drivers/net/wireless/ath/regd.c

   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/slab.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, 0x6A and 0x68 */
 102 static const struct ieee80211_regdomain ath_world_regdom_67_68_6A = {
 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                 return &ath_world_regdom_67_68_6A;
 156         default:
 157                 WARN_ON(1);
 158                 return ath_default_world_regdomain();
 159         }
 160 }
 161
 162 /* Frequency is one where radar detection is required */
 163 static bool ath_is_radar_freq(u16 center_freq)
 164 {
 165         return (center_freq >= 5260 && center_freq <= 5700);
 166 }
 167
 168 /*
 169  * N.B: These exception rules do not apply radar freqs.
 170  *
 171  * - We enable adhoc (or beaconing) if allowed by 11d
 172  * - We enable active scan if the channel is allowed by 11d
 173  * - If no country IE has been processed and a we determine we have
 174  *   received a beacon on a channel we can enable active scan and
 175  *   adhoc (or beaconing).
 176  */
 177 static void
 178 ath_reg_apply_beaconing_flags(struct wiphy *wiphy,
 179                               enum nl80211_reg_initiator initiator)
 180 {
 181         enum ieee80211_band band;
 182         struct ieee80211_supported_band *sband;
 183         const struct ieee80211_reg_rule *reg_rule;
 184         struct ieee80211_channel *ch;
 185         unsigned int i;
 186         u32 bandwidth = 0;
 187         int r;
 188
 189         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 190
 191                 if (!wiphy->bands[band])
 192                         continue;
 193
 194                 sband = wiphy->bands[band];
 195
 196                 for (i = 0; i < sband->n_channels; i++) {
 197
 198                         ch = &sband->channels[i];
 199
 200                         if (ath_is_radar_freq(ch->center_freq) ||
 201                             (ch->flags & IEEE80211_CHAN_RADAR))
 202                                 continue;
 203
 204                         if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
 205                                 r = freq_reg_info(wiphy,
 206                                                   ch->center_freq,
 207                                                   bandwidth,
 208                                                   &reg_rule);
 209                                 if (r)
 210                                         continue;
 211                                 /*
 212                                  * If 11d had a rule for this channel ensure
 213                                  * we enable adhoc/beaconing if it allows us to
 214                                  * use it. Note that we would have disabled it
 215                                  * by applying our static world regdomain by
 216                                  * default during init, prior to calling our
 217                                  * regulatory_hint().
 218                                  */
 219                                 if (!(reg_rule->flags &
 220                                     NL80211_RRF_NO_IBSS))
 221                                         ch->flags &=
 222                                           ~IEEE80211_CHAN_NO_IBSS;
 223                                 if (!(reg_rule->flags &
 224                                     NL80211_RRF_PASSIVE_SCAN))
 225                                         ch->flags &=
 226                                           ~IEEE80211_CHAN_PASSIVE_SCAN;
 227                         } else {
 228                                 if (ch->beacon_found)
 229                                         ch->flags &= ~(IEEE80211_CHAN_NO_IBSS |
 230                                           IEEE80211_CHAN_PASSIVE_SCAN);
 231                         }
 232                 }
 233         }
 234
 235 }
 236
 237 /* Allows active scan scan on Ch 12 and 13 */
 238 static void
 239 ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
 240                                 enum nl80211_reg_initiator initiator)
 241 {
 242         struct ieee80211_supported_band *sband;
 243         struct ieee80211_channel *ch;
 244         const struct ieee80211_reg_rule *reg_rule;
 245         u32 bandwidth = 0;
 246         int r;
 247
 248         sband = wiphy->bands[IEEE80211_BAND_2GHZ];
 249
 250         /*
 251          * If no country IE has been received always enable active scan
 252          * on these channels. This is only done for specific regulatory SKUs
 253          */
 254         if (initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
 255                 ch = &sband->channels[11]; /* CH 12 */
 256                 if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 257                         ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
 258                 ch = &sband->channels[12]; /* CH 13 */
 259                 if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 260                         ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
 261                 return;
 262         }
 263
 264         /*
 265          * If a country IE has been recieved check its rule for this
 266          * channel first before enabling active scan. The passive scan
 267          * would have been enforced by the initial processing of our
 268          * custom regulatory domain.
