reg.c

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/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2007   Johannes Berg <[email protected]>
 * Copyright 2008-2011  Luis R. Rodriguez <[email protected]>
 *
 * 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 <linux/slab.h>
#include <linux/list.h>
#include <linux/random.h>
#include <linux/ctype.h>
#include <linux/nl80211.h>
#include <linux/platform_device.h>
#include <linux/moduleparam.h>
#include <net/cfg80211.h>
#include "core.h"
#include "reg.h"
#include "regdb.h"
#include "nl80211.h"

#ifdef CONFIG_CFG80211_REG_DEBUG
#define REG_DBG_PRINT(format, args...)          \
    printk(KERN_DEBUG pr_fmt(format), ##args)
#else
#define REG_DBG_PRINT(args...)
#endif

static struct regulatory_request core_request_world = {
    .initiator = NL80211_REGDOM_SET_BY_CORE,
    .alpha2[0] = '0',
    .alpha2[1] = '0',
    .intersect = false,
    .processed = true,
    .country_ie_env = ENVIRON_ANY,
};

/* Receipt of information from last regulatory request */
static struct regulatory_request *last_request = &core_request_world;

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

static struct device_type reg_device_type = {
    .uevent = reg_device_uevent,
};

/*
 * 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
 */
const struct ieee80211_regdomain *cfg80211_regdomain;

/*
 * Protects static reg.c components:
 *     - cfg80211_world_regdom
 *     - cfg80211_regdom
 *     - last_request
 *     - reg_num_devs_support_basehint
 */
static DEFINE_MUTEX(reg_mutex);

/*
 * Number of devices that registered to the core
 * that support cellular base station regulatory hints
 */
static int reg_num_devs_support_basehint;

static inline void assert_reg_lock(void)
{
    lockdep_assert_held(&reg_mutex);
}

/* Used to queue up regulatory hints */
static LIST_HEAD(reg_requests_list);
static spinlock_t reg_requests_lock;

/* Used to queue up beacon hints for review */
static LIST_HEAD(reg_pending_beacons);
static spinlock_t reg_pending_beacons_lock;

/* Used to keep track of processed beacon hints */
static LIST_HEAD(reg_beacon_list);

struct reg_beacon {
    struct list_head list;
    struct ieee80211_channel chan;
};

static void reg_todo(struct work_struct *work);
static DECLARE_WORK(reg_work, reg_todo);

static void reg_timeout_work(struct work_struct *work);
static DECLARE_DELAYED_WORK(reg_timeout, reg_timeout_work);

/* We keep a static world regulatory domain in case of the absence of CRDA */
static const struct ieee80211_regdomain world_regdom = {
    .n_reg_rules = 6,
    .alpha2 =  "00",
    .reg_rules = {
        /* IEEE 802.11b/g, channels 1..11 */
        REG_RULE(2412-10, 2462+10, 40, 6, 20, 0),
        /* IEEE 802.11b/g, channels 12..13. */
        REG_RULE(2467-10, 2472+10, 40, 6, 20,
            NL80211_RRF_PASSIVE_SCAN |
            NL80211_RRF_NO_IBSS),
        /* IEEE 802.11 channel 14 - Only JP enables
         * this and for 802.11b only */
        REG_RULE(2484-10, 2484+10, 20, 6, 20,
            NL80211_RRF_PASSIVE_SCAN |
            NL80211_RRF_NO_IBSS |
            NL80211_RRF_NO_OFDM),
        /* IEEE 802.11a, channel 36..48 */
        REG_RULE(5180-10, 5240+10, 40, 6, 20,
                        NL80211_RRF_PASSIVE_SCAN |
                        NL80211_RRF_NO_IBSS),

        /* NB: 5260 MHz - 5700 MHz requies DFS */

        /* IEEE 802.11a, channel 149..165 */
        REG_RULE(5745-10, 5825+10, 40, 6, 20,
            NL80211_RRF_PASSIVE_SCAN |
            NL80211_RRF_NO_IBSS),

        /* IEEE 802.11ad (60gHz), channels 1..3 */
        REG_RULE(56160+2160*1-1080, 56160+2160*3+1080, 2160, 0, 0, 0),
    }
};

static const struct ieee80211_regdomain *cfg80211_world_regdom =
    &world_regdom;

static char *ieee80211_regdom = "00";
static char user_alpha2[2];

module_param(ieee80211_regdom, charp, 0444);
MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");

static void reset_regdomains(bool full_reset)
{
    /* 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;

    kfree(cfg80211_regdomain);
    kfree(cfg80211_world_regdom);

    cfg80211_world_regdom = &world_regdom;
    cfg80211_regdomain = NULL;

    if (!full_reset)
        return;

    if (last_request != &core_request_world)
        kfree(last_request);
    last_request = &core_request_world;
}

/*
 * 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(false);

    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_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_intersected_alpha2(const char *alpha2)
{
    if (!alpha2)
        return false;
    /*
     * Special case where regulatory domain is the
     * result of an intersection between two regulatory domain
     * structures
     */
    if (alpha2[0] == '9' && alpha2[1] == '8')
        return true;
    return false;
}

static bool is_an_alpha2(const char *alpha2)
{
    if (!alpha2)
        return false;
    if (isalpha(alpha2[0]) && isalpha(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_changes(const char *alpha2)
{
    assert_cfg80211_lock();

    if (!cfg80211_regdomain)
        return true;
    if (alpha2_equal(cfg80211_regdomain->alpha2, alpha2))
        return false;
    return true;
}

/*
 * The NL80211_REGDOM_SET_BY_USER regdom alpha2 is cached, this lets
 * you know if a valid regulatory hint with NL80211_REGDOM_SET_BY_USER
 * has ever been issued.
 */
static bool is_user_regdom_saved(void)
{
    if (user_alpha2[0] == '9' && user_alpha2[1] == '7')
        return false;

    /* This would indicate a mistake on the design */
    if (WARN((!is_world_regdom(user_alpha2) &&
          !is_an_alpha2(user_alpha2)),
         "Unexpected user alpha2: %c%c\n",
         user_alpha2[0],
             user_alpha2[1]))
        return false;

    return true;
}

static int reg_copy_regd(const struct ieee80211_regdomain **dst_regd,
             const struct ieee80211_regdomain *src_regd)
{
    struct ieee80211_regdomain *regd;
    int size_of_regd = 0;
    unsigned int i;

    size_of_regd = sizeof(struct ieee80211_regdomain) +
      ((src_regd->n_reg_rules + 1) * sizeof(struct ieee80211_reg_rule));

    regd = kzalloc(size_of_regd, GFP_KERNEL);
    if (!regd)
        return -ENOMEM;

    memcpy(regd, src_regd, sizeof(struct ieee80211_regdomain));

    for (i = 0; i < src_regd->n_reg_rules; i++)
        memcpy(&regd->reg_rules[i], &src_regd->reg_rules[i],
            sizeof(struct ieee80211_reg_rule));

    *dst_regd = regd;
    return 0;
}

#ifdef CONFIG_CFG80211_INTERNAL_REGDB
struct reg_regdb_search_request {
    char alpha2[2];
    struct list_head list;
};

static LIST_HEAD(reg_regdb_search_list);
static DEFINE_MUTEX(reg_regdb_search_mutex);

static void reg_regdb_search(struct work_struct *work)
{
    struct reg_regdb_search_request *request;
    const struct ieee80211_regdomain *curdom, *regdom;
    int i, r;
    bool set_reg = false;

    mutex_lock(&cfg80211_mutex);

    mutex_lock(&reg_regdb_search_mutex);
    while (!list_empty(&reg_regdb_search_list)) {
        request = list_first_entry(&reg_regdb_search_list,
                       struct reg_regdb_search_request,
                       list);
        list_del(&request->list);

        for (i=0; i<reg_regdb_size; i++) {
            curdom = reg_regdb[i];

            if (!memcmp(request->alpha2, curdom->alpha2, 2)) {
                r = reg_copy_regd(&regdom, curdom);
                if (r)
                    break;
                set_reg = true;
                break;
            }
        }

        kfree(request);
    }
    mutex_unlock(&reg_regdb_search_mutex);

    if (set_reg)
        set_regdom(regdom);

    mutex_unlock(&cfg80211_mutex);
}

static DECLARE_WORK(reg_regdb_work, reg_regdb_search);

static void reg_regdb_query(const char *alpha2)
{
    struct reg_regdb_search_request *request;

    if (!alpha2)
        return;

    request = kzalloc(sizeof(struct reg_regdb_search_request), GFP_KERNEL);
    if (!request)
        return;

    memcpy(request->alpha2, alpha2, 2);

    mutex_lock(&reg_regdb_search_mutex);
    list_add_tail(&request->list, &reg_regdb_search_list);
    mutex_unlock(&reg_regdb_search_mutex);

    schedule_work(&reg_regdb_work);
}

/* Feel free to add any other sanity checks here */
static void reg_regdb_size_check(void)
{
    /* We should ideally BUILD_BUG_ON() but then random builds would fail */
    WARN_ONCE(!reg_regdb_size, "db.txt is empty, you should update it...");
}
#else
static inline void reg_regdb_size_check(void) {}
static inline void reg_regdb_query(const char *alpha2) {}
#endif /* CONFIG_CFG80211_INTERNAL_REGDB */

