mac80211: fix PS-poll response, race

When a station queries us for a PS-poll response, we wrongly
queue the frame on the virtual interface's queue rather than
the pending queue.

Additionally, fix a race condition where we could potentially
send multiple frames to the sleeping station due to using a
station flag rather than a packet flag. When converting to a
packet flag, we can also convert p54 and remove the filter
clearing we added for it.

(Also remove a now dead function)

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Bob Copeland <me@bobcopeland.com>
Tested-by: Bob Copeland <me@bobcopeland.com>
Cc: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index cb95a3116034..f195705146bd 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -783,7 +783,7 @@ static void ap_sta_ps_start(struct sta_info *sta)
         struct ieee80211_local *local = sdata->local;
 
         atomic_inc(&sdata->bss->num_sta_ps);
-        set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
+        set_sta_flags(sta, WLAN_STA_PS);
         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
@@ -799,7 +799,7 @@ static int ap_sta_ps_end(struct sta_info *sta)
 
         atomic_dec(&sdata->bss->num_sta_ps);
 
-        clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
+        clear_sta_flags(sta, WLAN_STA_PS);
         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_AWAKE, &sta->sta);
 
         if (!skb_queue_empty(&sta->ps_tx_buf))
@@ -1117,14 +1117,15 @@ ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
                 skb_queue_empty(&rx->sta->ps_tx_buf);
 
         if (skb) {
+                struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
                 struct ieee80211_hdr *hdr =
                         (struct ieee80211_hdr *) skb->data;
 
                 /*
-                 * Tell TX path to send one frame even though the STA may
+                 * Tell TX path to send this frame even though the STA may
                  * still remain is PS mode after this frame exchange.
                  */
-                set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
+                info->flags |= IEEE80211_TX_CTL_PSPOLL_RESPONSE;
 
 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
                 printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
@@ -1139,7 +1140,7 @@ ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
                 else
                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 
-                dev_queue_xmit(skb);
+                ieee80211_add_pending_skb(rx->local, skb);
 
                 if (no_pending_pkts)
                         sta_info_clear_tim_bit(rx->sta);