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ath9k: Perform integrity checks when processing FFT frames

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a) Check that the maximum magnitude is at the specified index

b) Check if the maximum magnitude index is at dc_pos and if so
calculate a new one (value at dc_pos is invalid)

c) Check if the specified maximum magnitude is indeed the maximum

Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
This commit is contained in:
Nick Kossifidis 2015-04-29 23:51:15 +00:00 committed by Kalle Valo
parent 58b5e4c731
commit 7fa580c193
1 changed files with 163 additions and 6 deletions
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169
drivers/net/wireless/ath/ath9k/common-spectral.c
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@ -47,12 +47,15 @@ ath_cmn_process_ht20_fft(struct ath_rx_status *rs,
u64 tsf, u16 freq, int chan_type)
{
struct fft_sample_ht20 fft_sample_20;
struct ath_common *common = ath9k_hw_common(spec_priv->ah);
struct ath_hw *ah = spec_priv->ah;
struct ath_ht20_mag_info *mag_info;
struct fft_sample_tlv *tlv;
int i = 0;
int ret = 0;
int dc_pos = SPECTRAL_HT20_NUM_BINS / 2;
u16 magnitude, length;
u8 max_index, bitmap_w;
u16 magnitude, tmp_mag, length;
u8 max_index, bitmap_w, max_exp;
length = sizeof(fft_sample_20) - sizeof(struct fft_sample_tlv);
fft_sample_20.tlv.type = ATH_FFT_SAMPLE_HT20;
@ -74,18 +77,66 @@ ath_cmn_process_ht20_fft(struct ath_rx_status *rs,
bitmap_w = spectral_bitmap_weight(mag_info->all_bins);
fft_sample_20.bitmap_weight = bitmap_w;
fft_sample_20.max_exp = mag_info->max_exp & 0xf;
max_exp = mag_info->max_exp & 0xf;
fft_sample_20.max_exp = max_exp;
fft_sample_20.tsf = __cpu_to_be64(tsf);
memcpy(fft_sample_20.data, sample_buf, SPECTRAL_HT20_NUM_BINS);
ath_dbg(common, SPECTRAL_SCAN, "FFT HT20 frame: max mag 0x%X,"
"max_mag_idx %i\n",
magnitude >> max_exp,
max_index);
if (fft_sample_20.data[max_index] != (magnitude >> max_exp)) {
ath_dbg(common, SPECTRAL_SCAN, "Magnitude mismatch !\n");
ret = -1;
}
/* DC value (value in the middle) is the blind spot of the spectral
* sample and invalid, interpolate it.
*/
fft_sample_20.data[dc_pos] = (fft_sample_20.data[dc_pos + 1] +
fft_sample_20.data[dc_pos - 1]) / 2;
/* Check if the maximum magnitude is indeed maximum,
* also if the maximum value was at dc_pos, calculate
* a new one (since value at dc_pos is invalid).
*/
if (max_index == dc_pos) {
tmp_mag = 0;
for (i = 0; i < dc_pos; i++) {
if (fft_sample_20.data[i] > tmp_mag) {
tmp_mag = fft_sample_20.data[i];
fft_sample_20.max_index = i;
}
}
magnitude = tmp_mag << max_exp;
fft_sample_20.max_magnitude = __cpu_to_be16(magnitude);
ath_dbg(common, SPECTRAL_SCAN,
"Calculated new lower max 0x%X at %i\n",
tmp_mag, fft_sample_20.max_index);
} else
for (i = 0; i < SPECTRAL_HT20_NUM_BINS; i++) {
if (fft_sample_20.data[i] == (magnitude >> max_exp))
ath_dbg(common, SPECTRAL_SCAN,
"Got max: 0x%X at index %i\n",
fft_sample_20.data[i], i);
if (fft_sample_20.data[i] > (magnitude >> max_exp)) {
ath_dbg(common, SPECTRAL_SCAN,
"Got bin %i greater than max: 0x%X\n",
i, fft_sample_20.data[i]);
ret = -1;
}
}
if (ret < 0)
return ret;
tlv = (struct fft_sample_tlv *)&fft_sample_20;
ath_debug_send_fft_sample(spec_priv, tlv);
@ -100,16 +151,19 @@ ath_cmn_process_ht20_40_fft(struct ath_rx_status *rs,
u64 tsf, u16 freq, int chan_type)
{
struct fft_sample_ht20_40 fft_sample_40;
struct ath_common *common = ath9k_hw_common(spec_priv->ah);
struct ath_hw *ah = spec_priv->ah;
struct ath9k_hw_cal_data *caldata = ah->caldata;
struct ath_ht20_40_mag_info *mag_info;
struct fft_sample_tlv *tlv;
int dc_pos = SPECTRAL_HT20_40_NUM_BINS / 2;
int i = 0;
int ret = 0;
s16 ext_nf;
