diff options
| -rw-r--r-- | drivers/net/wireless/rtlwifi/usb.c | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/drivers/net/wireless/rtlwifi/usb.c b/drivers/net/wireless/rtlwifi/usb.c index a7b54f631293..72c2614213c4 100644 --- a/drivers/net/wireless/rtlwifi/usb.c +++ b/drivers/net/wireless/rtlwifi/usb.c @@ -569,6 +569,37 @@ static void _rtl_rx_work(unsigned long param) } } +static unsigned int _rtl_rx_get_padding(struct ieee80211_hdr *hdr, + unsigned int len) +{ + unsigned int padding = 0; + + /* make function no-op when possible */ + if (NET_IP_ALIGN == 0 || len < sizeof(*hdr)) + return 0; + + /* alignment calculation as in lbtf_rx() / carl9170_rx_copy_data() */ + /* TODO: deduplicate common code, define helper function instead? */ + + if (ieee80211_is_data_qos(hdr->frame_control)) { + u8 *qc = ieee80211_get_qos_ctl(hdr); + + padding ^= NET_IP_ALIGN; + + /* Input might be invalid, avoid accessing memory outside + * the buffer. + */ + if ((unsigned long)qc - (unsigned long)hdr < len && + *qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT) + padding ^= NET_IP_ALIGN; + } + + if (ieee80211_has_a4(hdr->frame_control)) + padding ^= NET_IP_ALIGN; + + return padding; +} + #define __RADIO_TAP_SIZE_RSV 32 static void _rtl_rx_completed(struct urb *_urb) @@ -582,9 +613,11 @@ static void _rtl_rx_completed(struct urb *_urb) goto free; if (likely(0 == _urb->status)) { + unsigned int padding; struct sk_buff *skb; unsigned int qlen; unsigned int size = _urb->actual_length; + struct ieee80211_hdr *hdr; if (size < RTL_RX_DESC_SIZE + sizeof(struct ieee80211_hdr)) { RT_TRACE(rtlpriv, COMP_USB, DBG_EMERG, @@ -601,7 +634,10 @@ static void _rtl_rx_completed(struct urb *_urb) goto resubmit; } - skb = dev_alloc_skb(size + __RADIO_TAP_SIZE_RSV); + hdr = (void *)(_urb->transfer_buffer + RTL_RX_DESC_SIZE); + padding = _rtl_rx_get_padding(hdr, size - RTL_RX_DESC_SIZE); + + skb = dev_alloc_skb(size + __RADIO_TAP_SIZE_RSV + padding); if (!skb) { RT_TRACE(rtlpriv, COMP_USB, DBG_EMERG, "Can't allocate skb for bulk IN!\n"); @@ -610,6 +646,9 @@ static void _rtl_rx_completed(struct urb *_urb) _rtl_install_trx_info(rtlusb, skb, rtlusb->in_ep); + /* Make sure the payload data is 4 byte aligned. */ + skb_reserve(skb, padding); + /* reserve some space for mac80211's radiotap */ skb_reserve(skb, __RADIO_TAP_SIZE_RSV); |