xref: /linux/net/wireless/reg.c (revision b233b28eac0cc37d07c2d007ea08c86c778c5af4)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
5  * Copyright 2008	Luis R. Rodriguez <lrodriguz@atheros.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 /**
13  * DOC: Wireless regulatory infrastructure
14  *
15  * The usual implementation is for a driver to read a device EEPROM to
16  * determine which regulatory domain it should be operating under, then
17  * looking up the allowable channels in a driver-local table and finally
18  * registering those channels in the wiphy structure.
19  *
20  * Another set of compliance enforcement is for drivers to use their
21  * own compliance limits which can be stored on the EEPROM. The host
22  * driver or firmware may ensure these are used.
23  *
24  * In addition to all this we provide an extra layer of regulatory
25  * conformance. For drivers which do not have any regulatory
26  * information CRDA provides the complete regulatory solution.
27  * For others it provides a community effort on further restrictions
28  * to enhance compliance.
29  *
30  * Note: When number of rules --> infinity we will not be able to
31  * index on alpha2 any more, instead we'll probably have to
32  * rely on some SHA1 checksum of the regdomain for example.
33  *
34  */
35 #include <linux/kernel.h>
36 #include <linux/list.h>
37 #include <linux/random.h>
38 #include <linux/nl80211.h>
39 #include <linux/platform_device.h>
40 #include <net/wireless.h>
41 #include <net/cfg80211.h>
42 #include "core.h"
43 #include "reg.h"
44 
45 /**
46  * struct regulatory_request - receipt of last regulatory request
47  *
48  * @wiphy: this is set if this request's initiator is
49  * 	%REGDOM_SET_BY_COUNTRY_IE or %REGDOM_SET_BY_DRIVER. This
50  * 	can be used by the wireless core to deal with conflicts
51  * 	and potentially inform users of which devices specifically
52  * 	cased the conflicts.
53  * @initiator: indicates who sent this request, could be any of
54  * 	of those set in reg_set_by, %REGDOM_SET_BY_*
55  * @alpha2: the ISO / IEC 3166 alpha2 country code of the requested
56  * 	regulatory domain. We have a few special codes:
57  * 	00 - World regulatory domain
58  * 	99 - built by driver but a specific alpha2 cannot be determined
59  * 	98 - result of an intersection between two regulatory domains
60  * @intersect: indicates whether the wireless core should intersect
61  * 	the requested regulatory domain with the presently set regulatory
62  * 	domain.
63  * @country_ie_checksum: checksum of the last processed and accepted
64  * 	country IE
65  * @country_ie_env: lets us know if the AP is telling us we are outdoor,
66  * 	indoor, or if it doesn't matter
67  */
68 struct regulatory_request {
69 	struct wiphy *wiphy;
70 	enum reg_set_by initiator;
71 	char alpha2[2];
72 	bool intersect;
73 	u32 country_ie_checksum;
74 	enum environment_cap country_ie_env;
75 };
76 
77 /* Receipt of information from last regulatory request */
78 static struct regulatory_request *last_request;
79 
80 /* To trigger userspace events */
81 static struct platform_device *reg_pdev;
82 
83 /* Keep the ordering from large to small */
84 static u32 supported_bandwidths[] = {
85 	MHZ_TO_KHZ(40),
86 	MHZ_TO_KHZ(20),
87 };
88 
89 /* Central wireless core regulatory domains, we only need two,
90  * the current one and a world regulatory domain in case we have no
91  * information to give us an alpha2 */
92 static const struct ieee80211_regdomain *cfg80211_regdomain;
93 
94 /* We use this as a place for the rd structure built from the
95  * last parsed country IE to rest until CRDA gets back to us with
96  * what it thinks should apply for the same country */
97 static const struct ieee80211_regdomain *country_ie_regdomain;
98 
99 /* We keep a static world regulatory domain in case of the absence of CRDA */
100 static const struct ieee80211_regdomain world_regdom = {
101 	.n_reg_rules = 1,
102 	.alpha2 =  "00",
103 	.reg_rules = {
104 		REG_RULE(2412-10, 2462+10, 40, 6, 20,
105 			NL80211_RRF_PASSIVE_SCAN |
106 			NL80211_RRF_NO_IBSS),
107 	}
108 };
109 
110 static const struct ieee80211_regdomain *cfg80211_world_regdom =
111 	&world_regdom;
112 
113 #ifdef CONFIG_WIRELESS_OLD_REGULATORY
114 static char *ieee80211_regdom = "US";
115 module_param(ieee80211_regdom, charp, 0444);
116 MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");
117 
118 /* We assume 40 MHz bandwidth for the old regulatory work.
119  * We make emphasis we are using the exact same frequencies
120  * as before */
121 
122 static const struct ieee80211_regdomain us_regdom = {
123 	.n_reg_rules = 6,
124 	.alpha2 =  "US",
125 	.reg_rules = {
126 		/* IEEE 802.11b/g, channels 1..11 */
127 		REG_RULE(2412-10, 2462+10, 40, 6, 27, 0),
128 		/* IEEE 802.11a, channel 36 */
129 		REG_RULE(5180-10, 5180+10, 40, 6, 23, 0),
130 		/* IEEE 802.11a, channel 40 */
131 		REG_RULE(5200-10, 5200+10, 40, 6, 23, 0),
132 		/* IEEE 802.11a, channel 44 */
133 		REG_RULE(5220-10, 5220+10, 40, 6, 23, 0),
134 		/* IEEE 802.11a, channels 48..64 */
135 		REG_RULE(5240-10, 5320+10, 40, 6, 23, 0),
136 		/* IEEE 802.11a, channels 149..165, outdoor */
137 		REG_RULE(5745-10, 5825+10, 40, 6, 30, 0),
138 	}
139 };
140 
141 static const struct ieee80211_regdomain jp_regdom = {
142 	.n_reg_rules = 3,
143 	.alpha2 =  "JP",
144 	.reg_rules = {
145 		/* IEEE 802.11b/g, channels 1..14 */
146 		REG_RULE(2412-10, 2484+10, 40, 6, 20, 0),
147 		/* IEEE 802.11a, channels 34..48 */
148 		REG_RULE(5170-10, 5240+10, 40, 6, 20,
149 			NL80211_RRF_PASSIVE_SCAN),
150 		/* IEEE 802.11a, channels 52..64 */
151 		REG_RULE(5260-10, 5320+10, 40, 6, 20,
152 			NL80211_RRF_NO_IBSS |
153 			NL80211_RRF_DFS),
154 	}
155 };
156 
157 static const struct ieee80211_regdomain eu_regdom = {
158 	.n_reg_rules = 6,
159 	/* This alpha2 is bogus, we leave it here just for stupid
160 	 * backward compatibility */
161 	.alpha2 =  "EU",
162 	.reg_rules = {
163 		/* IEEE 802.11b/g, channels 1..13 */
164 		REG_RULE(2412-10, 2472+10, 40, 6, 20, 0),
165 		/* IEEE 802.11a, channel 36 */
166 		REG_RULE(5180-10, 5180+10, 40, 6, 23,
167 			NL80211_RRF_PASSIVE_SCAN),
168 		/* IEEE 802.11a, channel 40 */
169 		REG_RULE(5200-10, 5200+10, 40, 6, 23,
170 			NL80211_RRF_PASSIVE_SCAN),
171 		/* IEEE 802.11a, channel 44 */
172 		REG_RULE(5220-10, 5220+10, 40, 6, 23,
173 			NL80211_RRF_PASSIVE_SCAN),
174 		/* IEEE 802.11a, channels 48..64 */
175 		REG_RULE(5240-10, 5320+10, 40, 6, 20,
176 			NL80211_RRF_NO_IBSS |
177 			NL80211_RRF_DFS),
178 		/* IEEE 802.11a, channels 100..140 */
179 		REG_RULE(5500-10, 5700+10, 40, 6, 30,
180 			NL80211_RRF_NO_IBSS |
181 			NL80211_RRF_DFS),
182 	}
183 };
184 
185 static const struct ieee80211_regdomain *static_regdom(char *alpha2)
186 {
187 	if (alpha2[0] == 'U' && alpha2[1] == 'S')
188 		return &us_regdom;
189 	if (alpha2[0] == 'J' && alpha2[1] == 'P')
190 		return &jp_regdom;
191 	if (alpha2[0] == 'E' && alpha2[1] == 'U')
192 		return &eu_regdom;
193 	/* Default, as per the old rules */
