mac80211: let the driver reserve extra tailroom in beacons

Can be used to add extra IEs (such as P2P NoA) without having to
reallocate the buffer.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 22b6dd9..531785f 100644 (file)
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1613,6 +1613,9 @@ enum ieee80211_hw_flags {
  * @extra_tx_headroom: headroom to reserve in each transmit skb
  *     for use by the driver (e.g. for transmit headers.)
  *
+ * @extra_beacon_tailroom: tailroom to reserve in each beacon tx skb.
+ *     Can be used by drivers to add extra IEs.
+ *
  * @channel_change_time: time (in microseconds) it takes to change channels.
  *
  * @max_signal: Maximum value for signal (rssi) in RX information, used
@@ -1695,6 +1698,7 @@ struct ieee80211_hw {
        void *priv;
        u32 flags;
        unsigned int extra_tx_headroom;
+       unsigned int extra_beacon_tailroom;
        int channel_change_time;
        int vif_data_size;
        int sta_data_size;

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 6d59e21..002ded2 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2549,7 +2549,8 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
                         */
                        skb = dev_alloc_skb(local->tx_headroom +
                                            beacon->head_len +
-                                           beacon->tail_len + 256);
+                                           beacon->tail_len + 256 +
+                                           local->hw.extra_beacon_tailroom);
                        if (!skb)
                                goto out;
 
@@ -2581,7 +2582,8 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
                        ieee80211_update_csa(sdata, presp);
 
 
-               skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
+               skb = dev_alloc_skb(local->tx_headroom + presp->head_len +
+                                   local->hw.extra_beacon_tailroom);
                if (!skb)
                        goto out;
                skb_reserve(skb, local->tx_headroom);
@@ -2608,7 +2610,8 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
                skb = dev_alloc_skb(local->tx_headroom +
                                    bcn->head_len +
                                    256 + /* TIM IE */
-                                   bcn->tail_len);
+                                   bcn->tail_len +
+                                   local->hw.extra_beacon_tailroom);
                if (!skb)
                        goto out;
                skb_reserve(skb, local->tx_headroom);