/*
 * This lets us keep regulatory code which is updated on a regulatory
 * basis in userspace. Country information is filled in by
 * reg_device_uevent
 */
static int call_crda(const char *alpha2)
{
    if (!is_world_regdom((char *) alpha2))
        pr_info("Calling CRDA for country: %c%c\n",
            alpha2[0], alpha2[1]);
    else
        pr_info("Calling CRDA to update world regulatory domain\n");

    /* query internal regulatory database (if it exists) */
    reg_regdb_query(alpha2);

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

/* Used by nl80211 before kmalloc'ing our regulatory domain */
bool reg_is_valid_request(const char *alpha2)
{
    assert_cfg80211_lock();

    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->end_freq_khz <= freq_range->start_freq_khz ||
            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;

    if (WARN_ON(rd->n_reg_rules > NL80211_MAX_SUPP_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;
}

static bool reg_does_bw_fit(const struct ieee80211_freq_range *freq_range,
                u32 center_freq_khz,
                u32 bw_khz)
{
    u32 start_freq_khz, end_freq_khz;

    start_freq_khz = center_freq_khz - (bw_khz/2);
    end_freq_khz = center_freq_khz + (bw_khz/2);

    if (start_freq_khz >= freq_range->start_freq_khz &&
        end_freq_khz <= freq_range->end_freq_khz)
        return true;

    return false;
}

static bool freq_in_rule_band(const struct ieee80211_freq_range *freq_range,
    u32 freq_khz)
{
#define ONE_GHZ_IN_KHZ  1000000
    /*
     * From 802.11ad: directional multi-gigabit (DMG):
     * Pertaining to operation in a frequency band containing a channel
     * with the Channel starting frequency above 45 GHz.
     */
    u32 limit = freq_khz > 45 * ONE_GHZ_IN_KHZ ?
            10 * ONE_GHZ_IN_KHZ : 2 * ONE_GHZ_IN_KHZ;
    if (abs(freq_khz - freq_range->start_freq_khz) <= limit)
        return true;
    if (abs(freq_khz - freq_range->end_freq_khz) <= limit)
        return true;
    return false;
#undef ONE_GHZ_IN_KHZ
}

/*
 * Helper for regdom_intersect(), this does the real
 * mathematical intersection fun
 */
static int reg_rules_intersect(
    const struct ieee80211_reg_rule *rule1,
    const struct ieee80211_reg_rule *rule2,
    struct ieee80211_reg_rule *intersected_rule)
{
    const struct ieee80211_freq_range *freq_range1, *freq_range2;
    struct ieee80211_freq_range *freq_range;
    const struct ieee80211_power_rule *power_rule1, *power_rule2;
    struct ieee80211_power_rule *power_rule;
    u32 freq_diff;

    freq_range1 = &rule1->freq_range;
    freq_range2 = &rule2->freq_range;
    freq_range = &intersected_rule->freq_range;

    power_rule1 = &rule1->power_rule;
    power_rule2 = &rule2->power_rule;
    power_rule = &intersected_rule->power_rule;

    freq_range->start_freq_khz = max(freq_range1->start_freq_khz,
        freq_range2->start_freq_khz);
    freq_range->end_freq_khz = min(freq_range1->end_freq_khz,
        freq_range2->end_freq_khz);
    freq_range->max_bandwidth_khz = min(freq_range1->max_bandwidth_khz,
        freq_range2->max_bandwidth_khz);

    freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz;
    if (freq_range->max_bandwidth_khz > freq_diff)
        freq_range->max_bandwidth_khz = freq_diff;

    power_rule->max_eirp = min(power_rule1->max_eirp,
        power_rule2->max_eirp);
    power_rule->max_antenna_gain = min(power_rule1->max_antenna_gain,
        power_rule2->max_antenna_gain);

    intersected_rule->flags = (rule1->flags | rule2->flags);

    if (!is_valid_reg_rule(intersected_rule))
        return -EINVAL;

    return 0;
}

static struct ieee80211_regdomain *regdom_intersect(
    const struct ieee80211_regdomain *rd1,
    const struct ieee80211_regdomain *rd2)
{
    int r, size_of_regd;
    unsigned int x, y;
    unsigned int num_rules = 0, rule_idx = 0;
    const struct ieee80211_reg_rule *rule1, *rule2;
    struct ieee80211_reg_rule *intersected_rule;
    struct ieee80211_regdomain *rd;
    /* This is just a dummy holder to help us count */
    struct ieee80211_reg_rule irule;

    /* Uses the stack temporarily for counter arithmetic */
    intersected_rule = &irule;

    memset(intersected_rule, 0, sizeof(struct ieee80211_reg_rule));

    if (!rd1 || !rd2)
        return NULL;

    /*
     * First we get a count of the rules we'll need, then we actually
     * build them. This is to so we can malloc() and free() a
     * regdomain once. The reason we use reg_rules_intersect() here
     * is it will return -EINVAL if the rule computed makes no sense.
     * All rules that do check out OK are valid.
     */

    for (x = 0; x < rd1->n_reg_rules; x++) {
        rule1 = &rd1->reg_rules[x];
        for (y = 0; y < rd2->n_reg_rules; y++) {
            rule2 = &rd2->reg_rules[y];
            if (!reg_rules_intersect(rule1, rule2,
                    intersected_rule))
                num_rules++;
            memset(intersected_rule, 0,
                    sizeof(struct ieee80211_reg_rule));
        }
    }

    if (!num_rules)
        return NULL;

    size_of_regd = sizeof(struct ieee80211_regdomain) +
        ((num_rules + 1) * sizeof(struct ieee80211_reg_rule));

    rd = kzalloc(size_of_regd, GFP_KERNEL);
    if (!rd)
        return NULL;

    for (x = 0; x < rd1->n_reg_rules; x++) {
        rule1 = &rd1->reg_rules[x];
        for (y = 0; y < rd2->n_reg_rules; y++) {
            rule2 = &rd2->reg_rules[y];
            /*
             * This time around instead of using the stack lets
             * write to the target rule directly saving ourselves
             * a memcpy()
             */
            intersected_rule = &rd->reg_rules[rule_idx];
            r = reg_rules_intersect(rule1, rule2,
                intersected_rule);
            /*
             * No need to memset here the intersected rule here as
             * we're not using the stack anymore
             */
            if (r)
                continue;
            rule_idx++;
        }
    }

    if (rule_idx != num_rules) {
        kfree(rd);
        return NULL;
    }

    rd->n_reg_rules = num_rules;
    rd->alpha2[0] = '9';
    rd->alpha2[1] = '8';

    return rd;
}

/*
 * 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;
    if (rd_flags & NL80211_RRF_NO_OFDM)
        channel_flags |= IEEE80211_CHAN_NO_OFDM;
    return channel_flags;
}

static int freq_reg_info_regd(struct wiphy *wiphy,
                  u32 center_freq,
                  u32 desired_bw_khz,
                  const struct ieee80211_reg_rule **reg_rule,
                  const struct ieee80211_regdomain *custom_regd)
{
    int i;
    bool band_rule_found = false;
    const struct ieee80211_regdomain *regd;
    bool bw_fits = false;

    if (!desired_bw_khz)
        desired_bw_khz = MHZ_TO_KHZ(20);

    regd = custom_regd ? custom_regd : cfg80211_regdomain;

    /*
     * Follow the driver's regulatory domain, if present, unless a country
     * IE has been processed or a user wants to help complaince further
     */
    if (!custom_regd &&
        last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
        last_request->initiator != NL80211_REGDOM_SET_BY_USER &&
        wiphy->regd)
        regd = wiphy->regd;

    if (!regd)
        return -EINVAL;