 269          */
 270
 271         ch = &sband->channels[11]; /* CH 12 */
 272         r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
 273         if (!r) {
 274                 if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
 275                         if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 276                                 ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
 277         }
 278
 279         ch = &sband->channels[12]; /* CH 13 */
 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
 288 /* Always apply Radar/DFS rules on freq range 5260 MHz - 5700 MHz */
 289 static void ath_reg_apply_radar_flags(struct wiphy *wiphy)
 290 {
 291         struct ieee80211_supported_band *sband;
 292         struct ieee80211_channel *ch;
 293         unsigned int i;
 294
 295         if (!wiphy->bands[IEEE80211_BAND_5GHZ])
 296                 return;
 297
 298         sband = wiphy->bands[IEEE80211_BAND_5GHZ];
 299
 300         for (i = 0; i < sband->n_channels; i++) {
 301                 ch = &sband->channels[i];
 302                 if (!ath_is_radar_freq(ch->center_freq))
 303                         continue;
 304                 /* We always enable radar detection/DFS on this
 305                  * frequency range. Additionally we also apply on
 306                  * this frequency range:
 307                  * - If STA mode does not yet have DFS supports disable
 308                  *   active scanning
 309                  * - If adhoc mode does not support DFS yet then
 310                  *   disable adhoc in the frequency.
 311                  * - If AP mode does not yet support radar detection/DFS
 312                  *   do not allow AP mode
 313                  */
 314                 if (!(ch->flags & IEEE80211_CHAN_DISABLED))
 315                         ch->flags |= IEEE80211_CHAN_RADAR |
 316                                      IEEE80211_CHAN_NO_IBSS |
 317                                      IEEE80211_CHAN_PASSIVE_SCAN;
 318         }
 319 }
 320
 321 static void ath_reg_apply_world_flags(struct wiphy *wiphy,
 322                                       enum nl80211_reg_initiator initiator,
 323                                       struct ath_regulatory *reg)
 324 {
 325         switch (reg->regpair->regDmnEnum) {
 326         case 0x60:
 327         case 0x63:
 328         case 0x66:
 329         case 0x67:
 330                 ath_reg_apply_beaconing_flags(wiphy, initiator);
 331                 break;
 332         case 0x68:
 333                 ath_reg_apply_beaconing_flags(wiphy, initiator);
 334                 ath_reg_apply_active_scan_flags(wiphy, initiator);
 335                 break;
 336         }
 337         return;
 338 }
 339
 340 int ath_reg_notifier_apply(struct wiphy *wiphy,
 341                            struct regulatory_request *request,
 342                            struct ath_regulatory *reg)
 343 {
 344         /* We always apply this */
 345         ath_reg_apply_radar_flags(wiphy);
 346
 347         switch (request->initiator) {
 348         case NL80211_REGDOM_SET_BY_DRIVER:
 349         case NL80211_REGDOM_SET_BY_CORE:
 350         case NL80211_REGDOM_SET_BY_USER:
 351                 break;
 352         case NL80211_REGDOM_SET_BY_COUNTRY_IE:
 353                 if (ath_is_world_regd(reg))
 354                         ath_reg_apply_world_flags(wiphy, request->initiator,
 355                                                   reg);
 356                 break;
 357         }
 358
 359         return 0;
 360 }
 361 EXPORT_SYMBOL(ath_reg_notifier_apply);
 362
 363 static bool ath_regd_is_eeprom_valid(struct ath_regulatory *reg)
 364 {
 365         u16 rd = ath_regd_get_eepromRD(reg);
 366         int i;
 367
 368         if (rd & COUNTRY_ERD_FLAG) {
 369                 /* EEPROM value is a country code */
 370                 u16 cc = rd & ~COUNTRY_ERD_FLAG;
 371                 printk(KERN_DEBUG
 372                        "ath: EEPROM indicates we should expect "
 373                         "a country code\n");
 374                 for (i = 0; i < ARRAY_SIZE(allCountries); i++)
