[mirror_ubuntu-bionic-kernel.git] / net / wireless / reg.c

/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
 * Copyright 2008       Luis R. Rodriguez <lrodriguz@atheros.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/**
 * DOC: Wireless regulatory infrastructure
 *
 * The usual implementation is for a driver to read a device EEPROM to
 * determine which regulatory domain it should be operating under, then
 * looking up the allowable channels in a driver-local table and finally
 * registering those channels in the wiphy structure.
 *
 * Another set of compliance enforcement is for drivers to use their
 * own compliance limits which can be stored on the EEPROM. The host
 * driver or firmware may ensure these are used.
 *
 * In addition to all this we provide an extra layer of regulatory
 * conformance. For drivers which do not have any regulatory
 * information CRDA provides the complete regulatory solution.
 * For others it provides a community effort on further restrictions
 * to enhance compliance.
 *
 * Note: When number of rules --> infinity we will not be able to
 * index on alpha2 any more, instead we'll probably have to
 * rely on some SHA1 checksum of the regdomain for example.
 *
 */
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/random.h>
#include <linux/nl80211.h>
#include <linux/platform_device.h>
#include <net/wireless.h>
#include <net/cfg80211.h>
#include "core.h"
#include "reg.h"

/*
 * wiphy is set if this request's initiator is
 * REGDOM_SET_BY_COUNTRY_IE or _DRIVER
 */
struct regulatory_request {
        struct wiphy *wiphy;
        enum reg_set_by initiator;
        char alpha2[2];
};

static struct regulatory_request *last_request;

/* To trigger userspace events */
static struct platform_device *reg_pdev;

/* Keep the ordering from large to small */
static u32 supported_bandwidths[] = {
        MHZ_TO_KHZ(40),
        MHZ_TO_KHZ(20),
};

/* Central wireless core regulatory domains, we only need two,
 * the current one and a world regulatory domain in case we have no
 * information to give us an alpha2 */
static const struct ieee80211_regdomain *cfg80211_regdomain;

/* We keep a static world regulatory domain in case of the absence of CRDA */
static const struct ieee80211_regdomain world_regdom = {
        .n_reg_rules = 1,
        .alpha2 =  "00",
        .reg_rules = {
                REG_RULE(2412-10, 2462+10, 40, 6, 20,
                        NL80211_RRF_PASSIVE_SCAN |
                        NL80211_RRF_NO_IBSS),
        }
};

static const struct ieee80211_regdomain *cfg80211_world_regdom =
        &world_regdom;

#ifdef CONFIG_WIRELESS_OLD_REGULATORY
static char *ieee80211_regdom = "US";
module_param(ieee80211_regdom, charp, 0444);
MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");

/* We assume 40 MHz bandwidth for the old regulatory work.
 * We make emphasis we are using the exact same frequencies
 * as before */

static const struct ieee80211_regdomain us_regdom = {
        .n_reg_rules = 6,
        .alpha2 =  "US",
        .reg_rules = {
                /* IEEE 802.11b/g, channels 1..11 */
                REG_RULE(2412-10, 2462+10, 40, 6, 27, 0),
                /* IEEE 802.11a, channel 36 */
                REG_RULE(5180-10, 5180+10, 40, 6, 23, 0),
                /* IEEE 802.11a, channel 40 */
                REG_RULE(5200-10, 5200+10, 40, 6, 23, 0),
                /* IEEE 802.11a, channel 44 */
                REG_RULE(5220-10, 5220+10, 40, 6, 23, 0),
                /* IEEE 802.11a, channels 48..64 */
                REG_RULE(5240-10, 5320+10, 40, 6, 23, 0),
                /* IEEE 802.11a, channels 149..165, outdoor */
                REG_RULE(5745-10, 5825+10, 40, 6, 30, 0),
        }
};

static const struct ieee80211_regdomain jp_regdom = {
        .n_reg_rules = 3,
        .alpha2 =  "JP",
        .reg_rules = {
                /* IEEE 802.11b/g, channels 1..14 */
                REG_RULE(2412-10, 2484+10, 40, 6, 20, 0),
                /* IEEE 802.11a, channels 34..48 */
                REG_RULE(5170-10, 5240+10, 40, 6, 20,
                        NL80211_RRF_PASSIVE_SCAN),
                /* IEEE 802.11a, channels 52..64 */
                REG_RULE(5260-10, 5320+10, 40, 6, 20,
                        NL80211_RRF_NO_IBSS |
                        NL80211_RRF_DFS),
        }
};

