drivers/net/wireless/mediatek/mt7601u/util.c

   1 /*
   2  * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include "mt7601u.h"
  15
  16 void mt76_remove_hdr_pad(struct sk_buff *skb)
  17 {
  18         int len = ieee80211_get_hdrlen_from_skb(skb);
  19
  20         memmove(skb->data + 2, skb->data, len);
  21         skb_pull(skb, 2);
  22 }
  23
  24 int mt76_insert_hdr_pad(struct sk_buff *skb)
  25 {
  26         int len = ieee80211_get_hdrlen_from_skb(skb);
  27         int ret;
  28
  29         if (len % 4 == 0)
  30                 return 0;
  31
  32         ret = skb_cow(skb, 2);
  33         if (ret)
  34                 return ret;
  35
  36         skb_push(skb, 2);
  37         memmove(skb->data, skb->data + 2, len);
  38
  39         skb->data[len] = 0;
  40         skb->data[len + 1] = 0;
  41         return 0;
  42 }