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

        rr = &regd->reg_rules[i];
        fr = &rr->freq_range;

        /*
         * We only need to know if one frequency rule was
         * was in center_freq's band, that's enough, so lets
         * not overwrite it once found
         */
        if (!band_rule_found)
            band_rule_found = freq_in_rule_band(fr, center_freq);

        bw_fits = reg_does_bw_fit(fr,
                      center_freq,
                      desired_bw_khz);

        if (band_rule_found && bw_fits) {
            *reg_rule = rr;
            return 0;
        }
    }

    if (!band_rule_found)
        return -ERANGE;

    return -EINVAL;
}

int freq_reg_info(struct wiphy *wiphy,
          u32 center_freq,
          u32 desired_bw_khz,
          const struct ieee80211_reg_rule **reg_rule)
{
    assert_cfg80211_lock();
    return freq_reg_info_regd(wiphy,
                  center_freq,
                  desired_bw_khz,
                  reg_rule,
                  NULL);
}
EXPORT_SYMBOL(freq_reg_info);

#ifdef CONFIG_CFG80211_REG_DEBUG
static const char *reg_initiator_name(enum nl80211_reg_initiator initiator)
{
    switch (initiator) {
    case NL80211_REGDOM_SET_BY_CORE:
        return "Set by core";
    case NL80211_REGDOM_SET_BY_USER:
        return "Set by user";
    case NL80211_REGDOM_SET_BY_DRIVER:
        return "Set by driver";
    case NL80211_REGDOM_SET_BY_COUNTRY_IE:
        return "Set by country IE";
    default:
        WARN_ON(1);
        return "Set by bug";
    }
}

static void chan_reg_rule_print_dbg(struct ieee80211_channel *chan,
                    u32 desired_bw_khz,
                    const struct ieee80211_reg_rule *reg_rule)
{
    const struct ieee80211_power_rule *power_rule;
    const struct ieee80211_freq_range *freq_range;
    char max_antenna_gain[32];

    power_rule = &reg_rule->power_rule;
    freq_range = &reg_rule->freq_range;

    if (!power_rule->max_antenna_gain)
        snprintf(max_antenna_gain, 32, "N/A");
    else
        snprintf(max_antenna_gain, 32, "%d", power_rule->max_antenna_gain);

    REG_DBG_PRINT("Updating information on frequency %d MHz "
              "for a %d MHz width channel with regulatory rule:\n",
              chan->center_freq,
              KHZ_TO_MHZ(desired_bw_khz));

    REG_DBG_PRINT("%d KHz - %d KHz @ %d KHz), (%s mBi, %d mBm)\n",
              freq_range->start_freq_khz,
              freq_range->end_freq_khz,
              freq_range->max_bandwidth_khz,
              max_antenna_gain,
              power_rule->max_eirp);
}
#else
static void chan_reg_rule_print_dbg(struct ieee80211_channel *chan,
                    u32 desired_bw_khz,
                    const struct ieee80211_reg_rule *reg_rule)
{
    return;
}
#endif

/*
 * Note that right now we assume the desired channel bandwidth
 * is always 20 MHz for each individual channel (HT40 uses 20 MHz
 * per channel, the primary and the extension channel). To support
 * smaller custom bandwidths such as 5 MHz or 10 MHz we'll need a
 * new ieee80211_channel.target_bw and re run the regulatory check
 * on the wiphy with the target_bw specified. Then we can simply use
 * that below for the desired_bw_khz below.
 */
static void handle_channel(struct wiphy *wiphy,
               enum nl80211_reg_initiator initiator,
               enum ieee80211_band band,
               unsigned int chan_idx)
{
    int r;
    u32 flags, bw_flags = 0;
    u32 desired_bw_khz = MHZ_TO_KHZ(20);
    const struct ieee80211_reg_rule *reg_rule = NULL;
    const struct ieee80211_power_rule *power_rule = NULL;
    const struct ieee80211_freq_range *freq_range = NULL;
    struct ieee80211_supported_band *sband;
    struct ieee80211_channel *chan;
    struct wiphy *request_wiphy = NULL;

    assert_cfg80211_lock();

    request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);

    sband = wiphy->bands[band];
    BUG_ON(chan_idx >= sband->n_channels);
    chan = &sband->channels[chan_idx];

    flags = chan->orig_flags;

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

    if (r) {
        /*
         * We will disable all channels that do not match our
         * received regulatory rule unless the hint is coming
         * from a Country IE and the Country IE had no information
         * about a band. The IEEE 802.11 spec allows for an AP
         * to send only a subset of the regulatory rules allowed,
         * so an AP in the US that only supports 2.4 GHz may only send
         * a country IE with information for the 2.4 GHz band
         * while 5 GHz is still supported.
         */
        if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
            r == -ERANGE)
            return;

        REG_DBG_PRINT("Disabling freq %d MHz\n", chan->center_freq);
        chan->flags = IEEE80211_CHAN_DISABLED;
        return;
    }

    chan_reg_rule_print_dbg(chan, desired_bw_khz, reg_rule);

    power_rule = &reg_rule->power_rule;
    freq_range = &reg_rule->freq_range;

    if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(40))
        bw_flags = IEEE80211_CHAN_NO_HT40;

    if (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
        request_wiphy && request_wiphy == wiphy &&
        request_wiphy->flags & WIPHY_FLAG_STRICT_REGULATORY) {
        /*
         * This guarantees the driver's requested regulatory domain
         * will always be used as a base for further regulatory
         * settings
         */
        chan->flags = chan->orig_flags =
            map_regdom_flags(reg_rule->flags) | bw_flags;
        chan->max_antenna_gain = chan->orig_mag =
            (int) MBI_TO_DBI(power_rule->max_antenna_gain);
        chan->max_reg_power = chan->max_power = chan->orig_mpwr =
            (int) MBM_TO_DBM(power_rule->max_eirp);
        return;
    }

    chan->beacon_found = false;
    chan->flags = flags | bw_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_reg_power = (int) MBM_TO_DBM(power_rule->max_eirp);
    if (chan->orig_mpwr) {
        /*
         * Devices that have their own custom regulatory domain
         * but also use WIPHY_FLAG_STRICT_REGULATORY will follow the
         * passed country IE power settings.
         */
        if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
            wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY &&
            wiphy->flags & WIPHY_FLAG_STRICT_REGULATORY)
            chan->max_power = chan->max_reg_power;
        else
            chan->max_power = min(chan->orig_mpwr,
                          chan->max_reg_power);
    } else
        chan->max_power = chan->max_reg_power;
}

static void handle_band(struct wiphy *wiphy,
            enum ieee80211_band band,
            enum nl80211_reg_initiator initiator)
{
    unsigned int i;
    struct ieee80211_supported_band *sband;

    BUG_ON(!wiphy->bands[band]);
    sband = wiphy->bands[band];

    for (i = 0; i < sband->n_channels; i++)
        handle_channel(wiphy, initiator, band, i);
}

static bool reg_request_cell_base(struct regulatory_request *request)
{
    if (request->initiator != NL80211_REGDOM_SET_BY_USER)
        return false;
    if (request->user_reg_hint_type != NL80211_USER_REG_HINT_CELL_BASE)
        return false;
    return true;
}

bool reg_last_request_cell_base(void)
{
    bool val;
    assert_cfg80211_lock();

    mutex_lock(&reg_mutex);
    val = reg_request_cell_base(last_request);
    mutex_unlock(&reg_mutex);
    return val;
}

#ifdef CONFIG_CFG80211_CERTIFICATION_ONUS

/* Core specific check */
static int reg_ignore_cell_hint(struct regulatory_request *pending_request)
{
    if (!reg_num_devs_support_basehint)
        return -EOPNOTSUPP;

    if (reg_request_cell_base(last_request)) {
        if (!regdom_changes(pending_request->alpha2))
            return -EALREADY;
        return 0;
    }
    return 0;
}

/* Device specific check */
static bool reg_dev_ignore_cell_hint(struct wiphy *wiphy)
{
    if (!(wiphy->features & NL80211_FEATURE_CELL_BASE_REG_HINTS))
        return true;
    return false;
}
#else
static int reg_ignore_cell_hint(struct regulatory_request *pending_request)
{
    return -EOPNOTSUPP;
}
static int reg_dev_ignore_cell_hint(struct wiphy *wiphy)
{
    return true;
}
#endif


static bool ignore_reg_update(struct wiphy *wiphy,
                  enum nl80211_reg_initiator initiator)
{
    if (!last_request) {
        REG_DBG_PRINT("Ignoring regulatory request %s since "
                  "last_request is not set\n",
                  reg_initiator_name(initiator));
        return true;
    }

    if (initiator == NL80211_REGDOM_SET_BY_CORE &&
        wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY) {
        REG_DBG_PRINT("Ignoring regulatory request %s "
                  "since the driver uses its own custom "
                  "regulatory domain\n",
                  reg_initiator_name(initiator));
        return true;
    }

