cfg80211: Add support to notify station's opmode change to userspace

ht/vht action frames will be sent to AP from station to notify
change of its ht/vht opmode(max bandwidth, smps mode or nss) modified
values. Currently these valuse used by driver/firmware for rate control
algorithm. This patch introduces NL80211_CMD_STA_OPMODE_CHANGED
command to notify those modified/current supported values(max bandwidth,
smps mode, max nss) to userspace application. This will be useful for the
application like steering, which closely monitoring station's capability
changes. Since the application has taken these values during station
association.

Signed-off-by: Tamizh chelvam <tamizhr@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -3553,6 +3553,35 @@ enum wiphy_vendor_command_flags {
 	WIPHY_VENDOR_CMD_NEED_RUNNING = BIT(2),
 };
 
+/**
+ * enum wiphy_opmode_flag - Station's ht/vht operation mode information flags
+ *
+ * @STA_OPMODE_MAX_BW_CHANGED: Max Bandwidth changed
+ * @STA_OPMODE_SMPS_MODE_CHANGED: SMPS mode changed
+ * @STA_OPMODE_N_SS_CHANGED: max N_SS (number of spatial streams) changed
+ *
+ */
+enum wiphy_opmode_flag {
+	STA_OPMODE_MAX_BW_CHANGED	= BIT(0),
+	STA_OPMODE_SMPS_MODE_CHANGED	= BIT(1),
+	STA_OPMODE_N_SS_CHANGED		= BIT(2),
+};
+
+/**
+ * struct sta_opmode_info - Station's ht/vht operation mode information
+ * @changed: contains value from &enum wiphy_opmode_flag
+ * @smps_mode: New SMPS mode of a station
+ * @bw: new max bandwidth value of a station
+ * @rx_nss: new rx_nss value of a station
+ */
+
+struct sta_opmode_info {
+	u32 changed;
+	u8 smps_mode;
+	u8 bw;
+	u8 rx_nss;
+};
+
 /**
  * struct wiphy_vendor_command - vendor command definition
  * @info: vendor command identifying information, as used in nl80211
@@ -5721,6 +5750,20 @@ void cfg80211_cqm_beacon_loss_notify(struct net_device *dev, gfp_t gfp);
 void cfg80211_radar_event(struct wiphy *wiphy,
 			  struct cfg80211_chan_def *chandef, gfp_t gfp);
 
+/**
+ * cfg80211_sta_opmode_change_notify - STA's ht/vht operation mode change event
+ * @dev: network device
+ * @mac: MAC address of a station which opmode got modified
+ * @sta_opmode: station's current opmode value
+ * @gfp: context flags
+ *
+ * Driver should call this function when station's opmode modified via action
+ * frame.
+ */
+void cfg80211_sta_opmode_change_notify(struct net_device *dev, const u8 *mac,
+				       struct sta_opmode_info *sta_opmode,
+				       gfp_t gfp);
+
 /**
  * cfg80211_cac_event - Channel availability check (CAC) event
  * @netdev: network device

include/uapi/linux/nl80211.h

@@ -1013,6 +1013,11 @@
  *	user space through the connect result as the user space would have
  *	initiated the connection through the connect request.
  *
+ * @NL80211_CMD_STA_OPMODE_CHANGED: An event that notify station's
+ *	ht opmode or vht opmode changes using any of &NL80211_ATTR_SMPS_MODE,
+ *	&NL80211_ATTR_CHANNEL_WIDTH,&NL80211_ATTR_NSS attributes with its
+ *	address(specified in &NL80211_ATTR_MAC).
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -1221,6 +1226,8 @@ enum nl80211_commands {
 
 	NL80211_CMD_EXTERNAL_AUTH,
 
+	NL80211_CMD_STA_OPMODE_CHANGED,
+
 	/* add new commands above here */
 
 	/* used to define NL80211_CMD_MAX below */
@@ -2186,6 +2193,9 @@ enum nl80211_commands {
  *     authentication processing to user space if this capability is indicated
  *     in NL80211_CMD_CONNECT requests from the user space.
  *
+ * @NL80211_ATTR_NSS: Station's New/updated  RX_NSS value notified using this
+ *	u8 attribute. This is used with %NL80211_CMD_STA_OPMODE_CHANGED.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -2615,6 +2625,8 @@ enum nl80211_attrs {
 	NL80211_ATTR_EXTERNAL_AUTH_ACTION,
 	NL80211_ATTR_EXTERNAL_AUTH_SUPPORT,
 
+	NL80211_ATTR_NSS,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,

net/wireless/nl80211.c

@@ -14950,6 +14950,61 @@ nl80211_radar_notify(struct cfg80211_registered_device *rdev,
 	nlmsg_free(msg);
 }
 
+void cfg80211_sta_opmode_change_notify(struct net_device *dev, const u8 *mac,
+				       struct sta_opmode_info *sta_opmode,
+				       gfp_t gfp)
+{
+	struct sk_buff *msg;
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
+	void *hdr;
+
+	if (WARN_ON(!mac))
+		return;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
+	if (!msg)
+		return;
+
+	hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_STA_OPMODE_CHANGED);
+	if (!hdr) {
+		nlmsg_free(msg);
+		return;
+	}
+
+	if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx))
+		goto nla_put_failure;
+
+	if (nla_put_u32(msg, NL80211_ATTR_IFINDEX, dev->ifindex))
+		goto nla_put_failure;
+
+	if (nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN, mac))
+		goto nla_put_failure;
+
+	if ((sta_opmode->changed & STA_OPMODE_SMPS_MODE_CHANGED) &&
+	    nla_put_u8(msg, NL80211_ATTR_SMPS_MODE, sta_opmode->smps_mode))
+		goto nla_put_failure;
+
+	if ((sta_opmode->changed & STA_OPMODE_MAX_BW_CHANGED) &&
+	    nla_put_u8(msg, NL80211_ATTR_CHANNEL_WIDTH, sta_opmode->bw))
+		goto nla_put_failure;
+
+	if ((sta_opmode->changed & STA_OPMODE_N_SS_CHANGED) &&
+	    nla_put_u8(msg, NL80211_ATTR_NSS, sta_opmode->rx_nss))
+		goto nla_put_failure;
+
+	genlmsg_end(msg, hdr);
+
+	genlmsg_multicast_netns(&nl80211_fam, wiphy_net(&rdev->wiphy), msg, 0,
+				NL80211_MCGRP_MLME, gfp);
+
+	return;
+
+nla_put_failure:
+	nlmsg_free(msg);
+}
+EXPORT_SYMBOL(cfg80211_sta_opmode_change_notify);
+
 void cfg80211_probe_status(struct net_device *dev, const u8 *addr,
 			   u64 cookie, bool acked, gfp_t gfp)
 {