From 3fa52056f3a8e755708241d5795e6d3e6f55ad85 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 24 Jul 2009 13:23:09 +0200 Subject: [PATCH] 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 Reported-by: Bob Copeland Tested-by: Bob Copeland Cc: Christian Lamparter Signed-off-by: John W. Linville --- drivers/net/wireless/p54/txrx.c | 2 +- include/net/mac80211.h | 4 ++++ net/mac80211/rx.c | 11 ++++++----- net/mac80211/sta_info.h | 13 ------------- net/mac80211/tx.c | 19 +------------------ 5 files changed, 12 insertions(+), 37 deletions(-) diff --git a/drivers/net/wireless/p54/txrx.c b/drivers/net/wireless/p54/txrx.c index 0d589d68e54..c32a0d2fa1f 100644 --- a/drivers/net/wireless/p54/txrx.c +++ b/drivers/net/wireless/p54/txrx.c @@ -614,7 +614,7 @@ static void p54_tx_80211_header(struct p54_common *priv, struct sk_buff *skb, if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) *flags |= P54_HDR_FLAG_DATA_OUT_SEQNR; - if (info->flags & IEEE80211_TX_CTL_CLEAR_PS_FILT) + if (info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE) *flags |= P54_HDR_FLAG_DATA_OUT_NOCANCEL; *queue = skb_get_queue_mapping(skb) + P54_QUEUE_DATA; diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 7dd67a1ff4d..d4e09a06b4a 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -243,6 +243,9 @@ struct ieee80211_bss_conf { * used to indicate that a frame was already retried due to PS * @IEEE80211_TX_INTFL_DONT_ENCRYPT: completely internal to mac80211, * used to indicate frame should not be encrypted + * @IEEE80211_TX_CTL_PSPOLL_RESPONSE: (internal?) + * This frame is a response to a PS-poll frame and should be sent + * although the station is in powersave mode. */ enum mac80211_tx_control_flags { IEEE80211_TX_CTL_REQ_TX_STATUS = BIT(0), @@ -262,6 +265,7 @@ enum mac80211_tx_control_flags { IEEE80211_TX_INTFL_NEED_TXPROCESSING = BIT(14), IEEE80211_TX_INTFL_RETRIED = BIT(15), IEEE80211_TX_INTFL_DONT_ENCRYPT = BIT(16), + IEEE80211_TX_CTL_PSPOLL_RESPONSE = BIT(17), }; /** diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index cb95a311603..f195705146b 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); diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h index 4ecf10a9bd0..ccc3adf962c 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 @@ enum ieee80211_sta_info_flags { 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 @@ static inline void clear_sta_flags(struct sta_info *sta, const u32 flags) 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 70ff4f06566..edacad1fb1d 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -373,7 +373,7 @@ ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx) 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 @@ ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx) 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; }