    /*
     * wiphy->regd will be set once the device has its own
     * desired regulatory domain set
     */
    if (wiphy->flags & WIPHY_FLAG_STRICT_REGULATORY && !wiphy->regd &&
        initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
        !is_world_regdom(last_request->alpha2)) {
        REG_DBG_PRINT("Ignoring regulatory request %s "
                  "since the driver requires its own regulatory "
                  "domain to be set first\n",
                  reg_initiator_name(initiator));
        return true;
    }

    if (reg_request_cell_base(last_request))
        return reg_dev_ignore_cell_hint(wiphy);

    return false;
}

static void handle_reg_beacon(struct wiphy *wiphy,
                  unsigned int chan_idx,
                  struct reg_beacon *reg_beacon)
{
    struct ieee80211_supported_band *sband;
    struct ieee80211_channel *chan;
    bool channel_changed = false;
    struct ieee80211_channel chan_before;

    assert_cfg80211_lock();

    sband = wiphy->bands[reg_beacon->chan.band];
    chan = &sband->channels[chan_idx];

    if (likely(chan->center_freq != reg_beacon->chan.center_freq))
        return;

    if (chan->beacon_found)
        return;

    chan->beacon_found = true;

    if (wiphy->flags & WIPHY_FLAG_DISABLE_BEACON_HINTS)
        return;

    chan_before.center_freq = chan->center_freq;
    chan_before.flags = chan->flags;

    if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) {
        chan->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
        channel_changed = true;
    }

    if (chan->flags & IEEE80211_CHAN_NO_IBSS) {
        chan->flags &= ~IEEE80211_CHAN_NO_IBSS;
        channel_changed = true;
    }

    if (channel_changed)
        nl80211_send_beacon_hint_event(wiphy, &chan_before, chan);
}

/*
 * Called when a scan on a wiphy finds a beacon on
 * new channel
 */
static void wiphy_update_new_beacon(struct wiphy *wiphy,
                    struct reg_beacon *reg_beacon)
{
    unsigned int i;
    struct ieee80211_supported_band *sband;

    assert_cfg80211_lock();

    if (!wiphy->bands[reg_beacon->chan.band])
        return;

    sband = wiphy->bands[reg_beacon->chan.band];

    for (i = 0; i < sband->n_channels; i++)
        handle_reg_beacon(wiphy, i, reg_beacon);
}

/*
 * Called upon reg changes or a new wiphy is added
 */
static void wiphy_update_beacon_reg(struct wiphy *wiphy)
{
    unsigned int i;
    struct ieee80211_supported_band *sband;
    struct reg_beacon *reg_beacon;

    assert_cfg80211_lock();

    if (list_empty(&reg_beacon_list))
        return;

    list_for_each_entry(reg_beacon, &reg_beacon_list, list) {
        if (!wiphy->bands[reg_beacon->chan.band])
            continue;
        sband = wiphy->bands[reg_beacon->chan.band];
        for (i = 0; i < sband->n_channels; i++)
            handle_reg_beacon(wiphy, i, reg_beacon);
    }
}

static bool reg_is_world_roaming(struct wiphy *wiphy)
{
    if (is_world_regdom(cfg80211_regdomain->alpha2) ||
        (wiphy->regd && is_world_regdom(wiphy->regd->alpha2)))
        return true;
    if (last_request &&
        last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
        wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY)
        return true;
    return false;
}

/* Reap the advantages of previously found beacons */
static void reg_process_beacons(struct wiphy *wiphy)
{
    /*
     * Means we are just firing up cfg80211, so no beacons would
     * have been processed yet.
     */
    if (!last_request)
        return;
    if (!reg_is_world_roaming(wiphy))
        return;
    wiphy_update_beacon_reg(wiphy);
}

static bool is_ht40_not_allowed(struct ieee80211_channel *chan)
{
    if (!chan)
        return true;
    if (chan->flags & IEEE80211_CHAN_DISABLED)
        return true;
    /* This would happen when regulatory rules disallow HT40 completely */
    if (IEEE80211_CHAN_NO_HT40 == (chan->flags & (IEEE80211_CHAN_NO_HT40)))
        return true;
    return false;
}

static void reg_process_ht_flags_channel(struct wiphy *wiphy,
                     enum ieee80211_band band,
                     unsigned int chan_idx)
{
    struct ieee80211_supported_band *sband;
    struct ieee80211_channel *channel;
    struct ieee80211_channel *channel_before = NULL, *channel_after = NULL;
    unsigned int i;

    assert_cfg80211_lock();

    sband = wiphy->bands[band];
    BUG_ON(chan_idx >= sband->n_channels);
    channel = &sband->channels[chan_idx];

    if (is_ht40_not_allowed(channel)) {
        channel->flags |= IEEE80211_CHAN_NO_HT40;
        return;
    }

    /*
     * We need to ensure the extension channels exist to
     * be able to use HT40- or HT40+, this finds them (or not)
     */
    for (i = 0; i < sband->n_channels; i++) {
        struct ieee80211_channel *c = &sband->channels[i];
        if (c->center_freq == (channel->center_freq - 20))
            channel_before = c;
        if (c->center_freq == (channel->center_freq + 20))
            channel_after = c;
    }

    /*
     * Please note that this assumes target bandwidth is 20 MHz,
     * if that ever changes we also need to change the below logic
     * to include that as well.
     */
    if (is_ht40_not_allowed(channel_before))
        channel->flags |= IEEE80211_CHAN_NO_HT40MINUS;
    else
        channel->flags &= ~IEEE80211_CHAN_NO_HT40MINUS;

    if (is_ht40_not_allowed(channel_after))
        channel->flags |= IEEE80211_CHAN_NO_HT40PLUS;
    else
        channel->flags &= ~IEEE80211_CHAN_NO_HT40PLUS;
}

static void reg_process_ht_flags_band(struct wiphy *wiphy,
                      enum ieee80211_band band)
{
    unsigned int i;
    struct ieee80211_supported_band *sband;

    BUG_ON(!wiphy->bands[band]);
    sband = wiphy->bands[band];

    for (i = 0; i < sband->n_channels; i++)
        reg_process_ht_flags_channel(wiphy, band, i);
}

static void reg_process_ht_flags(struct wiphy *wiphy)
{
    enum ieee80211_band band;

    if (!wiphy)
        return;

    for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
        if (wiphy->bands[band])
            reg_process_ht_flags_band(wiphy, band);
    }

}

static void wiphy_update_regulatory(struct wiphy *wiphy,
                    enum nl80211_reg_initiator initiator)
{
    enum ieee80211_band band;

    assert_reg_lock();

    if (ignore_reg_update(wiphy, initiator))
        return;

    last_request->dfs_region = cfg80211_regdomain->dfs_region;

    for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
        if (wiphy->bands[band])
            handle_band(wiphy, band, initiator);
    }

    reg_process_beacons(wiphy);
    reg_process_ht_flags(wiphy);
    if (wiphy->reg_notifier)
        wiphy->reg_notifier(wiphy, last_request);
}

static void update_all_wiphy_regulatory(enum nl80211_reg_initiator initiator)
{
    struct cfg80211_registered_device *rdev;
    struct wiphy *wiphy;

    list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
        wiphy = &rdev->wiphy;
        wiphy_update_regulatory(wiphy, initiator);
        /*
         * Regulatory updates set by CORE are ignored for custom
         * regulatory cards. Let us notify the changes to the driver,
         * as some drivers used this to restore its orig_* reg domain.
         */
        if (initiator == NL80211_REGDOM_SET_BY_CORE &&
            wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY &&
            wiphy->reg_notifier)
            wiphy->reg_notifier(wiphy, last_request);
    }
}

static void handle_channel_custom(struct wiphy *wiphy,
                  enum ieee80211_band band,
                  unsigned int chan_idx,
                  const struct ieee80211_regdomain *regd)
{
    int r;
    u32 desired_bw_khz = MHZ_TO_KHZ(20);
    u32 bw_flags = 0;
    const struct ieee80211_reg_rule *reg_rule = NULL;
    const struct ieee80211_power_rule *power_rule = NULL;
    const struct ieee80211_freq_range *freq_range = NULL;
    struct ieee80211_supported_band *sband;
    struct ieee80211_channel *chan;

