GNU Linux-libre 6.8.9-gnu

[releases.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 2008-2011  Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
 * Copyright 2013-2014  Intel Mobile Communications GmbH
 * Copyright      2017  Intel Deutschland GmbH
 * Copyright (C) 2018 - 2023 Intel Corporation
 *
 * 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.
 */


/**
 * 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.
 *
 */

#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/ctype.h>
#include <linux/nl80211.h>
#include <linux/platform_device.h>
#include <linux/verification.h>
#include <linux/moduleparam.h>
#include <linux/firmware.h>
#include <net/cfg80211.h>
#include "core.h"
#include "reg.h"
#include "rdev-ops.h"
#include "nl80211.h"

/*
 * Grace period we give before making sure all current interfaces reside on
 * channels allowed by the current regulatory domain.
 */
#define REG_ENFORCE_GRACE_MS 60000

/**
 * enum reg_request_treatment - regulatory request treatment
 *
 * @REG_REQ_OK: continue processing the regulatory request
 * @REG_REQ_IGNORE: ignore the regulatory request
 * @REG_REQ_INTERSECT: the regulatory domain resulting from this request should
 *      be intersected with the current one.
 * @REG_REQ_ALREADY_SET: the regulatory request will not change the current
 *      regulatory settings, and no further processing is required.
 */
enum reg_request_treatment {
        REG_REQ_OK,
        REG_REQ_IGNORE,
        REG_REQ_INTERSECT,
        REG_REQ_ALREADY_SET,
};

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,
 * protected by RTNL (and can be accessed with RCU protection)
 */
static struct regulatory_request __rcu *last_request =
        (void __force __rcu *)&core_request_world;

/* To trigger userspace events and load firmware */
static struct platform_device *reg_pdev;

/*
 * 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.
 * (protected by RTNL, can be read under RCU)
 */
const struct ieee80211_regdomain __rcu *cfg80211_regdomain;

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

/*
 * State variable indicating if the platform on which the devices
 * are attached is operating in an indoor environment. The state variable
 * is relevant for all registered devices.
 */
static bool reg_is_indoor;
static DEFINE_SPINLOCK(reg_indoor_lock);

/* Used to track the userspace process controlling the indoor setting */
static u32 reg_is_indoor_portid;

static void restore_regulatory_settings(bool reset_user, bool cached);
static void print_regdomain(const struct ieee80211_regdomain *rd);
static void reg_process_hint(struct regulatory_request *reg_request);

static const struct ieee80211_regdomain *get_cfg80211_regdom(void)
{
        return rcu_dereference_rtnl(cfg80211_regdomain);
}

/*
 * Returns the regulatory domain associated with the wiphy.
 *
 * Requires any of RTNL, wiphy mutex or RCU protection.
 */
const struct ieee80211_regdomain *get_wiphy_regdom(struct wiphy *wiphy)
{
        return rcu_dereference_check(wiphy->regd,
                                     lockdep_is_held(&wiphy->mtx) ||
                                     lockdep_rtnl_is_held());
}
EXPORT_SYMBOL(get_wiphy_regdom);

static const char *reg_dfs_region_str(enum nl80211_dfs_regions dfs_region)
{
        switch (dfs_region) {
        case NL80211_DFS_UNSET:
                return "unset";
        case NL80211_DFS_FCC:
                return "FCC";
        case NL80211_DFS_ETSI:
                return "ETSI";
        case NL80211_DFS_JP:
                return "JP";
        }
        return "Unknown";
}

enum nl80211_dfs_regions reg_get_dfs_region(struct wiphy *wiphy)
{
        const struct ieee80211_regdomain *regd = NULL;
        const struct ieee80211_regdomain *wiphy_regd = NULL;
        enum nl80211_dfs_regions dfs_region;

        rcu_read_lock();
        regd = get_cfg80211_regdom();
        dfs_region = regd->dfs_region;

        if (!wiphy)
                goto out;

        wiphy_regd = get_wiphy_regdom(wiphy);
        if (!wiphy_regd)
                goto out;

        if (wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED) {
                dfs_region = wiphy_regd->dfs_region;
                goto out;
        }

        if (wiphy_regd->dfs_region == regd->dfs_region)
                goto out;

        pr_debug("%s: device specific dfs_region (%s) disagrees with cfg80211's central dfs_region (%s)\n",
                 dev_name(&wiphy->dev),
                 reg_dfs_region_str(wiphy_regd->dfs_region),
                 reg_dfs_region_str(regd->dfs_region));

out:
        rcu_read_unlock();

        return dfs_region;
}

static void rcu_free_regdom(const struct ieee80211_regdomain *r)
{
        if (!r)
                return;
        kfree_rcu((struct ieee80211_regdomain *)r, rcu_head);
}

static struct regulatory_request *get_last_request(void)
{
        return rcu_dereference_rtnl(last_request);
}