194 	return &us_regdom;
195 }
196 
197 static bool is_old_static_regdom(const struct ieee80211_regdomain *rd)
198 {
199 	if (rd == &us_regdom || rd == &jp_regdom || rd == &eu_regdom)
200 		return true;
201 	return false;
202 }
203 #else
204 static inline bool is_old_static_regdom(const struct ieee80211_regdomain *rd)
205 {
206 	return false;
207 }
208 #endif
209 
210 static void reset_regdomains(void)
211 {
212 	/* avoid freeing static information or freeing something twice */
213 	if (cfg80211_regdomain == cfg80211_world_regdom)
214 		cfg80211_regdomain = NULL;
215 	if (cfg80211_world_regdom == &world_regdom)
216 		cfg80211_world_regdom = NULL;
217 	if (cfg80211_regdomain == &world_regdom)
218 		cfg80211_regdomain = NULL;
219 	if (is_old_static_regdom(cfg80211_regdomain))
220 		cfg80211_regdomain = NULL;
221 
222 	kfree(cfg80211_regdomain);
223 	kfree(cfg80211_world_regdom);
224 
225 	cfg80211_world_regdom = &world_regdom;
226 	cfg80211_regdomain = NULL;
227 }
228 
229 /* Dynamic world regulatory domain requested by the wireless
230  * core upon initialization */
231 static void update_world_regdomain(const struct ieee80211_regdomain *rd)
232 {
233 	BUG_ON(!last_request);
234 
235 	reset_regdomains();
236 
237 	cfg80211_world_regdom = rd;
238 	cfg80211_regdomain = rd;
239 }
240 
241 bool is_world_regdom(const char *alpha2)
242 {
243 	if (!alpha2)
244 		return false;
245 	if (alpha2[0] == '0' && alpha2[1] == '0')
246 		return true;
247 	return false;
248 }
249 
250 static bool is_alpha2_set(const char *alpha2)
251 {
252 	if (!alpha2)
253 		return false;
254 	if (alpha2[0] != 0 && alpha2[1] != 0)
255 		return true;
256 	return false;
257 }
258 
259 static bool is_alpha_upper(char letter)
260 {
261 	/* ASCII A - Z */
262 	if (letter >= 65 && letter <= 90)
263 		return true;
264 	return false;
265 }
266 
267 static bool is_unknown_alpha2(const char *alpha2)
268 {
269 	if (!alpha2)
270 		return false;
271 	/* Special case where regulatory domain was built by driver
272 	 * but a specific alpha2 cannot be determined */
273 	if (alpha2[0] == '9' && alpha2[1] == '9')
274 		return true;
275 	return false;
276 }
277 
278 static bool is_intersected_alpha2(const char *alpha2)
279 {
280 	if (!alpha2)
281 		return false;
282 	/* Special case where regulatory domain is the
283 	 * result of an intersection between two regulatory domain
284 	 * structures */
285 	if (alpha2[0] == '9' && alpha2[1] == '8')
286 		return true;
287 	return false;
288 }
289 
290 static bool is_an_alpha2(const char *alpha2)
291 {
292 	if (!alpha2)
293 		return false;
294 	if (is_alpha_upper(alpha2[0]) && is_alpha_upper(alpha2[1]))
295 		return true;
296 	return false;
297 }
298 
299 static bool alpha2_equal(const char *alpha2_x, const char *alpha2_y)
300 {
301 	if (!alpha2_x || !alpha2_y)
302 		return false;
303 	if (alpha2_x[0] == alpha2_y[0] &&
304 		alpha2_x[1] == alpha2_y[1])
305 		return true;
306 	return false;
307 }
308 
309 static bool regdom_changed(const char *alpha2)
310 {
311 	if (!cfg80211_regdomain)
312 		return true;
313 	if (alpha2_equal(cfg80211_regdomain->alpha2, alpha2))
314 		return false;
315 	return true;
316 }
317 
318 /**
319  * country_ie_integrity_changes - tells us if the country IE has changed
320  * @checksum: checksum of country IE of fields we are interested in
321  *
322  * If the country IE has not changed you can ignore it safely. This is
323  * useful to determine if two devices are seeing two different country IEs
324  * even on the same alpha2. Note that this will return false if no IE has
325  * been set on the wireless core yet.
326  */
327 static bool country_ie_integrity_changes(u32 checksum)
328 {
329 	/* If no IE has been set then the checksum doesn't change */
330 	if (unlikely(!last_request->country_ie_checksum))
331 		return false;
332 	if (unlikely(last_request->country_ie_checksum != checksum))
333 		return true;
334 	return false;
335 }
336 
337 /* This lets us keep regulatory code which is updated on a regulatory
338  * basis in userspace. */
339 static int call_crda(const char *alpha2)
340 {
341 	char country_env[9 + 2] = "COUNTRY=";
342 	char *envp[] = {
343 		country_env,
344 		NULL
345 	};
346 
347 	if (!is_world_regdom((char *) alpha2))
348 		printk(KERN_INFO "cfg80211: Calling CRDA for country: %c%c\n",
349 			alpha2[0], alpha2[1]);
350 	else
351 		printk(KERN_INFO "cfg80211: Calling CRDA to update world "
352 			"regulatory domain\n");
353 
354 	country_env[8] = alpha2[0];
355 	country_env[9] = alpha2[1];
356 
357 	return kobject_uevent_env(&reg_pdev->dev.kobj, KOBJ_CHANGE, envp);
358 }
359 
360 /* Used by nl80211 before kmalloc'ing our regulatory domain */
361 bool reg_is_valid_request(const char *alpha2)
362 {
363 	if (!last_request)
364 		return false;
365 
366 	return alpha2_equal(last_request->alpha2, alpha2);
367 }
368 
369 /* Sanity check on a regulatory rule */
370 static bool is_valid_reg_rule(const struct ieee80211_reg_rule *rule)
371 {
372 	const struct ieee80211_freq_range *freq_range = &rule->freq_range;
373 	u32 freq_diff;
374 
375 	if (freq_range->start_freq_khz <= 0 || freq_range->end_freq_khz <= 0)
376 		return false;
377 
378 	if (freq_range->start_freq_khz > freq_range->end_freq_khz)
379 		return false;
380 
381 	freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz;
382 
383 	if (freq_diff <= 0 || freq_range->max_bandwidth_khz > freq_diff)
384 		return false;
385 
386 	return true;
387 }
388 
389 static bool is_valid_rd(const struct ieee80211_regdomain *rd)
390 {
391 	const struct ieee80211_reg_rule *reg_rule = NULL;
392 	unsigned int i;
393 
394 	if (!rd->n_reg_rules)
395 		return false;
396 
397 	if (WARN_ON(rd->n_reg_rules > NL80211_MAX_SUPP_REG_RULES))
398 		return false;
399 
400 	for (i = 0; i < rd->n_reg_rules; i++) {
401 		reg_rule = &rd->reg_rules[i];
402 		if (!is_valid_reg_rule(reg_rule))
403 			return false;
404 	}
405 
406 	return true;
407 }
408 
409 /* Returns value in KHz */
410 static u32 freq_max_bandwidth(const struct ieee80211_freq_range *freq_range,
411 	u32 freq)
412 {
413 	unsigned int i;
414 	for (i = 0; i < ARRAY_SIZE(supported_bandwidths); i++) {
415 		u32 start_freq_khz = freq - supported_bandwidths[i]/2;
416 		u32 end_freq_khz = freq + supported_bandwidths[i]/2;
417 		if (start_freq_khz >= freq_range->start_freq_khz &&
418 			end_freq_khz <= freq_range->end_freq_khz)
419 			return supported_bandwidths[i];
420 	}
421 	return 0;
422 }
423 
424 /**
425  * freq_in_rule_band - tells us if a frequency is in a frequency band
426  * @freq_range: frequency rule we want to query
427  * @freq_khz: frequency we are inquiring about
428  *
429  * This lets us know if a specific frequency rule is or is not relevant to
430  * a specific frequency's band. Bands are device specific and artificial
431  * definitions (the "2.4 GHz band" and the "5 GHz band"), however it is
432  * safe for now to assume that a frequency rule should not be part of a
433  * frequency's band if the start freq or end freq are off by more than 2 GHz.
