1 /*
2 * Common hostapd/wpa_supplicant HW features
3 * Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
4 * Copyright (c) 2015, Qualcomm Atheros, Inc.
5 *
6 * This software may be distributed under the terms of the BSD license.
7 * See README for more details.
8 */
9
10 #include "includes.h"
11
12 #include "common.h"
13 #include "defs.h"
14 #include "ieee802_11_defs.h"
15 #include "ieee802_11_common.h"
16 #include "hw_features_common.h"
17
18
hw_get_channel_chan(struct hostapd_hw_modes * mode,int chan,int * freq)19 struct hostapd_channel_data * hw_get_channel_chan(struct hostapd_hw_modes *mode,
20 int chan, int *freq)
21 {
22 int i;
23
24 if (freq)
25 *freq = 0;
26
27 if (!mode)
28 return NULL;
29
30 for (i = 0; i < mode->num_channels; i++) {
31 struct hostapd_channel_data *ch = &mode->channels[i];
32 if (ch->chan == chan) {
33 if (freq)
34 *freq = ch->freq;
35 return ch;
36 }
37 }
38
39 return NULL;
40 }
41
42
hw_get_channel_freq(struct hostapd_hw_modes * mode,int freq,int * chan)43 struct hostapd_channel_data * hw_get_channel_freq(struct hostapd_hw_modes *mode,
44 int freq, int *chan)
45 {
46 int i;
47
48 if (chan)
49 *chan = 0;
50
51 if (!mode)
52 return NULL;
53
54 for (i = 0; i < mode->num_channels; i++) {
55 struct hostapd_channel_data *ch = &mode->channels[i];
56 if (ch->freq == freq) {
57 if (chan)
58 *chan = ch->chan;
59 return ch;
60 }
61 }
62
63 return NULL;
64 }
65
66
hw_get_freq(struct hostapd_hw_modes * mode,int chan)67 int hw_get_freq(struct hostapd_hw_modes *mode, int chan)
68 {
69 int freq;
70
71 hw_get_channel_chan(mode, chan, &freq);
72
73 return freq;
74 }
75
76
hw_get_chan(struct hostapd_hw_modes * mode,int freq)77 int hw_get_chan(struct hostapd_hw_modes *mode, int freq)
78 {
79 int chan;
80
81 hw_get_channel_freq(mode, freq, &chan);
82
83 return chan;
84 }
85
86
allowed_ht40_channel_pair(struct hostapd_hw_modes * mode,int pri_chan,int sec_chan)87 int allowed_ht40_channel_pair(struct hostapd_hw_modes *mode, int pri_chan,
88 int sec_chan)
89 {
90 int ok, j, first;
91 int allowed[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 140,
92 149, 157, 184, 192 };
93 size_t k;
94
95 if (pri_chan == sec_chan || !sec_chan)
96 return 1; /* HT40 not used */
97
98 wpa_printf(MSG_DEBUG,
99 "HT40: control channel: %d secondary channel: %d",
100 pri_chan, sec_chan);
101
102 /* Verify that HT40 secondary channel is an allowed 20 MHz
103 * channel */
104 ok = 0;
105 for (j = 0; j < mode->num_channels; j++) {
106 struct hostapd_channel_data *chan = &mode->channels[j];
107 if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
108 chan->chan == sec_chan) {
109 ok = 1;
110 break;
111 }
112 }
113 if (!ok) {
114 wpa_printf(MSG_ERROR, "HT40 secondary channel %d not allowed",
115 sec_chan);
116 return 0;
117 }
118
119 /*
120 * Verify that HT40 primary,secondary channel pair is allowed per
121 * IEEE 802.11n Annex J. This is only needed for 5 GHz band since
122 * 2.4 GHz rules allow all cases where the secondary channel fits into
123 * the list of allowed channels (already checked above).