static const struct ieee80211_regdomain eu_regdom = {
        .n_reg_rules = 6,
        /* This alpha2 is bogus, we leave it here just for stupid
         * backward compatibility */
        .alpha2 =  "EU",
        .reg_rules = {
                /* IEEE 802.11b/g, channels 1..13 */
                REG_RULE(2412-10, 2472+10, 40, 6, 20, 0),
                /* IEEE 802.11a, channel 36 */
                REG_RULE(5180-10, 5180+10, 40, 6, 23,
                        NL80211_RRF_PASSIVE_SCAN),
                /* IEEE 802.11a, channel 40 */
                REG_RULE(5200-10, 5200+10, 40, 6, 23,
                        NL80211_RRF_PASSIVE_SCAN),
                /* IEEE 802.11a, channel 44 */
                REG_RULE(5220-10, 5220+10, 40, 6, 23,
                        NL80211_RRF_PASSIVE_SCAN),
                /* IEEE 802.11a, channels 48..64 */
                REG_RULE(5240-10, 5320+10, 40, 6, 20,
                        NL80211_RRF_NO_IBSS |
                        NL80211_RRF_DFS),
                /* IEEE 802.11a, channels 100..140 */
                REG_RULE(5500-10, 5700+10, 40, 6, 30,
                        NL80211_RRF_NO_IBSS |
                        NL80211_RRF_DFS),
        }
};

static const struct ieee80211_regdomain *static_regdom(char *alpha2)
{
        if (alpha2[0] == 'U' && alpha2[1] == 'S')
                return &us_regdom;
        if (alpha2[0] == 'J' && alpha2[1] == 'P')
                return &jp_regdom;
        if (alpha2[0] == 'E' && alpha2[1] == 'U')
                return &eu_regdom;
        /* Default, as per the old rules */
        return &us_regdom;
}

static bool is_old_static_regdom(const struct ieee80211_regdomain *rd)
{
        if (rd == &us_regdom || rd == &jp_regdom || rd == &eu_regdom)
                return true;
        return false;
}
#else
static inline bool is_old_static_regdom(const struct ieee80211_regdomain *rd)
{
        return false;
}
#endif

static void reset_regdomains(void)
{
        /* avoid freeing static information or freeing something twice */
        if (cfg80211_regdomain == cfg80211_world_regdom)
                cfg80211_regdomain = NULL;
        if (cfg80211_world_regdom == &world_regdom)
                cfg80211_world_regdom = NULL;
        if (cfg80211_regdomain == &world_regdom)
                cfg80211_regdomain = NULL;
        if (is_old_static_regdom(cfg80211_regdomain))
                cfg80211_regdomain = NULL;

        kfree(cfg80211_regdomain);
        kfree(cfg80211_world_regdom);

        cfg80211_world_regdom = &world_regdom;
        cfg80211_regdomain = NULL;
}

/* Dynamic world regulatory domain requested by the wireless
 * core upon initialization */
static void update_world_regdomain(const struct ieee80211_regdomain *rd)
{
        BUG_ON(!last_request);

        reset_regdomains();

        cfg80211_world_regdom = rd;
        cfg80211_regdomain = rd;
}

bool is_world_regdom(const char *alpha2)
{
        if (!alpha2)
                return false;
        if (alpha2[0] == '0' && alpha2[1] == '0')
                return true;
        return false;
}

static bool is_alpha2_set(const char *alpha2)
{
        if (!alpha2)
                return false;
        if (alpha2[0] != 0 && alpha2[1] != 0)
                return true;
        return false;
}

static bool is_alpha_upper(char letter)
{
        /* ASCII A - Z */
        if (letter >= 65 && letter <= 90)
                return true;
        return false;
}

static bool is_unknown_alpha2(const char *alpha2)
{
        if (!alpha2)
                return false;
        /* Special case where regulatory domain was built by driver
         * but a specific alpha2 cannot be determined */
        if (alpha2[0] == '9' && alpha2[1] == '9')
                return true;
        return false;
}