434  * This resolution can be lowered and should be considered as we add
435  * regulatory rule support for other "bands".
436  **/
437 static bool freq_in_rule_band(const struct ieee80211_freq_range *freq_range,
438 	u32 freq_khz)
439 {
440 #define ONE_GHZ_IN_KHZ	1000000
441 	if (abs(freq_khz - freq_range->start_freq_khz) <= (2 * ONE_GHZ_IN_KHZ))
442 		return true;
443 	if (abs(freq_khz - freq_range->end_freq_khz) <= (2 * ONE_GHZ_IN_KHZ))
444 		return true;
445 	return false;
446 #undef ONE_GHZ_IN_KHZ
447 }
448 
449 /* Converts a country IE to a regulatory domain. A regulatory domain
450  * structure has a lot of information which the IE doesn't yet have,
451  * so for the other values we use upper max values as we will intersect
452  * with our userspace regulatory agent to get lower bounds. */
453 static struct ieee80211_regdomain *country_ie_2_rd(
454 				u8 *country_ie,
455 				u8 country_ie_len,
456 				u32 *checksum)
457 {
458 	struct ieee80211_regdomain *rd = NULL;
459 	unsigned int i = 0;
460 	char alpha2[2];
461 	u32 flags = 0;
462 	u32 num_rules = 0, size_of_regd = 0;
463 	u8 *triplets_start = NULL;
464 	u8 len_at_triplet = 0;
465 	/* the last channel we have registered in a subband (triplet) */
466 	int last_sub_max_channel = 0;
467 
468 	*checksum = 0xDEADBEEF;
469 
470 	/* Country IE requirements */
471 	BUG_ON(country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN ||
472 		country_ie_len & 0x01);
473 
474 	alpha2[0] = country_ie[0];
475 	alpha2[1] = country_ie[1];
476 
477 	/*
478 	 * Third octet can be:
479 	 *    'I' - Indoor
480 	 *    'O' - Outdoor
481 	 *
482 	 *  anything else we assume is no restrictions
483 	 */
484 	if (country_ie[2] == 'I')
485 		flags = NL80211_RRF_NO_OUTDOOR;
486 	else if (country_ie[2] == 'O')
487 		flags = NL80211_RRF_NO_INDOOR;
488 
489 	country_ie += 3;
490 	country_ie_len -= 3;
491 
492 	triplets_start = country_ie;
493 	len_at_triplet = country_ie_len;
494 
495 	*checksum ^= ((flags ^ alpha2[0] ^ alpha2[1]) << 8);
496 
497 	/* We need to build a reg rule for each triplet, but first we must
498 	 * calculate the number of reg rules we will need. We will need one
499 	 * for each channel subband */
500 	while (country_ie_len >= 3) {
501 		int end_channel = 0;
502 		struct ieee80211_country_ie_triplet *triplet =
503 			(struct ieee80211_country_ie_triplet *) country_ie;
504 		int cur_sub_max_channel = 0, cur_channel = 0;
505 
506 		if (triplet->ext.reg_extension_id >=
507 				IEEE80211_COUNTRY_EXTENSION_ID) {
508 			country_ie += 3;
509 			country_ie_len -= 3;
510 			continue;
511 		}
512 
513 		/* 2 GHz */
514 		if (triplet->chans.first_channel <= 14)
515 			end_channel = triplet->chans.first_channel +
516 				triplet->chans.num_channels;
517 		else
518 			/*
519 			 * 5 GHz -- For example in country IEs if the first
520 			 * channel given is 36 and the number of channels is 4
521 			 * then the individual channel numbers defined for the
522 			 * 5 GHz PHY by these parameters are: 36, 40, 44, and 48
523 			 * and not 36, 37, 38, 39.