124 */
125 if (mode->mode != HOSTAPD_MODE_IEEE80211A)
126 return 1;
127
128 first = pri_chan < sec_chan ? pri_chan : sec_chan;
129
130 ok = 0;
131 for (k = 0; k < ARRAY_SIZE(allowed); k++) {
132 if (first == allowed[k]) {
133 ok = 1;
134 break;
135 }
136 }
137 if (!ok) {
138 wpa_printf(MSG_ERROR, "HT40 channel pair (%d, %d) not allowed",
139 pri_chan, sec_chan);
140 return 0;
141 }
142
143 return 1;
144 }
145
146
get_pri_sec_chan(struct wpa_scan_res * bss,int * pri_chan,int * sec_chan)147 void get_pri_sec_chan(struct wpa_scan_res *bss, int *pri_chan, int *sec_chan)
148 {
149 struct ieee80211_ht_operation *oper;
150 struct ieee802_11_elems elems;
151
152 *pri_chan = *sec_chan = 0;
153
154 ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
155 if (elems.ht_operation) {
156 oper = (struct ieee80211_ht_operation *) elems.ht_operation;
157 *pri_chan = oper->primary_chan;
158 if (oper->ht_param & HT_INFO_HT_PARAM_STA_CHNL_WIDTH) {
159 int sec = oper->ht_param &
160 HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK;
161 if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE)
162 *sec_chan = *pri_chan + 4;
163 else if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW)
164 *sec_chan = *pri_chan - 4;
165 }
166 }
167 }
168
169
check_40mhz_5g(struct hostapd_hw_modes * mode,struct wpa_scan_results * scan_res,int pri_chan,int sec_chan)170 int check_40mhz_5g(struct hostapd_hw_modes *mode,
171 struct wpa_scan_results *scan_res, int pri_chan,
172 int sec_chan)
173 {
174 int pri_freq, sec_freq, pri_bss, sec_bss;
175 int bss_pri_chan, bss_sec_chan;
176 size_t i;
177 int match;
178
179 if (!mode || !scan_res || !pri_chan || !sec_chan ||
180 pri_chan == sec_chan)
181 return 0;
182
183 pri_freq = hw_get_freq(mode, pri_chan);
184 sec_freq = hw_get_freq(mode, sec_chan);
185
186 /*
187 * Switch PRI/SEC channels if Beacons were detected on selected SEC
188 * channel, but not on selected PRI channel.
189 */
190 pri_bss = sec_bss = 0;
191 for (i = 0; i < scan_res->num; i++) {
192 struct wpa_scan_res *bss = scan_res->res[i];
193 if (bss->freq == pri_freq)
194 pri_bss++;
195 else if (bss->freq == sec_freq)
196 sec_bss++;
197 }
198 if (sec_bss && !pri_bss) {
199 wpa_printf(MSG_INFO,
200 "Switch own primary and secondary channel to get secondary channel with no Beacons from other BSSes");
201 return 2;
202 }
203
204 /*
205 * Match PRI/SEC channel with any existing HT40 BSS on the same
206 * channels that we are about to use (if already mixed order in
207 * existing BSSes, use own preference).
208 */
209 match = 0;
210 for (i = 0; i < scan_res->num; i++) {
211 struct wpa_scan_res *bss = scan_res->res[i];
212 get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
213 if (pri_chan == bss_pri_chan &&
214 sec_chan == bss_sec_chan) {
215 match = 1;
216 break;
217 }
218 }
219 if (!match) {
220 for (i = 0; i < scan_res->num; i++) {
221 struct wpa_scan_res *bss = scan_res->res[i];
222 get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
223 if (pri_chan == bss_sec_chan &&
224 sec_chan == bss_pri_chan) {
225 wpa_printf(MSG_INFO, "Switch own primary and "
226 "secondary channel due to BSS "
227 "overlap with " MACSTR,
228 MAC2STR(bss->bssid));
229 return 2;
230 }
231 }
232 }
233
234 return 1;
235 }
236
237
check_20mhz_bss(struct wpa_scan_res * bss,int pri_freq,int start,int end)238 static int check_20mhz_bss(struct wpa_scan_res *bss, int pri_freq, int start,