u16 lower_mag, upper_mag, length;
u16 lower_mag, upper_mag, tmp_mag, length;
s8 lower_rssi, upper_rssi;
u8 lower_max_index, upper_max_index;
u8 lower_bitmap_w, upper_bitmap_w;
u8 lower_bitmap_w, upper_bitmap_w, max_exp;
if (caldata)
ext_nf = ath9k_hw_getchan_noise(ah, ah->curchan,
@ -163,18 +217,121 @@ ath_cmn_process_ht20_40_fft(struct ath_rx_status *rs,
upper_bitmap_w = spectral_bitmap_weight(mag_info->upper_bins);
fft_sample_40.upper_bitmap_weight = upper_bitmap_w;
fft_sample_40.max_exp = mag_info->max_exp & 0xf;
max_exp = mag_info->max_exp & 0xf;
fft_sample_40.max_exp = max_exp;
fft_sample_40.tsf = __cpu_to_be64(tsf);
memcpy(fft_sample_40.data, sample_buf, SPECTRAL_HT20_40_NUM_BINS);
ath_dbg(common, SPECTRAL_SCAN, "FFT HT20/40 frame: lower mag 0x%X,"
"lower_mag_idx %i, upper mag 0x%X,"
"upper_mag_idx %i\n",
lower_mag >> max_exp,
lower_max_index,
upper_mag >> max_exp,
upper_max_index);
/* Some time hardware messes up the index and adds
* the index of the middle point (dc_pos). Try to fix it.
*/
if ((upper_max_index - dc_pos > 0) &&
(fft_sample_40.data[upper_max_index] == (upper_mag >> max_exp))) {
upper_max_index -= dc_pos;
fft_sample_40.upper_max_index = upper_max_index;
}
if ((lower_max_index - dc_pos > 0) &&
(fft_sample_40.data[lower_max_index - dc_pos] ==
(lower_mag >> max_exp))) {
lower_max_index -= dc_pos;
fft_sample_40.lower_max_index = lower_max_index;
}
/* Check if we got the expected magnitude values at
* the expected bins
*/
if ((fft_sample_40.data[upper_max_index + dc_pos]
!= (upper_mag >> max_exp)) ||
(fft_sample_40.data[lower_max_index]
!= (lower_mag >> max_exp))) {
ath_dbg(common, SPECTRAL_SCAN, "Magnitude mismatch !\n");
ret = -1;
}
/* DC value (value in the middle) is the blind spot of the spectral
* sample and invalid, interpolate it.
*/
fft_sample_40.data[dc_pos] = (fft_sample_40.data[dc_pos + 1] +
fft_sample_40.data[dc_pos - 1]) / 2;
/* Check if the maximum magnitudes are indeed maximum,
* also if the maximum value was at dc_pos, calculate
* a new one (since value at dc_pos is invalid).
*/
if (lower_max_index == dc_pos) {
tmp_mag = 0;
for (i = 0; i < dc_pos; i++) {
if (fft_sample_40.data[i] > tmp_mag) {
tmp_mag = fft_sample_40.data[i];
fft_sample_40.lower_max_index = i;
}
}
lower_mag = tmp_mag << max_exp;
fft_sample_40.lower_max_magnitude = __cpu_to_be16(lower_mag);
ath_dbg(common, SPECTRAL_SCAN,
"Calculated new lower max 0x%X at %i\n",
tmp_mag, fft_sample_40.lower_max_index);
} else
for (i = 0; i < dc_pos; i++) {
if (fft_sample_40.data[i] == (lower_mag >> max_exp))
ath_dbg(common, SPECTRAL_SCAN,
"Got lower mag: 0x%X at index %i\n",
fft_sample_40.data[i], i);
if (fft_sample_40.data[i] > (lower_mag >> max_exp)) {
ath_dbg(common, SPECTRAL_SCAN,
"Got lower bin %i higher than max: 0x%X\n",
i, fft_sample_40.data[i]);
ret = -1;
}
}
if (upper_max_index == dc_pos) {
tmp_mag = 0;
for (i = dc_pos; i < SPECTRAL_HT20_40_NUM_BINS; i++) {
if (fft_sample_40.data[i] > tmp_mag) {
tmp_mag = fft_sample_40.data[i];
fft_sample_40.upper_max_index = i;
}
}
upper_mag = tmp_mag << max_exp;
fft_sample_40.upper_max_magnitude = __cpu_to_be16(upper_mag);
ath_dbg(common, SPECTRAL_SCAN,
"Calculated new upper max 0x%X at %i\n",
tmp_mag, i);
} else
for (i = dc_pos; i < SPECTRAL_HT20_40_NUM_BINS; i++) {
if (fft_sample_40.data[i] == (upper_mag >> max_exp))
ath_dbg(common, SPECTRAL_SCAN,
"Got upper mag: 0x%X at index %i\n",
fft_sample_40.data[i], i);
if (fft_sample_40.data[i] > (upper_mag >> max_exp)) {
ath_dbg(common, SPECTRAL_SCAN,
"Got upper bin %i higher than max: 0x%X\n",
i, fft_sample_40.data[i]);
ret = -1;
}
}
if (ret < 0)
return ret;
tlv = (struct fft_sample_tlv *)&fft_sample_40;
ath_debug_send_fft_sample(spec_priv, tlv);