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>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index cb95a31..f195705 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -783,7 +783,7 @@
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 @@
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 @@
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 @@
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);
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 4ecf10a..ccc3adf 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -30,7 +30,6 @@
* @WLAN_STA_ASSOC_AP: We're associated to that station, it is an AP.
* @WLAN_STA_WME: Station is a QoS-STA.
* @WLAN_STA_WDS: Station is one of our WDS peers.
- * @WLAN_STA_PSPOLL: Station has just PS-polled us.
* @WLAN_STA_CLEAR_PS_FILT: Clear PS filter in hardware (using the
* IEEE80211_TX_CTL_CLEAR_PS_FILT control flag) when the next
* frame to this station is transmitted.
@@ -47,7 +46,6 @@
WLAN_STA_ASSOC_AP = 1<<5,
WLAN_STA_WME = 1<<6,
WLAN_STA_WDS = 1<<7,
- WLAN_STA_PSPOLL = 1<<8,
WLAN_STA_CLEAR_PS_FILT = 1<<9,
WLAN_STA_MFP = 1<<10,
WLAN_STA_SUSPEND = 1<<11
@@ -359,17 +357,6 @@
spin_unlock_irqrestore(&sta->flaglock, irqfl);
}
-static inline void set_and_clear_sta_flags(struct sta_info *sta,
- const u32 set, const u32 clear)
-{
- unsigned long irqfl;
-
- spin_lock_irqsave(&sta->flaglock, irqfl);
- sta->flags |= set;
- sta->flags &= ~clear;
- spin_unlock_irqrestore(&sta->flaglock, irqfl);
-}
-
static inline u32 test_sta_flags(struct sta_info *sta, const u32 flags)
{
u32 ret;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 70ff4f06..edacad1 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -373,7 +373,7 @@
staflags = get_sta_flags(sta);
if (unlikely((staflags & WLAN_STA_PS) &&
- !(staflags & WLAN_STA_PSPOLL))) {
+ !(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE))) {
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries "
"before %d)\n",
@@ -412,24 +412,7 @@
sta->sta.addr);
}
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
- if (test_and_clear_sta_flags(sta, WLAN_STA_PSPOLL)) {
- /*
- * The sleeping station with pending data is now snoozing.
- * It queried us for its buffered frames and will go back
- * to deep sleep once it got everything.
- *
- * inform the driver, in case the hardware does powersave
- * frame filtering and keeps a station blacklist on its own
- * (e.g: p54), so that frames can be delivered unimpeded.
- *
- * Note: It should be safe to disable the filter now.
- * As, it is really unlikely that we still have any pending
- * frame for this station in the hw's buffers/fifos left,
- * that is not rejected with a unsuccessful tx_status yet.
- */
- info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
- }
return TX_CONTINUE;
}