mac80211: fix regression in skb resizing optimization in monitor mode (FS#2254)

struct ieee80211_local needs to be passed in separately instead of
dereferencing the (potentially NULL) sdata

Signed-off-by: Felix Fietkau <[email protected]>

package/kernel/mac80211/patches/subsys/357-mac80211-optimize-skb-resizing.patch

@@ -24,11 +24,12 @@ Signed-off-by: Felix Fietkau <[email protected]>
 
 --- a/net/mac80211/ieee80211_i.h
 +++ b/net/mac80211/ieee80211_i.h
-@@ -1761,6 +1761,8 @@ void ieee80211_clear_fast_xmit(struct st
+@@ -1761,6 +1761,9 @@ void ieee80211_clear_fast_xmit(struct st
  int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev,
  			      const u8 *buf, size_t len,
  			      const u8 *dest, __be16 proto, bool unencrypted);
-+int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
++int ieee80211_skb_resize(struct ieee80211_local *local,
++			 struct ieee80211_sub_if_data *sdata,
 +			 struct sk_buff *skb, int hdrlen, int hdr_add);
  
  /* HT */
@@ -39,7 +40,7 @@ Signed-off-by: Felix Fietkau <[email protected]>
  		}
  	}
  
-+	if (ieee80211_skb_resize(NULL, skb, 0, 0)) {
++	if (ieee80211_skb_resize(local, NULL, skb, 0, 0)) {
 +		dev_kfree_skb(skb);
 +		return;
 +	}
@@ -57,28 +58,23 @@ Signed-off-by: Felix Fietkau <[email protected]>
 -static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
 -				struct sk_buff *skb,
 -				int head_need, bool may_encrypt)
-+int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
++int ieee80211_skb_resize(struct ieee80211_local *local,
++			 struct ieee80211_sub_if_data *sdata,
 +			 struct sk_buff *skb, int hdr_len, int hdr_extra)
  {
- 	struct ieee80211_local *local = sdata->local;
+-	struct ieee80211_local *local = sdata->local;
 +	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  	struct ieee80211_hdr *hdr;
 -	bool enc_tailroom;
 -	int tail_need = 0;
--
++	int head_need, head_max;
++	int tail_need, tail_max;
++	bool enc_tailroom = false;
+ 
 -	hdr = (struct ieee80211_hdr *) skb->data;
 -	enc_tailroom = may_encrypt &&
 -		       (sdata->crypto_tx_tailroom_needed_cnt ||
 -			ieee80211_is_mgmt(hdr->frame_control));
--
--	if (enc_tailroom) {
--		tail_need = IEEE80211_ENCRYPT_TAILROOM;
--		tail_need -= skb_tailroom(skb);
--		tail_need = max_t(int, tail_need, 0);
-+	int head_need, head_max;
-+	int tail_need, tail_max;
-+	bool enc_tailroom = false;
-+
 +	if (sdata && !hdr_len &&
 +	    !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT)) {
 +		hdr = (struct ieee80211_hdr *) skb->data;
@@ -86,7 +82,11 @@ Signed-off-by: Felix Fietkau <[email protected]>
 +				ieee80211_is_mgmt(hdr->frame_control));
 +		hdr_len += sdata->encrypt_headroom;
 +	}
-+
+ 
+-	if (enc_tailroom) {
+-		tail_need = IEEE80211_ENCRYPT_TAILROOM;
+-		tail_need -= skb_tailroom(skb);
+-		tail_need = max_t(int, tail_need, 0);
 +	head_need = head_max = hdr_len;
 +	tail_need = tail_max = 0;
 +	if (!sdata) {
@@ -129,15 +129,15 @@ Signed-off-by: Felix Fietkau <[email protected]>
 -	bool may_encrypt;
 -
 -	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
- 
+-
 -	headroom = local->tx_headroom;
 -	if (may_encrypt)
 -		headroom += sdata->encrypt_headroom;
 -	headroom -= skb_headroom(skb);
 -	headroom = max_t(int, 0, headroom);
--
+ 
 -	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
-+	if (ieee80211_skb_resize(sdata, skb, 0, 0)) {
++	if (ieee80211_skb_resize(local, sdata, skb, 0, 0)) {
  		ieee80211_free_txskb(&local->hw, skb);
  		return;
  	}
@@ -170,7 +170,7 @@ Signed-off-by: Felix Fietkau <[email protected]>
 -			skb = NULL;
 -			return ERR_PTR(-ENOMEM);
 -		}
-+	if (ieee80211_skb_resize(sdata, skb, head_need,
++	if (ieee80211_skb_resize(local, sdata, skb, head_need,
 +				 sdata->encrypt_headroom)) {
 +		ieee80211_free_txskb(&local->hw, skb);
 +		skb = NULL;
@@ -194,7 +194,7 @@ Signed-off-by: Felix Fietkau <[email protected]>
 -					  max_t(int, extra_head + hw_headroom -
 -						     skb_headroom(skb), 0),
 -					  false))) {
-+	if (unlikely(ieee80211_skb_resize(sdata, skb, extra_head, 0))) {
++	if (unlikely(ieee80211_skb_resize(local, sdata, skb, extra_head, 0))) {
  		kfree_skb(skb);
  		return true;
  	}