static bool is_an_alpha2(const char *alpha2)
{
        if (!alpha2)
                return false;
        if (is_alpha_upper(alpha2[0]) && is_alpha_upper(alpha2[1]))
                return true;
        return false;
}

static bool alpha2_equal(const char *alpha2_x, const char *alpha2_y)
{
        if (!alpha2_x || !alpha2_y)
                return false;
        if (alpha2_x[0] == alpha2_y[0] &&
                alpha2_x[1] == alpha2_y[1])
                return true;
        return false;
}

static bool regdom_changed(const char *alpha2)
{
        if (!cfg80211_regdomain)
                return true;
        if (alpha2_equal(cfg80211_regdomain->alpha2, alpha2))
                return false;
        return true;
}

/* This lets us keep regulatory code which is updated on a regulatory
 * basis in userspace. */
static int call_crda(const char *alpha2)
{
        char country_env[9 + 2] = "COUNTRY=";
        char *envp[] = {
                country_env,
                NULL
        };

        if (!is_world_regdom((char *) alpha2))
                printk(KERN_INFO "cfg80211: Calling CRDA for country: %c%c\n",
                        alpha2[0], alpha2[1]);
        else
                printk(KERN_INFO "cfg80211: Calling CRDA to update world "
                        "regulatory domain\n");

        country_env[8] = alpha2[0];
        country_env[9] = alpha2[1];

        return kobject_uevent_env(&reg_pdev->dev.kobj, KOBJ_CHANGE, envp);
}

/* Used by nl80211 before kmalloc'ing our regulatory domain */
bool reg_is_valid_request(const char *alpha2)
{
        if (!last_request)
                return false;

        return alpha2_equal(last_request->alpha2, alpha2);
}

/* Sanity check on a regulatory rule */
static bool is_valid_reg_rule(const struct ieee80211_reg_rule *rule)
{
        const struct ieee80211_freq_range *freq_range = &rule->freq_range;
        u32 freq_diff;

        if (freq_range->start_freq_khz == 0 || freq_range->end_freq_khz == 0)
                return false;

        if (freq_range->start_freq_khz > freq_range->end_freq_khz)
                return false;

        freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz;

        if (freq_range->max_bandwidth_khz > freq_diff)
                return false;

        return true;
}

static bool is_valid_rd(const struct ieee80211_regdomain *rd)
{
        const struct ieee80211_reg_rule *reg_rule = NULL;
        unsigned int i;

        if (!rd->n_reg_rules)
                return false;

        for (i = 0; i < rd->n_reg_rules; i++) {
                reg_rule = &rd->reg_rules[i];
                if (!is_valid_reg_rule(reg_rule))
                        return false;
        }

        return true;
}

/* Returns value in KHz */
static u32 freq_max_bandwidth(const struct ieee80211_freq_range *freq_range,
        u32 freq)
{
        unsigned int i;
        for (i = 0; i < ARRAY_SIZE(supported_bandwidths); i++) {
                u32 start_freq_khz = freq - supported_bandwidths[i]/2;
                u32 end_freq_khz = freq + supported_bandwidths[i]/2;
                if (start_freq_khz >= freq_range->start_freq_khz &&
                        end_freq_khz <= freq_range->end_freq_khz)
                        return supported_bandwidths[i];
        }
        return 0;
}

/* XXX: add support for the rest of enum nl80211_reg_rule_flags, we may
 * want to just have the channel structure use these */
static u32 map_regdom_flags(u32 rd_flags)
{
        u32 channel_flags = 0;
        if (rd_flags & NL80211_RRF_PASSIVE_SCAN)
                channel_flags |= IEEE80211_CHAN_PASSIVE_SCAN;
        if (rd_flags & NL80211_RRF_NO_IBSS)
                channel_flags |= IEEE80211_CHAN_NO_IBSS;
        if (rd_flags & NL80211_RRF_DFS)
                channel_flags |= IEEE80211_CHAN_RADAR;
        return channel_flags;
}

