cfg80211: allow including station info in delete event

When a station is removed, its statistics may be interesting to
userspace, for example for further aggregation of statistics of
all stations that ever connected to an AP.

Introduce a new cfg80211_del_sta_sinfo() function (and make the
cfg80211_del_sta() a static inline calling it) to allow passing
a struct station_info along with this, and send the data in the
nl80211 event message.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 16 insertions, 22 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f56309bd21bd..a75dc91976d3 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3650,8 +3650,8 @@ static bool nl80211_put_signal(struct sk_buff *msg, u8 mask, s8 *signal,
         return true;
 }
 
-static int nl80211_send_station(struct sk_buff *msg, u32 portid, u32 seq,
-                                int flags,
+static int nl80211_send_station(struct sk_buff *msg, u32 cmd, u32 portid,
+                                u32 seq, int flags,
                                 struct cfg80211_registered_device *rdev,
                                 struct net_device *dev,
                                 const u8 *mac_addr, struct station_info *sinfo)
@@ -3659,7 +3659,7 @@ static int nl80211_send_station(struct sk_buff *msg, u32 portid, u32 seq,
         void *hdr;
         struct nlattr *sinfoattr, *bss_param;
 
-        hdr = nl80211hdr_put(msg, portid, seq, flags, NL80211_CMD_NEW_STATION);
+        hdr = nl80211hdr_put(msg, portid, seq, flags, cmd);
         if (!hdr)
                 return -1;
 
@@ -3854,7 +3854,7 @@ static int nl80211_dump_station(struct sk_buff *skb,
                 if (err)
                         goto out_err;
 
-                if (nl80211_send_station(skb,
+                if (nl80211_send_station(skb, NL80211_CMD_NEW_STATION,
                                 NETLINK_CB(cb->skb).portid,
                                 cb->nlh->nlmsg_seq, NLM_F_MULTI,
                                 rdev, wdev->netdev, mac_addr,
@@ -3901,7 +3901,8 @@ static int nl80211_get_station(struct sk_buff *skb, struct genl_info *info)
         if (!msg)
                 return -ENOMEM;
 
-        if (nl80211_send_station(msg, info->snd_portid, info->snd_seq, 0,
+        if (nl80211_send_station(msg, NL80211_CMD_NEW_STATION,
+                                 info->snd_portid, info->snd_seq, 0,
                                  rdev, dev, mac_addr, &sinfo) < 0) {
                 nlmsg_free(msg);
                 return -ENOBUFS;
@@ -11687,7 +11688,7 @@ void cfg80211_new_sta(struct net_device *dev, const u8 *mac_addr,
         if (!msg)
                 return;
 
-        if (nl80211_send_station(msg, 0, 0, 0,
+        if (nl80211_send_station(msg, NL80211_CMD_NEW_STATION, 0, 0, 0,
                                  rdev, dev, mac_addr, sinfo) < 0) {
                 nlmsg_free(msg);
                 return;
@@ -11698,12 +11699,16 @@ void cfg80211_new_sta(struct net_device *dev, const u8 *mac_addr,
 }
 EXPORT_SYMBOL(cfg80211_new_sta);
 
-void cfg80211_del_sta(struct net_device *dev, const u8 *mac_addr, gfp_t gfp)
+void cfg80211_del_sta_sinfo(struct net_device *dev, const u8 *mac_addr,
+                            struct station_info *sinfo, gfp_t gfp)
 {
         struct wiphy *wiphy = dev->ieee80211_ptr->wiphy;
         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
         struct sk_buff *msg;
-        void *hdr;
+        struct station_info empty_sinfo = {};
+
+        if (!sinfo)
+                sinfo = &empty_sinfo;
 
         trace_cfg80211_del_sta(dev, mac_addr);
 
@@ -11711,27 +11716,16 @@ void cfg80211_del_sta(struct net_device *dev, const u8 *mac_addr, gfp_t gfp)
         if (!msg)
                 return;
 
-        hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_DEL_STATION);
-        if (!hdr) {
+        if (nl80211_send_station(msg, NL80211_CMD_DEL_STATION, 0, 0, 0,
+                                 rdev, dev, mac_addr, sinfo)) {
                 nlmsg_free(msg);
                 return;
         }
 
-        if (nla_put_u32(msg, NL80211_ATTR_IFINDEX, dev->ifindex) ||
-            nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN, mac_addr))
-                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:
-        genlmsg_cancel(msg, hdr);
-        nlmsg_free(msg);
 }
-EXPORT_SYMBOL(cfg80211_del_sta);
+EXPORT_SYMBOL(cfg80211_del_sta_sinfo);
 
 void cfg80211_conn_failed(struct net_device *dev, const u8 *mac_addr,
                           enum nl80211_connect_failed_reason reason,