zd1211rw: fix alignment for QOS and WDS frames
This patch fixes RX packet alignment issues in the zd1211rw driver.
This is based on a patch by Johannes Berg.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/zd1211rw/zd_mac.c b/drivers/net/wireless/zd1211rw/zd_mac.c
index 14fb727..7b86930 100644
--- a/drivers/net/wireless/zd1211rw/zd_mac.c
+++ b/drivers/net/wireless/zd1211rw/zd_mac.c
@@ -623,6 +623,8 @@
const struct rx_status *status;
struct sk_buff *skb;
int bad_frame = 0;
+ u16 fc;
+ bool is_qos, is_4addr, need_padding;
if (length < ZD_PLCP_HEADER_SIZE + 10 /* IEEE80211_1ADDR_LEN */ +
FCS_LEN + sizeof(struct rx_status))
@@ -674,9 +676,22 @@
&& !mac->pass_ctrl)
return 0;
- skb = dev_alloc_skb(length);
+ fc = le16_to_cpu(*((__le16 *) buffer));
+
+ is_qos = ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
+ ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_QOS_DATA);
+ is_4addr = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
+ (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
+ need_padding = is_qos ^ is_4addr;
+
+ skb = dev_alloc_skb(length + (need_padding ? 2 : 0));
if (skb == NULL)
return -ENOMEM;
+ if (need_padding) {
+ /* Make sure the the payload data is 4 byte aligned. */
+ skb_reserve(skb, 2);
+ }
+
memcpy(skb_put(skb, length), buffer, length);
ieee80211_rx_irqsafe(hw, skb, &stats);