regd.c

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/*
 * Copyright (c) 2008-2009 Atheros Communications Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/export.h>
#include <net/cfg80211.h>
#include <net/mac80211.h>
#include "regd.h"
#include "regd_common.h"

static int __ath_regd_init(struct ath_regulatory *reg);

/*
 * This is a set of common rules used by our world regulatory domains.
 * We have 12 world regulatory domains. To save space we consolidate
 * the regulatory domains in 5 structures by frequency and change
 * the flags on our reg_notifier() on a case by case basis.
 */

/* Only these channels all allow active scan on all world regulatory domains */
#define ATH9K_2GHZ_CH01_11  REG_RULE(2412-10, 2462+10, 40, 0, 20, 0)

/* We enable active scan on these a case by case basis by regulatory domain */
#define ATH9K_2GHZ_CH12_13  REG_RULE(2467-10, 2472+10, 40, 0, 20,\
                    NL80211_RRF_PASSIVE_SCAN)
#define ATH9K_2GHZ_CH14     REG_RULE(2484-10, 2484+10, 40, 0, 20,\
                NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_OFDM)

/* We allow IBSS on these on a case by case basis by regulatory domain */
#define ATH9K_5GHZ_5150_5350    REG_RULE(5150-10, 5350+10, 40, 0, 30,\
                NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
#define ATH9K_5GHZ_5470_5850    REG_RULE(5470-10, 5850+10, 40, 0, 30,\
                NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
#define ATH9K_5GHZ_5725_5850    REG_RULE(5725-10, 5850+10, 40, 0, 30,\
                NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)

#define ATH9K_2GHZ_ALL      ATH9K_2GHZ_CH01_11, \
                ATH9K_2GHZ_CH12_13, \
                ATH9K_2GHZ_CH14

#define ATH9K_5GHZ_ALL      ATH9K_5GHZ_5150_5350, \
                ATH9K_5GHZ_5470_5850

/* This one skips what we call "mid band" */
#define ATH9K_5GHZ_NO_MIDBAND   ATH9K_5GHZ_5150_5350, \
                ATH9K_5GHZ_5725_5850

/* Can be used for:
 * 0x60, 0x61, 0x62 */
static const struct ieee80211_regdomain ath_world_regdom_60_61_62 = {
    .n_reg_rules = 5,
    .alpha2 =  "99",
    .reg_rules = {
        ATH9K_2GHZ_ALL,
        ATH9K_5GHZ_ALL,
    }
};

/* Can be used by 0x63 and 0x65 */
static const struct ieee80211_regdomain ath_world_regdom_63_65 = {
    .n_reg_rules = 4,
    .alpha2 =  "99",
    .reg_rules = {
        ATH9K_2GHZ_CH01_11,
        ATH9K_2GHZ_CH12_13,
        ATH9K_5GHZ_NO_MIDBAND,
    }
};

/* Can be used by 0x64 only */
static const struct ieee80211_regdomain ath_world_regdom_64 = {
    .n_reg_rules = 3,
    .alpha2 =  "99",
    .reg_rules = {
        ATH9K_2GHZ_CH01_11,
        ATH9K_5GHZ_NO_MIDBAND,
    }
};

/* Can be used by 0x66 and 0x69 */
static const struct ieee80211_regdomain ath_world_regdom_66_69 = {
    .n_reg_rules = 3,
    .alpha2 =  "99",
    .reg_rules = {
        ATH9K_2GHZ_CH01_11,
        ATH9K_5GHZ_ALL,
    }
};

/* Can be used by 0x67, 0x68, 0x6A and 0x6C */
static const struct ieee80211_regdomain ath_world_regdom_67_68_6A_6C = {
    .n_reg_rules = 4,
    .alpha2 =  "99",
    .reg_rules = {
        ATH9K_2GHZ_CH01_11,
        ATH9K_2GHZ_CH12_13,
        ATH9K_5GHZ_ALL,
    }
};

static inline bool is_wwr_sku(u16 regd)
{
    return ((regd & COUNTRY_ERD_FLAG) != COUNTRY_ERD_FLAG) &&
        (((regd & WORLD_SKU_MASK) == WORLD_SKU_PREFIX) ||
        (regd == WORLD));
}