/**
 * freq_reg_info - get regulatory information for the given frequency
 * @center_freq: Frequency in KHz for which we want regulatory information for
 * @bandwidth: the bandwidth requirement you have in KHz, if you do not have one
 *      you can set this to 0. If this frequency is allowed we then set
 *      this value to the maximum allowed bandwidth.
 * @reg_rule: the regulatory rule which we have for this frequency
 *
 * Use this function to get the regulatory rule for a specific frequency.
 */
static int freq_reg_info(u32 center_freq, u32 *bandwidth,
                         const struct ieee80211_reg_rule **reg_rule)
{
        int i;
        u32 max_bandwidth = 0;

        if (!cfg80211_regdomain)
                return -EINVAL;

        for (i = 0; i < cfg80211_regdomain->n_reg_rules; i++) {
                const struct ieee80211_reg_rule *rr;
                const struct ieee80211_freq_range *fr = NULL;
                const struct ieee80211_power_rule *pr = NULL;

                rr = &cfg80211_regdomain->reg_rules[i];
                fr = &rr->freq_range;
                pr = &rr->power_rule;
                max_bandwidth = freq_max_bandwidth(fr, center_freq);
                if (max_bandwidth && *bandwidth <= max_bandwidth) {
                        *reg_rule = rr;
                        *bandwidth = max_bandwidth;
                        break;
                }
        }

        return !max_bandwidth;
}

static void handle_channel(struct ieee80211_channel *chan)
{
        int r;
        u32 flags = chan->orig_flags;
        u32 max_bandwidth = 0;
        const struct ieee80211_reg_rule *reg_rule = NULL;
        const struct ieee80211_power_rule *power_rule = NULL;

        r = freq_reg_info(MHZ_TO_KHZ(chan->center_freq),
                &max_bandwidth, &reg_rule);

        if (r) {
                flags |= IEEE80211_CHAN_DISABLED;
                chan->flags = flags;
                return;
        }

        power_rule = &reg_rule->power_rule;

        chan->flags = flags | map_regdom_flags(reg_rule->flags);
        chan->max_antenna_gain = min(chan->orig_mag,
                (int) MBI_TO_DBI(power_rule->max_antenna_gain));
        chan->max_bandwidth = KHZ_TO_MHZ(max_bandwidth);
        if (chan->orig_mpwr)
                chan->max_power = min(chan->orig_mpwr,
                        (int) MBM_TO_DBM(power_rule->max_eirp));
        else
                chan->max_power = (int) MBM_TO_DBM(power_rule->max_eirp);
}

static void handle_band(struct ieee80211_supported_band *sband)
{
        int i;

        for (i = 0; i < sband->n_channels; i++)
                handle_channel(&sband->channels[i]);
}

static void update_all_wiphy_regulatory(enum reg_set_by setby)
{
        struct cfg80211_registered_device *drv;

        list_for_each_entry(drv, &cfg80211_drv_list, list)
                wiphy_update_regulatory(&drv->wiphy, setby);
}

void wiphy_update_regulatory(struct wiphy *wiphy, enum reg_set_by setby)
{
        enum ieee80211_band band;
        for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
                if (wiphy->bands[band])
                        handle_band(wiphy->bands[band]);
                if (wiphy->reg_notifier)
                        wiphy->reg_notifier(wiphy, setby);
        }
}

/* This has the logic which determines when a new request
 * should be ignored. */
static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
                          const char *alpha2)
{
        /* All initial requests are respected */
        if (!last_request)
                return 0;

        switch (set_by) {
        case REGDOM_SET_BY_INIT:
                return -EINVAL;
        case REGDOM_SET_BY_CORE:
                /*
                 * Always respect new wireless core hints, should only happen
                 * when updating the world regulatory domain at init.
                 */
                return 0;
        case REGDOM_SET_BY_COUNTRY_IE:
                if (unlikely(!is_an_alpha2(alpha2)))
                        return -EINVAL;
                if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
                        if (last_request->wiphy != wiphy) {
                                /*
                                 * Two cards with two APs claiming different
                                 * different Country IE alpha2s. We could
                                 * intersect them, but that seems unlikely
                                 * to be correct. Reject second one for now.
                                 */
                                if (!alpha2_equal(alpha2,
                                                  cfg80211_regdomain->alpha2))
                                        return -EOPNOTSUPP;
                                return -EALREADY;
                        }
                        /* Two consecutive Country IE hints on the same wiphy */
                        if (!alpha2_equal(cfg80211_regdomain->alpha2, alpha2))
                                return 0;
                        return -EALREADY;
                }
                /*
                 * Ignore Country IE hints for now, need to think about
                 * what we need to do to support multi-domain operation.
                 */
                return -EOPNOTSUPP;
        case REGDOM_SET_BY_DRIVER:
                if (last_request->initiator == REGDOM_SET_BY_DRIVER)
                        return -EALREADY;
                return 0;
        case REGDOM_SET_BY_USER:
                /*
                 * If the user wants to override the AP's hint, we may
                 * need to follow both and use the intersection. For now,
                 * reject any such attempt (but we don't support country
                 * IEs right now anyway.)
                 */
                if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE)
                        return -EOPNOTSUPP;
                return 0;
        }

