nl80211: Add signal strength and bandwith to nl80211station info

This patch adds signal strength and transmission bitrate
to the station_info of nl80211.

Signed-off-by: Henning Rogge <rogge@fgan.de>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 57 insertions, 1 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 4335f76..93c9b98 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1091,12 +1091,46 @@ static int parse_station_flags(struct nlattr *nla, u32 *staflags)
 	return 0;
 }
 
+static u16 nl80211_calculate_bitrate(struct rate_info *rate)
+{
+	int modulation, streams, bitrate;
+
+	if (!(rate->flags & RATE_INFO_FLAGS_MCS))
+		return rate->legacy;
+
+	/* the formula below does only work for MCS values smaller than 32 */
+	if (rate->mcs >= 32)
+		return 0;
+
+	modulation = rate->mcs & 7;
+	streams = (rate->mcs >> 3) + 1;
+
+	bitrate = (rate->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH) ?
+			13500000 : 6500000;
+
+	if (modulation < 4)
+		bitrate *= (modulation + 1);
+	else if (modulation == 4)
+		bitrate *= (modulation + 2);
+	else
+		bitrate *= (modulation + 3);
+
+	bitrate *= streams;
+
+	if (rate->flags & RATE_INFO_FLAGS_SHORT_GI)
+		bitrate = (bitrate / 9) * 10;
+
+	/* do NOT round down here */
+	return (bitrate + 50000) / 100000;
+}
+
 static int nl80211_send_station(struct sk_buff *msg, u32 pid, u32 seq,
 				int flags, struct net_device *dev,
 				u8 *mac_addr, struct station_info *sinfo)
 {
 	void *hdr;
-	struct nlattr *sinfoattr;
+	struct nlattr *sinfoattr, *txrate;
+	u16 bitrate;
 
 	hdr = nl80211hdr_put(msg, pid, seq, flags, NL80211_CMD_NEW_STATION);
 	if (!hdr)
@@ -1126,7 +1160,29 @@ static int nl80211_send_station(struct sk_buff *msg, u32 pid, u32 seq,
 	if (sinfo->filled & STATION_INFO_PLINK_STATE)
 		NLA_PUT_U8(msg, NL80211_STA_INFO_PLINK_STATE,
 			    sinfo->plink_state);
+	if (sinfo->filled & STATION_INFO_SIGNAL)
+		NLA_PUT_U8(msg, NL80211_STA_INFO_SIGNAL,
+			   sinfo->signal);
+	if (sinfo->filled & STATION_INFO_TX_BITRATE) {
+		txrate = nla_nest_start(msg, NL80211_STA_INFO_TX_BITRATE);
+		if (!txrate)
+			goto nla_put_failure;
+
+		/* nl80211_calculate_bitrate will return 0 for mcs >= 32 */
+		bitrate = nl80211_calculate_bitrate(&sinfo->txrate);
+		if (bitrate > 0)
+			NLA_PUT_U16(msg, NL80211_RATE_INFO_BITRATE, bitrate);
 
+		if (sinfo->txrate.flags & RATE_INFO_FLAGS_MCS)
+			NLA_PUT_U8(msg, NL80211_RATE_INFO_MCS,
+				    sinfo->txrate.mcs);
+		if (sinfo->txrate.flags & RATE_INFO_FLAGS_40_MHZ_WIDTH)
+			NLA_PUT_FLAG(msg, NL80211_RATE_INFO_40_MHZ_WIDTH);
+		if (sinfo->txrate.flags & RATE_INFO_FLAGS_SHORT_GI)
+			NLA_PUT_FLAG(msg, NL80211_RATE_INFO_SHORT_GI);
+
+		nla_nest_end(msg, txrate);
+	}
 	nla_nest_end(msg, sinfoattr);
 
 	return genlmsg_end(msg, hdr);