ath9k: move ath9k_rx_accept to common.c

we can reuse it on ath9k_htc

Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 88 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/common.c b/drivers/net/wireless/ath/ath9k/common.c
index 120fd46edf0f..5c0d94936a0f 100644
--- a/drivers/net/wireless/ath/ath9k/common.c
+++ b/drivers/net/wireless/ath/ath9k/common.c
@@ -27,6 +27,94 @@ MODULE_AUTHOR("Atheros Communications");
 MODULE_DESCRIPTION("Shared library for Atheros wireless 802.11n LAN cards.");
 MODULE_LICENSE("Dual BSD/GPL");
 
+/* Assumes you've already done the endian to CPU conversion */
+bool ath9k_cmn_rx_accept(struct ath_common *common,
+			 struct ieee80211_hdr *hdr,
+			 struct ieee80211_rx_status *rxs,
+			 struct ath_rx_status *rx_stats,
+			 bool *decrypt_error,
+			 unsigned int rxfilter)
+{
+	struct ath_hw *ah = common->ah;
+	bool is_mc, is_valid_tkip, strip_mic, mic_error;
+	__le16 fc;
+
+	fc = hdr->frame_control;
+
+	is_mc = !!is_multicast_ether_addr(hdr->addr1);
+	is_valid_tkip = rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID &&
+		test_bit(rx_stats->rs_keyix, common->tkip_keymap);
+	strip_mic = is_valid_tkip && ieee80211_is_data(fc) &&
+		ieee80211_has_protected(fc) &&
+		!(rx_stats->rs_status &
+		(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_CRC | ATH9K_RXERR_MIC |
+		 ATH9K_RXERR_KEYMISS));
+
+	/*
+	 * Key miss events are only relevant for pairwise keys where the
+	 * descriptor does contain a valid key index. This has been observed
+	 * mostly with CCMP encryption.
+	 */
+	if (rx_stats->rs_keyix == ATH9K_RXKEYIX_INVALID ||
+	    !test_bit(rx_stats->rs_keyix, common->ccmp_keymap))
+		rx_stats->rs_status &= ~ATH9K_RXERR_KEYMISS;
+
+	mic_error = is_valid_tkip && !ieee80211_is_ctl(fc) &&
+		!ieee80211_has_morefrags(fc) &&
+		!(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
+		(rx_stats->rs_status & ATH9K_RXERR_MIC);
+
+	/*
+	 * The rx_stats->rs_status will not be set until the end of the
+	 * chained descriptors so it can be ignored if rs_more is set. The
+	 * rs_more will be false at the last element of the chained
+	 * descriptors.
+	 */
+	if (rx_stats->rs_status != 0) {
+		u8 status_mask;
+
+		if (rx_stats->rs_status & ATH9K_RXERR_CRC) {
+			rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
+			mic_error = false;
+		}
+
+		if ((rx_stats->rs_status & ATH9K_RXERR_DECRYPT) ||
+		    (!is_mc && (rx_stats->rs_status & ATH9K_RXERR_KEYMISS))) {
+			*decrypt_error = true;
+			mic_error = false;
+		}
+
+
+		/*
+		 * Reject error frames with the exception of
+		 * decryption and MIC failures. For monitor mode,
+		 * we also ignore the CRC error.
+		 */
+		status_mask = ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
+			      ATH9K_RXERR_KEYMISS;
+
+		if (ah->is_monitoring && (rxfilter & FIF_FCSFAIL))
+			status_mask |= ATH9K_RXERR_CRC;
+
+		if (rx_stats->rs_status & ~status_mask)
+			return false;
+	}
+
+	/*
+	 * For unicast frames the MIC error bit can have false positives,
+	 * so all MIC error reports need to be validated in software.
+	 * False negatives are not common, so skip software verification
+	 * if the hardware considers the MIC valid.
+	 */
+	if (strip_mic)
+		rxs->flag |= RX_FLAG_MMIC_STRIPPED;
+	else if (is_mc && mic_error)
+		rxs->flag |= RX_FLAG_MMIC_ERROR;
+
+	return true;
+}
+EXPORT_SYMBOL(ath9k_cmn_rx_accept);
+
 int ath9k_cmn_process_rate(struct ath_common *common,
 			   struct ieee80211_hw *hw,
 			   struct ath_rx_status *rx_stats,