static u16 ath_regd_get_eepromRD(struct ath_regulatory *reg)
{
    return reg->current_rd & ~WORLDWIDE_ROAMING_FLAG;
}

bool ath_is_world_regd(struct ath_regulatory *reg)
{
    return is_wwr_sku(ath_regd_get_eepromRD(reg));
}
EXPORT_SYMBOL(ath_is_world_regd);

static const struct ieee80211_regdomain *ath_default_world_regdomain(void)
{
    /* this is the most restrictive */
    return &ath_world_regdom_64;
}

static const struct
ieee80211_regdomain *ath_world_regdomain(struct ath_regulatory *reg)
{
    switch (reg->regpair->regDmnEnum) {
    case 0x60:
    case 0x61:
    case 0x62:
        return &ath_world_regdom_60_61_62;
    case 0x63:
    case 0x65:
        return &ath_world_regdom_63_65;
    case 0x64:
        return &ath_world_regdom_64;
    case 0x66:
    case 0x69:
        return &ath_world_regdom_66_69;
    case 0x67:
    case 0x68:
    case 0x6A:
    case 0x6C:
        return &ath_world_regdom_67_68_6A_6C;
    default:
        WARN_ON(1);
        return ath_default_world_regdomain();
    }
}

bool ath_is_49ghz_allowed(u16 regdomain)
{
    /* possibly more */
    return regdomain == MKK9_MKKC;
}
EXPORT_SYMBOL(ath_is_49ghz_allowed);

/* Frequency is one where radar detection is required */
static bool ath_is_radar_freq(u16 center_freq)
{
    return (center_freq >= 5260 && center_freq <= 5700);
}

/*
 * N.B: These exception rules do not apply radar freqs.
 *
 * - We enable adhoc (or beaconing) if allowed by 11d
 * - We enable active scan if the channel is allowed by 11d
 * - If no country IE has been processed and a we determine we have
 *   received a beacon on a channel we can enable active scan and
 *   adhoc (or beaconing).
 */
static void
ath_reg_apply_beaconing_flags(struct wiphy *wiphy,
                  enum nl80211_reg_initiator initiator)
{
    enum ieee80211_band band;
    struct ieee80211_supported_band *sband;
    const struct ieee80211_reg_rule *reg_rule;
    struct ieee80211_channel *ch;
    unsigned int i;
    u32 bandwidth = 0;
    int r;

    for (band = 0; band < IEEE80211_NUM_BANDS; band++) {

        if (!wiphy->bands[band])
            continue;

        sband = wiphy->bands[band];

        for (i = 0; i < sband->n_channels; i++) {

            ch = &sband->channels[i];

            if (ath_is_radar_freq(ch->center_freq) ||
                (ch->flags & IEEE80211_CHAN_RADAR))
                continue;

            if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
                r = freq_reg_info(wiphy,
                          ch->center_freq,
                          bandwidth,
                          &reg_rule);
                if (r)
                    continue;
                /*
                 * If 11d had a rule for this channel ensure
                 * we enable adhoc/beaconing if it allows us to
                 * use it. Note that we would have disabled it
                 * by applying our static world regdomain by
                 * default during init, prior to calling our
                 * regulatory_hint().
                 */
                if (!(reg_rule->flags &
                    NL80211_RRF_NO_IBSS))
                    ch->flags &=
                      ~IEEE80211_CHAN_NO_IBSS;
                if (!(reg_rule->flags &
                    NL80211_RRF_PASSIVE_SCAN))
                    ch->flags &=
                      ~IEEE80211_CHAN_PASSIVE_SCAN;
            } else {
                if (ch->beacon_found)
                    ch->flags &= ~(IEEE80211_CHAN_NO_IBSS |
                      IEEE80211_CHAN_PASSIVE_SCAN);
            }
        }
    }

}

/* Allows active scan scan on Ch 12 and 13 */
static void
ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
                enum nl80211_reg_initiator initiator)
{
    struct ieee80211_supported_band *sband;
    struct ieee80211_channel *ch;
    const struct ieee80211_reg_rule *reg_rule;
    u32 bandwidth = 0;
    int r;

    sband = wiphy->bands[IEEE80211_BAND_2GHZ];
    if (!sband)
        return;

