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 
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 
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 
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 
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 
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, 165, 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 
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 
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 
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 
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 	    pri_chan == sec_chan)
277 		return 0;
278 
279 	pri_freq = hw_get_freq(mode, pri_chan);
280 	sec_freq = hw_get_freq(mode, sec_chan);
281 
282 	affected_start = (pri_freq + sec_freq) / 2 - 25;
283 	affected_end = (pri_freq + sec_freq) / 2 + 25;
284 	wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
285 		   affected_start, affected_end);
286 	for (i = 0; i < scan_res->num; i++) {
287 		struct wpa_scan_res *bss = scan_res->res[i];
288 		int pri = bss->freq;
289 		int sec = pri;
290 		struct ieee802_11_elems elems;
291 
292 		/* Check for overlapping 20 MHz BSS */
293 		if (check_20mhz_bss(bss, pri_freq, affected_start,
294 				    affected_end)) {
295 			wpa_printf(MSG_DEBUG,
296 				   "Overlapping 20 MHz BSS is found");
297 			return 0;
298 		}
299 
300 		get_pri_sec_chan(bss, &pri_chan, &sec_chan);
301 
302 		if (sec_chan) {
303 			if (sec_chan < pri_chan)
304 				sec = pri - 20;
305 			else
306 				sec = pri + 20;
307 		}
308 
309 		if ((pri < affected_start || pri > affected_end) &&
310 		    (sec < affected_start || sec > affected_end))
311 			continue; /* not within affected channel range */
312 
313 		wpa_printf(MSG_DEBUG, "Neighboring BSS: " MACSTR
314 			   " freq=%d pri=%d sec=%d",
315 			   MAC2STR(bss->bssid), bss->freq, pri_chan, sec_chan);
316 
317 		if (sec_chan) {
318 			if (pri_freq != pri || sec_freq != sec) {
319 				wpa_printf(MSG_DEBUG,
320 					   "40 MHz pri/sec mismatch with BSS "
321 					   MACSTR
322 					   " <%d,%d> (chan=%d%c) vs. <%d,%d>",
323 					   MAC2STR(bss->bssid),
324 					   pri, sec, pri_chan,
325 					   sec > pri ? '+' : '-',
326 					   pri_freq, sec_freq);
327 				return 0;
328 			}
329 		}
330 
331 		ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems,
332 				       0);
333 		if (elems.ht_capabilities) {
334 			struct ieee80211_ht_capabilities *ht_cap =
335 				(struct ieee80211_ht_capabilities *)
336 				elems.ht_capabilities;
337 
338 			if (le_to_host16(ht_cap->ht_capabilities_info) &
339 			    HT_CAP_INFO_40MHZ_INTOLERANT) {
340 				wpa_printf(MSG_DEBUG,
341 					   "40 MHz Intolerant is set on channel %d in BSS "
342 					   MACSTR, pri, MAC2STR(bss->bssid));
343 				return 0;
344 			}
345 		}
346 	}
347 
348 	return 1;
349 }
350 
351 
352 int hostapd_set_freq_params(struct hostapd_freq_params *data,
353 			    enum hostapd_hw_mode mode,
354 			    int freq, int channel, int ht_enabled,
355 			    int vht_enabled, int sec_channel_offset,
356 			    int vht_oper_chwidth, int center_segment0,
357 			    int center_segment1, u32 vht_caps)
358 {
359 	os_memset(data, 0, sizeof(*data));
360 	data->mode = mode;
361 	data->freq = freq;
362 	data->channel = channel;
363 	data->ht_enabled = ht_enabled;
364 	data->vht_enabled = vht_enabled;
365 	data->sec_channel_offset = sec_channel_offset;
366 	data->center_freq1 = freq + sec_channel_offset * 10;
367 	data->center_freq2 = 0;
368 	data->bandwidth = sec_channel_offset ? 40 : 20;
369 
370 	if (data->vht_enabled) switch (vht_oper_chwidth) {
371 	case VHT_CHANWIDTH_USE_HT:
372 		if (center_segment1 ||
373 		    (center_segment0 != 0 &&
374 		     5000 + center_segment0 * 5 != data->center_freq1 &&
375 		     2407 + center_segment0 * 5 != data->center_freq1))
376 			return -1;
377 		break;
378 	case VHT_CHANWIDTH_80P80MHZ:
379 		if (!(vht_caps & VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)) {
380 			wpa_printf(MSG_ERROR,
381 				   "80+80 channel width is not supported!");
382 			return -1;
383 		}
384 		if (center_segment1 == center_segment0 + 4 ||
385 		    center_segment1 == center_segment0 - 4)
386 			return -1;
387 		data->center_freq2 = 5000 + center_segment1 * 5;
388 		/* fall through */
389 	case VHT_CHANWIDTH_80MHZ:
390 		data->bandwidth = 80;
391 		if ((vht_oper_chwidth == VHT_CHANWIDTH_80MHZ &&
392 		     center_segment1) ||
393 		    (vht_oper_chwidth == VHT_CHANWIDTH_80P80MHZ &&
394 		     !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 
459 
460 void set_disable_ht40(struct ieee80211_ht_capabilities *htcaps,
461 		      int disabled)
462 {
463 	/* Masking these out disables HT40 */
464 	le16 msk = host_to_le16(HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET |
465 				HT_CAP_INFO_SHORT_GI40MHZ);
466 
467 	if (disabled)
468 		htcaps->ht_capabilities_info &= ~msk;
469 	else
470 		htcaps->ht_capabilities_info |= msk;
471 }
472 
473 
474 #ifdef CONFIG_IEEE80211AC
475 
476 static int _ieee80211ac_cap_check(u32 hw, u32 conf, u32 cap,
477 				  const char *name)
478 {
479 	u32 req_cap = conf & cap;
480 
481 	/*
482 	 * Make sure we support all requested capabilities.