    assert_reg_lock();

    sband = wiphy->bands[band];
    BUG_ON(chan_idx >= sband->n_channels);
    chan = &sband->channels[chan_idx];

    r = freq_reg_info_regd(wiphy,
                   MHZ_TO_KHZ(chan->center_freq),
                   desired_bw_khz,
                   &reg_rule,
                   regd);

    if (r) {
        REG_DBG_PRINT("Disabling freq %d MHz as custom "
                  "regd has no rule that fits a %d MHz "
                  "wide channel\n",
                  chan->center_freq,
                  KHZ_TO_MHZ(desired_bw_khz));
        chan->flags = IEEE80211_CHAN_DISABLED;
        return;
    }

    chan_reg_rule_print_dbg(chan, desired_bw_khz, reg_rule);

    power_rule = &reg_rule->power_rule;
    freq_range = &reg_rule->freq_range;

    if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(40))
        bw_flags = IEEE80211_CHAN_NO_HT40;

    chan->flags |= map_regdom_flags(reg_rule->flags) | bw_flags;
    chan->max_antenna_gain = (int) MBI_TO_DBI(power_rule->max_antenna_gain);
    chan->max_reg_power = chan->max_power =
        (int) MBM_TO_DBM(power_rule->max_eirp);
}

static void handle_band_custom(struct wiphy *wiphy, enum ieee80211_band band,
                   const struct ieee80211_regdomain *regd)
{
    unsigned int i;
    struct ieee80211_supported_band *sband;

    BUG_ON(!wiphy->bands[band]);
    sband = wiphy->bands[band];

    for (i = 0; i < sband->n_channels; i++)
        handle_channel_custom(wiphy, band, i, regd);
}

/* Used by drivers prior to wiphy registration */
void wiphy_apply_custom_regulatory(struct wiphy *wiphy,
                   const struct ieee80211_regdomain *regd)
{
    enum ieee80211_band band;
    unsigned int bands_set = 0;

    mutex_lock(&reg_mutex);
    for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
        if (!wiphy->bands[band])
            continue;
        handle_band_custom(wiphy, band, regd);
        bands_set++;
    }
    mutex_unlock(&reg_mutex);

    /*
     * no point in calling this if it won't have any effect
     * on your device's supportd bands.
     */
    WARN_ON(!bands_set);
}
EXPORT_SYMBOL(wiphy_apply_custom_regulatory);

/*
 * Return value which can be used by ignore_request() to indicate
 * it has been determined we should intersect two regulatory domains
 */
#define REG_INTERSECT   1

/* This has the logic which determines when a new request
 * should be ignored. */
static int ignore_request(struct wiphy *wiphy,
              struct regulatory_request *pending_request)
{
    struct wiphy *last_wiphy = NULL;

    assert_cfg80211_lock();

    /* All initial requests are respected */
    if (!last_request)
        return 0;

    switch (pending_request->initiator) {
    case NL80211_REGDOM_SET_BY_CORE:
        return 0;
    case NL80211_REGDOM_SET_BY_COUNTRY_IE:

        if (reg_request_cell_base(last_request)) {
            /* Trust a Cell base station over the AP's country IE */
            if (regdom_changes(pending_request->alpha2))
                return -EOPNOTSUPP;
            return -EALREADY;
        }

        last_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);

        if (unlikely(!is_an_alpha2(pending_request->alpha2)))
            return -EINVAL;
        if (last_request->initiator ==
            NL80211_REGDOM_SET_BY_COUNTRY_IE) {
            if (last_wiphy != wiphy) {
                /*
                 * Two cards with two APs claiming different
                 * Country IE alpha2s. We could
                 * intersect them, but that seems unlikely
                 * to be correct. Reject second one for now.
                 */
                if (regdom_changes(pending_request->alpha2))
                    return -EOPNOTSUPP;
                return -EALREADY;
            }
            /*
             * Two consecutive Country IE hints on the same wiphy.
             * This should be picked up early by the driver/stack
             */
            if (WARN_ON(regdom_changes(pending_request->alpha2)))
                return 0;
            return -EALREADY;
        }
        return 0;
    case NL80211_REGDOM_SET_BY_DRIVER:
        if (last_request->initiator == NL80211_REGDOM_SET_BY_CORE) {
            if (regdom_changes(pending_request->alpha2))
                return 0;
            return -EALREADY;
        }

        /*
         * This would happen if you unplug and plug your card
         * back in or if you add a new device for which the previously
         * loaded card also agrees on the regulatory domain.
         */
        if (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
            !regdom_changes(pending_request->alpha2))
            return -EALREADY;

        return REG_INTERSECT;
    case NL80211_REGDOM_SET_BY_USER:
        if (reg_request_cell_base(pending_request))
            return reg_ignore_cell_hint(pending_request);

        if (reg_request_cell_base(last_request))
            return -EOPNOTSUPP;

        if (last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE)
            return REG_INTERSECT;
        /*
         * If the user knows better the user should set the regdom
         * to their country before the IE is picked up
         */
        if (last_request->initiator == NL80211_REGDOM_SET_BY_USER &&
              last_request->intersect)
            return -EOPNOTSUPP;
        /*
         * Process user requests only after previous user/driver/core
         * requests have been processed
         */
        if (last_request->initiator == NL80211_REGDOM_SET_BY_CORE ||
            last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER ||
            last_request->initiator == NL80211_REGDOM_SET_BY_USER) {
            if (regdom_changes(last_request->alpha2))
                return -EAGAIN;
        }

        if (!regdom_changes(pending_request->alpha2))
            return -EALREADY;

        return 0;
    }

    return -EINVAL;
}

static void reg_set_request_processed(void)
{
    bool need_more_processing = false;

    last_request->processed = true;

    spin_lock(&reg_requests_lock);
    if (!list_empty(&reg_requests_list))
        need_more_processing = true;
    spin_unlock(&reg_requests_lock);

    if (last_request->initiator == NL80211_REGDOM_SET_BY_USER)
        cancel_delayed_work(&reg_timeout);

    if (need_more_processing)
        schedule_work(&reg_work);
}

static int __regulatory_hint(struct wiphy *wiphy,
                 struct regulatory_request *pending_request)
{
    bool intersect = false;
    int r = 0;

    assert_cfg80211_lock();

    r = ignore_request(wiphy, pending_request);

    if (r == REG_INTERSECT) {
        if (pending_request->initiator ==
            NL80211_REGDOM_SET_BY_DRIVER) {
            r = reg_copy_regd(&wiphy->regd, cfg80211_regdomain);
            if (r) {
                kfree(pending_request);
                return r;
            }
        }
        intersect = true;
    } else if (r) {
        /*
         * If the regulatory domain being requested by the
         * driver has already been set just copy it to the
         * wiphy
         */
        if (r == -EALREADY &&
            pending_request->initiator ==
            NL80211_REGDOM_SET_BY_DRIVER) {
            r = reg_copy_regd(&wiphy->regd, cfg80211_regdomain);
            if (r) {
                kfree(pending_request);
                return r;
            }
            r = -EALREADY;
            goto new_request;
        }
        kfree(pending_request);
        return r;
    }

new_request:
    if (last_request != &core_request_world)
        kfree(last_request);

    last_request = pending_request;
    last_request->intersect = intersect;

    pending_request = NULL;

    if (last_request->initiator == NL80211_REGDOM_SET_BY_USER) {
        user_alpha2[0] = last_request->alpha2[0];
        user_alpha2[1] = last_request->alpha2[1];
    }

    /* When r == REG_INTERSECT we do need to call CRDA */
    if (r < 0) {
        /*
         * Since CRDA will not be called in this case as we already
         * have applied the requested regulatory domain before we just
         * inform userspace we have processed the request
         */
        if (r == -EALREADY) {
            nl80211_send_reg_change_event(last_request);
            reg_set_request_processed();
        }
        return r;
    }

    return call_crda(last_request->alpha2);
}

/* This processes *all* regulatory hints */
static void reg_process_hint(struct regulatory_request *reg_request,
                 enum nl80211_reg_initiator reg_initiator)
{
    int r = 0;
    struct wiphy *wiphy = NULL;