    /*
     * If no country IE has been received always enable active scan
     * on these channels. This is only done for specific regulatory SKUs
     */
    if (initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
        ch = &sband->channels[11]; /* CH 12 */
        if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
            ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
        ch = &sband->channels[12]; /* CH 13 */
        if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
            ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
        return;
    }

    /*
     * If a country IE has been received check its rule for this
     * channel first before enabling active scan. The passive scan
     * would have been enforced by the initial processing of our
     * custom regulatory domain.
     */

    ch = &sband->channels[11]; /* CH 12 */
    r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
    if (!r) {
        if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
            if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
                ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
    }

    ch = &sband->channels[12]; /* CH 13 */
    r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
    if (!r) {
        if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
            if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
                ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
    }
}

/* Always apply Radar/DFS rules on freq range 5260 MHz - 5700 MHz */
static void ath_reg_apply_radar_flags(struct wiphy *wiphy)
{
    struct ieee80211_supported_band *sband;
    struct ieee80211_channel *ch;
    unsigned int i;

    if (!wiphy->bands[IEEE80211_BAND_5GHZ])
        return;

    sband = wiphy->bands[IEEE80211_BAND_5GHZ];

    for (i = 0; i < sband->n_channels; i++) {
        ch = &sband->channels[i];
        if (!ath_is_radar_freq(ch->center_freq))
            continue;
        /* We always enable radar detection/DFS on this
         * frequency range. Additionally we also apply on
         * this frequency range:
         * - If STA mode does not yet have DFS supports disable
         *   active scanning
         * - If adhoc mode does not support DFS yet then
         *   disable adhoc in the frequency.
         * - If AP mode does not yet support radar detection/DFS
         *   do not allow AP mode
         */
        if (!(ch->flags & IEEE80211_CHAN_DISABLED))
            ch->flags |= IEEE80211_CHAN_RADAR |
                     IEEE80211_CHAN_NO_IBSS |
                     IEEE80211_CHAN_PASSIVE_SCAN;
    }
}

static void ath_reg_apply_world_flags(struct wiphy *wiphy,
                      enum nl80211_reg_initiator initiator,
                      struct ath_regulatory *reg)
{
    switch (reg->regpair->regDmnEnum) {
    case 0x60:
    case 0x63:
    case 0x66:
    case 0x67:
    case 0x6C:
        ath_reg_apply_beaconing_flags(wiphy, initiator);
        break;
    case 0x68:
        ath_reg_apply_beaconing_flags(wiphy, initiator);
        ath_reg_apply_active_scan_flags(wiphy, initiator);
        break;
    }
}

static u16 ath_regd_find_country_by_name(char *alpha2)
{
    unsigned int i;

    for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
        if (!memcmp(allCountries[i].isoName, alpha2, 2))
            return allCountries[i].countryCode;
    }

    return -1;
}

int ath_reg_notifier_apply(struct wiphy *wiphy,
               struct regulatory_request *request,
               struct ath_regulatory *reg)
{
    struct ath_common *common = container_of(reg, struct ath_common,
                         regulatory);
    u16 country_code;

    /* We always apply this */
    ath_reg_apply_radar_flags(wiphy);

    /*
     * This would happen when we have sent a custom regulatory request
     * a world regulatory domain and the scheduler hasn't yet processed
     * any pending requests in the queue.
     */
    if (!request)
        return 0;

    switch (request->initiator) {
    case NL80211_REGDOM_SET_BY_CORE:
        /*
         * If common->reg_world_copy is world roaming it means we *were*
         * world roaming... so we now have to restore that data.
         */
        if (!ath_is_world_regd(&common->reg_world_copy))
            break;

        memcpy(reg, &common->reg_world_copy,
               sizeof(struct ath_regulatory));
        break;
    case NL80211_REGDOM_SET_BY_DRIVER:
    case NL80211_REGDOM_SET_BY_USER:
        break;
    case NL80211_REGDOM_SET_BY_COUNTRY_IE:
        if (!ath_is_world_regd(reg))
            break;