        return -EINVAL;
}

/* Caller must hold &cfg80211_drv_mutex */
int __regulatory_hint(struct wiphy *wiphy, enum reg_set_by set_by,
                      const char *alpha2)
{
        struct regulatory_request *request;
        int r = 0;

        r = ignore_request(wiphy, set_by, alpha2);
        if (r)
                return r;

        switch (set_by) {
        case REGDOM_SET_BY_CORE:
        case REGDOM_SET_BY_COUNTRY_IE:
        case REGDOM_SET_BY_DRIVER:
        case REGDOM_SET_BY_USER:
                request = kzalloc(sizeof(struct regulatory_request),
                                  GFP_KERNEL);
                if (!request)
                        return -ENOMEM;

                request->alpha2[0] = alpha2[0];
                request->alpha2[1] = alpha2[1];
                request->initiator = set_by;
                request->wiphy = wiphy;

                kfree(last_request);
                last_request = request;
                r = call_crda(alpha2);
#ifndef CONFIG_WIRELESS_OLD_REGULATORY
                if (r)
                        printk(KERN_ERR "cfg80211: Failed calling CRDA\n");
#endif
                break;
        default:
                r = -ENOTSUPP;
                break;
        }

        return r;
}

void regulatory_hint(struct wiphy *wiphy, const char *alpha2)
{
        BUG_ON(!alpha2);

        mutex_lock(&cfg80211_drv_mutex);
        __regulatory_hint(wiphy, REGDOM_SET_BY_DRIVER, alpha2);
        mutex_unlock(&cfg80211_drv_mutex);
}
EXPORT_SYMBOL(regulatory_hint);


static void print_rd_rules(const struct ieee80211_regdomain *rd)
{
        unsigned int i;
        const struct ieee80211_reg_rule *reg_rule = NULL;
        const struct ieee80211_freq_range *freq_range = NULL;
        const struct ieee80211_power_rule *power_rule = NULL;

        printk(KERN_INFO "\t(start_freq - end_freq @ bandwidth), "
                "(max_antenna_gain, max_eirp)\n");

        for (i = 0; i < rd->n_reg_rules; i++) {
                reg_rule = &rd->reg_rules[i];
                freq_range = &reg_rule->freq_range;
                power_rule = &reg_rule->power_rule;

                /* There may not be documentation for max antenna gain
                 * in certain regions */
                if (power_rule->max_antenna_gain)
                        printk(KERN_INFO "\t(%d KHz - %d KHz @ %d KHz), "
                                "(%d mBi, %d mBm)\n",
                                freq_range->start_freq_khz,
                                freq_range->end_freq_khz,
                                freq_range->max_bandwidth_khz,
                                power_rule->max_antenna_gain,
                                power_rule->max_eirp);
                else
                        printk(KERN_INFO "\t(%d KHz - %d KHz @ %d KHz), "
                                "(N/A, %d mBm)\n",
                                freq_range->start_freq_khz,
                                freq_range->end_freq_khz,
                                freq_range->max_bandwidth_khz,
                                power_rule->max_eirp);
        }
}

static void print_regdomain(const struct ieee80211_regdomain *rd)
{

        if (is_world_regdom(rd->alpha2))
                printk(KERN_INFO "cfg80211: World regulatory "
                        "domain updated:\n");
        else {
                if (is_unknown_alpha2(rd->alpha2))
                        printk(KERN_INFO "cfg80211: Regulatory domain "
                                "changed to driver built-in settings "
                                "(unknown country)\n");
                else
                        printk(KERN_INFO "cfg80211: Regulatory domain "
                                "changed to country: %c%c\n",
                                rd->alpha2[0], rd->alpha2[1]);
        }
        print_rd_rules(rd);
}

void print_regdomain_info(const struct ieee80211_regdomain *rd)
{
        printk(KERN_INFO "cfg80211: Regulatory domain: %c%c\n",
                rd->alpha2[0], rd->alpha2[1]);
        print_rd_rules(rd);
}