524 			 *
525 			 * See: http://tinyurl.com/11d-clarification
526 			 */
527 			end_channel =  triplet->chans.first_channel +
528 				(4 * (triplet->chans.num_channels - 1));
529 
530 		cur_channel = triplet->chans.first_channel;
531 		cur_sub_max_channel = end_channel;
532 
533 		/* Basic sanity check */
534 		if (cur_sub_max_channel < cur_channel)
535 			return NULL;
536 
537 		/* Do not allow overlapping channels. Also channels
538 		 * passed in each subband must be monotonically
539 		 * increasing */
540 		if (last_sub_max_channel) {
541 			if (cur_channel <= last_sub_max_channel)
542 				return NULL;
543 			if (cur_sub_max_channel <= last_sub_max_channel)
544 				return NULL;
545 		}
546 
547 		/* When dot11RegulatoryClassesRequired is supported
548 		 * we can throw ext triplets as part of this soup,
549 		 * for now we don't care when those change as we
550 		 * don't support them */
551 		*checksum ^= ((cur_channel ^ cur_sub_max_channel) << 8) |
552 		  ((cur_sub_max_channel ^ cur_sub_max_channel) << 16) |
553 		  ((triplet->chans.max_power ^ cur_sub_max_channel) << 24);
554 
555 		last_sub_max_channel = cur_sub_max_channel;
556 
557 		country_ie += 3;
558 		country_ie_len -= 3;
559 		num_rules++;
560 
561 		/* Note: this is not a IEEE requirement but
562 		 * simply a memory requirement */
563 		if (num_rules > NL80211_MAX_SUPP_REG_RULES)
564 			return NULL;
565 	}
566 
567 	country_ie = triplets_start;
568 	country_ie_len = len_at_triplet;
569 
570 	size_of_regd = sizeof(struct ieee80211_regdomain) +
571 		(num_rules * sizeof(struct ieee80211_reg_rule));
572 
573 	rd = kzalloc(size_of_regd, GFP_KERNEL);
574 	if (!rd)
575 		return NULL;
576 
577 	rd->n_reg_rules = num_rules;
578 	rd->alpha2[0] = alpha2[0];
579 	rd->alpha2[1] = alpha2[1];
580 
581 	/* This time around we fill in the rd */
582 	while (country_ie_len >= 3) {
583 		int end_channel = 0;
584 		struct ieee80211_country_ie_triplet *triplet =
585 			(struct ieee80211_country_ie_triplet *) country_ie;
586 		struct ieee80211_reg_rule *reg_rule = NULL;
587 		struct ieee80211_freq_range *freq_range = NULL;
588 		struct ieee80211_power_rule *power_rule = NULL;
589 
590 		/* Must parse if dot11RegulatoryClassesRequired is true,
591 		 * we don't support this yet */
592 		if (triplet->ext.reg_extension_id >=
593 				IEEE80211_COUNTRY_EXTENSION_ID) {
594 			country_ie += 3;
595 			country_ie_len -= 3;
596 			continue;
597 		}
598 
599 		reg_rule = &rd->reg_rules[i];
600 		freq_range = &reg_rule->freq_range;
601 		power_rule = &reg_rule->power_rule;
602 
603 		reg_rule->flags = flags;
604 
605 		/* 2 GHz */
606 		if (triplet->chans.first_channel <= 14)
607 			end_channel = triplet->chans.first_channel +
608 				triplet->chans.num_channels;
609 		else
610 			end_channel =  triplet->chans.first_channel +
611 				(4 * (triplet->chans.num_channels - 1));
612 
613 		/* The +10 is since the regulatory domain expects
614 		 * the actual band edge, not the center of freq for
615 		 * its start and end freqs, assuming 20 MHz bandwidth on
616 		 * the channels passed */
617 		freq_range->start_freq_khz =
618 			MHZ_TO_KHZ(ieee80211_channel_to_frequency(
619 				triplet->chans.first_channel) - 10);
620 		freq_range->end_freq_khz =
621 			MHZ_TO_KHZ(ieee80211_channel_to_frequency(
622 				end_channel) + 10);
623 
624 		/* Large arbitrary values, we intersect later */
625 		/* Increment this if we ever support >= 40 MHz channels
626 		 * in IEEE 802.11 */
627 		freq_range->max_bandwidth_khz = MHZ_TO_KHZ(40);
628 		power_rule->max_antenna_gain = DBI_TO_MBI(100);
629 		power_rule->max_eirp = DBM_TO_MBM(100);
630 
631 		country_ie += 3;
632 		country_ie_len -= 3;
633 		i++;
634 
635 		BUG_ON(i > NL80211_MAX_SUPP_REG_RULES);
636 	}
637 
638 	return rd;
639 }
640 
641 
642 /* Helper for regdom_intersect(), this does the real
643  * mathematical intersection fun */
644 static int reg_rules_intersect(
645 	const struct ieee80211_reg_rule *rule1,
646 	const struct ieee80211_reg_rule *rule2,
647 	struct ieee80211_reg_rule *intersected_rule)
648 {
649 	const struct ieee80211_freq_range *freq_range1, *freq_range2;
650 	struct ieee80211_freq_range *freq_range;
651 	const struct ieee80211_power_rule *power_rule1, *power_rule2;
652 	struct ieee80211_power_rule *power_rule;
653 	u32 freq_diff;
654 
655 	freq_range1 = &rule1->freq_range;
656 	freq_range2 = &rule2->freq_range;
657 	freq_range = &intersected_rule->freq_range;
658 
659 	power_rule1 = &rule1->power_rule;
660 	power_rule2 = &rule2->power_rule;
661 	power_rule = &intersected_rule->power_rule;
662 
663 	freq_range->start_freq_khz = max(freq_range1->start_freq_khz,
664 		freq_range2->start_freq_khz);
665 	freq_range->end_freq_khz = min(freq_range1->end_freq_khz,
666 		freq_range2->end_freq_khz);
667 	freq_range->max_bandwidth_khz = min(freq_range1->max_bandwidth_khz,
668 		freq_range2->max_bandwidth_khz);
669 
670 	freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz;
671 	if (freq_range->max_bandwidth_khz > freq_diff)
672 		freq_range->max_bandwidth_khz = freq_diff;
673 
674 	power_rule->max_eirp = min(power_rule1->max_eirp,
675 		power_rule2->max_eirp);
676 	power_rule->max_antenna_gain = min(power_rule1->max_antenna_gain,
677 		power_rule2->max_antenna_gain);
678 
679 	intersected_rule->flags = (rule1->flags | rule2->flags);
680 
681 	if (!is_valid_reg_rule(intersected_rule))
682 		return -EINVAL;
683 
684 	return 0;
685 }
686 
687 /**
688  * regdom_intersect - do the intersection between two regulatory domains
689  * @rd1: first regulatory domain
690  * @rd2: second regulatory domain
691  *
692  * Use this function to get the intersection between two regulatory domains.
693  * Once completed we will mark the alpha2 for the rd as intersected, "98",
694  * as no one single alpha2 can represent this regulatory domain.
695  *
696  * Returns a pointer to the regulatory domain structure which will hold the
697  * resulting intersection of rules between rd1 and rd2. We will
698  * kzalloc() this structure for you.
699  */
700 static struct ieee80211_regdomain *regdom_intersect(
701 	const struct ieee80211_regdomain *rd1,
702 	const struct ieee80211_regdomain *rd2)
703 {
704 	int r, size_of_regd;
705 	unsigned int x, y;
706 	unsigned int num_rules = 0, rule_idx = 0;
707 	const struct ieee80211_reg_rule *rule1, *rule2;
708 	struct ieee80211_reg_rule *intersected_rule;
709 	struct ieee80211_regdomain *rd;
710 	/* This is just a dummy holder to help us count */
711 	struct ieee80211_reg_rule irule;
712 
713 	/* Uses the stack temporarily for counter arithmetic */
714 	intersected_rule = &irule;
715 
716 	memset(intersected_rule, 0, sizeof(struct ieee80211_reg_rule));
717 
718 	if (!rd1 || !rd2)
719 		return NULL;
720 
721 	/* First we get a count of the rules we'll need, then we actually
722 	 * build them. This is to so we can malloc() and free() a
723 	 * regdomain once. The reason we use reg_rules_intersect() here
724 	 * is it will return -EINVAL if the rule computed makes no sense.