        country_code = ath_regd_find_country_by_name(request->alpha2);
        if (country_code == (u16) -1)
            break;

        reg->current_rd = COUNTRY_ERD_FLAG;
        reg->current_rd |= country_code;

        printk(KERN_DEBUG "ath: regdomain 0x%0x updated by CountryIE\n",
            reg->current_rd);
        __ath_regd_init(reg);

        ath_reg_apply_world_flags(wiphy, request->initiator, reg);

        break;
    }

    return 0;
}
EXPORT_SYMBOL(ath_reg_notifier_apply);

static bool ath_regd_is_eeprom_valid(struct ath_regulatory *reg)
{
    u16 rd = ath_regd_get_eepromRD(reg);
    int i;

    if (rd & COUNTRY_ERD_FLAG) {
        /* EEPROM value is a country code */
        u16 cc = rd & ~COUNTRY_ERD_FLAG;
        printk(KERN_DEBUG
               "ath: EEPROM indicates we should expect "
            "a country code\n");
        for (i = 0; i < ARRAY_SIZE(allCountries); i++)
            if (allCountries[i].countryCode == cc)
                return true;
    } else {
        /* EEPROM value is a regpair value */
        if (rd != CTRY_DEFAULT)
            printk(KERN_DEBUG "ath: EEPROM indicates we "
                   "should expect a direct regpair map\n");
        for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++)
            if (regDomainPairs[i].regDmnEnum == rd)
                return true;
    }
    printk(KERN_DEBUG
         "ath: invalid regulatory domain/country code 0x%x\n", rd);
    return false;
}

/* EEPROM country code to regpair mapping */
static struct country_code_to_enum_rd*
ath_regd_find_country(u16 countryCode)
{
    int i;

    for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
        if (allCountries[i].countryCode == countryCode)
            return &allCountries[i];
    }
    return NULL;
}

/* EEPROM rd code to regpair mapping */
static struct country_code_to_enum_rd*
ath_regd_find_country_by_rd(int regdmn)
{
    int i;

    for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
        if (allCountries[i].regDmnEnum == regdmn)
            return &allCountries[i];
    }
    return NULL;
}

/* Returns the map of the EEPROM set RD to a country code */
static u16 ath_regd_get_default_country(u16 rd)
{
    if (rd & COUNTRY_ERD_FLAG) {
        struct country_code_to_enum_rd *country = NULL;
        u16 cc = rd & ~COUNTRY_ERD_FLAG;

        country = ath_regd_find_country(cc);
        if (country != NULL)
            return cc;
    }

    return CTRY_DEFAULT;
}

static struct reg_dmn_pair_mapping*
ath_get_regpair(int regdmn)
{
    int i;

    if (regdmn == NO_ENUMRD)
        return NULL;
    for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++) {
        if (regDomainPairs[i].regDmnEnum == regdmn)
            return &regDomainPairs[i];
    }
    return NULL;
}

static int
ath_regd_init_wiphy(struct ath_regulatory *reg,
            struct wiphy *wiphy,
            int (*reg_notifier)(struct wiphy *wiphy,
                    struct regulatory_request *request))
{
    const struct ieee80211_regdomain *regd;

    wiphy->reg_notifier = reg_notifier;
    wiphy->flags |= WIPHY_FLAG_STRICT_REGULATORY;

    if (ath_is_world_regd(reg)) {
        /*
         * Anything applied here (prior to wiphy registration) gets
         * saved on the wiphy orig_* parameters
         */
        regd = ath_world_regdomain(reg);
        wiphy->flags |= WIPHY_FLAG_CUSTOM_REGULATORY;
    } else {
        /*
         * This gets applied in the case of the absence of CRDA,
         * it's our own custom world regulatory domain, similar to
         * cfg80211's but we enable passive scanning.
         */
        regd = ath_default_world_regdomain();
    }
    wiphy_apply_custom_regulatory(wiphy, regd);
    ath_reg_apply_radar_flags(wiphy);
    ath_reg_apply_world_flags(wiphy, NL80211_REGDOM_SET_BY_DRIVER, reg);
    return 0;
}

