xref: /linux/drivers/net/wireless/ath/regd.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
1 /*
2  * Copyright (c) 2008-2009 Atheros Communications Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/export.h>
19 #include <net/cfg80211.h>
20 #include <net/mac80211.h>
21 #include "regd.h"
22 #include "regd_common.h"
23 
24 /*
25  * This is a set of common rules used by our world regulatory domains.
26  * We have 12 world regulatory domains. To save space we consolidate
27  * the regulatory domains in 5 structures by frequency and change
28  * the flags on our reg_notifier() on a case by case basis.
29  */
30 
31 /* Only these channels all allow active scan on all world regulatory domains */
32 #define ATH9K_2GHZ_CH01_11	REG_RULE(2412-10, 2462+10, 40, 0, 20, 0)
33 
34 /* We enable active scan on these a case by case basis by regulatory domain */
35 #define ATH9K_2GHZ_CH12_13	REG_RULE(2467-10, 2472+10, 40, 0, 20,\
36 					NL80211_RRF_PASSIVE_SCAN)
37 #define ATH9K_2GHZ_CH14		REG_RULE(2484-10, 2484+10, 40, 0, 20,\
38 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_OFDM)
39 
40 /* We allow IBSS on these on a case by case basis by regulatory domain */
41 #define ATH9K_5GHZ_5150_5350	REG_RULE(5150-10, 5350+10, 40, 0, 30,\
42 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
43 #define ATH9K_5GHZ_5470_5850	REG_RULE(5470-10, 5850+10, 40, 0, 30,\
44 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
45 #define ATH9K_5GHZ_5725_5850	REG_RULE(5725-10, 5850+10, 40, 0, 30,\
46 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
47 
48 #define ATH9K_2GHZ_ALL		ATH9K_2GHZ_CH01_11, \
49 				ATH9K_2GHZ_CH12_13, \
50 				ATH9K_2GHZ_CH14
51 
52 #define ATH9K_5GHZ_ALL		ATH9K_5GHZ_5150_5350, \
53 				ATH9K_5GHZ_5470_5850
54 
55 /* This one skips what we call "mid band" */
56 #define ATH9K_5GHZ_NO_MIDBAND	ATH9K_5GHZ_5150_5350, \
57 				ATH9K_5GHZ_5725_5850
58 
59 /* Can be used for:
60  * 0x60, 0x61, 0x62 */
61 static const struct ieee80211_regdomain ath_world_regdom_60_61_62 = {
62 	.n_reg_rules = 5,
63 	.alpha2 =  "99",
64 	.reg_rules = {
65 		ATH9K_2GHZ_ALL,
66 		ATH9K_5GHZ_ALL,
67 	}
68 };
69 
70 /* Can be used by 0x63 and 0x65 */
71 static const struct ieee80211_regdomain ath_world_regdom_63_65 = {
72 	.n_reg_rules = 4,
73 	.alpha2 =  "99",
74 	.reg_rules = {
75 		ATH9K_2GHZ_CH01_11,
76 		ATH9K_2GHZ_CH12_13,
77 		ATH9K_5GHZ_NO_MIDBAND,
78 	}
79 };
80 
81 /* Can be used by 0x64 only */
82 static const struct ieee80211_regdomain ath_world_regdom_64 = {
83 	.n_reg_rules = 3,
84 	.alpha2 =  "99",
85 	.reg_rules = {
86 		ATH9K_2GHZ_CH01_11,
87 		ATH9K_5GHZ_NO_MIDBAND,
88 	}
89 };
90 
91 /* Can be used by 0x66 and 0x69 */
92 static const struct ieee80211_regdomain ath_world_regdom_66_69 = {
93 	.n_reg_rules = 3,
94 	.alpha2 =  "99",
95 	.reg_rules = {
96 		ATH9K_2GHZ_CH01_11,
97 		ATH9K_5GHZ_ALL,
98 	}
99 };
100 
101 /* Can be used by 0x67, 0x68, 0x6A and 0x6C */
102 static const struct ieee80211_regdomain ath_world_regdom_67_68_6A_6C = {
103 	.n_reg_rules = 4,
104 	.alpha2 =  "99",
105 	.reg_rules = {
106 		ATH9K_2GHZ_CH01_11,
107 		ATH9K_2GHZ_CH12_13,
108 		ATH9K_5GHZ_ALL,
109 	}
110 };
111 
112 static inline bool is_wwr_sku(u16 regd)
113 {
