mac80211: pass in PS_POLL frames

This patch fixes should_drop_frame function to pass in ps poll control
frames required for power save functioanlity. Interface types that do not
have interest for PS POLL frames now drop it in handler.
Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mac80211/rx.c

@@ -61,8 +61,10 @@ static inline int should_drop_frame(struct ieee80211_rx_status *status,
 		return 1;
 	if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
 		return 1;
-	if ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
-			cpu_to_le16(IEEE80211_FTYPE_CTL))
+	if (((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
+			cpu_to_le16(IEEE80211_FTYPE_CTL)) &&
+	    ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
+			cpu_to_le16(IEEE80211_STYPE_PSPOLL)))
 		return 1;
 	return 0;
 }
@@ -896,6 +898,7 @@ ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx)
 static ieee80211_txrx_result
 ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
 {
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
 	struct sk_buff *skb;
 	int no_pending_pkts;
 	DECLARE_MAC_BUF(mac);
@@ -906,6 +909,10 @@ ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
 		   !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)))
 		return TXRX_CONTINUE;
 
+	if ((sdata->type != IEEE80211_IF_TYPE_AP) &&
+	    (sdata->type != IEEE80211_IF_TYPE_VLAN))
+		return TXRX_DROP;
+
 	skb = skb_dequeue(&rx->sta->tx_filtered);
 	if (!skb) {
 		skb = skb_dequeue(&rx->sta->ps_tx_buf);

net/mac80211/util.c

@@ -135,13 +135,16 @@ u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len)
 {
 	u16 fc;
 
-	if (len < 24)
+	 /* drop ACK/CTS frames and incorrect hdr len (ctrl) */
+	if (len < 16)
 		return NULL;
 
 	fc = le16_to_cpu(hdr->frame_control);
 
 	switch (fc & IEEE80211_FCTL_FTYPE) {
 	case IEEE80211_FTYPE_DATA:
+		if (len < 24) /* drop incorrect hdr len (data) */
+			return NULL;
 		switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
 		case IEEE80211_FCTL_TODS:
 			return hdr->addr1;
@@ -154,6 +157,8 @@ u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len)
 		}
 		break;
 	case IEEE80211_FTYPE_MGMT:
+		if (len < 24) /* drop incorrect hdr len (mgmt) */
+			return NULL;
 		return hdr->addr3;
 	case IEEE80211_FTYPE_CTL:
 		if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)