mac80211: IBSS join rework

I hold back this patch for around a week to avoid
confusion. This is the second step of
"mac80211: Fixed BSSID handling revisited".

With it, in the situation of a strange merge to the
same BSSID (e.g. caused by a TSF overflow) only
reset_tsf() is called.

And sta_info_flush_delayed() is only called if you
change the network manually, not on an automatic
BSSID merge.

Signed-off-by: Alina Friedrichsen <x-alina@gmx.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 14 insertions, 7 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 0ece151659c0..73808780f538 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1503,13 +1503,22 @@ static int ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
                                    struct ieee80211_bss *bss)
 {
         struct ieee80211_local *local = sdata->local;
-        int res, rates, i, j;
+        int res = 0, rates, i, j;
         struct sk_buff *skb;
         struct ieee80211_mgmt *mgmt;
         u8 *pos;
         struct ieee80211_supported_band *sband;
         union iwreq_data wrqu;
 
+        if (local->ops->reset_tsf) {
+                /* Reset own TSF to allow time synchronization work. */
+                local->ops->reset_tsf(local_to_hw(local));
+        }
+
+        if ((ifsta->flags & IEEE80211_STA_PREV_BSSID_SET) &&
+           memcmp(ifsta->bssid, bss->bssid, ETH_ALEN) == 0)
+                return res;
+
         skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400 +
                             sdata->u.sta.ie_proberesp_len);
         if (!skb) {
@@ -1520,13 +1529,11 @@ static int ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 
         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 
-        /* Remove possible STA entries from other IBSS networks. */
-        sta_info_flush_delayed(sdata);
-
-        if (local->ops->reset_tsf) {
-                /* Reset own TSF to allow time synchronization work. */
-                local->ops->reset_tsf(local_to_hw(local));
+        if (!(ifsta->flags & IEEE80211_STA_PREV_BSSID_SET)) {
+                /* Remove possible STA entries from other IBSS networks. */
+                sta_info_flush_delayed(sdata);
         }
+
         memcpy(ifsta->bssid, bss->bssid, ETH_ALEN);
         res = ieee80211_if_config(sdata, IEEE80211_IFCC_BSSID);
         if (res)