cfg80211: add channel utilization stats to the survey command

Using these, user space can calculate a relative channel utilization
with arbitrary intervals by regularly taking snapshots of the survey
results.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/linux/nl80211.h

@@ -1413,6 +1413,16 @@ enum nl80211_reg_rule_flags {
  * @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_CHANNEL_TIME: amount of time (in ms) that the radio
+ *	spent on this channel
+ * @NL80211_SURVEY_INFO_CHANNEL_TIME_BUSY: amount of the time the primary
+ *	channel was sensed busy (either due to activity or energy detect)
+ * @NL80211_SURVEY_INFO_CHANNEL_TIME_EXT_BUSY: amount of time the extension
+ *	channel was sensed busy
+ * @NL80211_SURVEY_INFO_CHANNEL_TIME_RX: amount of time the radio spent
+ *	receiving data
+ * @NL80211_SURVEY_INFO_CHANNEL_TIME_TX: amount of time the radio spent
+ *	transmitting data
  * @NL80211_SURVEY_INFO_MAX: highest survey info attribute number
  *	currently defined
  * @__NL80211_SURVEY_INFO_AFTER_LAST: internal use
@@ -1422,6 +1432,11 @@ enum nl80211_survey_info {
 	NL80211_SURVEY_INFO_FREQUENCY,
 	NL80211_SURVEY_INFO_NOISE,
 	NL80211_SURVEY_INFO_IN_USE,
+	NL80211_SURVEY_INFO_CHANNEL_TIME,
+	NL80211_SURVEY_INFO_CHANNEL_TIME_BUSY,
+	NL80211_SURVEY_INFO_CHANNEL_TIME_EXT_BUSY,
+	NL80211_SURVEY_INFO_CHANNEL_TIME_RX,
+	NL80211_SURVEY_INFO_CHANNEL_TIME_TX,
 
 	/* keep last */
 	__NL80211_SURVEY_INFO_AFTER_LAST,

include/net/cfg80211.h

@@ -294,6 +294,11 @@ struct key_params {
  *
  * @SURVEY_INFO_NOISE_DBM: noise (in dBm) was filled in
  * @SURVEY_INFO_IN_USE: channel is currently being used
+ * @SURVEY_INFO_CHANNEL_TIME: channel active time (in ms) was filled in
+ * @SURVEY_INFO_CHANNEL_TIME_BUSY: channel busy time was filled in
+ * @SURVEY_INFO_CHANNEL_TIME_EXT_BUSY: extension channel busy time was filled in
+ * @SURVEY_INFO_CHANNEL_TIME_RX: channel receive time was filled in
+ * @SURVEY_INFO_CHANNEL_TIME_TX: channel transmit time was filled in
  *
  * Used by the driver to indicate which info in &struct survey_info
  * it has filled in during the get_survey().
@@ -301,6 +306,11 @@ struct key_params {
 enum survey_info_flags {
 	SURVEY_INFO_NOISE_DBM = 1<<0,
 	SURVEY_INFO_IN_USE = 1<<1,
+	SURVEY_INFO_CHANNEL_TIME = 1<<2,
+	SURVEY_INFO_CHANNEL_TIME_BUSY = 1<<3,
+	SURVEY_INFO_CHANNEL_TIME_EXT_BUSY = 1<<4,
+	SURVEY_INFO_CHANNEL_TIME_RX = 1<<5,
+	SURVEY_INFO_CHANNEL_TIME_TX = 1<<6,
 };
 
 /**
@@ -310,6 +320,11 @@ enum survey_info_flags {
  * @filled: bitflag of flags from &enum survey_info_flags
  * @noise: channel noise in dBm. This and all following fields are
  *     optional
+ * @channel_time: amount of time in ms the radio spent on the channel
+ * @channel_time_busy: amount of time the primary channel was sensed busy
+ * @channel_time_ext_busy: amount of time the extension channel was sensed busy
+ * @channel_time_rx: amount of time the radio spent receiving data
+ * @channel_time_tx: amount of time the radio spent transmitting data
  *
  * Used by dump_survey() to report back per-channel survey information.
  *
@@ -318,6 +333,11 @@ enum survey_info_flags {
  */
 struct survey_info {
 	struct ieee80211_channel *channel;
+	u64 channel_time;
+	u64 channel_time_busy;
+	u64 channel_time_ext_busy;
+	u64 channel_time_rx;
+	u64 channel_time_tx;
 	u32 filled;
 	s8 noise;
 };

net/wireless/nl80211.c

@@ -3153,6 +3153,21 @@ static int nl80211_send_survey(struct sk_buff *msg, u32 pid, u32 seq,
 			    survey->noise);
 	if (survey->filled & SURVEY_INFO_IN_USE)
 		NLA_PUT_FLAG(msg, NL80211_SURVEY_INFO_IN_USE);
+	if (survey->filled & SURVEY_INFO_CHANNEL_TIME)
+		NLA_PUT_U64(msg, NL80211_SURVEY_INFO_CHANNEL_TIME,
+			    survey->channel_time);
+	if (survey->filled & SURVEY_INFO_CHANNEL_TIME_BUSY)
+		NLA_PUT_U64(msg, NL80211_SURVEY_INFO_CHANNEL_TIME_BUSY,
+			    survey->channel_time_busy);
+	if (survey->filled & SURVEY_INFO_CHANNEL_TIME_EXT_BUSY)
+		NLA_PUT_U64(msg, NL80211_SURVEY_INFO_CHANNEL_TIME_EXT_BUSY,
+			    survey->channel_time_ext_busy);
+	if (survey->filled & SURVEY_INFO_CHANNEL_TIME_RX)
+		NLA_PUT_U64(msg, NL80211_SURVEY_INFO_CHANNEL_TIME_RX,
+			    survey->channel_time_rx);
+	if (survey->filled & SURVEY_INFO_CHANNEL_TIME_TX)
+		NLA_PUT_U64(msg, NL80211_SURVEY_INFO_CHANNEL_TIME_TX,
+			    survey->channel_time_tx);
 
 	nla_nest_end(msg, infoattr);