/*
 * Some users have reported their EEPROM programmed with
 * 0x8000 set, this is not a supported regulatory domain
 * but since we have more than one user with it we need
 * a solution for them. We default to 0x64, which is the
 * default Atheros world regulatory domain.
 */
static void ath_regd_sanitize(struct ath_regulatory *reg)
{
    if (reg->current_rd != COUNTRY_ERD_FLAG)
        return;
    printk(KERN_DEBUG "ath: EEPROM regdomain sanitized\n");
    reg->current_rd = 0x64;
}

static int __ath_regd_init(struct ath_regulatory *reg)
{
    struct country_code_to_enum_rd *country = NULL;
    u16 regdmn;

    if (!reg)
        return -EINVAL;

    ath_regd_sanitize(reg);

    printk(KERN_DEBUG "ath: EEPROM regdomain: 0x%0x\n", reg->current_rd);

    if (!ath_regd_is_eeprom_valid(reg)) {
        pr_err("Invalid EEPROM contents\n");
        return -EINVAL;
    }

    regdmn = ath_regd_get_eepromRD(reg);
    reg->country_code = ath_regd_get_default_country(regdmn);

    if (reg->country_code == CTRY_DEFAULT &&
        regdmn == CTRY_DEFAULT) {
        printk(KERN_DEBUG "ath: EEPROM indicates default "
               "country code should be used\n");
        reg->country_code = CTRY_UNITED_STATES;
    }

    if (reg->country_code == CTRY_DEFAULT) {
        country = NULL;
    } else {
        printk(KERN_DEBUG "ath: doing EEPROM country->regdmn "
               "map search\n");
        country = ath_regd_find_country(reg->country_code);
        if (country == NULL) {
            printk(KERN_DEBUG
                "ath: no valid country maps found for "
                "country code: 0x%0x\n",
                reg->country_code);
            return -EINVAL;
        } else {
            regdmn = country->regDmnEnum;
            printk(KERN_DEBUG "ath: country maps to "
                   "regdmn code: 0x%0x\n",
                   regdmn);
        }
    }

    reg->regpair = ath_get_regpair(regdmn);

    if (!reg->regpair) {
        printk(KERN_DEBUG "ath: "
            "No regulatory domain pair found, cannot continue\n");
        return -EINVAL;
    }

    if (!country)
        country = ath_regd_find_country_by_rd(regdmn);

    if (country) {
        reg->alpha2[0] = country->isoName[0];
        reg->alpha2[1] = country->isoName[1];
    } else {
        reg->alpha2[0] = '0';
        reg->alpha2[1] = '0';
    }

    printk(KERN_DEBUG "ath: Country alpha2 being used: %c%c\n",
        reg->alpha2[0], reg->alpha2[1]);
    printk(KERN_DEBUG "ath: Regpair used: 0x%0x\n",
        reg->regpair->regDmnEnum);

    return 0;
}

int
ath_regd_init(struct ath_regulatory *reg,
          struct wiphy *wiphy,
          int (*reg_notifier)(struct wiphy *wiphy,
                  struct regulatory_request *request))
{
    struct ath_common *common = container_of(reg, struct ath_common,
                         regulatory);
    int r;

    r = __ath_regd_init(reg);
    if (r)
        return r;

    if (ath_is_world_regd(reg))
        memcpy(&common->reg_world_copy, reg,
               sizeof(struct ath_regulatory));

    ath_regd_init_wiphy(reg, wiphy, reg_notifier);

    return 0;
}
EXPORT_SYMBOL(ath_regd_init);

u32 ath_regd_get_band_ctl(struct ath_regulatory *reg,
              enum ieee80211_band band)
{
    if (!reg->regpair ||
        (reg->country_code == CTRY_DEFAULT &&
         is_wwr_sku(ath_regd_get_eepromRD(reg)))) {
        return SD_NO_CTL;
    }

    switch (band) {
    case IEEE80211_BAND_2GHZ:
        return reg->regpair->reg_2ghz_ctl;
    case IEEE80211_BAND_5GHZ:
        return reg->regpair->reg_5ghz_ctl;
    default:
        return NO_CTL;
    }
}
EXPORT_SYMBOL(ath_regd_get_band_ctl);