package/mac80211/patches/550-ath9k_mmic_verify.patch

   1 --- a/drivers/net/wireless/ath/ath9k/recv.c
   2 +++ b/drivers/net/wireless/ath/ath9k/recv.c
   3 @@ -814,16 +814,17 @@ static bool ath9k_rx_accept(struct ath_c
   4                             struct ath_rx_status *rx_stats,
   5                             bool *decrypt_error)
   6  {
   7 -#define is_mc_or_valid_tkip_keyix ((is_mc ||                   \
   8 -               (rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID && \
   9 -               test_bit(rx_stats->rs_keyix, common->tkip_keymap))))
  10 -
  11 +       bool is_mc, is_valid_tkip, mic_error = false;
  12         struct ath_hw *ah = common->ah;
  13         __le16 fc;
  14         u8 rx_status_len = ah->caps.rx_status_len;
  15
  16         fc = hdr->frame_control;
  17
  18 +       is_mc = !!is_multicast_ether_addr(hdr->addr1);
  19 +       is_valid_tkip = rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID &&
  20 +               test_bit(rx_stats->rs_keyix, common->tkip_keymap);
  21 +
  22         if (!rx_stats->rs_datalen)
  23                 return false;
  24          /*
  25 @@ -853,19 +854,19 @@ static bool ath9k_rx_accept(struct ath_c
  26                 if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
  27                         *decrypt_error = true;
  28                 } else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
  29 -                       bool is_mc;
  30                         /*
  31                          * The MIC error bit is only valid if the frame
  32                          * is not a control frame or fragment, and it was
  33 -                        * decrypted using a valid TKIP key.
  34 +                        * decrypted using a valid TKIP key. For multicast
  35 +                        * frames the hardware will not return a valid
  36 +                        * key index, so accept the MIC bit for those
  37 +                        * as well.
  38                          */
  39 -                       is_mc = !!is_multicast_ether_addr(hdr->addr1);
  40 -
  41                         if (!ieee80211_is_ctl(fc) &&
  42                             !ieee80211_has_morefrags(fc) &&
  43                             !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
  44 -                           is_mc_or_valid_tkip_keyix)
  45 -                               rxs->flag |= RX_FLAG_MMIC_ERROR;
  46 +                           (is_mc || is_valid_tkip))
  47 +                               mic_error = true;
  48                         else
  49                                 rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
  50                 }
  51 @@ -886,6 +887,22 @@ static bool ath9k_rx_accept(struct ath_c
  52                         }
  53                 }
  54         }
  55 +
  56 +       /*
  57 +        * For unicast frames the MIC error bit can have false positives,
  58 +        * so all MIC error reports need to be validated in software.
  59 +        * False negatives are not common, so skip software verification
  60 +        * if the hardware considers the MIC valid.
  61 +        */
  62 +       if (is_valid_tkip && ieee80211_is_data_present(hdr->frame_control) &&
  63 +           !(rx_stats->rs_status & (ATH9K_RXERR_DECRYPT | ATH9K_RXERR_CRC |
  64 +                                    ATH9K_RXERR_MIC))) {
  65 +               /* Strip the Michael MIC */
  66 +               rx_stats->rs_datalen -= 8;
  67 +               rxs->flag |= RX_FLAG_MMIC_STRIPPED;
  68 +       } else if (is_mc && mic_error) {
  69 +               rxs->flag |= RX_FLAG_MMIC_ERROR;
  70 +       }
  71         return true;
  72  }
  73