Hi, we are working on a sophisticated Wifi simulation framework based on mac80211_hwsim. This includes the simulation of frame transmissions with realistic channel access and channel conditions. Therefore we need several information (e.g. long/short gi, usage of RTS/CTS, ...), which are available on a per frame/rate basis from struct ieee80211_tx_rate. But this information is thrown away by the conversation to struct hwsim_tx_rate (eg. in mac80211_hwsim_tx_frame_nl)
Firstly I think this information is valuable and I don't believe, the 4 Byte per frame greatly influences speed. Moreover the explicit double copy (firstly from the info->status.rates to tx_attempts, secondly by nla_put), takes longer than simply put the whole info->status.rates into the netlink message. So I would propose to put the whole struct into the netlink messages, but I think that will break up the communication to e.g. bob copelands wmediumd and similar simulations. I would like to have our Implementation working with mainline kernels and therefore ask how we could achieve this easily. Obviously, we could define another field in the hwsim messages, but as bob copeland already stated, significantly more information within the netlink messages could intensify the timing overhead of hwsim. Any suggestions?
