| /* |
| * Copyright (c) 2009 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"); |
| |
| /* Common RX processing */ |
| |
| /* Assumes you've already done the endian to CPU conversion */ |
| static bool ath9k_rx_accept(struct ath_common *common, |
| struct sk_buff *skb, |
| struct ieee80211_rx_status *rxs, |
| struct ath_rx_status *rx_stats, |
| bool *decrypt_error) |
| { |
| struct ath_hw *ah = common->ah; |
| struct ieee80211_hdr *hdr; |
| __le16 fc; |
| |
| hdr = (struct ieee80211_hdr *) skb->data; |
| fc = hdr->frame_control; |
| |
| if (!rx_stats->rs_datalen) |
| return false; |
| /* |
| * rs_status follows rs_datalen so if rs_datalen is too large |
| * we can take a hint that hardware corrupted it, so ignore |
| * those frames. |
| */ |
| if (rx_stats->rs_datalen > common->rx_bufsize) |
| return false; |
| |
| /* |
| * rs_more indicates chained descriptors which can be used |
| * to link buffers together for a sort of scatter-gather |
| * operation. |
| * |
| * 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_more && rx_stats->rs_status != 0) { |
| if (rx_stats->rs_status & ATH9K_RXERR_CRC) |
| rxs->flag |= RX_FLAG_FAILED_FCS_CRC; |
| if (rx_stats->rs_status & ATH9K_RXERR_PHY) |
| return false; |
| |
| if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) { |
| *decrypt_error = true; |
| } else if (rx_stats->rs_status & ATH9K_RXERR_MIC) { |
| if (ieee80211_is_ctl(fc)) |
| /* |
| * Sometimes, we get invalid |
| * MIC failures on valid control frames. |
| * Remove these mic errors. |
| */ |
| rx_stats->rs_status &= ~ATH9K_RXERR_MIC; |
| else |
| rxs->flag |= RX_FLAG_MMIC_ERROR; |
| } |
| /* |
| * Reject error frames with the exception of |
| * decryption and MIC failures. For monitor mode, |
| * we also ignore the CRC error. |
| */ |
| if (ah->opmode == NL80211_IFTYPE_MONITOR) { |
| if (rx_stats->rs_status & |
| ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC | |
| ATH9K_RXERR_CRC)) |
| return false; |
| } else { |
| if (rx_stats->rs_status & |
| ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) { |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| static u8 ath9k_process_rate(struct ath_common *common, |
| struct ieee80211_hw *hw, |
| struct ath_rx_status *rx_stats, |
| struct ieee80211_rx_status *rxs, |
| struct sk_buff *skb) |
| { |
| struct ieee80211_supported_band *sband; |
| enum ieee80211_band band; |
| unsigned int i = 0; |
| |
| band = hw->conf.channel->band; |
| sband = hw->wiphy->bands[band]; |
| |
| if (rx_stats->rs_rate & 0x80) { |
| /* HT rate */ |
| rxs->flag |= RX_FLAG_HT; |
| if (rx_stats->rs_flags & ATH9K_RX_2040) |
| rxs->flag |= RX_FLAG_40MHZ; |
| if (rx_stats->rs_flags & ATH9K_RX_GI) |
| rxs->flag |= RX_FLAG_SHORT_GI; |
| return rx_stats->rs_rate & 0x7f; |
| } |
| |
| for (i = 0; i < sband->n_bitrates; i++) { |
| if (sband->bitrates[i].hw_value == rx_stats->rs_rate) |
| return i; |
| if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) { |
| rxs->flag |= RX_FLAG_SHORTPRE; |
| return i; |
| } |
| } |
| |
| /* No valid hardware bitrate found -- we should not get here */ |
| ath_print(common, ATH_DBG_XMIT, "unsupported hw bitrate detected " |
| "0x%02x using 1 Mbit\n", rx_stats->rs_rate); |
| if ((common->debug_mask & ATH_DBG_XMIT)) |
| print_hex_dump_bytes("", DUMP_PREFIX_NONE, skb->data, skb->len); |
| |
| return 0; |
| } |
| |
