ath9k: Discard invalid frames early

Frames with invalid or zero length can be discarded
early, there is no need to check the crypto bits.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 83b3fc5..f8cc2b3 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -764,7 +764,6 @@ static bool ath9k_rx_accept(struct ath_common *common,
        bool is_mc, is_valid_tkip, strip_mic, mic_error;
        struct ath_hw *ah = common->ah;
        __le16 fc;
-       u8 rx_status_len = ah->caps.rx_status_len;
 
        fc = hdr->frame_control;
 
@@ -786,21 +785,6 @@ static bool ath9k_rx_accept(struct ath_common *common,
            !test_bit(rx_stats->rs_keyix, common->ccmp_keymap))
                rx_stats->rs_status &= ~ATH9K_RXERR_KEYMISS;
 
-       if (!rx_stats->rs_datalen) {
-               RX_STAT_INC(rx_len_err);
-               return false;
-       }
-
-        /*
-         * rs_status follows rs_datalen so if rs_datalen is too large
-         * we can take a hint that hardware corrupted it, so ignore
-         * those frames.
-         */
-       if (rx_stats->rs_datalen > (common->rx_bufsize - rx_status_len)) {
-               RX_STAT_INC(rx_len_err);
-               return false;
-       }
-
        /* Only use error bits from the last fragment */
        if (rx_stats->rs_more)
                return true;
@@ -949,10 +933,32 @@ static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
        struct ath_common *common = ath9k_hw_common(ah);
        bool discard_current = sc->rx.discard_next;
 
+       /*
+        * Discard corrupt descriptors which are marked in
+        * ath_get_next_rx_buf().
+        */
        sc->rx.discard_next = rx_stats->rs_more;
        if (discard_current)
                return -EINVAL;
 
+       /*
+        * Discard zero-length packets.
+        */
+       if (!rx_stats->rs_datalen) {
+               RX_STAT_INC(rx_len_err);
+               return -EINVAL;
+       }
+
+        /*
+         * rs_status follows rs_datalen so if rs_datalen is too large
+         * we can take a hint that hardware corrupted it, so ignore
+         * those frames.
+         */
+       if (rx_stats->rs_datalen > (common->rx_bufsize - ah->caps.rx_status_len)) {
+               RX_STAT_INC(rx_len_err);
+               return -EINVAL;
+       }
+
        /*
         * everything but the rate is checked here, the rate check is done
         * separately to avoid doing two lookups for a rate for each frame.