cfg80211: Add support to set tx power for a station associated

This patch adds support to set transmit power setting type and transmit
power level attributes to NL80211_CMD_SET_STATION in order to facilitate
adjusting the transmit power level of a station associated to the AP.

The added attributes allow selection of automatic and limited transmit
power level, with the level defined in dBm format.

Co-developed-by: Balaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: Ashok Raj Nagarajan <arnagara@codeaurora.org>
Signed-off-by: Balaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 64f191244c67..0524a6fb84ad 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -331,6 +331,11 @@ const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 					       .len = NL80211_MAX_SUPP_RATES },
 	[NL80211_ATTR_STA_PLINK_ACTION] =
 		NLA_POLICY_MAX(NLA_U8, NUM_NL80211_PLINK_ACTIONS - 1),
+	[NL80211_ATTR_STA_TX_POWER_SETTING] =
+		NLA_POLICY_RANGE(NLA_U8,
+				 NL80211_TX_POWER_AUTOMATIC,
+				 NL80211_TX_POWER_FIXED),
+	[NL80211_ATTR_STA_TX_POWER] = { .type = NLA_S16 },
 	[NL80211_ATTR_STA_VLAN] = { .type = NLA_U32 },
 	[NL80211_ATTR_MNTR_FLAGS] = { /* NLA_NESTED can't be empty */ },
 	[NL80211_ATTR_MESH_ID] = { .type = NLA_BINARY,
@@ -5420,6 +5425,36 @@ static int nl80211_set_station_tdls(struct genl_info *info,
 	return nl80211_parse_sta_wme(info, params);
 }
 
+static int nl80211_parse_sta_txpower_setting(struct genl_info *info,
+					     struct station_parameters *params)
+{
+	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	int idx;
+
+	if (info->attrs[NL80211_ATTR_STA_TX_POWER_SETTING]) {
+		if (!rdev->ops->set_tx_power ||
+		    !wiphy_ext_feature_isset(&rdev->wiphy,
+					 NL80211_EXT_FEATURE_STA_TX_PWR))
+			return -EOPNOTSUPP;
+
+		idx = NL80211_ATTR_STA_TX_POWER_SETTING;
+		params->txpwr.type = nla_get_u8(info->attrs[idx]);
+
+		if (params->txpwr.type == NL80211_TX_POWER_LIMITED) {
+			idx = NL80211_ATTR_STA_TX_POWER;
+
+			if (info->attrs[idx])
+				params->txpwr.power =
+					nla_get_s16(info->attrs[idx]);
+			else
+				return -EINVAL;
+		}
+		params->sta_modify_mask |= STATION_PARAM_APPLY_STA_TXPOWER;
+	}
+
+	return 0;
+}
+
 static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -5513,6 +5548,10 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
 				     NL80211_EXT_FEATURE_AIRTIME_FAIRNESS))
 		return -EOPNOTSUPP;
 
+	err = nl80211_parse_sta_txpower_setting(info, &params);
+	if (err)
+		return err;
+
 	/* Include parameters for TDLS peer (will check later) */
 	err = nl80211_set_station_tdls(info, &params);
 	if (err)
@@ -5650,6 +5689,10 @@ static int nl80211_new_station(struct sk_buff *skb, struct genl_info *info)
 				     NL80211_EXT_FEATURE_AIRTIME_FAIRNESS))
 		return -EOPNOTSUPP;
 
+	err = nl80211_parse_sta_txpower_setting(info, &params);
+	if (err)
+		return err;
+
 	err = nl80211_parse_sta_channel_info(info, &params);
 	if (err)
 		return err;