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

drivers/net/wireless/ath5k/base.c

+21 −17
Original line number Diff line number Diff line
@@ -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 @@ ath5k_tasklet_rx(unsigned long data) 


		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);