xref: /freebsd/contrib/wpa/src/common/hw_features_common.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
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, 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 	struct hostapd_channel_data *p_chan, *s_chan;
95 	const int ht40_plus = pri_chan < sec_chan;
96 
97 	p_chan = hw_get_channel_chan(mode, pri_chan, NULL);
98 	if (!p_chan)
99 		return 0;
100 
101 	if (pri_chan == sec_chan || !sec_chan) {
102 		if (chan_pri_allowed(p_chan))
103 			return 1; /* HT40 not used */
104 
105 		wpa_printf(MSG_ERROR, "Channel %d is not allowed as primary",
106 			   pri_chan);
107 		return 0;
108 	}
109 
110 	s_chan = hw_get_channel_chan(mode, sec_chan, NULL);
111 	if (!s_chan)
112 		return 0;
113 
114 	wpa_printf(MSG_DEBUG,
115 		   "HT40: control channel: %d  secondary channel: %d",
116 		   pri_chan, sec_chan);
117 
118 	/* Verify that HT40 secondary channel is an allowed 20 MHz
119 	 * channel */
120 	if ((s_chan->flag & HOSTAPD_CHAN_DISABLED) ||
121 	    (ht40_plus && !(p_chan->allowed_bw & HOSTAPD_CHAN_WIDTH_40P)) ||
122 	    (!ht40_plus && !(p_chan->allowed_bw & HOSTAPD_CHAN_WIDTH_40M))) {
123 		wpa_printf(MSG_ERROR, "HT40 secondary channel %d not allowed",
124 			   sec_chan);
125 		return 0;
126 	}
127 
128 	/*
129 	 * Verify that HT40 primary,secondary channel pair is allowed per
130 	 * IEEE 802.11n Annex J. This is only needed for 5 GHz band since
131 	 * 2.4 GHz rules allow all cases where the secondary channel fits into
132 	 * the list of allowed channels (already checked above).
133 	 */
134 	if (mode->mode != HOSTAPD_MODE_IEEE80211A)
135 		return 1;
136 
137 	first = pri_chan < sec_chan ? pri_chan : sec_chan;
138 
139 	ok = 0;
140 	for (k = 0; k < ARRAY_SIZE(allowed); k++) {
141 		if (first == allowed[k]) {
142 			ok = 1;
143 			break;
144 		}
145 	}
146 	if (!ok) {
147 		wpa_printf(MSG_ERROR, "HT40 channel pair (%d, %d) not allowed",
148 			   pri_chan, sec_chan);
149 		return 0;
150 	}
151 
152 	return 1;
153 }
154 
155 
156 void get_pri_sec_chan(struct wpa_scan_res *bss, int *pri_chan, int *sec_chan)
157 {
158 	struct ieee80211_ht_operation *oper;
159 	struct ieee802_11_elems elems;
160 
161 	*pri_chan = *sec_chan = 0;
162 
163 	ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
164 	if (elems.ht_operation) {
165 		oper = (struct ieee80211_ht_operation *) elems.ht_operation;
166 		*pri_chan = oper->primary_chan;
167 		if (oper->ht_param & HT_INFO_HT_PARAM_STA_CHNL_WIDTH) {
168 			int sec = oper->ht_param &
169 				HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK;
170 			if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE)
171 				*sec_chan = *pri_chan + 4;
172 			else if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW)
173 				*sec_chan = *pri_chan - 4;
174 		}
175 	}
176 }
177 
178 
179 int check_40mhz_5g(struct hostapd_hw_modes *mode,
180 		   struct wpa_scan_results *scan_res, int pri_chan,
181 		   int sec_chan)
182 {
183 	int pri_freq, sec_freq, pri_bss, sec_bss;
184 	int bss_pri_chan, bss_sec_chan;
185 	size_t i;
186 	int match;
187 
188 	if (!mode || !scan_res || !pri_chan || !sec_chan ||
189 	    pri_chan == sec_chan)
190 		return 0;
191 
192 	pri_freq = hw_get_freq(mode, pri_chan);
193 	sec_freq = hw_get_freq(mode, sec_chan);
194 
195 	/*
196 	 * Switch PRI/SEC channels if Beacons were detected on selected SEC
197 	 * channel, but not on selected PRI channel.