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

/* Used to queue up beacon hints for review */
static LIST_HEAD(reg_pending_beacons);
static DEFINE_SPINLOCK(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_check_chans_work(struct work_struct *work);
static DECLARE_DELAYED_WORK(reg_check_chans, reg_check_chans_work);

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

/* We keep a static world regulatory domain in case of the absence of CRDA */
static const struct ieee80211_regdomain world_regdom = {
        .n_reg_rules = 8,
        .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, 20, 6, 20,
                        NL80211_RRF_NO_IR | NL80211_RRF_AUTO_BW),
                /* 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_NO_IR |
                        NL80211_RRF_NO_OFDM),
                /* IEEE 802.11a, channel 36..48 */
                REG_RULE(5180-10, 5240+10, 80, 6, 20,
                        NL80211_RRF_NO_IR |
                        NL80211_RRF_AUTO_BW),

                /* IEEE 802.11a, channel 52..64 - DFS required */
                REG_RULE(5260-10, 5320+10, 80, 6, 20,
                        NL80211_RRF_NO_IR |
                        NL80211_RRF_AUTO_BW |
                        NL80211_RRF_DFS),

                /* IEEE 802.11a, channel 100..144 - DFS required */
                REG_RULE(5500-10, 5720+10, 160, 6, 20,
                        NL80211_RRF_NO_IR |
                        NL80211_RRF_DFS),

                /* IEEE 802.11a, channel 149..165 */
                REG_RULE(5745-10, 5825+10, 80, 6, 20,
                        NL80211_RRF_NO_IR),

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

/* protected by RTNL */
static const struct ieee80211_regdomain *cfg80211_world_regdom =
        &world_regdom;

static char *ieee80211_regdom = "00";
static char user_alpha2[2];
static const struct ieee80211_regdomain *cfg80211_user_regdom;

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

static void reg_free_request(struct regulatory_request *request)
{
        if (request == &core_request_world)
                return;

        if (request != get_last_request())
                kfree(request);
}

static void reg_free_last_request(void)
{
        struct regulatory_request *lr = get_last_request();

        if (lr != &core_request_world && lr)
                kfree_rcu(lr, rcu_head);
}

static void reg_update_last_request(struct regulatory_request *request)
{
        struct regulatory_request *lr;

        lr = get_last_request();
        if (lr == request)
                return;

        reg_free_last_request();
        rcu_assign_pointer(last_request, request);
}

static void reset_regdomains(bool full_reset,
                             const struct ieee80211_regdomain *new_regdom)
{
        const struct ieee80211_regdomain *r;

        ASSERT_RTNL();

        r = get_cfg80211_regdom();

        /* avoid freeing static information or freeing something twice */
        if (r == cfg80211_world_regdom)
                r = NULL;
        if (cfg80211_world_regdom == &world_regdom)
                cfg80211_world_regdom = NULL;
        if (r == &world_regdom)
                r = NULL;

        rcu_free_regdom(r);
        rcu_free_regdom(cfg80211_world_regdom);

        cfg80211_world_regdom = &world_regdom;
        rcu_assign_pointer(cfg80211_regdomain, new_regdom);

        if (!full_reset)
                return;

        reg_update_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)
{
        struct regulatory_request *lr;

        lr = get_last_request();

        WARN_ON(!lr);

        reset_regdomains(false, rd);

        cfg80211_world_regdom = rd;
}

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

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

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
         */
        return alpha2[0] == '9' && alpha2[1] == '9';
}

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
         */
        return alpha2[0] == '9' && alpha2[1] == '8';
}

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

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

static bool regdom_changes(const char *alpha2)
{
        const struct ieee80211_regdomain *r = get_cfg80211_regdom();