725 	 * All rules that do check out OK are valid. */
726 
727 	for (x = 0; x < rd1->n_reg_rules; x++) {
728 		rule1 = &rd1->reg_rules[x];
729 		for (y = 0; y < rd2->n_reg_rules; y++) {
730 			rule2 = &rd2->reg_rules[y];
731 			if (!reg_rules_intersect(rule1, rule2,
732 					intersected_rule))
733 				num_rules++;
734 			memset(intersected_rule, 0,
735 					sizeof(struct ieee80211_reg_rule));
736 		}
737 	}
738 
739 	if (!num_rules)
740 		return NULL;
741 
742 	size_of_regd = sizeof(struct ieee80211_regdomain) +
743 		((num_rules + 1) * sizeof(struct ieee80211_reg_rule));
744 
745 	rd = kzalloc(size_of_regd, GFP_KERNEL);
746 	if (!rd)
747 		return NULL;
748 
749 	for (x = 0; x < rd1->n_reg_rules; x++) {
750 		rule1 = &rd1->reg_rules[x];
751 		for (y = 0; y < rd2->n_reg_rules; y++) {
752 			rule2 = &rd2->reg_rules[y];
753 			/* This time around instead of using the stack lets
754 			 * write to the target rule directly saving ourselves
755 			 * a memcpy() */
756 			intersected_rule = &rd->reg_rules[rule_idx];
757 			r = reg_rules_intersect(rule1, rule2,
758 				intersected_rule);
759 			/* No need to memset here the intersected rule here as
760 			 * we're not using the stack anymore */
761 			if (r)
762 				continue;
763 			rule_idx++;
764 		}
765 	}
766 
767 	if (rule_idx != num_rules) {
768 		kfree(rd);
769 		return NULL;
770 	}
771 
772 	rd->n_reg_rules = num_rules;
773 	rd->alpha2[0] = '9';
774 	rd->alpha2[1] = '8';
775 
776 	return rd;
777 }
778 
779 /* XXX: add support for the rest of enum nl80211_reg_rule_flags, we may
780  * want to just have the channel structure use these */
781 static u32 map_regdom_flags(u32 rd_flags)
782 {
783 	u32 channel_flags = 0;
784 	if (rd_flags & NL80211_RRF_PASSIVE_SCAN)
785 		channel_flags |= IEEE80211_CHAN_PASSIVE_SCAN;
786 	if (rd_flags & NL80211_RRF_NO_IBSS)
787 		channel_flags |= IEEE80211_CHAN_NO_IBSS;
788 	if (rd_flags & NL80211_RRF_DFS)
789 		channel_flags |= IEEE80211_CHAN_RADAR;
790 	return channel_flags;
791 }
792 
793 /**
794  * freq_reg_info - get regulatory information for the given frequency
795  * @center_freq: Frequency in KHz for which we want regulatory information for
796  * @bandwidth: the bandwidth requirement you have in KHz, if you do not have one
797  * 	you can set this to 0. If this frequency is allowed we then set
798  * 	this value to the maximum allowed bandwidth.
799  * @reg_rule: the regulatory rule which we have for this frequency
800  *
801  * Use this function to get the regulatory rule for a specific frequency on
802  * a given wireless device. If the device has a specific regulatory domain
803  * it wants to follow we respect that unless a country IE has been received
804  * and processed already.
805  *
806  * Returns 0 if it was able to find a valid regulatory rule which does
807  * apply to the given center_freq otherwise it returns non-zero. It will
808  * also return -ERANGE if we determine the given center_freq does not even have
809  * a regulatory rule for a frequency range in the center_freq's band. See
810  * freq_in_rule_band() for our current definition of a band -- this is purely
811  * subjective and right now its 802.11 specific.
812  */
813 static int freq_reg_info(u32 center_freq, u32 *bandwidth,
814 			 const struct ieee80211_reg_rule **reg_rule)
815 {
816 	int i;
817 	bool band_rule_found = false;
818 	u32 max_bandwidth = 0;
819 
820 	if (!cfg80211_regdomain)
821 		return -EINVAL;
822 
823 	for (i = 0; i < cfg80211_regdomain->n_reg_rules; i++) {
824 		const struct ieee80211_reg_rule *rr;
825 		const struct ieee80211_freq_range *fr = NULL;
826 		const struct ieee80211_power_rule *pr = NULL;
827 
828 		rr = &cfg80211_regdomain->reg_rules[i];
829 		fr = &rr->freq_range;
830 		pr = &rr->power_rule;
831 
832 		/* We only need to know if one frequency rule was
833 		 * was in center_freq's band, that's enough, so lets
834 		 * not overwrite it once found */
835 		if (!band_rule_found)
836 			band_rule_found = freq_in_rule_band(fr, center_freq);
837 
838 		max_bandwidth = freq_max_bandwidth(fr, center_freq);
839 
840 		if (max_bandwidth && *bandwidth <= max_bandwidth) {
841 			*reg_rule = rr;
842 			*bandwidth = max_bandwidth;
843 			break;
844 		}
845 	}
846 
847 	if (!band_rule_found)
848 		return -ERANGE;
849 
850 	return !max_bandwidth;
851 }
852 
853 static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band,
854 			   unsigned int chan_idx)
855 {
856 	int r;
857 	u32 flags;
858 	u32 max_bandwidth = 0;
859 	const struct ieee80211_reg_rule *reg_rule = NULL;
860 	const struct ieee80211_power_rule *power_rule = NULL;
861 	struct ieee80211_supported_band *sband;
862 	struct ieee80211_channel *chan;
863 
864 	sband = wiphy->bands[band];
865 	BUG_ON(chan_idx >= sband->n_channels);
866 	chan = &sband->channels[chan_idx];
867 
868 	flags = chan->orig_flags;
869 
870 	r = freq_reg_info(MHZ_TO_KHZ(chan->center_freq),
871 		&max_bandwidth, &reg_rule);
872 
873 	if (r) {
874 		/* This means no regulatory rule was found in the country IE
875 		 * with a frequency range on the center_freq's band, since
876 		 * IEEE-802.11 allows for a country IE to have a subset of the
877 		 * regulatory information provided in a country we ignore
878 		 * disabling the channel unless at least one reg rule was
879 		 * found on the center_freq's band. For details see this
880 		 * clarification:
881 		 *
882 		 * http://tinyurl.com/11d-clarification
883 		 */
884 		if (r == -ERANGE &&
885 		    last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
886 #ifdef CONFIG_CFG80211_REG_DEBUG
887 			printk(KERN_DEBUG "cfg80211: Leaving channel %d MHz "
888 				"intact on %s - no rule found in band on "
889 				"Country IE\n",
890 				chan->center_freq, wiphy_name(wiphy));
891 #endif
892 		} else {
893 		/* In this case we know the country IE has at least one reg rule
894 		 * for the band so we respect its band definitions */
895 #ifdef CONFIG_CFG80211_REG_DEBUG
896 			if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE)
897 				printk(KERN_DEBUG "cfg80211: Disabling "
898 					"channel %d MHz on %s due to "
899 					"Country IE\n",
900 					chan->center_freq, wiphy_name(wiphy));
901 #endif
902 			flags |= IEEE80211_CHAN_DISABLED;
903 			chan->flags = flags;
904 		}
905 		return;
906 	}
907 
908 	power_rule = &reg_rule->power_rule;
909 
910 	chan->flags = flags | map_regdom_flags(reg_rule->flags);
911 	chan->max_antenna_gain = min(chan->orig_mag,
912 		(int) MBI_TO_DBI(power_rule->max_antenna_gain));
913 	chan->max_bandwidth = KHZ_TO_MHZ(max_bandwidth);
914 	if (chan->orig_mpwr)
915 		chan->max_power = min(chan->orig_mpwr,
916 			(int) MBM_TO_DBM(power_rule->max_eirp));
917 	else
918 		chan->max_power = (int) MBM_TO_DBM(power_rule->max_eirp);
919 }
920 
921 static void handle_band(struct wiphy *wiphy, enum ieee80211_band band)
922 {
923 	unsigned int i;
924 	struct ieee80211_supported_band *sband;
925 
926 	BUG_ON(!wiphy->bands[band]);
927 	sband = wiphy->bands[band];
928 
929 	for (i = 0; i < sband->n_channels; i++)
930 		handle_channel(wiphy, band, i);
931 }
932 
933 static bool ignore_reg_update(struct wiphy *wiphy, enum reg_set_by setby)
934 {
935 	if (!last_request)
936 		return true;
937 	if (setby == REGDOM_SET_BY_CORE &&
938 		  wiphy->fw_handles_regulatory)
939 		return true;
940 	return false;
941 }
942 
943 static void update_all_wiphy_regulatory(enum reg_set_by setby)
944 {
945 	struct cfg80211_registered_device *drv;
946 
947 	list_for_each_entry(drv, &cfg80211_drv_list, list)
948 		if (!ignore_reg_update(&drv->wiphy, setby))
949 			wiphy_update_regulatory(&drv->wiphy, setby);
950 }
951 
952 void wiphy_update_regulatory(struct wiphy *wiphy, enum reg_set_by setby)
953 {
954 	enum ieee80211_band band;
955 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
956 		if (wiphy->bands[band])
957 			handle_band(wiphy, band);
958 		if (wiphy->reg_notifier)
959 			wiphy->reg_notifier(wiphy, setby);
960 	}
961 }
962 
963 /* Return value which can be used by ignore_request() to indicate
964  * it has been determined we should intersect two regulatory domains */
965 #define REG_INTERSECT	1
966 
967 /* This has the logic which determines when a new request
968  * should be ignored. */
969 static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
970 			  const char *alpha2)
971 {
972 	/* All initial requests are respected */
973 	if (!last_request)
974 		return 0;
975 
976 	switch (set_by) {
977 	case REGDOM_SET_BY_INIT:
978 		return -EINVAL;
979 	case REGDOM_SET_BY_CORE:
980 		/*
981 		 * Always respect new wireless core hints, should only happen
982 		 * when updating the world regulatory domain at init.