    BUG_ON(!reg_request->alpha2);

    if (wiphy_idx_valid(reg_request->wiphy_idx))
        wiphy = wiphy_idx_to_wiphy(reg_request->wiphy_idx);

    if (reg_initiator == NL80211_REGDOM_SET_BY_DRIVER &&
        !wiphy) {
        kfree(reg_request);
        return;
    }

    r = __regulatory_hint(wiphy, reg_request);
    /* This is required so that the orig_* parameters are saved */
    if (r == -EALREADY && wiphy &&
        wiphy->flags & WIPHY_FLAG_STRICT_REGULATORY) {
        wiphy_update_regulatory(wiphy, reg_initiator);
        return;
    }

    /*
     * We only time out user hints, given that they should be the only
     * source of bogus requests.
     */
    if (r != -EALREADY &&
        reg_initiator == NL80211_REGDOM_SET_BY_USER)
        schedule_delayed_work(&reg_timeout, msecs_to_jiffies(3142));
}

/*
 * Processes regulatory hints, this is all the NL80211_REGDOM_SET_BY_*
 * Regulatory hints come on a first come first serve basis and we
 * must process each one atomically.
 */
static void reg_process_pending_hints(void)
{
    struct regulatory_request *reg_request;

    mutex_lock(&cfg80211_mutex);
    mutex_lock(&reg_mutex);

    /* When last_request->processed becomes true this will be rescheduled */
    if (last_request && !last_request->processed) {
        REG_DBG_PRINT("Pending regulatory request, waiting "
                  "for it to be processed...\n");
        goto out;
    }

    spin_lock(&reg_requests_lock);

    if (list_empty(&reg_requests_list)) {
        spin_unlock(&reg_requests_lock);
        goto out;
    }

    reg_request = list_first_entry(&reg_requests_list,
                       struct regulatory_request,
                       list);
    list_del_init(&reg_request->list);

    spin_unlock(&reg_requests_lock);

    reg_process_hint(reg_request, reg_request->initiator);

out:
    mutex_unlock(&reg_mutex);
    mutex_unlock(&cfg80211_mutex);
}

/* Processes beacon hints -- this has nothing to do with country IEs */
static void reg_process_pending_beacon_hints(void)
{
    struct cfg80211_registered_device *rdev;
    struct reg_beacon *pending_beacon, *tmp;

    /*
     * No need to hold the reg_mutex here as we just touch wiphys
     * and do not read or access regulatory variables.
     */
    mutex_lock(&cfg80211_mutex);

    /* This goes through the _pending_ beacon list */
    spin_lock_bh(&reg_pending_beacons_lock);

    if (list_empty(&reg_pending_beacons)) {
        spin_unlock_bh(&reg_pending_beacons_lock);
        goto out;
    }

    list_for_each_entry_safe(pending_beacon, tmp,
                 &reg_pending_beacons, list) {

        list_del_init(&pending_beacon->list);

        /* Applies the beacon hint to current wiphys */
        list_for_each_entry(rdev, &cfg80211_rdev_list, list)
            wiphy_update_new_beacon(&rdev->wiphy, pending_beacon);

        /* Remembers the beacon hint for new wiphys or reg changes */
        list_add_tail(&pending_beacon->list, &reg_beacon_list);
    }

    spin_unlock_bh(&reg_pending_beacons_lock);
out:
    mutex_unlock(&cfg80211_mutex);
}

static void reg_todo(struct work_struct *work)
{
    reg_process_pending_hints();
    reg_process_pending_beacon_hints();
}

static void queue_regulatory_request(struct regulatory_request *request)
{
    if (isalpha(request->alpha2[0]))
        request->alpha2[0] = toupper(request->alpha2[0]);
    if (isalpha(request->alpha2[1]))
        request->alpha2[1] = toupper(request->alpha2[1]);

    spin_lock(&reg_requests_lock);
    list_add_tail(&request->list, &reg_requests_list);
    spin_unlock(&reg_requests_lock);

    schedule_work(&reg_work);
}

/*
 * Core regulatory hint -- happens during cfg80211_init()
 * and when we restore regulatory settings.
 */
static int regulatory_hint_core(const char *alpha2)
{
    struct regulatory_request *request;

    request = kzalloc(sizeof(struct regulatory_request),
              GFP_KERNEL);
    if (!request)
        return -ENOMEM;

    request->alpha2[0] = alpha2[0];
    request->alpha2[1] = alpha2[1];
    request->initiator = NL80211_REGDOM_SET_BY_CORE;

    queue_regulatory_request(request);

    return 0;
}

/* User hints */
int regulatory_hint_user(const char *alpha2,
             enum nl80211_user_reg_hint_type user_reg_hint_type)
{
    struct regulatory_request *request;

    BUG_ON(!alpha2);

    request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL);
    if (!request)
        return -ENOMEM;

    request->wiphy_idx = WIPHY_IDX_STALE;
    request->alpha2[0] = alpha2[0];
    request->alpha2[1] = alpha2[1];
    request->initiator = NL80211_REGDOM_SET_BY_USER;
    request->user_reg_hint_type = user_reg_hint_type;

    queue_regulatory_request(request);

    return 0;
}

/* Driver hints */
int regulatory_hint(struct wiphy *wiphy, const char *alpha2)
{
    struct regulatory_request *request;

    BUG_ON(!alpha2);
    BUG_ON(!wiphy);

    request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL);
    if (!request)
        return -ENOMEM;

    request->wiphy_idx = get_wiphy_idx(wiphy);

    /* Must have registered wiphy first */
    BUG_ON(!wiphy_idx_valid(request->wiphy_idx));

    request->alpha2[0] = alpha2[0];
    request->alpha2[1] = alpha2[1];
    request->initiator = NL80211_REGDOM_SET_BY_DRIVER;

    queue_regulatory_request(request);

    return 0;
}
EXPORT_SYMBOL(regulatory_hint);

/*
 * We hold wdev_lock() here so we cannot hold cfg80211_mutex() and
 * therefore cannot iterate over the rdev list here.
 */
void regulatory_hint_11d(struct wiphy *wiphy,
             enum ieee80211_band band,
             u8 *country_ie,
             u8 country_ie_len)
{
    char alpha2[2];
    enum environment_cap env = ENVIRON_ANY;
    struct regulatory_request *request;

    mutex_lock(&reg_mutex);

    if (unlikely(!last_request))
        goto out;

    /* IE len must be evenly divisible by 2 */
    if (country_ie_len & 0x01)
        goto out;

    if (country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN)
        goto out;

    alpha2[0] = country_ie[0];
    alpha2[1] = country_ie[1];

    if (country_ie[2] == 'I')
        env = ENVIRON_INDOOR;
    else if (country_ie[2] == 'O')
        env = ENVIRON_OUTDOOR;

    /*
     * We will run this only upon a successful connection on cfg80211.
     * We leave conflict resolution to the workqueue, where can hold
     * cfg80211_mutex.
     */
    if (likely(last_request->initiator ==
        NL80211_REGDOM_SET_BY_COUNTRY_IE &&
        wiphy_idx_valid(last_request->wiphy_idx)))
        goto out;

    request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL);
    if (!request)
        goto out;

    request->wiphy_idx = get_wiphy_idx(wiphy);
    request->alpha2[0] = alpha2[0];
    request->alpha2[1] = alpha2[1];
    request->initiator = NL80211_REGDOM_SET_BY_COUNTRY_IE;
    request->country_ie_env = env;

    mutex_unlock(&reg_mutex);

    queue_regulatory_request(request);

    return;

out:
    mutex_unlock(&reg_mutex);
}

static void restore_alpha2(char *alpha2, bool reset_user)
{
    /* indicates there is no alpha2 to consider for restoration */
    alpha2[0] = '9';
    alpha2[1] = '7';

    /* The user setting has precedence over the module parameter */
    if (is_user_regdom_saved()) {
        /* Unless we're asked to ignore it and reset it */
        if (reset_user) {
            REG_DBG_PRINT("Restoring regulatory settings "
                   "including user preference\n");
            user_alpha2[0] = '9';
            user_alpha2[1] = '7';