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

/*
 * 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 const struct ieee80211_regdomain *
reg_copy_regd(const struct ieee80211_regdomain *src_regd)
{
        struct ieee80211_regdomain *regd;
        unsigned int i;

        regd = kzalloc(struct_size(regd, reg_rules, src_regd->n_reg_rules),
                       GFP_KERNEL);
        if (!regd)
                return ERR_PTR(-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));

        return regd;
}

static void cfg80211_save_user_regdom(const struct ieee80211_regdomain *rd)
{
        ASSERT_RTNL();

        if (!IS_ERR(cfg80211_user_regdom))
                kfree(cfg80211_user_regdom);
        cfg80211_user_regdom = reg_copy_regd(rd);
}

struct reg_regdb_apply_request {
        struct list_head list;
        const struct ieee80211_regdomain *regdom;
};

static LIST_HEAD(reg_regdb_apply_list);
static DEFINE_MUTEX(reg_regdb_apply_mutex);

static void reg_regdb_apply(struct work_struct *work)
{
        struct reg_regdb_apply_request *request;

        rtnl_lock();

        mutex_lock(&reg_regdb_apply_mutex);
        while (!list_empty(&reg_regdb_apply_list)) {
                request = list_first_entry(&reg_regdb_apply_list,
                                           struct reg_regdb_apply_request,
                                           list);
                list_del(&request->list);

                set_regdom(request->regdom, REGD_SOURCE_INTERNAL_DB);
                kfree(request);
        }
        mutex_unlock(&reg_regdb_apply_mutex);

        rtnl_unlock();
}

static DECLARE_WORK(reg_regdb_work, reg_regdb_apply);

static int reg_schedule_apply(const struct ieee80211_regdomain *regdom)
{
        struct reg_regdb_apply_request *request;

        request = kzalloc(sizeof(struct reg_regdb_apply_request), GFP_KERNEL);
        if (!request) {
                kfree(regdom);
                return -ENOMEM;
        }

        request->regdom = regdom;

        mutex_lock(&reg_regdb_apply_mutex);
        list_add_tail(&request->list, &reg_regdb_apply_list);
        mutex_unlock(&reg_regdb_apply_mutex);

        schedule_work(&reg_regdb_work);
        return 0;
}

#ifdef CONFIG_CFG80211_CRDA_SUPPORT
/* Max number of consecutive attempts to communicate with CRDA  */
#define REG_MAX_CRDA_TIMEOUTS 10

static u32 reg_crda_timeouts;

static void crda_timeout_work(struct work_struct *work);
static DECLARE_DELAYED_WORK(crda_timeout, crda_timeout_work);

static void crda_timeout_work(struct work_struct *work)
{
        pr_debug("Timeout while waiting for CRDA to reply, restoring regulatory settings\n");
        rtnl_lock();
        reg_crda_timeouts++;
        restore_regulatory_settings(true, false);
        rtnl_unlock();
}

static void cancel_crda_timeout(void)
{
        cancel_delayed_work(&crda_timeout);
}

static void cancel_crda_timeout_sync(void)
{
        cancel_delayed_work_sync(&crda_timeout);
}

static void reset_crda_timeouts(void)
{
        reg_crda_timeouts = 0;
}

/*
 * This lets us keep regulatory code which is updated on a regulatory
 * basis in userspace.
 */
static int call_crda(const char *alpha2)
{
        char country[12];
        char *env[] = { country, NULL };
        int ret;

        snprintf(country, sizeof(country), "COUNTRY=%c%c",
                 alpha2[0], alpha2[1]);

        if (reg_crda_timeouts > REG_MAX_CRDA_TIMEOUTS) {
                pr_debug("Exceeded CRDA call max attempts. Not calling CRDA\n");
                return -EINVAL;
        }

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

        ret = kobject_uevent_env(&reg_pdev->dev.kobj, KOBJ_CHANGE, env);
        if (ret)
                return ret;

        queue_delayed_work(system_power_efficient_wq,
                           &crda_timeout, msecs_to_jiffies(3142));
        return 0;
}
#else
static inline void cancel_crda_timeout(void) {}
static inline void cancel_crda_timeout_sync(void) {}
static inline void reset_crda_timeouts(void) {}
static inline int call_crda(const char *alpha2)
{
        return -ENODATA;
}
#endif /* CONFIG_CFG80211_CRDA_SUPPORT */

