mac80211: fix network header breakage during encryption

When an IV is generated, only the MAC header is moved back. The network
header location remains the same relative to the skb head, as the new IV
is using headroom space that was reserved in advance.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/wep.c

@@ -111,8 +111,6 @@ static u8 *ieee80211_wep_add_iv(struct ieee80211_local *local,
 	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
 		return newhdr + hdrlen;
 
-	skb_set_network_header(skb, skb_network_offset(skb) +
-				    IEEE80211_WEP_IV_LEN);
 	ieee80211_wep_get_iv(local, keylen, keyidx, newhdr + hdrlen);
 	return newhdr + hdrlen;
 }

net/mac80211/wpa.c

@@ -209,8 +209,6 @@ static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 
 	pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
 	memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
-	skb_set_network_header(skb, skb_network_offset(skb) +
-				    IEEE80211_TKIP_IV_LEN);
 	pos += hdrlen;
 
 	/* the HW only needs room for the IV, but not the actual IV */
@@ -434,8 +432,6 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 
 	pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
 	memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
-	skb_set_network_header(skb, skb_network_offset(skb) +
-				    IEEE80211_CCMP_HDR_LEN);
 
 	/* the HW only needs room for the IV, but not the actual IV */
 	if (info->control.hw_key &&
@@ -575,7 +571,6 @@ ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
 
 	pos = skb_push(skb, cs->hdr_len);
 	memmove(pos, pos + cs->hdr_len, hdrlen);
-	skb_set_network_header(skb, skb_network_offset(skb) + cs->hdr_len);
 
 	return TX_CONTINUE;
 }