nl80211: allow drivers to indicate whether the survey data channel is in use

Some user space applications only want to display survey data for
the operating channel, however there is no API to get that yet.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/linux/nl80211.h

@@ -1400,6 +1400,7 @@ enum nl80211_reg_rule_flags {
  * @__NL80211_SURVEY_INFO_INVALID: attribute number 0 is reserved
  * @NL80211_SURVEY_INFO_FREQUENCY: center frequency of channel
  * @NL80211_SURVEY_INFO_NOISE: noise level of channel (u8, dBm)
+ * @NL80211_SURVEY_INFO_IN_USE: channel is currently being used
  * @NL80211_SURVEY_INFO_MAX: highest survey info attribute number
  *	currently defined
  * @__NL80211_SURVEY_INFO_AFTER_LAST: internal use
@@ -1408,6 +1409,7 @@ enum nl80211_survey_info {
 	__NL80211_SURVEY_INFO_INVALID,
 	NL80211_SURVEY_INFO_FREQUENCY,
 	NL80211_SURVEY_INFO_NOISE,
+	NL80211_SURVEY_INFO_IN_USE,
 
 	/* keep last */
 	__NL80211_SURVEY_INFO_AFTER_LAST,

include/net/cfg80211.h

@@ -293,12 +293,14 @@ struct key_params {
  * enum survey_info_flags - survey information flags
  *
  * @SURVEY_INFO_NOISE_DBM: noise (in dBm) was filled in
+ * @SURVEY_INFO_IN_USE: channel is currently being used
  *
  * Used by the driver to indicate which info in &struct survey_info
  * it has filled in during the get_survey().
  */
 enum survey_info_flags {
 	SURVEY_INFO_NOISE_DBM = 1<<0,
+	SURVEY_INFO_IN_USE = 1<<1,
 };
 
 /**

net/wireless/nl80211.c

@@ -3489,6 +3489,8 @@ static int nl80211_send_survey(struct sk_buff *msg, u32 pid, u32 seq,
 	if (survey->filled & SURVEY_INFO_NOISE_DBM)
 		NLA_PUT_U8(msg, NL80211_SURVEY_INFO_NOISE,
 			    survey->noise);
+	if (survey->filled & SURVEY_INFO_IN_USE)
+		NLA_PUT_FLAG(msg, NL80211_SURVEY_INFO_IN_USE);
 
 	nla_nest_end(msg, infoattr);