114 	return ((regd & COUNTRY_ERD_FLAG) != COUNTRY_ERD_FLAG) &&
115 		(((regd & WORLD_SKU_MASK) == WORLD_SKU_PREFIX) ||
116 		(regd == WORLD));
117 }
118 
119 static u16 ath_regd_get_eepromRD(struct ath_regulatory *reg)
120 {
121 	return reg->current_rd & ~WORLDWIDE_ROAMING_FLAG;
122 }
123 
124 bool ath_is_world_regd(struct ath_regulatory *reg)
125 {
126 	return is_wwr_sku(ath_regd_get_eepromRD(reg));
127 }
128 EXPORT_SYMBOL(ath_is_world_regd);
129 
130 static const struct ieee80211_regdomain *ath_default_world_regdomain(void)
131 {
132 	/* this is the most restrictive */
133 	return &ath_world_regdom_64;
134 }
135 
136 static const struct
137 ieee80211_regdomain *ath_world_regdomain(struct ath_regulatory *reg)
138 {
139 	switch (reg->regpair->regDmnEnum) {
140 	case 0x60:
141 	case 0x61:
142 	case 0x62:
143 		return &ath_world_regdom_60_61_62;
144 	case 0x63:
145 	case 0x65:
146 		return &ath_world_regdom_63_65;
147 	case 0x64:
148 		return &ath_world_regdom_64;
149 	case 0x66:
150 	case 0x69:
151 		return &ath_world_regdom_66_69;
152 	case 0x67:
153 	case 0x68:
154 	case 0x6A:
155 	case 0x6C:
156 		return &ath_world_regdom_67_68_6A_6C;
157 	default:
158 		WARN_ON(1);
159 		return ath_default_world_regdomain();
160 	}
161 }
162 
163 bool ath_is_49ghz_allowed(u16 regdomain)
164 {
165 	/* possibly more */
166 	return regdomain == MKK9_MKKC;
167 }
168 EXPORT_SYMBOL(ath_is_49ghz_allowed);
169 
170 /* Frequency is one where radar detection is required */
171 static bool ath_is_radar_freq(u16 center_freq)
172 {
173 	return (center_freq >= 5260 && center_freq <= 5700);
174 }
175 
176 /*
177  * N.B: These exception rules do not apply radar freqs.
178  *
179  * - We enable adhoc (or beaconing) if allowed by 11d
180  * - We enable active scan if the channel is allowed by 11d
181  * - If no country IE has been processed and a we determine we have
182  *   received a beacon on a channel we can enable active scan and
183  *   adhoc (or beaconing).
184  */
185 static void
186 ath_reg_apply_beaconing_flags(struct wiphy *wiphy,
187 			      enum nl80211_reg_initiator initiator)
188 {
189 	enum ieee80211_band band;
190 	struct ieee80211_supported_band *sband;
191 	const struct ieee80211_reg_rule *reg_rule;
192 	struct ieee80211_channel *ch;
193 	unsigned int i;
194 	u32 bandwidth = 0;
195 	int r;
196 
197 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
198 
199 		if (!wiphy->bands[band])
200 			continue;
201 
202 		sband = wiphy->bands[band];
203 
204 		for (i = 0; i < sband->n_channels; i++) {
205 
206 			ch = &sband->channels[i];
207 
208 			if (ath_is_radar_freq(ch->center_freq) ||
209 			    (ch->flags & IEEE80211_CHAN_RADAR))
210 				continue;
211 
212 			if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
213 				r = freq_reg_info(wiphy,
214 						  ch->center_freq,
215 						  bandwidth,
216 						  &reg_rule);
217 				if (r)
218 					continue;
219 				/*
220 				 * If 11d had a rule for this channel ensure
221 				 * we enable adhoc/beaconing if it allows us to
222 				 * use it. Note that we would have disabled it
223 				 * by applying our static world regdomain by
224 				 * default during init, prior to calling our
225 				 * regulatory_hint().
