This is an early RFC of a possible channel switch announcement infrastructure. It adds CSA/ECSA handling support for AP. This is required for DFS operation (e.g. Wi-Fi Alliance requires this for 802.11h certification). This will also be required for IBSS-DFS later. I'd like to discuss if this design approach is going in the right direction. What is currently working: * channels are announced by adding IEs (CSA and Extended CSA) in beacons * after some (configurable) time, the channel is switched * with the channel switch, CSA/ECSA IEs are removed and channel information is updated. * Userspace calls a new command NL80211_CMD_CHANNEL_SWITCH along with channel info (freq + width), whether traffic should be blocked and timing information * it currently works for me [TM] on my ath9k based machine Questions: * We already have NL80211_CMD_CH_SWITCH_NOTIFY which is only used for notification. Maybe we can rename that and re-use it instead of adding a new command NL80211_CMD_CHANNEL_SWITCH? * Changes from HT20/NOHT to HT20/NOHT are handled with normal Channel Switch Announcements, everything else (for 40 MHz) is done with Extended Channel Switch Announcements. As far as I read the spec, we can't use the secondary channel offset IE in beacons, but maybe I'm wrong here? * could other drivers (next to ath9k) work with this API? Limitations: * only works for single interfaces (no plan to change that, due to lack of good concept) * Only changes in the same band (e.g. 2GHz -> 2GHz or 5GHz -> 5 GHz) and same operation mode (HT->HT or NOHT->NOHT) are supported. Especially the first restriction would be troublesome when rewriting the beacon (not only channel info has to be changed, but also basic rates, country information, etc ...). => What do you think about this approach? => (An alternative would be to require userspace to supply the next beacon too) * probe responses are not handled yet (have to look into it) * user notification is missing (we should send an event after this is finished) * locking and many corner cases are still broken (will fix that later) As always, any comments are appreciated. Cheers, Simon Simon Wunderlich (4): cfg80211: add chandef to operating class conversion nl80211/cfg80211: add channel switch command mac80211: add channel switch command and beacon callbacks ath9k: enable CSA functionality in ath9k drivers/net/wireless/ath/ath9k/main.c | 6 + include/linux/ieee80211.h | 9 ++ include/net/cfg80211.h | 15 ++ include/net/mac80211.h | 21 +++ include/uapi/linux/nl80211.h | 20 +++ net/mac80211/cfg.c | 262 +++++++++++++++++++++++++++++++++ net/mac80211/driver-ops.h | 11 ++ net/mac80211/ieee80211_i.h | 9 ++ net/mac80211/iface.c | 2 + net/mac80211/trace.h | 20 +++ net/mac80211/tx.c | 59 ++++++++ net/mac80211/util.c | 210 ++++++++++++++++++++++++++ net/wireless/nl80211.c | 76 +++++++++- net/wireless/util.c | 193 ++++++++++++++++++++++++ 14 files changed, 912 insertions(+), 1 deletion(-) -- 1.7.10.4 -- 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