198 	 */
199 	pri_bss = sec_bss = 0;
200 	for (i = 0; i < scan_res->num; i++) {
201 		struct wpa_scan_res *bss = scan_res->res[i];
202 		if (bss->freq == pri_freq)
203 			pri_bss++;
204 		else if (bss->freq == sec_freq)
205 			sec_bss++;
206 	}
207 	if (sec_bss && !pri_bss) {
208 		wpa_printf(MSG_INFO,
209 			   "Switch own primary and secondary channel to get secondary channel with no Beacons from other BSSes");
210 		return 2;
211 	}
212 
213 	/*
214 	 * Match PRI/SEC channel with any existing HT40 BSS on the same
215 	 * channels that we are about to use (if already mixed order in
216 	 * existing BSSes, use own preference).
217 	 */
218 	match = 0;
219 	for (i = 0; i < scan_res->num; i++) {
220 		struct wpa_scan_res *bss = scan_res->res[i];
221 		get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
222 		if (pri_chan == bss_pri_chan &&
223 		    sec_chan == bss_sec_chan) {
224 			match = 1;
225 			break;
226 		}
227 	}
228 	if (!match) {
229 		for (i = 0; i < scan_res->num; i++) {
230 			struct wpa_scan_res *bss = scan_res->res[i];
231 			get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
232 			if (pri_chan == bss_sec_chan &&
233 			    sec_chan == bss_pri_chan) {
234 				wpa_printf(MSG_INFO, "Switch own primary and "
235 					   "secondary channel due to BSS "
236 					   "overlap with " MACSTR,
237 					   MAC2STR(bss->bssid));
238 				return 2;
239 			}
240 		}
241 	}
242 
243 	return 1;
244 }
245 
246 
247 static int check_20mhz_bss(struct wpa_scan_res *bss, int pri_freq, int start,
248 			   int end)
249 {
250 	struct ieee802_11_elems elems;
251 	struct ieee80211_ht_operation *oper;
252 
253 	if (bss->freq < start || bss->freq > end || bss->freq == pri_freq)
254 		return 0;
255 
256 	ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
257 	if (!elems.ht_capabilities) {
258 		wpa_printf(MSG_DEBUG, "Found overlapping legacy BSS: "
259 			   MACSTR " freq=%d", MAC2STR(bss->bssid), bss->freq);
260 		return 1;
261 	}
262 
263 	if (elems.ht_operation) {
264 		oper = (struct ieee80211_ht_operation *) elems.ht_operation;
265 		if (oper->ht_param & HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK)
266 			return 0;
267 
268 		wpa_printf(MSG_DEBUG, "Found overlapping 20 MHz HT BSS: "
269 			   MACSTR " freq=%d", MAC2STR(bss->bssid), bss->freq);
270 		return 1;
271 	}
272 	return 0;
273 }
274 
275 
276 int check_40mhz_2g4(struct hostapd_hw_modes *mode,
277 		    struct wpa_scan_results *scan_res, int pri_chan,
278 		    int sec_chan)
279 {
280 	int pri_freq, sec_freq;
281 	int affected_start, affected_end;
282 	size_t i;
283 
284 	if (!mode || !scan_res || !pri_chan || !sec_chan ||
285 	    pri_chan == sec_chan)
286 		return 0;
287 
288 	pri_freq = hw_get_freq(mode, pri_chan);
289 	sec_freq = hw_get_freq(mode, sec_chan);
290 
291 	affected_start = (pri_freq + sec_freq) / 2 - 25;
292 	affected_end = (pri_freq + sec_freq) / 2 + 25;
293 	wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
294 		   affected_start, affected_end);
295 	for (i = 0; i < scan_res->num; i++) {
296 		struct wpa_scan_res *bss = scan_res->res[i];
297 		int pri = bss->freq;
298 		int sec = pri;
299 		struct ieee802_11_elems elems;
300 
301 		/* Check for overlapping 20 MHz BSS */
302 		if (check_20mhz_bss(bss, pri_freq, affected_start,
303 				    affected_end)) {
304 			wpa_printf(MSG_DEBUG,
305 				   "Overlapping 20 MHz BSS is found");
306 			return 0;
307 		}
308 
309 		get_pri_sec_chan(bss, &pri_chan, &sec_chan);
310 
311 		if (sec_chan) {
312 			if (sec_chan < pri_chan)
313 				sec = pri - 20;
314 			else
315 				sec = pri + 20;
316 		}
317 