226 				 */
227 				if (!(reg_rule->flags &
228 				    NL80211_RRF_NO_IBSS))
229 					ch->flags &=
230 					  ~IEEE80211_CHAN_NO_IBSS;
231 				if (!(reg_rule->flags &
232 				    NL80211_RRF_PASSIVE_SCAN))
233 					ch->flags &=
234 					  ~IEEE80211_CHAN_PASSIVE_SCAN;
235 			} else {
236 				if (ch->beacon_found)
237 					ch->flags &= ~(IEEE80211_CHAN_NO_IBSS |
238 					  IEEE80211_CHAN_PASSIVE_SCAN);
239 			}
240 		}
241 	}
242 
243 }
244 
245 /* Allows active scan scan on Ch 12 and 13 */
246 static void
247 ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
248 				enum nl80211_reg_initiator initiator)
249 {
250 	struct ieee80211_supported_band *sband;
251 	struct ieee80211_channel *ch;
252 	const struct ieee80211_reg_rule *reg_rule;
253 	u32 bandwidth = 0;
254 	int r;
255 
256 	sband = wiphy->bands[IEEE80211_BAND_2GHZ];
257 
258 	/*
259 	 * If no country IE has been received always enable active scan
260 	 * on these channels. This is only done for specific regulatory SKUs
261 	 */
262 	if (initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
263 		ch = &sband->channels[11]; /* CH 12 */
264 		if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
265 			ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
266 		ch = &sband->channels[12]; /* CH 13 */
267 		if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
268 			ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
269 		return;
270 	}
271 
272 	/*
273 	 * If a country IE has been received check its rule for this
274 	 * channel first before enabling active scan. The passive scan
275 	 * would have been enforced by the initial processing of our
276 	 * custom regulatory domain.
277 	 */
278 
279 	ch = &sband->channels[11]; /* CH 12 */
280 	r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
281 	if (!r) {
282 		if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
283 			if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
284 				ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
285 	}
286 
287 	ch = &sband->channels[12]; /* CH 13 */
288 	r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
289 	if (!r) {
290 		if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
291 			if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
292 				ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
293 	}
294 }
295 
296 /* Always apply Radar/DFS rules on freq range 5260 MHz - 5700 MHz */
297 static void ath_reg_apply_radar_flags(struct wiphy *wiphy)
298 {
299 	struct ieee80211_supported_band *sband;
300 	struct ieee80211_channel *ch;
301 	unsigned int i;
302 
303 	if (!wiphy->bands[IEEE80211_BAND_5GHZ])
304 		return;
305 
306 	sband = wiphy->bands[IEEE80211_BAND_5GHZ];
307 
308 	for (i = 0; i < sband->n_channels; i++) {
309 		ch = &sband->channels[i];
310 		if (!ath_is_radar_freq(ch->center_freq))
311 			continue;
312 		/* We always enable radar detection/DFS on this
313 		 * frequency range. Additionally we also apply on
314 		 * this frequency range:
315 		 * - If STA mode does not yet have DFS supports disable
316 		 *   active scanning
317 		 * - If adhoc mode does not support DFS yet then
318 		 *   disable adhoc in the frequency.
319 		 * - If AP mode does not yet support radar detection/DFS
320 		 *   do not allow AP mode
321 		 */
322 		if (!(ch->flags & IEEE80211_CHAN_DISABLED))
323 			ch->flags |= IEEE80211_CHAN_RADAR |
324 				     IEEE80211_CHAN_NO_IBSS |
325 				     IEEE80211_CHAN_PASSIVE_SCAN;
326 	}
327 }
328 
329 static void ath_reg_apply_world_flags(struct wiphy *wiphy,
330 				      enum nl80211_reg_initiator initiator,
331 				      struct ath_regulatory *reg)
332 {
333 	switch (reg->regpair->regDmnEnum) {
334 	case 0x60:
335 	case 0x63:
336 	case 0x66:
337 	case 0x67:
338 	case 0x6C:
339 		ath_reg_apply_beaconing_flags(wiphy, initiator);
340 		break;
341 	case 0x68:
342 		ath_reg_apply_beaconing_flags(wiphy, initiator);
343 		ath_reg_apply_active_scan_flags(wiphy, initiator);
344 		break;
345 	}
346 }
347 
348 int ath_reg_notifier_apply(struct wiphy *wiphy,
349 			   struct regulatory_request *request,
350 			   struct ath_regulatory *reg)
351 {
352 	/* We always apply this */
353 	ath_reg_apply_radar_flags(wiphy);
354 
355 	/*
356 	 * This would happen when we have sent a custom regulatory request
357 	 * a world regulatory domain and the scheduler hasn't yet processed
358 	 * any pending requests in the queue.
