cfg80211: export expected throughput through get_station()

Users may need information about the expected throughput
towards a given peer.
This value is supposed to consider the size overhead
generated by the 802.11 header.

This value is exported in kbps through the get_station() API
by including it into the station_info object.
Moreover, it is sent to user space when replying to the
nl80211 GET_STATION command.

This information will be useful to the batman-adv module
which will use it for its new metric computation.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -873,36 +873,38 @@ int cfg80211_check_station_change(struct wiphy *wiphy,
  * @STATION_INFO_NONPEER_PM: @nonpeer_pm filled
  * @STATION_INFO_CHAIN_SIGNAL: @chain_signal filled
  * @STATION_INFO_CHAIN_SIGNAL_AVG: @chain_signal_avg filled
+ * @STATION_INFO_EXPECTED_THROUGHPUT: @expected_throughput filled
  */
 enum station_info_flags {
-	STATION_INFO_INACTIVE_TIME	= 1<<0,
-	STATION_INFO_RX_BYTES		= 1<<1,
-	STATION_INFO_TX_BYTES		= 1<<2,
-	STATION_INFO_LLID		= 1<<3,
-	STATION_INFO_PLID		= 1<<4,
-	STATION_INFO_PLINK_STATE	= 1<<5,
-	STATION_INFO_SIGNAL		= 1<<6,
-	STATION_INFO_TX_BITRATE		= 1<<7,
-	STATION_INFO_RX_PACKETS		= 1<<8,
-	STATION_INFO_TX_PACKETS		= 1<<9,
-	STATION_INFO_TX_RETRIES		= 1<<10,
-	STATION_INFO_TX_FAILED		= 1<<11,
-	STATION_INFO_RX_DROP_MISC	= 1<<12,
-	STATION_INFO_SIGNAL_AVG		= 1<<13,
-	STATION_INFO_RX_BITRATE		= 1<<14,
-	STATION_INFO_BSS_PARAM          = 1<<15,
-	STATION_INFO_CONNECTED_TIME	= 1<<16,
-	STATION_INFO_ASSOC_REQ_IES	= 1<<17,
-	STATION_INFO_STA_FLAGS		= 1<<18,
-	STATION_INFO_BEACON_LOSS_COUNT	= 1<<19,
-	STATION_INFO_T_OFFSET		= 1<<20,
-	STATION_INFO_LOCAL_PM		= 1<<21,
-	STATION_INFO_PEER_PM		= 1<<22,
-	STATION_INFO_NONPEER_PM		= 1<<23,
-	STATION_INFO_RX_BYTES64		= 1<<24,
-	STATION_INFO_TX_BYTES64		= 1<<25,
-	STATION_INFO_CHAIN_SIGNAL	= 1<<26,
-	STATION_INFO_CHAIN_SIGNAL_AVG	= 1<<27,
+	STATION_INFO_INACTIVE_TIME		= BIT(0),
+	STATION_INFO_RX_BYTES			= BIT(1),
+	STATION_INFO_TX_BYTES			= BIT(2),
+	STATION_INFO_LLID			= BIT(3),
+	STATION_INFO_PLID			= BIT(4),
+	STATION_INFO_PLINK_STATE		= BIT(5),
+	STATION_INFO_SIGNAL			= BIT(6),
+	STATION_INFO_TX_BITRATE			= BIT(7),
+	STATION_INFO_RX_PACKETS			= BIT(8),
+	STATION_INFO_TX_PACKETS			= BIT(9),
+	STATION_INFO_TX_RETRIES			= BIT(10),
+	STATION_INFO_TX_FAILED			= BIT(11),
+	STATION_INFO_RX_DROP_MISC		= BIT(12),
+	STATION_INFO_SIGNAL_AVG			= BIT(13),
+	STATION_INFO_RX_BITRATE			= BIT(14),
+	STATION_INFO_BSS_PARAM			= BIT(15),
+	STATION_INFO_CONNECTED_TIME		= BIT(16),
+	STATION_INFO_ASSOC_REQ_IES		= BIT(17),
+	STATION_INFO_STA_FLAGS			= BIT(18),
+	STATION_INFO_BEACON_LOSS_COUNT		= BIT(19),
+	STATION_INFO_T_OFFSET			= BIT(20),
+	STATION_INFO_LOCAL_PM			= BIT(21),
+	STATION_INFO_PEER_PM			= BIT(22),
+	STATION_INFO_NONPEER_PM			= BIT(23),
+	STATION_INFO_RX_BYTES64			= BIT(24),
+	STATION_INFO_TX_BYTES64			= BIT(25),
+	STATION_INFO_CHAIN_SIGNAL		= BIT(26),
+	STATION_INFO_CHAIN_SIGNAL_AVG		= BIT(27),
+	STATION_INFO_EXPECTED_THROUGHPUT	= BIT(28),
 };
 
 /**
@@ -1024,6 +1026,8 @@ struct sta_bss_parameters {
  * @local_pm: local mesh STA power save mode
  * @peer_pm: peer mesh STA power save mode
  * @nonpeer_pm: non-peer mesh STA power save mode
+ * @expected_throughput: expected throughput in kbps (including 802.11 headers)
+ *	towards this station.
  */
 struct station_info {
 	u32 filled;
@@ -1062,6 +1066,8 @@ struct station_info {
 	enum nl80211_mesh_power_mode peer_pm;
 	enum nl80211_mesh_power_mode nonpeer_pm;
 
+	u32 expected_throughput;
+
 	/*
 	 * Note: Add a new enum station_info_flags value for each new field and
 	 * use it to check which fields are initialized.

include/uapi/linux/nl80211.h

@@ -2199,6 +2199,8 @@ enum nl80211_sta_bss_param {
  *	Contains a nested array of signal strength attributes (u8, dBm)
  * @NL80211_STA_INFO_CHAIN_SIGNAL_AVG: per-chain signal strength average
  *	Same format as NL80211_STA_INFO_CHAIN_SIGNAL.
+ * @NL80211_STA_EXPECTED_THROUGHPUT: expected throughput considering also the
+ *	802.11 header (u32, kbps)
  * @__NL80211_STA_INFO_AFTER_LAST: internal
  * @NL80211_STA_INFO_MAX: highest possible station info attribute
  */
@@ -2230,6 +2232,7 @@ enum nl80211_sta_info {
 	NL80211_STA_INFO_TX_BYTES64,
 	NL80211_STA_INFO_CHAIN_SIGNAL,
 	NL80211_STA_INFO_CHAIN_SIGNAL_AVG,
+	NL80211_STA_INFO_EXPECTED_THROUGHPUT,
 
 	/* keep last */
 	__NL80211_STA_INFO_AFTER_LAST,

net/wireless/nl80211.c

@@ -3650,6 +3650,10 @@ static int nl80211_send_station(struct sk_buff *msg, u32 portid, u32 seq,
 	    nla_put_u32(msg, NL80211_STA_INFO_TX_FAILED,
 			sinfo->tx_failed))
 		goto nla_put_failure;
+	if ((sinfo->filled & STATION_INFO_EXPECTED_THROUGHPUT) &&
+	    nla_put_u32(msg, NL80211_STA_INFO_EXPECTED_THROUGHPUT,
+			sinfo->expected_throughput))
+		goto nla_put_failure;
 	if ((sinfo->filled & STATION_INFO_BEACON_LOSS_COUNT) &&
 	    nla_put_u32(msg, NL80211_STA_INFO_BEACON_LOSS,
 			sinfo->beacon_loss_count))