318 		if ((pri < affected_start || pri > affected_end) &&
319 		    (sec < affected_start || sec > affected_end))
320 			continue; /* not within affected channel range */
321 
322 		wpa_printf(MSG_DEBUG, "Neighboring BSS: " MACSTR
323 			   " freq=%d pri=%d sec=%d",
324 			   MAC2STR(bss->bssid), bss->freq, pri_chan, sec_chan);
325 
326 		if (sec_chan) {
327 			if (pri_freq != pri || sec_freq != sec) {
328 				wpa_printf(MSG_DEBUG,
329 					   "40 MHz pri/sec mismatch with BSS "
330 					   MACSTR
331 					   " <%d,%d> (chan=%d%c) vs. <%d,%d>",
332 					   MAC2STR(bss->bssid),
333 					   pri, sec, pri_chan,
334 					   sec > pri ? '+' : '-',
335 					   pri_freq, sec_freq);
336 				return 0;
337 			}
338 		}
339 
340 		ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems,
341 				       0);
342 		if (elems.ht_capabilities) {
343 			struct ieee80211_ht_capabilities *ht_cap =
344 				(struct ieee80211_ht_capabilities *)
345 				elems.ht_capabilities;
346 
347 			if (le_to_host16(ht_cap->ht_capabilities_info) &
348 			    HT_CAP_INFO_40MHZ_INTOLERANT) {
349 				wpa_printf(MSG_DEBUG,
350 					   "40 MHz Intolerant is set on channel %d in BSS "
351 					   MACSTR, pri, MAC2STR(bss->bssid));
352 				return 0;
353 			}
354 		}
355 	}
356 
357 	return 1;
358 }
359 
360 
361 int hostapd_set_freq_params(struct hostapd_freq_params *data,
362 			    enum hostapd_hw_mode mode,
363 			    int freq, int channel, int ht_enabled,
364 			    int vht_enabled, int sec_channel_offset,
365 			    int vht_oper_chwidth, int center_segment0,
366 			    int center_segment1, u32 vht_caps)
367 {
368 	os_memset(data, 0, sizeof(*data));
369 	data->mode = mode;
370 	data->freq = freq;
371 	data->channel = channel;
372 	data->ht_enabled = ht_enabled;
373 	data->vht_enabled = vht_enabled;
374 	data->sec_channel_offset = sec_channel_offset;
375 	data->center_freq1 = freq + sec_channel_offset * 10;
376 	data->center_freq2 = 0;
377 	data->bandwidth = sec_channel_offset ? 40 : 20;
378 
379 	if (data->vht_enabled) switch (vht_oper_chwidth) {
380 	case VHT_CHANWIDTH_USE_HT:
381 		if (center_segment1 ||
382 		    (center_segment0 != 0 &&
383 		     5000 + center_segment0 * 5 != data->center_freq1 &&
384 		     2407 + center_segment0 * 5 != data->center_freq1))
385 			return -1;
386 		break;
387 	case VHT_CHANWIDTH_80P80MHZ:
388 		if (!(vht_caps & VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)) {
389 			wpa_printf(MSG_ERROR,
390 				   "80+80 channel width is not supported!");
391 			return -1;
392 		}
393 		if (center_segment1 == center_segment0 + 4 ||
394 		    center_segment1 == center_segment0 - 4)
395 			return -1;
396 		data->center_freq2 = 5000 + center_segment1 * 5;
397 		/* fall through */
398 	case VHT_CHANWIDTH_80MHZ:
399 		data->bandwidth = 80;
400 		if ((vht_oper_chwidth == VHT_CHANWIDTH_80MHZ &&
401 		     center_segment1) ||
402 		    (vht_oper_chwidth == VHT_CHANWIDTH_80P80MHZ &&
403 		     !center_segment1) ||
404 		    !sec_channel_offset)
405 			return -1;
406 		if (!center_segment0) {
407 			if (channel <= 48)
408 				center_segment0 = 42;
409 			else if (channel <= 64)
410 				center_segment0 = 58;
411 			else if (channel <= 112)
412 				center_segment0 = 106;
413 			else if (channel <= 128)
414 				center_segment0 = 122;
415 			else if (channel <= 144)
416 				center_segment0 = 138;
417 			else if (channel <= 161)
418 				center_segment0 = 155;
419 			data->center_freq1 = 5000 + center_segment0 * 5;
420 		} else {
421 			/*
422 			 * Note: HT/VHT config and params are coupled. Check if
423 			 * HT40 channel band is in VHT80 Pri channel band
424 			 * configuration.