359 	 */
360 	if (!request)
361 		return 0;
362 
363 	switch (request->initiator) {
364 	case NL80211_REGDOM_SET_BY_DRIVER:
365 	case NL80211_REGDOM_SET_BY_CORE:
366 	case NL80211_REGDOM_SET_BY_USER:
367 		break;
368 	case NL80211_REGDOM_SET_BY_COUNTRY_IE:
369 		if (ath_is_world_regd(reg))
370 			ath_reg_apply_world_flags(wiphy, request->initiator,
371 						  reg);
372 		break;
373 	}
374 
375 	return 0;
376 }
377 EXPORT_SYMBOL(ath_reg_notifier_apply);
378 
379 static bool ath_regd_is_eeprom_valid(struct ath_regulatory *reg)
380 {
381 	u16 rd = ath_regd_get_eepromRD(reg);
382 	int i;
383 
384 	if (rd & COUNTRY_ERD_FLAG) {
385 		/* EEPROM value is a country code */
386 		u16 cc = rd & ~COUNTRY_ERD_FLAG;
387 		printk(KERN_DEBUG
388 		       "ath: EEPROM indicates we should expect "
389 			"a country code\n");
390 		for (i = 0; i < ARRAY_SIZE(allCountries); i++)
391 			if (allCountries[i].countryCode == cc)
392 				return true;
393 	} else {
394 		/* EEPROM value is a regpair value */
395 		if (rd != CTRY_DEFAULT)
396 			printk(KERN_DEBUG "ath: EEPROM indicates we "
397 			       "should expect a direct regpair map\n");
398 		for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++)
399 			if (regDomainPairs[i].regDmnEnum == rd)
400 				return true;
401 	}
402 	printk(KERN_DEBUG
403 		 "ath: invalid regulatory domain/country code 0x%x\n", rd);
404 	return false;
405 }
406 
407 /* EEPROM country code to regpair mapping */
408 static struct country_code_to_enum_rd*
409 ath_regd_find_country(u16 countryCode)
410 {
411 	int i;
412 
413 	for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
414 		if (allCountries[i].countryCode == countryCode)
415 			return &allCountries[i];
416 	}
417 	return NULL;
418 }
419 
420 /* EEPROM rd code to regpair mapping */
421 static struct country_code_to_enum_rd*
422 ath_regd_find_country_by_rd(int regdmn)
423 {
424 	int i;
425 
426 	for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
427 		if (allCountries[i].regDmnEnum == regdmn)
428 			return &allCountries[i];
429 	}
430 	return NULL;
431 }
432 
433 /* Returns the map of the EEPROM set RD to a country code */
434 static u16 ath_regd_get_default_country(u16 rd)
435 {
436 	if (rd & COUNTRY_ERD_FLAG) {
437 		struct country_code_to_enum_rd *country = NULL;
438 		u16 cc = rd & ~COUNTRY_ERD_FLAG;
439 
440 		country = ath_regd_find_country(cc);
441 		if (country != NULL)
442 			return cc;
443 	}
444 
445 	return CTRY_DEFAULT;
446 }
447 
448 static struct reg_dmn_pair_mapping*
449 ath_get_regpair(int regdmn)
450 {
451 	int i;
452 
453 	if (regdmn == NO_ENUMRD)
454 		return NULL;
455 	for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++) {
456 		if (regDomainPairs[i].regDmnEnum == regdmn)
457 			return &regDomainPairs[i];
458 	}
459 	return NULL;
460 }
461 
462 static int
463 ath_regd_init_wiphy(struct ath_regulatory *reg,
464 		    struct wiphy *wiphy,
465 		    int (*reg_notifier)(struct wiphy *wiphy,
466 					struct regulatory_request *request))
467 {
468 	const struct ieee80211_regdomain *regd;
469 
470 	wiphy->reg_notifier = reg_notifier;
471 	wiphy->flags |= WIPHY_FLAG_STRICT_REGULATORY;
472 
473 	if (ath_is_world_regd(reg)) {
474 		/*
475 		 * Anything applied here (prior to wiphy registration) gets
476 		 * saved on the wiphy orig_* parameters
477 		 */
478 		regd = ath_world_regdomain(reg);
479 		wiphy->flags |= WIPHY_FLAG_CUSTOM_REGULATORY;
480 	} else {
481 		/*
482 		 * This gets applied in the case of the absence of CRDA,
483 		 * it's our own custom world regulatory domain, similar to
484 		 * cfg80211's but we enable passive scanning.
485 		 */
486 		regd = ath_default_world_regdomain();
487 	}
488 	wiphy_apply_custom_regulatory(wiphy, regd);
489 	ath_reg_apply_radar_flags(wiphy);
490 	ath_reg_apply_world_flags(wiphy, NL80211_REGDOM_SET_BY_DRIVER, reg);
491 	return 0;
492 }
493 
494 /*
495  * Some users have reported their EEPROM programmed with
496  * 0x8000 set, this is not a supported regulatory domain
497  * but since we have more than one user with it we need
498  * a solution for them. We default to 0x64, which is the
499  * default Atheros world regulatory domain.
