Commit 0fe45b1d authored by Benoit PAPILLAULT's avatar Benoit PAPILLAULT Committed by John W. Linville

ath5k: fix 802.11 header padding on RX, unpadding on TX

Padding the 802.11 header to a multiple of 4 bytes needs to be done only for
frames with a body. This fixes a bug where 2 bytes were missing in monitor
mode for ACK frames. Inspired by a patch from Jouni Malinen on ath9k.

Ref: http://bugzilla.kernel.org/show_bug.cgi?id=12101 :
Signed-off-by: default avatarBenoit Papillault <benoit.papillault@free.fr>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent baad1d92
......@@ -1668,7 +1668,7 @@ ath5k_tasklet_rx(unsigned long data)
struct ath5k_desc *ds;
int ret;
int hdrlen;
int pad;
int padsize;
spin_lock(&sc->rxbuflock);
if (list_empty(&sc->rxbuf)) {
......@@ -1753,16 +1753,19 @@ accept:
skb_put(skb, rs.rs_datalen);
/*
* the hardware adds a padding to 4 byte boundaries between
* the header and the payload data if the header length is
* not multiples of 4 - remove it
*/
/* 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. */
hdrlen = ieee80211_get_hdrlen_from_skb(skb);
if (hdrlen & 3) {
pad = hdrlen % 4;
memmove(skb->data + pad, skb->data, hdrlen);
skb_pull(skb, pad);
padsize = hdrlen & 3;
if (padsize && hdrlen >= 24) {
memmove(skb->data + padsize, skb->data, hdrlen);
skb_pull(skb, padsize);
}
/*
......@@ -2623,7 +2626,7 @@ ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
struct ath5k_buf *bf;
unsigned long flags;
int hdrlen;
int pad;
int padsize;
ath5k_debug_dump_skb(sc, skb, "TX ", 1);
......@@ -2635,15 +2638,16 @@ ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
* if this is not the case we add the padding after the header
*/
hdrlen = ieee80211_get_hdrlen_from_skb(skb);
if (hdrlen & 3) {
pad = hdrlen % 4;
if (skb_headroom(skb) < pad) {
padsize = hdrlen & 3;
if (padsize && hdrlen >= 24) {
if (skb_headroom(skb) < padsize) {
ATH5K_ERR(sc, "tx hdrlen not %%4: %d not enough"
" headroom to pad %d\n", hdrlen, pad);
" headroom to pad %d\n", hdrlen, padsize);
return -1;
}
skb_push(skb, pad);
memmove(skb->data, skb->data+pad, hdrlen);
skb_push(skb, padsize);
memmove(skb->data, skb->data+padsize, hdrlen);
}
spin_lock_irqsave(&sc->txbuflock, flags);
......
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