1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
|
/*
* 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);
|