            /*
             * If we're ignoring user settings, we still need to
             * check the module parameter to ensure we put things
             * back as they were for a full restore.
             */
            if (!is_world_regdom(ieee80211_regdom)) {
                REG_DBG_PRINT("Keeping preference on "
                       "module parameter ieee80211_regdom: %c%c\n",
                       ieee80211_regdom[0],
                       ieee80211_regdom[1]);
                alpha2[0] = ieee80211_regdom[0];
                alpha2[1] = ieee80211_regdom[1];
            }
        } else {
            REG_DBG_PRINT("Restoring regulatory settings "
                   "while preserving user preference for: %c%c\n",
                   user_alpha2[0],
                   user_alpha2[1]);
            alpha2[0] = user_alpha2[0];
            alpha2[1] = user_alpha2[1];
        }
    } else if (!is_world_regdom(ieee80211_regdom)) {
        REG_DBG_PRINT("Keeping preference on "
               "module parameter ieee80211_regdom: %c%c\n",
               ieee80211_regdom[0],
               ieee80211_regdom[1]);
        alpha2[0] = ieee80211_regdom[0];
        alpha2[1] = ieee80211_regdom[1];
    } else
        REG_DBG_PRINT("Restoring regulatory settings\n");
}

static void restore_custom_reg_settings(struct wiphy *wiphy)
{
    struct ieee80211_supported_band *sband;
    enum ieee80211_band band;
    struct ieee80211_channel *chan;
    int i;

    for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
        sband = wiphy->bands[band];
        if (!sband)
            continue;
        for (i = 0; i < sband->n_channels; i++) {
            chan = &sband->channels[i];
            chan->flags = chan->orig_flags;
            chan->max_antenna_gain = chan->orig_mag;
            chan->max_power = chan->orig_mpwr;
            chan->beacon_found = false;
        }
    }
}

/*
 * Restoring regulatory settings involves ingoring any
 * possibly stale country IE information and user regulatory
 * settings if so desired, this includes any beacon hints
 * learned as we could have traveled outside to another country
 * after disconnection. To restore regulatory settings we do
 * exactly what we did at bootup:
 *
 *   - send a core regulatory hint
 *   - send a user regulatory hint if applicable
 *
 * Device drivers that send a regulatory hint for a specific country
 * keep their own regulatory domain on wiphy->regd so that does does
 * not need to be remembered.
 */
static void restore_regulatory_settings(bool reset_user)
{
    char alpha2[2];
    char world_alpha2[2];
    struct reg_beacon *reg_beacon, *btmp;
    struct regulatory_request *reg_request, *tmp;
    LIST_HEAD(tmp_reg_req_list);
    struct cfg80211_registered_device *rdev;

    mutex_lock(&cfg80211_mutex);
    mutex_lock(&reg_mutex);

    reset_regdomains(true);
    restore_alpha2(alpha2, reset_user);

    /*
     * If there's any pending requests we simply
     * stash them to a temporary pending queue and
     * add then after we've restored regulatory
     * settings.
     */
    spin_lock(&reg_requests_lock);
    if (!list_empty(&reg_requests_list)) {
        list_for_each_entry_safe(reg_request, tmp,
                     &reg_requests_list, list) {
            if (reg_request->initiator !=
                NL80211_REGDOM_SET_BY_USER)
                continue;
            list_move_tail(&reg_request->list, &tmp_reg_req_list);
        }
    }
    spin_unlock(&reg_requests_lock);

    /* Clear beacon hints */
    spin_lock_bh(&reg_pending_beacons_lock);
    if (!list_empty(&reg_pending_beacons)) {
        list_for_each_entry_safe(reg_beacon, btmp,
                     &reg_pending_beacons, list) {
            list_del(&reg_beacon->list);
            kfree(reg_beacon);
        }
    }
    spin_unlock_bh(&reg_pending_beacons_lock);

    if (!list_empty(&reg_beacon_list)) {
        list_for_each_entry_safe(reg_beacon, btmp,
                     &reg_beacon_list, list) {
            list_del(&reg_beacon->list);
            kfree(reg_beacon);
        }
    }

    /* First restore to the basic regulatory settings */
    cfg80211_regdomain = cfg80211_world_regdom;
    world_alpha2[0] = cfg80211_regdomain->alpha2[0];
    world_alpha2[1] = cfg80211_regdomain->alpha2[1];

    list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
        if (rdev->wiphy.flags & WIPHY_FLAG_CUSTOM_REGULATORY)
            restore_custom_reg_settings(&rdev->wiphy);
    }

    mutex_unlock(&reg_mutex);
    mutex_unlock(&cfg80211_mutex);

    regulatory_hint_core(world_alpha2);

    /*
     * This restores the ieee80211_regdom module parameter
     * preference or the last user requested regulatory
     * settings, user regulatory settings takes precedence.
     */
    if (is_an_alpha2(alpha2))
        regulatory_hint_user(user_alpha2, NL80211_USER_REG_HINT_USER);

    if (list_empty(&tmp_reg_req_list))
        return;

    mutex_lock(&cfg80211_mutex);
    mutex_lock(&reg_mutex);

    spin_lock(&reg_requests_lock);
    list_for_each_entry_safe(reg_request, tmp, &tmp_reg_req_list, list) {
        REG_DBG_PRINT("Adding request for country %c%c back "
                  "into the queue\n",
                  reg_request->alpha2[0],
                  reg_request->alpha2[1]);
        list_move_tail(&reg_request->list, &reg_requests_list);
    }
    spin_unlock(&reg_requests_lock);

    mutex_unlock(&reg_mutex);
    mutex_unlock(&cfg80211_mutex);

    REG_DBG_PRINT("Kicking the queue\n");

    schedule_work(&reg_work);
}

void regulatory_hint_disconnect(void)
{
    REG_DBG_PRINT("All devices are disconnected, going to "
              "restore regulatory settings\n");
    restore_regulatory_settings(false);
}

static bool freq_is_chan_12_13_14(u16 freq)
{
    if (freq == ieee80211_channel_to_frequency(12, IEEE80211_BAND_2GHZ) ||
        freq == ieee80211_channel_to_frequency(13, IEEE80211_BAND_2GHZ) ||
        freq == ieee80211_channel_to_frequency(14, IEEE80211_BAND_2GHZ))
        return true;
    return false;
}

int regulatory_hint_found_beacon(struct wiphy *wiphy,
                 struct ieee80211_channel *beacon_chan,
                 gfp_t gfp)
{
    struct reg_beacon *reg_beacon;

    if (likely((beacon_chan->beacon_found ||
        (beacon_chan->flags & IEEE80211_CHAN_RADAR) ||
        (beacon_chan->band == IEEE80211_BAND_2GHZ &&
         !freq_is_chan_12_13_14(beacon_chan->center_freq)))))
        return 0;

    reg_beacon = kzalloc(sizeof(struct reg_beacon), gfp);
    if (!reg_beacon)
        return -ENOMEM;

    REG_DBG_PRINT("Found new beacon on "
              "frequency: %d MHz (Ch %d) on %s\n",
              beacon_chan->center_freq,
              ieee80211_frequency_to_channel(beacon_chan->center_freq),
              wiphy_name(wiphy));

    memcpy(&reg_beacon->chan, beacon_chan,
        sizeof(struct ieee80211_channel));


    /*
     * Since we can be called from BH or and non-BH context
     * we must use spin_lock_bh()
     */
    spin_lock_bh(&reg_pending_beacons_lock);
    list_add_tail(&reg_beacon->list, &reg_pending_beacons);
    spin_unlock_bh(&reg_pending_beacons_lock);

    schedule_work(&reg_work);

    return 0;
}

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;

    pr_info("  (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)
            pr_info("  (%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
            pr_info("  (%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);
    }
}

bool reg_supported_dfs_region(u8 dfs_region)
{
    switch (dfs_region) {
    case NL80211_DFS_UNSET:
    case NL80211_DFS_FCC:
    case NL80211_DFS_ETSI:
    case NL80211_DFS_JP:
        return true;
    default:
        REG_DBG_PRINT("Ignoring uknown DFS master region: %d\n",
                  dfs_region);
        return false;
    }
}

static void print_dfs_region(u8 dfs_region)
{
    if (!dfs_region)
        return;

    switch (dfs_region) {
    case NL80211_DFS_FCC:
        pr_info(" DFS Master region FCC");
        break;
    case NL80211_DFS_ETSI:
        pr_info(" DFS Master region ETSI");
        break;
    case NL80211_DFS_JP:
        pr_info(" DFS Master region JP");
        break;
    default:
        pr_info(" DFS Master region Uknown");
        break;
    }
}

