[RFC PATCH 2/2] nl80211: implement beacon change notifier

[Sergey Matyukevich <sergey.matyukevich.os@xxxxxxxxxxxxx>]

From: Vasily Ulyanov <vulyanov@xxxxxxxxxxxxx>

Notify user-space listeners about beacon data change.

Signed-off-by: Vasily Ulyanov <vulyanov@xxxxxxxxxxxxx>
---
 net/wireless/nl80211.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f03f9989efbc..98e52e5ffc13 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3950,6 +3950,26 @@ static int nl80211_send_beacon(struct sk_buff *msg, u32 portid,
 	return -EMSGSIZE;
 }
 
+static void nl80211_notify_beacon_change(struct net_device *dev,
+					 enum nl80211_commands cmd,
+					 struct cfg80211_beacon_data *bcn)
+{
+	struct wiphy *wiphy = dev->ieee80211_ptr->wiphy;
+	struct sk_buff *msg;
+
+	msg = nlmsg_new(nl80211_beacon_size(bcn), GFP_KERNEL);
+	if (!msg)
+		return;
+
+	if (nl80211_send_beacon(msg, cmd, 0, 0, 0, bcn) < 0) {
+		nlmsg_free(msg);
+		return;
+	}
+
+	genlmsg_multicast_netns(&nl80211_fam, wiphy_net(wiphy), msg, 0,
+				NL80211_MCGRP_MLME, GFP_KERNEL);
+}
+
 static void nl80211_check_ap_rate_selectors(struct cfg80211_ap_settings *params,
 					    const u8 *rates)
 {
@@ -4250,6 +4270,8 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 		wdev->ssid_len = params.ssid_len;
 		memcpy(wdev->ssid, params.ssid, wdev->ssid_len);
 		nl80211_assign_beacon(&wdev->beacon, &new_bcn);
+		nl80211_notify_beacon_change(dev, NL80211_CMD_START_AP,
+					     &wdev->beacon);
 	}
 	wdev_unlock(wdev);
 
@@ -4317,8 +4339,11 @@ static int nl80211_set_beacon(struct sk_buff *skb, struct genl_info *info)
 
 	wdev_lock(wdev);
 	err = rdev_change_beacon(rdev, dev, &params);
-	if (!err)
+	if (!err) {
 		nl80211_assign_beacon(&wdev->beacon, &merged_bcn);
+		nl80211_notify_beacon_change(dev, NL80211_CMD_SET_BEACON,
+					     &wdev->beacon);
+	}
 	wdev_unlock(wdev);
 
 	if (err)
-- 
2.11.0