provide an exported function which returns the rssi for a specific net_device (net_dev of the if_incoming) + the mac address of the other station (mac orig in orig_neigh_node). This function has to basically get the sinfo->signal_avg when the sta exists for this bss.
You have to make sure that this device is really a compatible ieee80211 device - otherwise your kernel might just crash when accessing the private data of the net_device. Maybe this is always true in your situation but I don't know your setup well enough. If it is a mixed setup then you can try the ieee80211_ptr trick from netdev_notify in net/mac80211/iface.c. This has to be done before you are using IEEE80211_DEV_TO_SUB_IF. You can check to ieee80211_get_station see a function which already does parts of what you want (but it has not yet this check). And also keep in mind that sinfo->signal_avg may not be set with correct data. You must check (sinfo->filled & STATION_INFO_SIGNAL_AVG) when you are creating a function similar to ieee80211_get_station for RSSI.
This code would have to be called when the neighbor tq is calculated in batadv_iv_ogm_calc_tq. It basically has to adjust batadv_ogm_packet->tq somewhere at the end of the function. The percentage of reduction would have to be chosen by you based on how "bad" the rssi value is. I don't have a good metric for that.
I am not sure if Antonio/Marek have some proof of concept in their BATMAN V branch. But I think they wanted to use the bandwidth based approach which is queries the mac80211 rate control information [1].
Kind regards, Sven
[1] http://thread.gmane.org/gmane.linux.kernel.wireless.general/123514