425 			 */
426 			if (center_segment0 == channel + 6 ||
427 			    center_segment0 == channel + 2 ||
428 			    center_segment0 == channel - 2 ||
429 			    center_segment0 == channel - 6)
430 				data->center_freq1 = 5000 + center_segment0 * 5;
431 			else
432 				return -1;
433 		}
434 		break;
435 	case VHT_CHANWIDTH_160MHZ:
436 		data->bandwidth = 160;
437 		if (!(vht_caps & (VHT_CAP_SUPP_CHAN_WIDTH_160MHZ |
438 				  VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))) {
439 			wpa_printf(MSG_ERROR,
440 				   "160MHZ channel width is not supported!");
441 			return -1;
442 		}
443 		if (center_segment1)
444 			return -1;
445 		if (!sec_channel_offset)
446 			return -1;
447 		/*
448 		 * Note: HT/VHT config and params are coupled. Check if
449 		 * HT40 channel band is in VHT160 channel band configuration.
450 		 */
451 		if (center_segment0 == channel + 14 ||
452 		    center_segment0 == channel + 10 ||
453 		    center_segment0 == channel + 6 ||
454 		    center_segment0 == channel + 2 ||
455 		    center_segment0 == channel - 2 ||
456 		    center_segment0 == channel - 6 ||
457 		    center_segment0 == channel - 10 ||
458 		    center_segment0 == channel - 14)
459 			data->center_freq1 = 5000 + center_segment0 * 5;
460 		else
461 			return -1;
462 		break;
463 	}
464 
465 	return 0;
466 }
467 
468 
469 void set_disable_ht40(struct ieee80211_ht_capabilities *htcaps,
470 		      int disabled)
471 {
472 	/* Masking these out disables HT40 */
473 	le16 msk = host_to_le16(HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET |
474 				HT_CAP_INFO_SHORT_GI40MHZ);
475 
476 	if (disabled)
477 		htcaps->ht_capabilities_info &= ~msk;
478 	else
479 		htcaps->ht_capabilities_info |= msk;
480 }
481 
482 
483 #ifdef CONFIG_IEEE80211AC
484 
485 static int _ieee80211ac_cap_check(u32 hw, u32 conf, u32 cap,
486 				  const char *name)
487 {
488 	u32 req_cap = conf & cap;
489 
490 	/*
491 	 * Make sure we support all requested capabilities.
492 	 * NOTE: We assume that 'cap' represents a capability mask,
493 	 * not a discrete value.
494 	 */
495 	if ((hw & req_cap) != req_cap) {
496 		wpa_printf(MSG_ERROR,
497 			   "Driver does not support configured VHT capability [%s]",
498 			   name);
499 		return 0;
500 	}
501 	return 1;
502 }
503 
504 
505 static int ieee80211ac_cap_check_max(u32 hw, u32 conf, u32 mask,
506 				     unsigned int shift,
507 				     const char *name)
508 {
509 	u32 hw_max = hw & mask;
510 	u32 conf_val = conf & mask;
511 
512 	if (conf_val > hw_max) {
513 		wpa_printf(MSG_ERROR,
514 			   "Configured VHT capability [%s] exceeds max value supported by the driver (%d > %d)",
515 			   name, conf_val >> shift, hw_max >> shift);
516 		return 0;
517 	}
518 	return 1;
519 }
520 
521 
522 int ieee80211ac_cap_check(u32 hw, u32 conf)