983 		 */
984 		return 0;
985 	case REGDOM_SET_BY_COUNTRY_IE:
986 		if (unlikely(!is_an_alpha2(alpha2)))
987 			return -EINVAL;
988 		if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
989 			if (last_request->wiphy != wiphy) {
990 				/*
991 				 * Two cards with two APs claiming different
992 				 * different Country IE alpha2s. We could
993 				 * intersect them, but that seems unlikely
994 				 * to be correct. Reject second one for now.
995 				 */
996 				if (!alpha2_equal(alpha2,
997 						  cfg80211_regdomain->alpha2))
998 					return -EOPNOTSUPP;
999 				return -EALREADY;
1000 			}
1001 			/* Two consecutive Country IE hints on the same wiphy.
1002 			 * This should be picked up early by the driver/stack */
1003 			if (WARN_ON(!alpha2_equal(cfg80211_regdomain->alpha2,
1004 				  alpha2)))
1005 				return 0;
1006 			return -EALREADY;
1007 		}
1008 		return REG_INTERSECT;
1009 	case REGDOM_SET_BY_DRIVER:
1010 		if (last_request->initiator == REGDOM_SET_BY_DRIVER)
1011 			return -EALREADY;
1012 		return 0;
1013 	case REGDOM_SET_BY_USER:
1014 		if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE)
1015 			return REG_INTERSECT;
1016 		/* If the user knows better the user should set the regdom
1017 		 * to their country before the IE is picked up */
1018 		if (last_request->initiator == REGDOM_SET_BY_USER &&
1019 			  last_request->intersect)
1020 			return -EOPNOTSUPP;
1021 		return 0;
1022 	}
1023 
1024 	return -EINVAL;
1025 }
1026 
1027 /* Caller must hold &cfg80211_drv_mutex */
1028 int __regulatory_hint(struct wiphy *wiphy, enum reg_set_by set_by,
1029 			const char *alpha2,
1030 			u32 country_ie_checksum,
1031 			enum environment_cap env)
1032 {
1033 	struct regulatory_request *request;
1034 	bool intersect = false;
1035 	int r = 0;
1036 
1037 	r = ignore_request(wiphy, set_by, alpha2);
1038 
1039 	if (r == REG_INTERSECT)
1040 		intersect = true;
1041 	else if (r)
1042 		return r;
1043 
1044 	request = kzalloc(sizeof(struct regulatory_request),
1045 			  GFP_KERNEL);
1046 	if (!request)
1047 		return -ENOMEM;
1048 
1049 	request->alpha2[0] = alpha2[0];
1050 	request->alpha2[1] = alpha2[1];
1051 	request->initiator = set_by;
1052 	request->wiphy = wiphy;
1053 	request->intersect = intersect;
1054 	request->country_ie_checksum = country_ie_checksum;
1055 	request->country_ie_env = env;
1056 
1057 	kfree(last_request);
1058 	last_request = request;
1059 	/*
1060 	 * Note: When CONFIG_WIRELESS_OLD_REGULATORY is enabled
1061 	 * AND if CRDA is NOT present nothing will happen, if someone
1062 	 * wants to bother with 11d with OLD_REG you can add a timer.
1063 	 * If after x amount of time nothing happens you can call:
1064 	 *
1065 	 * return set_regdom(country_ie_regdomain);
1066 	 *
1067 	 * to intersect with the static rd
1068 	 */
1069 	return call_crda(alpha2);
1070 }
1071 
1072 void regulatory_hint(struct wiphy *wiphy, const char *alpha2)
1073 {
1074 	BUG_ON(!alpha2);
1075 
1076 	mutex_lock(&cfg80211_drv_mutex);
1077 	__regulatory_hint(wiphy, REGDOM_SET_BY_DRIVER, alpha2, 0, ENVIRON_ANY);
1078 	mutex_unlock(&cfg80211_drv_mutex);
1079 }
1080 EXPORT_SYMBOL(regulatory_hint);
1081 
1082 static bool reg_same_country_ie_hint(struct wiphy *wiphy,
1083 			u32 country_ie_checksum)
1084 {
1085 	if (!last_request->wiphy)
1086 		return false;
1087 	if (likely(last_request->wiphy != wiphy))
1088 		return !country_ie_integrity_changes(country_ie_checksum);
1089 	/* We should not have let these through at this point, they
1090 	 * should have been picked up earlier by the first alpha2 check
1091 	 * on the device */
1092 	if (WARN_ON(!country_ie_integrity_changes(country_ie_checksum)))
1093 		return true;
1094 	return false;
1095 }
1096 
1097 void regulatory_hint_11d(struct wiphy *wiphy,
1098 			u8 *country_ie,
1099 			u8 country_ie_len)
1100 {
1101 	struct ieee80211_regdomain *rd = NULL;
1102 	char alpha2[2];
1103 	u32 checksum = 0;
1104 	enum environment_cap env = ENVIRON_ANY;
1105 
1106 	if (!last_request)
1107 		return;
1108 
1109 	mutex_lock(&cfg80211_drv_mutex);
1110 
1111 	/* IE len must be evenly divisible by 2 */
1112 	if (country_ie_len & 0x01)
1113 		goto out;
1114 
1115 	if (country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN)
1116 		goto out;
1117 
1118 	/* Pending country IE processing, this can happen after we
1119 	 * call CRDA and wait for a response if a beacon was received before
1120 	 * we were able to process the last regulatory_hint_11d() call */
1121 	if (country_ie_regdomain)
1122 		goto out;
1123 
1124 	alpha2[0] = country_ie[0];
1125 	alpha2[1] = country_ie[1];
1126 
1127 	if (country_ie[2] == 'I')
1128 		env = ENVIRON_INDOOR;
1129 	else if (country_ie[2] == 'O')
1130 		env = ENVIRON_OUTDOOR;
1131 
1132 	/* We will run this for *every* beacon processed for the BSSID, so
1133 	 * we optimize an early check to exit out early if we don't have to
1134 	 * do anything */
1135 	if (likely(last_request->wiphy)) {
1136 		struct cfg80211_registered_device *drv_last_ie;
1137 
1138 		drv_last_ie = wiphy_to_dev(last_request->wiphy);
1139 
1140 		/* Lets keep this simple -- we trust the first AP
1141 		 * after we intersect with CRDA */
1142 		if (likely(last_request->wiphy == wiphy)) {
1143 			/* Ignore IEs coming in on this wiphy with
1144 			 * the same alpha2 and environment cap */
1145 			if (likely(alpha2_equal(drv_last_ie->country_ie_alpha2,
1146 				  alpha2) &&
1147 				  env == drv_last_ie->env)) {
1148 				goto out;
1149 			}
1150 			/* the wiphy moved on to another BSSID or the AP
1151 			 * was reconfigured. XXX: We need to deal with the
1152 			 * case where the user suspends and goes to goes
1153 			 * to another country, and then gets IEs from an
1154 			 * AP with different settings */
1155 			goto out;
1156 		} else {