239 int end)
240 {
241 struct ieee802_11_elems elems;
242 struct ieee80211_ht_operation *oper;
243
244 if (bss->freq < start || bss->freq > end || bss->freq == pri_freq)
245 return 0;
246
247 ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
248 if (!elems.ht_capabilities) {
249 wpa_printf(MSG_DEBUG, "Found overlapping legacy BSS: "
250 MACSTR " freq=%d", MAC2STR(bss->bssid), bss->freq);
251 return 1;
252 }
253
254 if (elems.ht_operation) {
255 oper = (struct ieee80211_ht_operation *) elems.ht_operation;
256 if (oper->ht_param & HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK)
257 return 0;
258
259 wpa_printf(MSG_DEBUG, "Found overlapping 20 MHz HT BSS: "
260 MACSTR " freq=%d", MAC2STR(bss->bssid), bss->freq);
261 return 1;
262 }
263 return 0;
264 }
265
266
check_40mhz_2g4(struct hostapd_hw_modes * mode,struct wpa_scan_results * scan_res,int pri_chan,int sec_chan)267 int check_40mhz_2g4(struct hostapd_hw_modes *mode,
268 struct wpa_scan_results *scan_res, int pri_chan,
269 int sec_chan)
270 {
271 int pri_freq, sec_freq;
272 int affected_start, affected_end;
273 size_t i;
274
275 if (!mode || !scan_res || !pri_chan || !sec_chan)
276 return 0;
277
278 if (pri_chan == sec_chan)
279 return 0;
280
281 pri_freq = hw_get_freq(mode, pri_chan);
282 sec_freq = hw_get_freq(mode, sec_chan);
283
284 affected_start = (pri_freq + sec_freq) / 2 - 25;
285 affected_end = (pri_freq + sec_freq) / 2 + 25;
286 wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
287 affected_start, affected_end);
288 for (i = 0; i < scan_res->num; i++) {
289 struct wpa_scan_res *bss = scan_res->res[i];
290 int pri = bss->freq;
291 int sec = pri;
292 struct ieee802_11_elems elems;
293
294 /* Check for overlapping 20 MHz BSS */
295 if (check_20mhz_bss(bss, pri_freq, affected_start,
296 affected_end)) {
297 wpa_printf(MSG_DEBUG,
298 "Overlapping 20 MHz BSS is found");
299 return 0;
300 }
301
302 get_pri_sec_chan(bss, &pri_chan, &sec_chan);
303
304 if (sec_chan) {
305 if (sec_chan < pri_chan)
306 sec = pri - 20;
307 else
308 sec = pri + 20;
309 }
310
311 if ((pri < affected_start || pri > affected_end) &&
312 (sec < affected_start || sec > affected_end))
313 continue; /* not within affected channel range */
314
315 wpa_printf(MSG_DEBUG, "Neighboring BSS: " MACSTR
316 " freq=%d pri=%d sec=%d",
317 MAC2STR(bss->bssid), bss->freq, pri_chan, sec_chan);
318
319 if (sec_chan) {
320 if (pri_freq != pri || sec_freq != sec) {
321 wpa_printf(MSG_DEBUG,
322 "40 MHz pri/sec mismatch with BSS "
323 MACSTR
324 " <%d,%d> (chan=%d%c) vs. <%d,%d>",
325 MAC2STR(bss->bssid),
326 pri, sec, pri_chan,
327 sec > pri ? '+' : '-',
328 pri_freq, sec_freq);
329 return 0;
330 }
331 }
332
333 ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems,
334 0);
335 if (elems.ht_capabilities) {
336 struct ieee80211_ht_capabilities *ht_cap =
337 (struct ieee80211_ht_capabilities *)
338 elems.ht_capabilities;
339
340 if (le_to_host16(ht_cap->ht_capabilities_info) &
341 HT_CAP_INFO_40MHZ_INTOLERANT) {
342 wpa_printf(MSG_DEBUG,
343 "40 MHz Intolerant is set on channel %d in BSS "
344 MACSTR, pri, MAC2STR(bss->bssid));
345 return 0;
346 }
347 }
348 }
349
350 return 1;
351 }
352
353