523 {
524 #define VHT_CAP_CHECK(cap) \
525 	do { \
526 		if (!_ieee80211ac_cap_check(hw, conf, cap, #cap)) \
527 			return 0; \
528 	} while (0)
529 
530 #define VHT_CAP_CHECK_MAX(cap) \
531 	do { \
532 		if (!ieee80211ac_cap_check_max(hw, conf, cap, cap ## _SHIFT, \
533 					       #cap)) \
534 			return 0; \
535 	} while (0)
536 
537 	VHT_CAP_CHECK_MAX(VHT_CAP_MAX_MPDU_LENGTH_MASK);
538 	VHT_CAP_CHECK_MAX(VHT_CAP_SUPP_CHAN_WIDTH_MASK);
539 	VHT_CAP_CHECK(VHT_CAP_RXLDPC);
540 	VHT_CAP_CHECK(VHT_CAP_SHORT_GI_80);
541 	VHT_CAP_CHECK(VHT_CAP_SHORT_GI_160);
542 	VHT_CAP_CHECK(VHT_CAP_TXSTBC);
543 	VHT_CAP_CHECK_MAX(VHT_CAP_RXSTBC_MASK);
544 	VHT_CAP_CHECK(VHT_CAP_SU_BEAMFORMER_CAPABLE);
545 	VHT_CAP_CHECK(VHT_CAP_SU_BEAMFORMEE_CAPABLE);
546 	VHT_CAP_CHECK_MAX(VHT_CAP_BEAMFORMEE_STS_MAX);
547 	VHT_CAP_CHECK_MAX(VHT_CAP_SOUNDING_DIMENSION_MAX);
548 	VHT_CAP_CHECK(VHT_CAP_MU_BEAMFORMER_CAPABLE);
549 	VHT_CAP_CHECK(VHT_CAP_MU_BEAMFORMEE_CAPABLE);
550 	VHT_CAP_CHECK(VHT_CAP_VHT_TXOP_PS);
551 	VHT_CAP_CHECK(VHT_CAP_HTC_VHT);
552 	VHT_CAP_CHECK_MAX(VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MAX);
553 	VHT_CAP_CHECK(VHT_CAP_VHT_LINK_ADAPTATION_VHT_UNSOL_MFB);
554 	VHT_CAP_CHECK(VHT_CAP_VHT_LINK_ADAPTATION_VHT_MRQ_MFB);
555 	VHT_CAP_CHECK(VHT_CAP_RX_ANTENNA_PATTERN);
556 	VHT_CAP_CHECK(VHT_CAP_TX_ANTENNA_PATTERN);
557 
558 #undef VHT_CAP_CHECK
559 #undef VHT_CAP_CHECK_MAX
560 
561 	return 1;
562 }
563 
564 #endif /* CONFIG_IEEE80211AC */
565 
566 
567 u32 num_chan_to_bw(int num_chans)
568 {
569 	switch (num_chans) {
570 	case 2:
571 	case 4:
572 	case 8:
573 		return num_chans * 20;
574 	default:
575 		return 20;
576 	}
577 }
578 
579 
580 /* check if BW is applicable for channel */
581 int chan_bw_allowed(const struct hostapd_channel_data *chan, u32 bw,
582 		    int ht40_plus, int pri)
583 {
584 	u32 bw_mask;
585 
586 	switch (bw) {
587 	case 20:
588 		bw_mask = HOSTAPD_CHAN_WIDTH_20;
589 		break;
590 	case 40:
591 		/* HT 40 MHz support declared only for primary channel,
592 		 * just skip 40 MHz secondary checking */
593 		if (pri && ht40_plus)
594 			bw_mask = HOSTAPD_CHAN_WIDTH_40P;
595 		else if (pri && !ht40_plus)
596 			bw_mask = HOSTAPD_CHAN_WIDTH_40M;
597 		else
598 			bw_mask = 0;
599 		break;
600 	case 80:
601 		bw_mask = HOSTAPD_CHAN_WIDTH_80;
602 		break;
603 	case 160:
604 		bw_mask = HOSTAPD_CHAN_WIDTH_160;
605 		break;
606 	default:
607 		bw_mask = 0;
608 		break;
609 	}
610 
611 	return (chan->allowed_bw & bw_mask) == bw_mask;
612 }
613 
614 
615 /* check if channel is allowed to be used as primary */
616 int chan_pri_allowed(const struct hostapd_channel_data *chan)
617 {
618 	return !(chan->flag & HOSTAPD_CHAN_DISABLED) &&
619 		(chan->allowed_bw & HOSTAPD_CHAN_WIDTH_20);
620 }
621