static void print_regdomain(const struct ieee80211_regdomain *rd)
{

    if (is_intersected_alpha2(rd->alpha2)) {

        if (last_request->initiator ==
            NL80211_REGDOM_SET_BY_COUNTRY_IE) {
            struct cfg80211_registered_device *rdev;
            rdev = cfg80211_rdev_by_wiphy_idx(
                last_request->wiphy_idx);
            if (rdev) {
                pr_info("Current regulatory domain updated by AP to: %c%c\n",
                    rdev->country_ie_alpha2[0],
                    rdev->country_ie_alpha2[1]);
            } else
                pr_info("Current regulatory domain intersected:\n");
        } else
            pr_info("Current regulatory domain intersected:\n");
    } else if (is_world_regdom(rd->alpha2))
        pr_info("World regulatory domain updated:\n");
    else {
        if (is_unknown_alpha2(rd->alpha2))
            pr_info("Regulatory domain changed to driver built-in settings (unknown country)\n");
        else {
            if (reg_request_cell_base(last_request))
                pr_info("Regulatory domain changed "
                    "to country: %c%c by Cell Station\n",
                    rd->alpha2[0], rd->alpha2[1]);
            else
                pr_info("Regulatory domain changed "
                    "to country: %c%c\n",
                    rd->alpha2[0], rd->alpha2[1]);
        }
    }
    print_dfs_region(rd->dfs_region);
    print_rd_rules(rd);
}

static void print_regdomain_info(const struct ieee80211_regdomain *rd)
{
    pr_info("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)
{
    const struct ieee80211_regdomain *intersected_rd = NULL;
    struct wiphy *request_wiphy;
    /* 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;

    /*
     * Lets only bother proceeding on the same alpha2 if the current
     * rd is non static (it means CRDA was present and was used last)
     * and the pending request came in from a country IE
     */
    if (last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
        /*
         * If someone else asked us to change the rd lets only bother
         * checking if the alpha2 changes if CRDA was already called
         */
        if (!regdom_changes(rd->alpha2))
            return -EALREADY;
    }

    /*
     * 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;

    if (!is_valid_rd(rd)) {
        pr_err("Invalid regulatory domain detected:\n");
        print_regdomain_info(rd);
        return -EINVAL;
    }

    request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
    if (!request_wiphy &&
        (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER ||
         last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE)) {
        schedule_delayed_work(&reg_timeout, 0);
        return -ENODEV;
    }

    if (!last_request->intersect) {
        int r;

        if (last_request->initiator != NL80211_REGDOM_SET_BY_DRIVER) {
            reset_regdomains(false);
            cfg80211_regdomain = rd;
            return 0;
        }

        /*
         * For a driver hint, lets copy the regulatory domain the
         * driver wanted to the wiphy to deal with conflicts
         */

        /*
         * Userspace could have sent two replies with only
         * one kernel request.
         */
        if (request_wiphy->regd)
            return -EALREADY;

        r = reg_copy_regd(&request_wiphy->regd, rd);
        if (r)
            return r;

        reset_regdomains(false);
        cfg80211_regdomain = rd;
        return 0;
    }

    /* Intersection requires a bit more work */

    if (last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {

        intersected_rd = regdom_intersect(rd, cfg80211_regdomain);
        if (!intersected_rd)
            return -EINVAL;

        /*
         * We can trash what CRDA provided now.
         * However if a driver requested this specific regulatory
         * domain we keep it for its private use
         */
        if (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER)
            request_wiphy->regd = rd;
        else
            kfree(rd);

        rd = NULL;

        reset_regdomains(false);
        cfg80211_regdomain = intersected_rd;

        return 0;
    }

    return -EINVAL;
}


/*
 * 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_mutex
 */
int set_regdom(const struct ieee80211_regdomain *rd)
{
    int r;

    assert_cfg80211_lock();

    mutex_lock(&reg_mutex);

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

        kfree(rd);
        mutex_unlock(&reg_mutex);
        return r;
    }

    /* This would make this whole thing pointless */
    if (!last_request->intersect)
        BUG_ON(rd != cfg80211_regdomain);

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

    print_regdomain(cfg80211_regdomain);

    nl80211_send_reg_change_event(last_request);

    reg_set_request_processed();

    mutex_unlock(&reg_mutex);

    return r;
}

#ifdef CONFIG_HOTPLUG
int reg_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
    if (last_request && !last_request->processed) {
        if (add_uevent_var(env, "COUNTRY=%c%c",
                   last_request->alpha2[0],
                   last_request->alpha2[1]))
            return -ENOMEM;
    }

    return 0;
}
#else
int reg_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
    return -ENODEV;
}
#endif /* CONFIG_HOTPLUG */

void wiphy_regulatory_register(struct wiphy *wiphy)
{
    assert_cfg80211_lock();

    mutex_lock(&reg_mutex);

    if (!reg_dev_ignore_cell_hint(wiphy))
        reg_num_devs_support_basehint++;

    wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);

    mutex_unlock(&reg_mutex);
}

/* Caller must hold cfg80211_mutex */
void wiphy_regulatory_deregister(struct wiphy *wiphy)
{
    struct wiphy *request_wiphy = NULL;

    assert_cfg80211_lock();

    mutex_lock(&reg_mutex);

    if (!reg_dev_ignore_cell_hint(wiphy))
        reg_num_devs_support_basehint--;

    kfree(wiphy->regd);

    if (last_request)
        request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);

    if (!request_wiphy || request_wiphy != wiphy)
        goto out;

    last_request->wiphy_idx = WIPHY_IDX_STALE;
    last_request->country_ie_env = ENVIRON_ANY;
out:
    mutex_unlock(&reg_mutex);
}

static void reg_timeout_work(struct work_struct *work)
{
    REG_DBG_PRINT("Timeout while waiting for CRDA to reply, "
              "restoring regulatory settings\n");
    restore_regulatory_settings(true);
}

int __init regulatory_init(void)
{
    int err = 0;

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

    reg_pdev->dev.type = &reg_device_type;

    spin_lock_init(&reg_requests_lock);
    spin_lock_init(&reg_pending_beacons_lock);

    reg_regdb_size_check();

    cfg80211_regdomain = cfg80211_world_regdom;

    user_alpha2[0] = '9';
    user_alpha2[1] = '7';

    /* We always try to get an update for the static regdomain */
    err = regulatory_hint_core(cfg80211_regdomain->alpha2);
    if (err) {
        if (err == -ENOMEM)
            return err;
        /*
         * N.B. kobject_uevent_env() can fail mainly for when we're out
         * memory which is handled and propagated appropriately above
         * but it can also fail during a netlink_broadcast() or during
         * early boot for call_usermodehelper(). For now treat these
         * errors as non-fatal.
         */
        pr_err("kobject_uevent_env() was unable to call CRDA during init\n");
#ifdef CONFIG_CFG80211_REG_DEBUG
        /* We want to find out exactly why when debugging */
        WARN_ON(err);
#endif
    }

    /*
     * Finally, if the user set the module parameter treat it
     * as a user hint.
     */
    if (!is_world_regdom(ieee80211_regdom))
        regulatory_hint_user(ieee80211_regdom,
                     NL80211_USER_REG_HINT_USER);

    return 0;
}

void /* __init_or_exit */ regulatory_exit(void)
{
    struct regulatory_request *reg_request, *tmp;
    struct reg_beacon *reg_beacon, *btmp;

    cancel_work_sync(&reg_work);
    cancel_delayed_work_sync(&reg_timeout);

    mutex_lock(&cfg80211_mutex);
    mutex_lock(&reg_mutex);

    reset_regdomains(true);

    dev_set_uevent_suppress(&reg_pdev->dev, true);

    platform_device_unregister(reg_pdev);

    spin_lock_bh(&reg_pending_beacons_lock);
    if (!list_empty(&reg_pending_beacons)) {
        list_for_each_entry_safe(reg_beacon, btmp,
                     &reg_pending_beacons, list) {
            list_del(&reg_beacon->list);
            kfree(reg_beacon);
        }
    }
    spin_unlock_bh(&reg_pending_beacons_lock);

    if (!list_empty(&reg_beacon_list)) {
        list_for_each_entry_safe(reg_beacon, btmp,
                     &reg_beacon_list, list) {
            list_del(&reg_beacon->list);
            kfree(reg_beacon);
        }
    }

    spin_lock(&reg_requests_lock);
    if (!list_empty(&reg_requests_list)) {
        list_for_each_entry_safe(reg_request, tmp,
                     &reg_requests_list, list) {
            list_del(&reg_request->list);
            kfree(reg_request);
        }
    }
    spin_unlock(&reg_requests_lock);

    mutex_unlock(&reg_mutex);
    mutex_unlock(&cfg80211_mutex);
}