 375                         if (allCountries[i].countryCode == cc)
 376                                 return true;
 377         } else {
 378                 /* EEPROM value is a regpair value */
 379                 if (rd != CTRY_DEFAULT)
 380                         printk(KERN_DEBUG "ath: EEPROM indicates we "
 381                                "should expect a direct regpair map\n");
 382                 for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++)
 383                         if (regDomainPairs[i].regDmnEnum == rd)
 384                                 return true;
 385         }
 386         printk(KERN_DEBUG
 387                  "ath: invalid regulatory domain/country code 0x%x\n", rd);
 388         return false;
 389 }
 390
 391 /* EEPROM country code to regpair mapping */
 392 static struct country_code_to_enum_rd*
 393 ath_regd_find_country(u16 countryCode)
 394 {
 395         int i;
 396
 397         for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
 398                 if (allCountries[i].countryCode == countryCode)
 399                         return &allCountries[i];
 400         }
 401         return NULL;
 402 }
 403
 404 /* EEPROM rd code to regpair mapping */
 405 static struct country_code_to_enum_rd*
 406 ath_regd_find_country_by_rd(int regdmn)
 407 {
 408         int i;
 409
 410         for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
 411                 if (allCountries[i].regDmnEnum == regdmn)
 412                         return &allCountries[i];
 413         }
 414         return NULL;
 415 }
 416
 417 /* Returns the map of the EEPROM set RD to a country code */
 418 static u16 ath_regd_get_default_country(u16 rd)
 419 {
 420         if (rd & COUNTRY_ERD_FLAG) {
 421                 struct country_code_to_enum_rd *country = NULL;
 422                 u16 cc = rd & ~COUNTRY_ERD_FLAG;
 423
 424                 country = ath_regd_find_country(cc);
 425                 if (country != NULL)
 426                         return cc;
 427         }
 428
 429         return CTRY_DEFAULT;
 430 }
 431
 432 static struct reg_dmn_pair_mapping*
 433 ath_get_regpair(int regdmn)
 434 {
 435         int i;
 436
 437         if (regdmn == NO_ENUMRD)
 438                 return NULL;
 439         for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++) {
 440                 if (regDomainPairs[i].regDmnEnum == regdmn)
 441                         return &regDomainPairs[i];
 442         }
 443         return NULL;
 444 }
 445
 446 static int
 447 ath_regd_init_wiphy(struct ath_regulatory *reg,
 448                     struct wiphy *wiphy,
 449                     int (*reg_notifier)(struct wiphy *wiphy,
 450                                         struct regulatory_request *request))
 451 {
 452         const struct ieee80211_regdomain *regd;
 453
 454         wiphy->reg_notifier = reg_notifier;
 455         wiphy->flags |= WIPHY_FLAG_STRICT_REGULATORY;
 456
 457         if (ath_is_world_regd(reg)) {
 458                 /*
 459                  * Anything applied here (prior to wiphy registration) gets
 460                  * saved on the wiphy orig_* parameters
 461                  */
 462                 regd = ath_world_regdomain(reg);
 463                 wiphy->flags |= WIPHY_FLAG_CUSTOM_REGULATORY;
 464         } else {
 465                 /*
 466                  * This gets applied in the case of the absense of CRDA,
 467                  * it's our own custom world regulatory domain, similar to
 468                  * cfg80211's but we enable passive scanning.
 469                  */
 470                 regd = ath_default_world_regdomain();
 471         }
 472         wiphy_apply_custom_regulatory(wiphy, regd);
 473         ath_reg_apply_radar_flags(wiphy);
 474         ath_reg_apply_world_flags(wiphy, NL80211_REGDOM_SET_BY_DRIVER, reg);
 475         return 0;
 476 }
 477
 478 /*
 479  * Some users have reported their EEPROM programmed with
 480  * 0x8000 set, this is not a supported regulatory domain
 481  * but since we have more than one user with it we need
 482  * a solution for them. We default to 0x64, which is the
 483  * default Atheros world regulatory domain.
