diff options
| author | Jouni Malinen <jouni.malinen@atheros.com> | 2008-12-11 18:22:13 +0200 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2008-12-12 14:45:31 -0500 |
| commit | 9c5f89b3f6580cca21dca4ede940900c5b3c3a81 (patch) | |
| tree | 6d298387944cc089cd452bcb16e5854198a6feea /drivers/net/wireless/ath9k | |
| parent | f2f1ba253d970479343f97c4620e16842c695d03 (diff) | |
ath9k: Do not remove header padding on RX from short frames
The 802.11 header is only padded to 32-bit boundary when the frame has
a non-zero length payload. In other words, control frames (e.g., ACK)
do not have a padding and we should not try to remove it. This fixes
monitor mode for short control frames. In addition, the hdrlen&3 use
is described in more detail to make it easier to understand how the
padding length is calculated.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers/net/wireless/ath9k')
| -rw-r--r-- | drivers/net/wireless/ath9k/recv.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/net/wireless/ath9k/recv.c b/drivers/net/wireless/ath9k/recv.c index cb449f0b417..f2327d8e9c2 100644 --- a/drivers/net/wireless/ath9k/recv.c +++ b/drivers/net/wireless/ath9k/recv.c @@ -571,8 +571,16 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush) hdr = (struct ieee80211_hdr *)skb->data; hdrlen = ieee80211_get_hdrlen_from_skb(skb); - if (hdrlen & 3) { - padsize = hdrlen % 4; + /* The MAC header is padded to have 32-bit boundary if the + * packet payload is non-zero. The general calculation for + * padsize would take into account odd header lengths: + * padsize = (4 - hdrlen % 4) % 4; However, since only + * even-length headers are used, padding can only be 0 or 2 + * bytes and we can optimize this a bit. In addition, we must + * not try to remove padding from short control frames that do + * not have payload. */ + padsize = hdrlen & 3; + if (padsize && hdrlen >= 24) { memmove(skb->data + padsize, skb->data, hdrlen); skb_pull(skb, padsize); } |