mac80211: add functions to create PS Poll and Nullfunc templates

Some hardware, for example wl1251 and wl1271, handle the transmission
of power save related frames in hardware, but the driver is responsible
for creating the templates. It's better to create the templates in mac80211,
that way all drivers can benefit from this.

Add two new functions, ieee80211_pspoll_get() and ieee80211_nullfunc_get()
which drivers need to call to get the frame. Drivers are also responsible
for updating the templates after each association.

Also new struct ieee80211_hdr_3addr is added to ieee80211.h to make it
easy to calculate length of the Nullfunc frame.

Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 78 insertions, 0 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index d3a44812f8b..055b45b146d 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2200,6 +2200,84 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
 }
 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
 
+struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
+				     struct ieee80211_vif *vif)
+{
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_if_managed *ifmgd;
+	struct ieee80211_pspoll *pspoll;
+	struct ieee80211_local *local;
+	struct sk_buff *skb;
+
+	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
+		return NULL;
+
+	sdata = vif_to_sdata(vif);
+	ifmgd = &sdata->u.mgd;
+	local = sdata->local;
+
+	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
+	if (!skb) {
+		printk(KERN_DEBUG "%s: failed to allocate buffer for "
+		       "pspoll template\n", sdata->name);
+		return NULL;
+	}
+	skb_reserve(skb, local->hw.extra_tx_headroom);
+
+	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
+	memset(pspoll, 0, sizeof(*pspoll));
+	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
+					    IEEE80211_STYPE_PSPOLL);
+	pspoll->aid = cpu_to_le16(ifmgd->aid);
+
+	/* aid in PS-Poll has its two MSBs each set to 1 */
+	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
+
+	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
+	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
+
+	return skb;
+}
+EXPORT_SYMBOL(ieee80211_pspoll_get);
+
+struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
+				       struct ieee80211_vif *vif)
+{
+	struct ieee80211_hdr_3addr *nullfunc;
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_if_managed *ifmgd;
+	struct ieee80211_local *local;
+	struct sk_buff *skb;
+
+	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
+		return NULL;
+
+	sdata = vif_to_sdata(vif);
+	ifmgd = &sdata->u.mgd;
+	local = sdata->local;
+
+	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
+	if (!skb) {
+		printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
+		       "template\n", sdata->name);
+		return NULL;
+	}
+	skb_reserve(skb, local->hw.extra_tx_headroom);
+
+	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
+							  sizeof(*nullfunc));
+	memset(nullfunc, 0, sizeof(*nullfunc));
+	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
+					      IEEE80211_STYPE_NULLFUNC |
+					      IEEE80211_FCTL_TODS);
+	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
+	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
+	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
+
+	return skb;
+}
+EXPORT_SYMBOL(ieee80211_nullfunc_get);
+
 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		       const void *frame, size_t frame_len,
 		       const struct ieee80211_tx_info *frame_txctl,