483 	 * NOTE: We assume that 'cap' represents a capability mask,
484 	 * not a discrete value.
485 	 */
486 	if ((hw & req_cap) != req_cap) {
487 		wpa_printf(MSG_ERROR,
488 			   "Driver does not support configured VHT capability [%s]",
489 			   name);
490 		return 0;
491 	}
492 	return 1;
493 }
494 
495 
496 static int ieee80211ac_cap_check_max(u32 hw, u32 conf, u32 mask,
497 				     unsigned int shift,
498 				     const char *name)
499 {
500 	u32 hw_max = hw & mask;
501 	u32 conf_val = conf & mask;
502 
503 	if (conf_val > hw_max) {
504 		wpa_printf(MSG_ERROR,
505 			   "Configured VHT capability [%s] exceeds max value supported by the driver (%d > %d)",
506 			   name, conf_val >> shift, hw_max >> shift);
507 		return 0;
508 	}
509 	return 1;
510 }
511 
512 
513 int ieee80211ac_cap_check(u32 hw, u32 conf)
514 {
515 #define VHT_CAP_CHECK(cap) \
516 	do { \
517 		if (!_ieee80211ac_cap_check(hw, conf, cap, #cap)) \
518 			return 0; \
519 	} while (0)
520 
521 #define VHT_CAP_CHECK_MAX(cap) \
522 	do { \
523 		if (!ieee80211ac_cap_check_max(hw, conf, cap, cap ## _SHIFT, \
524 					       #cap)) \
525 			return 0; \
526 	} while (0)
527 
528 	VHT_CAP_CHECK_MAX(VHT_CAP_MAX_MPDU_LENGTH_MASK);
529 	VHT_CAP_CHECK_MAX(VHT_CAP_SUPP_CHAN_WIDTH_MASK);
530 	VHT_CAP_CHECK(VHT_CAP_RXLDPC);
531 	VHT_CAP_CHECK(VHT_CAP_SHORT_GI_80);
532 	VHT_CAP_CHECK(VHT_CAP_SHORT_GI_160);
533 	VHT_CAP_CHECK(VHT_CAP_TXSTBC);
534 	VHT_CAP_CHECK_MAX(VHT_CAP_RXSTBC_MASK);
535 	VHT_CAP_CHECK(VHT_CAP_SU_BEAMFORMER_CAPABLE);
536 	VHT_CAP_CHECK(VHT_CAP_SU_BEAMFORMEE_CAPABLE);
537 	VHT_CAP_CHECK_MAX(VHT_CAP_BEAMFORMEE_STS_MAX);
538 	VHT_CAP_CHECK_MAX(VHT_CAP_SOUNDING_DIMENSION_MAX);
539 	VHT_CAP_CHECK(VHT_CAP_MU_BEAMFORMER_CAPABLE);
540 	VHT_CAP_CHECK(VHT_CAP_MU_BEAMFORMEE_CAPABLE);
541 	VHT_CAP_CHECK(VHT_CAP_VHT_TXOP_PS);
542 	VHT_CAP_CHECK(VHT_CAP_HTC_VHT);
543 	VHT_CAP_CHECK_MAX(VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MAX);
544 	VHT_CAP_CHECK(VHT_CAP_VHT_LINK_ADAPTATION_VHT_UNSOL_MFB);
545 	VHT_CAP_CHECK(VHT_CAP_VHT_LINK_ADAPTATION_VHT_MRQ_MFB);
546 	VHT_CAP_CHECK(VHT_CAP_RX_ANTENNA_PATTERN);
547 	VHT_CAP_CHECK(VHT_CAP_TX_ANTENNA_PATTERN);
548 
549 #undef VHT_CAP_CHECK
550 #undef VHT_CAP_CHECK_MAX
551 
552 	return 1;
553 }
554 
555 #endif /* CONFIG_IEEE80211AC */
556