/* Takes ownership of rd only if it doesn't fail */
static int __set_regdom(const struct ieee80211_regdomain *rd)
{
        /* Some basic sanity checks first */

        if (is_world_regdom(rd->alpha2)) {
                if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
                        return -EINVAL;
                update_world_regdomain(rd);
                return 0;
        }

        if (!is_alpha2_set(rd->alpha2) && !is_an_alpha2(rd->alpha2) &&
                        !is_unknown_alpha2(rd->alpha2))
                return -EINVAL;

        if (!last_request)
                return -EINVAL;

        /* allow overriding the static definitions if CRDA is present */
        if (!is_old_static_regdom(cfg80211_regdomain) &&
            !regdom_changed(rd->alpha2))
                return -EINVAL;

        /* Now lets set the regulatory domain, update all driver channels
         * and finally inform them of what we have done, in case they want
         * to review or adjust their own settings based on their own
         * internal EEPROM data */

        if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
                return -EINVAL;

        reset_regdomains();

        /* Country IE parsing coming soon */
        switch (last_request->initiator) {
        case REGDOM_SET_BY_CORE:
        case REGDOM_SET_BY_DRIVER:
        case REGDOM_SET_BY_USER:
                if (!is_valid_rd(rd)) {
                        printk(KERN_ERR "cfg80211: Invalid "
                                "regulatory domain detected:\n");
                        print_regdomain_info(rd);
                        return -EINVAL;
                }
                break;
        case REGDOM_SET_BY_COUNTRY_IE: /* Not yet */
                WARN_ON(1);
        default:
                return -EOPNOTSUPP;
        }

        /* Tada! */
        cfg80211_regdomain = rd;

        return 0;
}


/* Use this call to set the current regulatory domain. Conflicts with
 * multiple drivers can be ironed out later. Caller must've already
 * kmalloc'd the rd structure. Caller must hold cfg80211_drv_mutex */
int set_regdom(const struct ieee80211_regdomain *rd)
{
        int r;

        /* Note that this doesn't update the wiphys, this is done below */
        r = __set_regdom(rd);
        if (r) {
                kfree(rd);
                return r;
        }

        /* This would make this whole thing pointless */
        BUG_ON(rd != cfg80211_regdomain);

        /* update all wiphys now with the new established regulatory domain */
        update_all_wiphy_regulatory(last_request->initiator);

        print_regdomain(rd);

        return r;
}

int regulatory_init(void)
{
        int err;

        reg_pdev = platform_device_register_simple("regulatory", 0, NULL, 0);
        if (IS_ERR(reg_pdev))
                return PTR_ERR(reg_pdev);

#ifdef CONFIG_WIRELESS_OLD_REGULATORY
        cfg80211_regdomain = static_regdom(ieee80211_regdom);

        printk(KERN_INFO "cfg80211: Using static regulatory domain info\n");
        print_regdomain_info(cfg80211_regdomain);
        /* The old code still requests for a new regdomain and if
         * you have CRDA you get it updated, otherwise you get
         * stuck with the static values. We ignore "EU" code as
         * that is not a valid ISO / IEC 3166 alpha2 */
        if (ieee80211_regdom[0] != 'E' || ieee80211_regdom[1] != 'U')
                err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE,
                                        ieee80211_regdom);
#else
        cfg80211_regdomain = cfg80211_world_regdom;

        err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE, "00");
        if (err)
                printk(KERN_ERR "cfg80211: calling CRDA failed - "
                       "unable to update world regulatory domain, "
                       "using static definition\n");
#endif

        return 0;
}

void regulatory_exit(void)
{
        mutex_lock(&cfg80211_drv_mutex);

        reset_regdomains();

        kfree(last_request);

        platform_device_unregister(reg_pdev);

        mutex_unlock(&cfg80211_drv_mutex);
}