cw1200: Purge cfg80211 beacon cache before authentication.

cw1200 device requires SSID to be available at AUTH stage.
cfg80211 beacon cache is designed to handle multi-SSID BSSes, so
bss struct returned by cfg80211_get_bss() has random SSID if BSS
just changed SSID before authentication (typical for p2p).

This is a firmware design fault, however as a workaround cfg80211
beacon cache is purged to make sure target BSS is searchable
in rb-tree at the AUTH stage.

Likely will not be accepted by community.

Change-Id: I38d071e0d32bf414906170a19134718b0e834cce
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/28558
Tested-by: Dmitry TARNYAGIN <dmitry.tarnyagin@stericsson.com>
Reviewed-by: Bartosz MARKOWSKI <bartosz.markowski@tieto.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/28696
Tested-by: Bartosz MARKOWSKI <bartosz.markowski@tieto.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/33504
Reviewed-by: Philippe LANGLAIS <philippe.langlais@stericsson.com>

4 files changed, 28 insertions, 1 deletions

diff --git a/drivers/staging/cw1200/sta.c b/drivers/staging/cw1200/sta.c
index 17a4184a360..d6a25a27358 100644
--- a/drivers/staging/cw1200/sta.c
+++ b/drivers/staging/cw1200/sta.c
@@ -1027,7 +1027,8 @@ void cw1200_join_work(struct work_struct *work)
 	cancel_delayed_work_sync(&priv->join_timeout);
 
 	priv->join_pending_frame = NULL;
-	bss = cfg80211_get_bss(priv->hw->wiphy, NULL, bssid, NULL, 0, 0, 0);
+	bss = cfg80211_get_bss(priv->hw->wiphy, priv->channel,
+			bssid, NULL, 0, 0, 0);
 	if (!bss) {
 		cw1200_queue_remove(&priv->tx_queue[queueId],
 			priv, __le32_to_cpu(wsm->packetID));
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4473e1c926d..625ee2cd8a4 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -308,6 +308,7 @@ struct ieee80211_work {
 			u8 key[WLAN_KEY_LEN_WEP104];
 			u8 key_len, key_idx;
 			bool privacy;
+			struct cfg80211_bss *bss;
 		} probe_auth;
 		struct {
 			struct cfg80211_bss *bss;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index d595265d6c2..96fda24bc8b 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2342,6 +2342,7 @@ int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata,
 
 	wk->probe_auth.algorithm = auth_alg;
 	wk->probe_auth.privacy = req->bss->capability & WLAN_CAPABILITY_PRIVACY;
+	wk->probe_auth.bss = req->bss;
 
 	/* if we already have a probe, don't probe again */
 	if (req->bss->proberesp_ies)
diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index d2e7f0e8667..59437667d75 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -465,6 +465,30 @@ ieee80211_authenticate(struct ieee80211_work *wk)
 	struct ieee80211_sub_if_data *sdata = wk->sdata;
 	struct ieee80211_local *local = sdata->local;
 
+	/* HACK!!! cw1200 device requires SSID to be available at AUTH stage.
+	 * cfg80211 beacon cache is designed to handle multi-SSID BSSes, so
+	 * bss struct returned by cfg80211_get_bss() has random SSID if BSS
+	 * just changed SSID before authentication (typical for p2p).
+	 * This is a firmware design fault, however as a workaround cfg80211
+	 * beacon cache is purged to make sure target BSS is searchable
+	 * in rb-tree at the AUTH stage.
+	 */
+	struct cfg80211_bss *bss;
+	while (true) {
+		bss = cfg80211_get_bss(local->hw.wiphy,
+				wk->probe_auth.bss->channel,
+				wk->probe_auth.bss->bssid,
+				NULL, 0, 0, 0);
+		if (WARN_ON(!bss))
+			break;
+		if (bss == wk->probe_auth.bss) {
+			cfg80211_put_bss(bss);
+			break;
+		}
+		cfg80211_unlink_bss(local->hw.wiphy, bss);
+	}
+	/* End of the hack */
+
 	wk->probe_auth.tries++;
 	if (wk->probe_auth.tries > IEEE80211_AUTH_MAX_TRIES) {
 		printk(KERN_DEBUG "%s: authentication with %pM"