1157 			/* Ignore IEs coming in on two separate wiphys with
1158 			 * the same alpha2 and environment cap */
1159 			if (likely(alpha2_equal(drv_last_ie->country_ie_alpha2,
1160 				  alpha2) &&
1161 				  env == drv_last_ie->env)) {
1162 				goto out;
1163 			}
1164 			/* We could potentially intersect though */
1165 			goto out;
1166 		}
1167 	}
1168 
1169 	rd = country_ie_2_rd(country_ie, country_ie_len, &checksum);
1170 	if (!rd)
1171 		goto out;
1172 
1173 	/* This will not happen right now but we leave it here for the
1174 	 * the future when we want to add suspend/resume support and having
1175 	 * the user move to another country after doing so, or having the user
1176 	 * move to another AP. Right now we just trust the first AP. This is why
1177 	 * this is marked as likley(). If we hit this before we add this support
1178 	 * we want to be informed of it as it would indicate a mistake in the
1179 	 * current design  */
1180 	if (likely(WARN_ON(reg_same_country_ie_hint(wiphy, checksum))))
1181 		goto out;
1182 
1183 	/* We keep this around for when CRDA comes back with a response so
1184 	 * we can intersect with that */
1185 	country_ie_regdomain = rd;
1186 
1187 	__regulatory_hint(wiphy, REGDOM_SET_BY_COUNTRY_IE,
1188 		country_ie_regdomain->alpha2, checksum, env);
1189 
1190 out:
1191 	mutex_unlock(&cfg80211_drv_mutex);
1192 }
1193 EXPORT_SYMBOL(regulatory_hint_11d);
1194 
1195 static void print_rd_rules(const struct ieee80211_regdomain *rd)
1196 {
1197 	unsigned int i;
1198 	const struct ieee80211_reg_rule *reg_rule = NULL;
1199 	const struct ieee80211_freq_range *freq_range = NULL;
1200 	const struct ieee80211_power_rule *power_rule = NULL;
1201 
1202 	printk(KERN_INFO "\t(start_freq - end_freq @ bandwidth), "
1203 		"(max_antenna_gain, max_eirp)\n");
1204 
1205 	for (i = 0; i < rd->n_reg_rules; i++) {
1206 		reg_rule = &rd->reg_rules[i];
1207 		freq_range = &reg_rule->freq_range;
1208 		power_rule = &reg_rule->power_rule;
1209 
1210 		/* There may not be documentation for max antenna gain
1211 		 * in certain regions */
1212 		if (power_rule->max_antenna_gain)
1213 			printk(KERN_INFO "\t(%d KHz - %d KHz @ %d KHz), "
1214 				"(%d mBi, %d mBm)\n",
1215 				freq_range->start_freq_khz,
1216 				freq_range->end_freq_khz,
1217 				freq_range->max_bandwidth_khz,
1218 				power_rule->max_antenna_gain,
1219 				power_rule->max_eirp);
1220 		else
1221 			printk(KERN_INFO "\t(%d KHz - %d KHz @ %d KHz), "
1222 				"(N/A, %d mBm)\n",
1223 				freq_range->start_freq_khz,
1224 				freq_range->end_freq_khz,
1225 				freq_range->max_bandwidth_khz,
1226 				power_rule->max_eirp);
1227 	}
1228 }
1229 
1230 static void print_regdomain(const struct ieee80211_regdomain *rd)
1231 {
1232 
1233 	if (is_intersected_alpha2(rd->alpha2)) {
1234 		struct wiphy *wiphy = NULL;
1235 		struct cfg80211_registered_device *drv;
1236 
1237 		if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
1238 			if (last_request->wiphy) {
1239 				wiphy = last_request->wiphy;
1240 				drv = wiphy_to_dev(wiphy);
1241 				printk(KERN_INFO "cfg80211: Current regulatory "
1242 					"domain updated by AP to: %c%c\n",
1243 					drv->country_ie_alpha2[0],
1244 					drv->country_ie_alpha2[1]);
1245 			} else
1246 				printk(KERN_INFO "cfg80211: Current regulatory "
1247 					"domain intersected: \n");
1248 		} else
1249 				printk(KERN_INFO "cfg80211: Current regulatory "
1250 					"intersected: \n");
1251 	} else if (is_world_regdom(rd->alpha2))
1252 		printk(KERN_INFO "cfg80211: World regulatory "
1253 			"domain updated:\n");
1254 	else {
1255 		if (is_unknown_alpha2(rd->alpha2))
1256 			printk(KERN_INFO "cfg80211: Regulatory domain "
1257 				"changed to driver built-in settings "
1258 				"(unknown country)\n");
1259 		else
1260 			printk(KERN_INFO "cfg80211: Regulatory domain "
1261 				"changed to country: %c%c\n",
1262 				rd->alpha2[0], rd->alpha2[1]);
1263 	}
1264 	print_rd_rules(rd);
1265 }
1266 
1267 static void print_regdomain_info(const struct ieee80211_regdomain *rd)
1268 {
1269 	printk(KERN_INFO "cfg80211: Regulatory domain: %c%c\n",
1270 		rd->alpha2[0], rd->alpha2[1]);
1271 	print_rd_rules(rd);
1272 }
1273 
1274 #ifdef CONFIG_CFG80211_REG_DEBUG
1275 static void reg_country_ie_process_debug(
1276 	const struct ieee80211_regdomain *rd,
1277 	const struct ieee80211_regdomain *country_ie_regdomain,
1278 	const struct ieee80211_regdomain *intersected_rd)
1279 {
1280 	printk(KERN_DEBUG "cfg80211: Received country IE:\n");
1281 	print_regdomain_info(country_ie_regdomain);
1282 	printk(KERN_DEBUG "cfg80211: CRDA thinks this should applied:\n");
1283 	print_regdomain_info(rd);
1284 	if (intersected_rd) {
1285 		printk(KERN_DEBUG "cfg80211: We intersect both of these "
1286 			"and get:\n");
1287 		print_regdomain_info(intersected_rd);
1288 		return;
1289 	}
1290 	printk(KERN_DEBUG "cfg80211: Intersection between both failed\n");
1291 }
1292 #else
1293 static inline void reg_country_ie_process_debug(
1294 	const struct ieee80211_regdomain *rd,
1295 	const struct ieee80211_regdomain *country_ie_regdomain,
1296 	const struct ieee80211_regdomain *intersected_rd)
1297 {
1298 }
1299 #endif
1300 
1301 /* Takes ownership of rd only if it doesn't fail */
1302 static int __set_regdom(const struct ieee80211_regdomain *rd)
1303 {
1304 	const struct ieee80211_regdomain *intersected_rd = NULL;
1305 	struct cfg80211_registered_device *drv = NULL;
1306 	struct wiphy *wiphy = NULL;
1307 	/* Some basic sanity checks first */
1308 
1309 	if (is_world_regdom(rd->alpha2)) {
1310 		if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
1311 			return -EINVAL;
1312 		update_world_regdomain(rd);
1313 		return 0;
1314 	}
1315 
1316 	if (!is_alpha2_set(rd->alpha2) && !is_an_alpha2(rd->alpha2) &&
1317 			!is_unknown_alpha2(rd->alpha2))
1318 		return -EINVAL;
