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Diffstat (limited to 'drivers/net/wireless/ath/ath9k/common.c')
-rw-r--r--drivers/net/wireless/ath/ath9k/common.c299
1 files changed, 299 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath9k/common.c b/drivers/net/wireless/ath/ath9k/common.c
new file mode 100644
index 000000000000..4d775ae141db
--- /dev/null
+++ b/drivers/net/wireless/ath/ath9k/common.c
@@ -0,0 +1,299 @@
+/*
+ * 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;
+
+ /* 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, 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 = ath9k_cmn_padpos(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 - 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) {
+ 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_padpos(__le16 frame_control)
+{
+ int padpos = 24;
+ if (ieee80211_has_a4(frame_control)) {
+ padpos += ETH_ALEN;
+ }
+ if (ieee80211_is_data_qos(frame_control)) {
+ padpos += IEEE80211_QOS_CTL_LEN;
+ }
+
+ return padpos;
+}
+EXPORT_SYMBOL(ath9k_cmn_padpos);
+
+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);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.