500  */
501 static void ath_regd_sanitize(struct ath_regulatory *reg)
502 {
503 	if (reg->current_rd != COUNTRY_ERD_FLAG)
504 		return;
505 	printk(KERN_DEBUG "ath: EEPROM regdomain sanitized\n");
506 	reg->current_rd = 0x64;
507 }
508 
509 int
510 ath_regd_init(struct ath_regulatory *reg,
511 	      struct wiphy *wiphy,
512 	      int (*reg_notifier)(struct wiphy *wiphy,
513 				  struct regulatory_request *request))
514 {
515 	struct country_code_to_enum_rd *country = NULL;
516 	u16 regdmn;
517 
518 	if (!reg)
519 		return -EINVAL;
520 
521 	ath_regd_sanitize(reg);
522 
523 	printk(KERN_DEBUG "ath: EEPROM regdomain: 0x%0x\n", reg->current_rd);
524 
525 	if (!ath_regd_is_eeprom_valid(reg)) {
526 		printk(KERN_ERR "ath: Invalid EEPROM contents\n");
527 		return -EINVAL;
528 	}
529 
530 	regdmn = ath_regd_get_eepromRD(reg);
531 	reg->country_code = ath_regd_get_default_country(regdmn);
532 
533 	if (reg->country_code == CTRY_DEFAULT &&
534 	    regdmn == CTRY_DEFAULT) {
535 		printk(KERN_DEBUG "ath: EEPROM indicates default "
536 		       "country code should be used\n");
537 		reg->country_code = CTRY_UNITED_STATES;
538 	}
539 
540 	if (reg->country_code == CTRY_DEFAULT) {
541 		country = NULL;
542 	} else {
543 		printk(KERN_DEBUG "ath: doing EEPROM country->regdmn "
544 		       "map search\n");
545 		country = ath_regd_find_country(reg->country_code);
546 		if (country == NULL) {
547 			printk(KERN_DEBUG
548 				"ath: no valid country maps found for "
549 				"country code: 0x%0x\n",
550 				reg->country_code);
551 			return -EINVAL;
552 		} else {
553 			regdmn = country->regDmnEnum;
554 			printk(KERN_DEBUG "ath: country maps to "
555 			       "regdmn code: 0x%0x\n",
556 			       regdmn);
557 		}
558 	}
559 
560 	reg->regpair = ath_get_regpair(regdmn);
561 
562 	if (!reg->regpair) {
563 		printk(KERN_DEBUG "ath: "
564 			"No regulatory domain pair found, cannot continue\n");
565 		return -EINVAL;
566 	}
567 
568 	if (!country)
569 		country = ath_regd_find_country_by_rd(regdmn);
570 
571 	if (country) {
572 		reg->alpha2[0] = country->isoName[0];
573 		reg->alpha2[1] = country->isoName[1];
574 	} else {
575 		reg->alpha2[0] = '0';
576 		reg->alpha2[1] = '0';
577 	}
578 
579 	printk(KERN_DEBUG "ath: Country alpha2 being used: %c%c\n",
580 		reg->alpha2[0], reg->alpha2[1]);
581 	printk(KERN_DEBUG "ath: Regpair used: 0x%0x\n",
582 		reg->regpair->regDmnEnum);
583 
584 	ath_regd_init_wiphy(reg, wiphy, reg_notifier);
585 	return 0;
586 }
587 EXPORT_SYMBOL(ath_regd_init);
588 
589 u32 ath_regd_get_band_ctl(struct ath_regulatory *reg,
590 			  enum ieee80211_band band)
591 {
592 	if (!reg->regpair ||
593 	    (reg->country_code == CTRY_DEFAULT &&
594 	     is_wwr_sku(ath_regd_get_eepromRD(reg)))) {
595 		return SD_NO_CTL;
596 	}
597 
598 	switch (band) {
599 	case IEEE80211_BAND_2GHZ:
600 		return reg->regpair->reg_2ghz_ctl;
601 	case IEEE80211_BAND_5GHZ:
602 		return reg->regpair->reg_5ghz_ctl;
603 	default:
604 		return NO_CTL;
605 	}
606 }
607 EXPORT_SYMBOL(ath_regd_get_band_ctl);
608