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/*
* Copyright (c) 2009-2011 Atheros Communications Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Module for common driver code between ath9k and ath9k_htc
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include "common.h"
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);
if (tx_info->control.hw_key) {
switch (tx_info->control.hw_key->cipher) {
case WLAN_CIPHER_SUITE_WEP40:
case WLAN_CIPHER_SUITE_WEP104:
return ATH9K_KEY_TYPE_WEP;
case WLAN_CIPHER_SUITE_TKIP:
return ATH9K_KEY_TYPE_TKIP;
case WLAN_CIPHER_SUITE_CCMP:
return ATH9K_KEY_TYPE_AES;
default:
break;
}
}
return ATH9K_KEY_TYPE_CLEAR;
}
EXPORT_SYMBOL(ath9k_cmn_get_hw_crypto_keytype);
/*
* Update internal channel flags.
*/
static void ath9k_cmn_update_ichannel(struct ath9k_channel *ichan,
struct cfg80211_chan_def *chandef)
{
struct ieee80211_channel *chan = chandef->chan;
u16 flags = 0;
ichan->channel = chan->center_freq;
ichan->chan = chan;
if (chan->band == IEEE80211_BAND_5GHZ)
flags |= CHANNEL_5GHZ;
switch (chandef->width) {
case NL80211_CHAN_WIDTH_5:
flags |= CHANNEL_QUARTER;
break;
case NL80211_CHAN_WIDTH_10:
flags |= CHANNEL_HALF;
break;
case NL80211_CHAN_WIDTH_20_NOHT:
break;
case NL80211_CHAN_WIDTH_20:
flags |= CHANNEL_HT;
break;
case NL80211_CHAN_WIDTH_40:
if (chandef->center_freq1 > chandef->chan->center_freq)
flags |= CHANNEL_HT40PLUS | CHANNEL_HT;
else
flags |= CHANNEL_HT40MINUS | CHANNEL_HT;
break;
default:
WARN_ON(1);
}
ichan->channelFlags = flags;
}
/*
* Get the internal channel reference.
*/
struct ath9k_channel *ath9k_cmn_get_channel(struct ieee80211_hw *hw,
struct ath_hw *ah,
struct cfg80211_chan_def *chandef)
{
struct ieee80211_channel *curchan = chandef->chan;
struct ath9k_channel *channel;
channel = &ah->channels[curchan->hw_value];
ath9k_cmn_update_ichannel(channel, chandef);
return channel;
}
EXPORT_SYMBOL(ath9k_cmn_get_channel);
int ath9k_cmn_count_streams(unsigned int chainmask, int max)
{
int streams = 0;
do {
if (++streams == max)
break;
} while ((chainmask = chainmask & (chainmask - 1)));
return streams;
}
EXPORT_SYMBOL(ath9k_cmn_count_streams);
void ath9k_cmn_update_txpow(struct ath_hw *ah, u16 cur_txpow,
u16 new_txpow, u16 *txpower)
{
struct ath_regulatory *reg = ath9k_hw_regulatory(ah);
if (reg->power_limit != new_txpow) {
ath9k_hw_set_txpowerlimit(ah, new_txpow, false);
/* read back in case value is clamped */
*txpower = reg->max_power_level;
}
}
EXPORT_SYMBOL(ath9k_cmn_update_txpow);
void ath9k_cmn_init_crypto(struct ath_hw *ah)
{
struct ath_common *common = ath9k_hw_common(ah);
int i = 0;
/* Get the hardware key cache size. */
common->keymax = AR_KEYTABLE_SIZE;
/*
* Check whether the separate key cache entries
* are required to handle both tx+rx MIC keys.
* With split mic keys the number of stations is limited
* to 27 otherwise 59.
*/
if (ah->misc_mode & AR_PCU_MIC_NEW_LOC_ENA)
common->crypt_caps |= ATH_CRYPT_CAP_MIC_COMBINED;
/*
* Reset the key cache since some parts do not
* reset the contents on initial power up.
*/
for (i = 0; i < common->keymax; i++)
ath_hw_keyreset(common, (u16) i);
}
EXPORT_SYMBOL(ath9k_cmn_init_crypto);
static int __init ath9k_cmn_init(void)
{
return 0;
}
module_init(ath9k_cmn_init);
static void __exit ath9k_cmn_exit(void)
{
return;
}
module_exit(ath9k_cmn_exit);