| static void ath9k_process_rssi(struct ath_common *common, |
| struct ieee80211_hw *hw, |
| struct sk_buff *skb, |
| struct ath_rx_status *rx_stats) |
| { |
| struct ath_hw *ah = common->ah; |
| struct ieee80211_sta *sta; |
| struct ieee80211_hdr *hdr; |
| struct ath_node *an; |
| int last_rssi = ATH_RSSI_DUMMY_MARKER; |
| __le16 fc; |
| |
| hdr = (struct ieee80211_hdr *)skb->data; |
| fc = hdr->frame_control; |
| |
| rcu_read_lock(); |
| /* |
| * XXX: use ieee80211_find_sta! This requires quite a bit of work |
| * under the current ath9k virtual wiphy implementation as we have |
| * no way of tying a vif to wiphy. Typically vifs are attached to |
| * at least one sdata of a wiphy on mac80211 but with ath9k virtual |
| * wiphy you'd have to iterate over every wiphy and each sdata. |
| */ |
| sta = ieee80211_find_sta_by_hw(hw, hdr->addr2); |
| if (sta) { |
| an = (struct ath_node *) sta->drv_priv; |
| if (rx_stats->rs_rssi != ATH9K_RSSI_BAD && |
| !rx_stats->rs_moreaggr) |
| ATH_RSSI_LPF(an->last_rssi, rx_stats->rs_rssi); |
| last_rssi = an->last_rssi; |
| } |
| rcu_read_unlock(); |
| |
| if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER)) |
| rx_stats->rs_rssi = ATH_EP_RND(last_rssi, |
| ATH_RSSI_EP_MULTIPLIER); |
| if (rx_stats->rs_rssi < 0) |
| rx_stats->rs_rssi = 0; |
| else if (rx_stats->rs_rssi > 127) |
| rx_stats->rs_rssi = 127; |
| |
| /* Update Beacon RSSI, this is used by ANI. */ |
| if (ieee80211_is_beacon(fc)) |
| ah->stats.avgbrssi = rx_stats->rs_rssi; |
| } |
| |
| /* |
| * For Decrypt or Demic errors, we only mark packet status here and always push |
| * up the frame up to let mac80211 handle the actual error case, be it no |
| * decryption key or real decryption error. This let us keep statistics there. |
| */ |
| int ath9k_cmn_rx_skb_preprocess(struct ath_common *common, |
| struct ieee80211_hw *hw, |
| struct sk_buff *skb, |
| struct ath_rx_status *rx_stats, |
| struct ieee80211_rx_status *rx_status, |
| bool *decrypt_error) |
| { |
| struct ath_hw *ah = common->ah; |
| |
| memset(rx_status, 0, sizeof(struct ieee80211_rx_status)); |
| if (!ath9k_rx_accept(common, skb, rx_status, rx_stats, decrypt_error)) |
| return -EINVAL; |
| |
| ath9k_process_rssi(common, hw, skb, rx_stats); |
| |
| rx_status->rate_idx = ath9k_process_rate(common, hw, |
| rx_stats, rx_status, skb); |
| rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp); |
| rx_status->band = hw->conf.channel->band; |
| rx_status->freq = hw->conf.channel->center_freq; |
| rx_status->noise = common->ani.noise_floor; |
| rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi; |
| rx_status->antenna = rx_stats->rs_antenna; |
| rx_status->flag |= RX_FLAG_TSFT; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(ath9k_cmn_rx_skb_preprocess); |
| |
| 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, 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; |
| |
| /* 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 - hdrlen % 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 = hdrlen & 3; |
| if (padsize && hdrlen >= 24) { |
| memmove(skb->data + padsize, skb->data, hdrlen); |
| skb_pull(skb, padsize); |
| } |
| |
| keyix = rx_stats->rs_keyix; |
| |
| if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) { |
| 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); |
| |
| 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); |