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path: root/drivers/net/wireless/ath/ath9k/common.c
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Diffstat (limited to 'drivers/net/wireless/ath/ath9k/common.c')
-rw-r--r--drivers/net/wireless/ath/ath9k/common.c244
1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath9k/common.c b/drivers/net/wireless/ath/ath9k/common.c
index 768c733cad31..c6dd7f1fed65 100644
--- a/drivers/net/wireless/ath/ath9k/common.c
+++ b/drivers/net/wireless/ath/ath9k/common.c
@@ -27,6 +27,250 @@ 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);
+
+void ath9k_cmn_rx_skb_postprocess(struct ath_common *common,
+ struct sk_buff *skb,
+ struct ath_rx_status *rx_stats,
+ struct ieee80211_rx_status *rxs,
+ bool decrypt_error)
+{
+ struct ath_hw *ah = common->ah;
+ struct ieee80211_hdr *hdr;
+ int hdrlen, padpos, padsize;
+ u8 keyix;
+ __le16 fc;
+
+ /* see if any padding is done by the hw and remove it */
+ hdr = (struct ieee80211_hdr *) skb->data;
+ hdrlen = ieee80211_get_hdrlen_from_skb(skb);
+ fc = hdr->frame_control;
+ padpos = ieee80211_hdrlen(fc);
+
+ /* 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 - padpos % 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. */
+ padsize = padpos & 3;
+ if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
+ memmove(skb->data + padsize, skb->data, padpos);
+ skb_pull(skb, padsize);
+ }
+
+ keyix = rx_stats->rs_keyix;
+
+ if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error &&
+ ieee80211_has_protected(fc)) {
+ rxs->flag |= RX_FLAG_DECRYPTED;
+ } else if (ieee80211_has_protected(fc)
+ && !decrypt_error && skb->len >= hdrlen + 4) {
+ keyix = skb->data[hdrlen + 3] >> 6;
+
+ if (test_bit(keyix, common->keymap))
+ rxs->flag |= RX_FLAG_DECRYPTED;
+ }
+ if (ah->sw_mgmt_crypto &&
+ (rxs->flag & RX_FLAG_DECRYPTED) &&
+ ieee80211_is_mgmt(fc))
+ /* Use software decrypt for management frames. */
+ rxs->flag &= ~RX_FLAG_DECRYPTED;
+}
+EXPORT_SYMBOL(ath9k_cmn_rx_skb_postprocess);
+
+int ath9k_cmn_process_rate(struct ath_common *common,
+ struct ieee80211_hw *hw,
+ struct ath_rx_status *rx_stats,
+ struct ieee80211_rx_status *rxs)
+{
+ struct ieee80211_supported_band *sband;
+ enum ieee80211_band band;
+ unsigned int i = 0;
+ struct ath_hw *ah = common->ah;
+
+ band = ah->curchan->chan->band;
+ sband = hw->wiphy->bands[band];
+
+ if (IS_CHAN_QUARTER_RATE(ah->curchan))
+ rxs->flag |= RX_FLAG_5MHZ;
+ else if (IS_CHAN_HALF_RATE(ah->curchan))
+ rxs->flag |= RX_FLAG_10MHZ;
+
+ if (rx_stats->rs_rate & 0x80) {
+ /* HT rate */
+ rxs->flag |= RX_FLAG_HT;
+ rxs->flag |= rx_stats->flag;
+ rxs->rate_idx = rx_stats->rs_rate & 0x7f;
+ return 0;
+ }
+
+ for (i = 0; i < sband->n_bitrates; i++) {
+ if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
+ rxs->rate_idx = i;
+ return 0;
+ }
+ if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
+ rxs->flag |= RX_FLAG_SHORTPRE;
+ rxs->rate_idx = i;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(ath9k_cmn_process_rate);
+
+void ath9k_cmn_process_rssi(struct ath_common *common,
+ struct ieee80211_hw *hw,
+ struct ath_rx_status *rx_stats,
+ struct ieee80211_rx_status *rxs)
+{
+ struct ath_hw *ah = common->ah;
+ int last_rssi;
+ int rssi = rx_stats->rs_rssi;
+ int i, j;
+
+ /*
+ * RSSI is not available for subframes in an A-MPDU.
+ */
+ if (rx_stats->rs_moreaggr) {
+ rxs->flag |= RX_FLAG_NO_SIGNAL_VAL;
+ return;
+ }
+
+ /*
+ * Check if the RSSI for the last subframe in an A-MPDU
+ * or an unaggregated frame is valid.
+ */
+ if (rx_stats->rs_rssi == ATH9K_RSSI_BAD) {
+ rxs->flag |= RX_FLAG_NO_SIGNAL_VAL;
+ return;
+ }
+
+ for (i = 0, j = 0; i < ARRAY_SIZE(rx_stats->rs_rssi_ctl); i++) {
+ s8 rssi;
+
+ if (!(ah->rxchainmask & BIT(i)))
+ continue;
+
+ rssi = rx_stats->rs_rssi_ctl[i];
+ if (rssi != ATH9K_RSSI_BAD) {
+ rxs->chains |= BIT(j);
+ rxs->chain_signal[j] = ah->noise + rssi;
+ }
+ j++;
+ }
+
+ /*
+ * Update Beacon RSSI, this is used by ANI.
+ */
+ if (rx_stats->is_mybeacon &&
+ ((ah->opmode == NL80211_IFTYPE_STATION) ||
+ (ah->opmode == NL80211_IFTYPE_ADHOC))) {
+ ATH_RSSI_LPF(common->last_rssi, rx_stats->rs_rssi);
+ last_rssi = common->last_rssi;
+
+ if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
+ rssi = ATH_EP_RND(last_rssi, ATH_RSSI_EP_MULTIPLIER);
+ if (rssi < 0)
+ rssi = 0;
+
+ ah->stats.avgbrssi = rssi;
+ }
+
+ rxs->signal = ah->noise + rx_stats->rs_rssi;
+}
+EXPORT_SYMBOL(ath9k_cmn_process_rssi);
+
int ath9k_cmn_get_hw_crypto_keytype(struct sk_buff *skb)
{
struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);