 484  */
 485 static void ath_regd_sanitize(struct ath_regulatory *reg)
 486 {
 487         if (reg->current_rd != COUNTRY_ERD_FLAG)
 488                 return;
 489         printk(KERN_DEBUG "ath: EEPROM regdomain sanitized\n");
 490         reg->current_rd = 0x64;
 491 }
 492
 493 int
 494 ath_regd_init(struct ath_regulatory *reg,
 495               struct wiphy *wiphy,
 496               int (*reg_notifier)(struct wiphy *wiphy,
 497                                   struct regulatory_request *request))
 498 {
 499         struct country_code_to_enum_rd *country = NULL;
 500         u16 regdmn;
 501
 502         if (!reg)
 503                 return -EINVAL;
 504
 505         ath_regd_sanitize(reg);
 506
 507         printk(KERN_DEBUG "ath: EEPROM regdomain: 0x%0x\n", reg->current_rd);
 508
 509         if (!ath_regd_is_eeprom_valid(reg)) {
 510                 printk(KERN_ERR "ath: Invalid EEPROM contents\n");
 511                 return -EINVAL;
 512         }
 513
 514         regdmn = ath_regd_get_eepromRD(reg);
 515         reg->country_code = ath_regd_get_default_country(regdmn);
 516
 517         if (reg->country_code == CTRY_DEFAULT &&
 518             regdmn == CTRY_DEFAULT) {
 519                 printk(KERN_DEBUG "ath: EEPROM indicates default "
 520                        "country code should be used\n");
 521                 reg->country_code = CTRY_UNITED_STATES;
 522         }
 523
 524         if (reg->country_code == CTRY_DEFAULT) {
 525                 country = NULL;
 526         } else {
 527                 printk(KERN_DEBUG "ath: doing EEPROM country->regdmn "
 528                        "map search\n");
 529                 country = ath_regd_find_country(reg->country_code);
 530                 if (country == NULL) {
 531                         printk(KERN_DEBUG
 532                                 "ath: no valid country maps found for "
 533                                 "country code: 0x%0x\n",
 534                                 reg->country_code);
 535                         return -EINVAL;
 536                 } else {
 537                         regdmn = country->regDmnEnum;
 538                         printk(KERN_DEBUG "ath: country maps to "
 539                                "regdmn code: 0x%0x\n",
 540                                regdmn);
 541                 }
 542         }
 543
 544         reg->regpair = ath_get_regpair(regdmn);
 545
 546         if (!reg->regpair) {
 547                 printk(KERN_DEBUG "ath: "
 548                         "No regulatory domain pair found, cannot continue\n");
 549                 return -EINVAL;
 550         }
 551
 552         if (!country)
 553                 country = ath_regd_find_country_by_rd(regdmn);
 554
 555         if (country) {
 556                 reg->alpha2[0] = country->isoName[0];
 557                 reg->alpha2[1] = country->isoName[1];
 558         } else {
 559                 reg->alpha2[0] = '0';
 560                 reg->alpha2[1] = '0';
 561         }
 562
 563         printk(KERN_DEBUG "ath: Country alpha2 being used: %c%c\n",
 564                 reg->alpha2[0], reg->alpha2[1]);
 565         printk(KERN_DEBUG "ath: Regpair used: 0x%0x\n",
 566                 reg->regpair->regDmnEnum);
 567
 568         ath_regd_init_wiphy(reg, wiphy, reg_notifier);
 569         return 0;
 570 }
 571 EXPORT_SYMBOL(ath_regd_init);
 572
 573 u32 ath_regd_get_band_ctl(struct ath_regulatory *reg,
 574                           enum ieee80211_band band)
 575 {
 576         if (!reg->regpair ||
 577             (reg->country_code == CTRY_DEFAULT &&
 578              is_wwr_sku(ath_regd_get_eepromRD(reg)))) {
 579                 return SD_NO_CTL;
 580         }
 581
 582         switch (band) {
 583         case IEEE80211_BAND_2GHZ:
 584                 return reg->regpair->reg_2ghz_ctl;
 585         case IEEE80211_BAND_5GHZ:
 586                 return reg->regpair->reg_5ghz_ctl;
 587         default:
 588                 return NO_CTL;
 589         }
 590 }
 591 EXPORT_SYMBOL(ath_regd_get_band_ctl);