1319 
1320 	if (!last_request)
1321 		return -EINVAL;
1322 
1323 	/* Lets only bother proceeding on the same alpha2 if the current
1324 	 * rd is non static (it means CRDA was present and was used last)
1325 	 * and the pending request came in from a country IE */
1326 	if (last_request->initiator != REGDOM_SET_BY_COUNTRY_IE) {
1327 		/* If someone else asked us to change the rd lets only bother
1328 		 * checking if the alpha2 changes if CRDA was already called */
1329 		if (!is_old_static_regdom(cfg80211_regdomain) &&
1330 		    !regdom_changed(rd->alpha2))
1331 			return -EINVAL;
1332 	}
1333 
1334 	wiphy = last_request->wiphy;
1335 
1336 	/* Now lets set the regulatory domain, update all driver channels
1337 	 * and finally inform them of what we have done, in case they want
1338 	 * to review or adjust their own settings based on their own
1339 	 * internal EEPROM data */
1340 
1341 	if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
1342 		return -EINVAL;
1343 
1344 	if (!is_valid_rd(rd)) {
1345 		printk(KERN_ERR "cfg80211: Invalid "
1346 			"regulatory domain detected:\n");
1347 		print_regdomain_info(rd);
1348 		return -EINVAL;
1349 	}
1350 
1351 	if (!last_request->intersect) {
1352 		reset_regdomains();
1353 		cfg80211_regdomain = rd;
1354 		return 0;
1355 	}
1356 
1357 	/* Intersection requires a bit more work */
1358 
1359 	if (last_request->initiator != REGDOM_SET_BY_COUNTRY_IE) {
1360 
1361 		intersected_rd = regdom_intersect(rd, cfg80211_regdomain);
1362 		if (!intersected_rd)
1363 			return -EINVAL;
1364 
1365 		/* We can trash what CRDA provided now */
1366 		kfree(rd);
1367 		rd = NULL;
1368 
1369 		reset_regdomains();
1370 		cfg80211_regdomain = intersected_rd;
1371 
1372 		return 0;
1373 	}
1374 
1375 	/*
1376 	 * Country IE requests are handled a bit differently, we intersect
1377 	 * the country IE rd with what CRDA believes that country should have
1378 	 */
1379 
1380 	BUG_ON(!country_ie_regdomain);
1381 
1382 	if (rd != country_ie_regdomain) {
1383 		/* Intersect what CRDA returned and our what we
1384 		 * had built from the Country IE received */
1385 
1386 		intersected_rd = regdom_intersect(rd, country_ie_regdomain);
1387 
1388 		reg_country_ie_process_debug(rd, country_ie_regdomain,
1389 			intersected_rd);
1390 
1391 		kfree(country_ie_regdomain);
1392 		country_ie_regdomain = NULL;
1393 	} else {
1394 		/* This would happen when CRDA was not present and
1395 		 * OLD_REGULATORY was enabled. We intersect our Country
1396 		 * IE rd and what was set on cfg80211 originally */
1397 		intersected_rd = regdom_intersect(rd, cfg80211_regdomain);
1398 	}
1399 
1400 	if (!intersected_rd)
1401 		return -EINVAL;
1402 
1403 	drv = wiphy_to_dev(wiphy);
1404 
1405 	drv->country_ie_alpha2[0] = rd->alpha2[0];
1406 	drv->country_ie_alpha2[1] = rd->alpha2[1];
1407 	drv->env = last_request->country_ie_env;
1408 
1409 	BUG_ON(intersected_rd == rd);
1410 
1411 	kfree(rd);
1412 	rd = NULL;
1413 
1414 	reset_regdomains();
1415 	cfg80211_regdomain = intersected_rd;
1416 
1417 	return 0;
1418 }
1419 
1420 
1421 /* Use this call to set the current regulatory domain. Conflicts with
1422  * multiple drivers can be ironed out later. Caller must've already
1423  * kmalloc'd the rd structure. Caller must hold cfg80211_drv_mutex */
1424 int set_regdom(const struct ieee80211_regdomain *rd)
1425 {
1426 	int r;
1427 
1428 	/* Note that this doesn't update the wiphys, this is done below */
1429 	r = __set_regdom(rd);
1430 	if (r) {
1431 		kfree(rd);
1432 		return r;
1433 	}
1434 
1435 	/* This would make this whole thing pointless */
1436 	if (!last_request->intersect)
1437 		BUG_ON(rd != cfg80211_regdomain);
1438 
1439 	/* update all wiphys now with the new established regulatory domain */
1440 	update_all_wiphy_regulatory(last_request->initiator);
1441 
1442 	print_regdomain(cfg80211_regdomain);
1443 
1444 	return r;
1445 }
1446 
1447 /* Caller must hold cfg80211_drv_mutex */
1448 void reg_device_remove(struct wiphy *wiphy)
1449 {
1450 	if (!last_request || !last_request->wiphy)
1451 		return;
1452 	if (last_request->wiphy != wiphy)
1453 		return;
1454 	last_request->wiphy = NULL;
1455 	last_request->country_ie_env = ENVIRON_ANY;
1456 }
1457 
1458 int regulatory_init(void)
1459 {
1460 	int err;
1461 
1462 	reg_pdev = platform_device_register_simple("regulatory", 0, NULL, 0);
1463 	if (IS_ERR(reg_pdev))
1464 		return PTR_ERR(reg_pdev);
1465 
1466 #ifdef CONFIG_WIRELESS_OLD_REGULATORY
1467 	cfg80211_regdomain = static_regdom(ieee80211_regdom);
1468 
1469 	printk(KERN_INFO "cfg80211: Using static regulatory domain info\n");
1470 	print_regdomain_info(cfg80211_regdomain);
1471 	/* The old code still requests for a new regdomain and if
1472 	 * you have CRDA you get it updated, otherwise you get
1473 	 * stuck with the static values. We ignore "EU" code as
1474 	 * that is not a valid ISO / IEC 3166 alpha2 */
1475 	if (ieee80211_regdom[0] != 'E' || ieee80211_regdom[1] != 'U')
1476 		err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE,
1477 					ieee80211_regdom, 0, ENVIRON_ANY);
1478 #else
1479 	cfg80211_regdomain = cfg80211_world_regdom;
1480 
1481 	err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE, "00", 0, ENVIRON_ANY);
1482 	if (err)
1483 		printk(KERN_ERR "cfg80211: calling CRDA failed - "
1484 		       "unable to update world regulatory domain, "
1485 		       "using static definition\n");
1486 #endif
1487 
1488 	return 0;
1489 }
1490 
1491 void regulatory_exit(void)
1492 {
1493 	mutex_lock(&cfg80211_drv_mutex);
1494 
1495 	reset_regdomains();
1496 
1497 	kfree(country_ie_regdomain);
1498 	country_ie_regdomain = NULL;
1499 
1500 	kfree(last_request);
1501 
1502 	platform_device_unregister(reg_pdev);
1503 
1504 	mutex_unlock(&cfg80211_drv_mutex);
1505 }
1506