hostapd_set_freq_params(struct hostapd_freq_params * data,enum hostapd_hw_mode mode,int freq,int channel,int ht_enabled,int vht_enabled,int sec_channel_offset,int vht_oper_chwidth,int center_segment0,int center_segment1,u32 vht_caps)354 int hostapd_set_freq_params(struct hostapd_freq_params *data,
355 enum hostapd_hw_mode mode,
356 int freq, int channel, int ht_enabled,
357 int vht_enabled, int sec_channel_offset,
358 int vht_oper_chwidth, int center_segment0,
359 int center_segment1, u32 vht_caps)
360 {
361 os_memset(data, 0, sizeof(*data));
362 data->mode = mode;
363 data->freq = freq;
364 data->channel = channel;
365 data->ht_enabled = ht_enabled;
366 data->vht_enabled = vht_enabled;
367 data->sec_channel_offset = sec_channel_offset;
368 data->center_freq1 = freq + sec_channel_offset * 10;
369 data->center_freq2 = 0;
370 data->bandwidth = sec_channel_offset ? 40 : 20;
371
372 if (data->vht_enabled) switch (vht_oper_chwidth) {
373 case VHT_CHANWIDTH_USE_HT:
374 if (center_segment1 ||
375 (center_segment0 != 0 &&
376 5000 + center_segment0 * 5 != data->center_freq1 &&
377 2407 + center_segment0 * 5 != data->center_freq1))
378 return -1;
379 break;
380 case VHT_CHANWIDTH_80P80MHZ:
381 if (!(vht_caps & VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)) {
382 wpa_printf(MSG_ERROR,
383 "80+80 channel width is not supported!");
384 return -1;
385 }
386 if (center_segment1 == center_segment0 + 4 ||
387 center_segment1 == center_segment0 - 4)
388 return -1;
389 data->center_freq2 = 5000 + center_segment1 * 5;
390 /* fall through */
391 case VHT_CHANWIDTH_80MHZ:
392 data->bandwidth = 80;
393 if ((vht_oper_chwidth == 1 && center_segment1) ||
394 (vht_oper_chwidth == 3 && !center_segment1) ||
395 !sec_channel_offset)
396 return -1;
397 if (!center_segment0) {
398 if (channel <= 48)
399 center_segment0 = 42;
400 else if (channel <= 64)
401 center_segment0 = 58;
402 else if (channel <= 112)
403 center_segment0 = 106;
404 else if (channel <= 128)
405 center_segment0 = 122;
406 else if (channel <= 144)
407 center_segment0 = 138;
408 else if (channel <= 161)
409 center_segment0 = 155;
410 data->center_freq1 = 5000 + center_segment0 * 5;
411 } else {
412 /*
413 * Note: HT/VHT config and params are coupled. Check if
414 * HT40 channel band is in VHT80 Pri channel band
415 * configuration.
416 */
417 if (center_segment0 == channel + 6 ||
418 center_segment0 == channel + 2 ||
419 center_segment0 == channel - 2 ||
420 center_segment0 == channel - 6)
421 data->center_freq1 = 5000 + center_segment0 * 5;
422 else
423 return -1;
424 }
425 break;
426 case VHT_CHANWIDTH_160MHZ:
427 data->bandwidth = 160;
428 if (!(vht_caps & (VHT_CAP_SUPP_CHAN_WIDTH_160MHZ |
429 VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))) {
430 wpa_printf(MSG_ERROR,
431 "160MHZ channel width is not supported!");
432 return -1;
433 }
434 if (center_segment1)
435 return -1;
436 if (!sec_channel_offset)
437 return -1;
438 /*
439 * Note: HT/VHT config and params are coupled. Check if
440 * HT40 channel band is in VHT160 channel band configuration.
441 */
442 if (center_segment0 == channel + 14 ||
443 center_segment0 == channel + 10 ||
444 center_segment0 == channel + 6 ||
445 center_segment0 == channel + 2 ||
446 center_segment0 == channel - 2 ||
447 center_segment0 == channel - 6 ||
448 center_segment0 == channel - 10 ||
449 center_segment0 == channel - 14)
450 data->center_freq1 = 5000 + center_segment0 * 5;
451 else
452 return -1;
453 break;
454 }
455
456 return 0;
457 }
458