mac80211: correct MU-MIMO monitor follow functionality

The MU-MIMO monitor follow functionality is broken because it
doesn't clear the MU-MIMO owner even if both follow features
are disabled. Fix that, and while at it move the code into a
new helper function. Call this also when creating a new monitor
interface to prepare for an upcoming cfg80211 change allowing
that.

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

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index ef7de9eb94b18d516db99a1d2ac4eaf4a9553d74..e276b8cb24a4f07949e7f8c15b4ee7dddd8fd35b 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -22,6 +22,49 @@
 #include "mesh.h"
 #include "wme.h"
 
+static int ieee80211_set_mu_mimo_follow(struct ieee80211_sub_if_data *sdata,
+                                       struct vif_params *params)
+{
+       struct ieee80211_local *local = sdata->local;
+       struct ieee80211_sub_if_data *monitor_sdata;
+       bool mu_mimo_groups = false;
+       bool mu_mimo_follow = false;
+
+       monitor_sdata = rtnl_dereference(local->monitor_sdata);
+
+       if (!monitor_sdata)
+               return -EOPNOTSUPP;
+
+       if (params->vht_mumimo_groups) {
+               u64 membership;
+
+               BUILD_BUG_ON(sizeof(membership) != WLAN_MEMBERSHIP_LEN);
+
+               memcpy(monitor_sdata->vif.bss_conf.mu_group.membership,
+                      params->vht_mumimo_groups, WLAN_MEMBERSHIP_LEN);
+               memcpy(monitor_sdata->vif.bss_conf.mu_group.position,
+                      params->vht_mumimo_groups + WLAN_MEMBERSHIP_LEN,
+                      WLAN_USER_POSITION_LEN);
+               ieee80211_bss_info_change_notify(monitor_sdata,
+                                                BSS_CHANGED_MU_GROUPS);
+               /* don't care about endianness - just check for 0 */
+               memcpy(&membership, params->vht_mumimo_groups,
+                      WLAN_MEMBERSHIP_LEN);
+               mu_mimo_groups = membership != 0;
+       }
+
+       if (params->vht_mumimo_follow_addr) {
+               mu_mimo_follow =
+                       is_valid_ether_addr(params->vht_mumimo_follow_addr);
+               ether_addr_copy(monitor_sdata->u.mntr.mu_follow_addr,
+                               params->vht_mumimo_follow_addr);
+       }
+
+       monitor_sdata->vif.mu_mimo_owner = mu_mimo_groups || mu_mimo_follow;
+
+       return 0;
+}
+
 static struct wireless_dev *ieee80211_add_iface(struct wiphy *wiphy,
                                                const char *name,
                                                unsigned char name_assign_type,
@@ -38,9 +81,17 @@ static struct wireless_dev *ieee80211_add_iface(struct wiphy *wiphy,
        if (err)
                return ERR_PTR(err);
 
-       if (type == NL80211_IFTYPE_MONITOR && flags) {
-               sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
-               sdata->u.mntr.flags = *flags;
+       sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
+
+       if (type == NL80211_IFTYPE_MONITOR) {
+               err = ieee80211_set_mu_mimo_follow(sdata, params);
+               if (err) {
+                       ieee80211_if_remove(sdata);
+                       return NULL;
+               }
+
+               if (flags)
+                       sdata->u.mntr.flags = *flags;
        }
 
        return wdev;
@@ -76,24 +127,11 @@ static int ieee80211_change_iface(struct wiphy *wiphy,
 
        if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
                struct ieee80211_local *local = sdata->local;
-               struct ieee80211_sub_if_data *monitor_sdata;
-               u32 mu_mntr_cap_flag = NL80211_EXT_FEATURE_MU_MIMO_AIR_SNIFFER;
-
-               monitor_sdata = rtnl_dereference(local->monitor_sdata);
-               if (monitor_sdata && params->vht_mumimo_groups) {
-                       memcpy(monitor_sdata->vif.bss_conf.mu_group.membership,
-                              params->vht_mumimo_groups, WLAN_MEMBERSHIP_LEN);
-                       memcpy(monitor_sdata->vif.bss_conf.mu_group.position,
-                              params->vht_mumimo_groups + WLAN_MEMBERSHIP_LEN,
-                              WLAN_USER_POSITION_LEN);
-                       monitor_sdata->vif.mu_mimo_owner = true;
-                       ieee80211_bss_info_change_notify(monitor_sdata,
-                                                        BSS_CHANGED_MU_GROUPS);
-               }
+               int err;
 
-               if (monitor_sdata && params->vht_mumimo_follow_addr)
-                       ether_addr_copy(monitor_sdata->u.mntr.mu_follow_addr,
-                                       params->vht_mumimo_follow_addr);
+               err = ieee80211_set_mu_mimo_follow(sdata, params);
+               if (err)
+                       return err;
 
                if (!flags)
                        return 0;