/* code to directly load a firmware database through request_firmware */
static const struct fwdb_header *regdb;

struct fwdb_country {
        u8 alpha2[2];
        __be16 coll_ptr;
        /* this struct cannot be extended */
} __packed __aligned(4);

struct fwdb_collection {
        u8 len;
        u8 n_rules;
        u8 dfs_region;
        /* no optional data yet */
        /* aligned to 2, then followed by __be16 array of rule pointers */
} __packed __aligned(4);

enum fwdb_flags {
        FWDB_FLAG_NO_OFDM       = BIT(0),
        FWDB_FLAG_NO_OUTDOOR    = BIT(1),
        FWDB_FLAG_DFS           = BIT(2),
        FWDB_FLAG_NO_IR         = BIT(3),
        FWDB_FLAG_AUTO_BW       = BIT(4),
};

struct fwdb_wmm_ac {
        u8 ecw;
        u8 aifsn;
        __be16 cot;
} __packed;

struct fwdb_wmm_rule {
        struct fwdb_wmm_ac client[IEEE80211_NUM_ACS];
        struct fwdb_wmm_ac ap[IEEE80211_NUM_ACS];
} __packed;

struct fwdb_rule {
        u8 len;
        u8 flags;
        __be16 max_eirp;
        __be32 start, end, max_bw;
        /* start of optional data */
        __be16 cac_timeout;
        __be16 wmm_ptr;
} __packed __aligned(4);

#define FWDB_MAGIC 0x52474442
#define FWDB_VERSION 20

struct fwdb_header {
        __be32 magic;
        __be32 version;
        struct fwdb_country country[];
} __packed __aligned(4);

static int ecw2cw(int ecw)
{
        return (1 << ecw) - 1;
}

static bool valid_wmm(struct fwdb_wmm_rule *rule)
{
        struct fwdb_wmm_ac *ac = (struct fwdb_wmm_ac *)rule;
        int i;

        for (i = 0; i < IEEE80211_NUM_ACS * 2; i++) {
                u16 cw_min = ecw2cw((ac[i].ecw & 0xf0) >> 4);
                u16 cw_max = ecw2cw(ac[i].ecw & 0x0f);
                u8 aifsn = ac[i].aifsn;

                if (cw_min >= cw_max)
                        return false;

                if (aifsn < 1)
                        return false;
        }

        return true;
}

static bool valid_rule(const u8 *data, unsigned int size, u16 rule_ptr)
{
        struct fwdb_rule *rule = (void *)(data + (rule_ptr << 2));

        if ((u8 *)rule + sizeof(rule->len) > data + size)
                return false;

        /* mandatory fields */
        if (rule->len < offsetofend(struct fwdb_rule, max_bw))
                return false;
        if (rule->len >= offsetofend(struct fwdb_rule, wmm_ptr)) {
                u32 wmm_ptr = be16_to_cpu(rule->wmm_ptr) << 2;
                struct fwdb_wmm_rule *wmm;

                if (wmm_ptr + sizeof(struct fwdb_wmm_rule) > size)
                        return false;

                wmm = (void *)(data + wmm_ptr);

                if (!valid_wmm(wmm))
                        return false;
        }
        return true;
}

static bool valid_country(const u8 *data, unsigned int size,
                          const struct fwdb_country *country)
{
        unsigned int ptr = be16_to_cpu(country->coll_ptr) << 2;
        struct fwdb_collection *coll = (void *)(data + ptr);
        __be16 *rules_ptr;
        unsigned int i;

        /* make sure we can read len/n_rules */
        if ((u8 *)coll + offsetofend(typeof(*coll), n_rules) > data + size)
                return false;

        /* make sure base struct and all rules fit */
        if ((u8 *)coll + ALIGN(coll->len, 2) +
            (coll->n_rules * 2) > data + size)
                return false;

        /* mandatory fields must exist */
        if (coll->len < offsetofend(struct fwdb_collection, dfs_region))
                return false;

        rules_ptr = (void *)((u8 *)coll + ALIGN(coll->len, 2));

        for (i = 0; i < coll->n_rules; i++) {
                u16 rule_ptr = be16_to_cpu(rules_ptr[i]);

                if (!valid_rule(data, size, rule_ptr))
                        return false;
        }

        return true;
}

#ifdef CONFIG_CFG80211_REQUIRE_SIGNED_REGDB
#include <keys/asymmetric-type.h>

static struct key *builtin_regdb_keys;

static int __init load_builtin_regdb_keys(void)
{
        builtin_regdb_keys =
                keyring_alloc(".builtin_regdb_keys",
                              KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
                              ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
                              KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH),
                              KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
        if (IS_ERR(builtin_regdb_keys))
                return PTR_ERR(builtin_regdb_keys);

        pr_notice("Loading compiled-in X.509 certificates for regulatory database\n");

#ifdef CONFIG_CFG80211_USE_KERNEL_REGDB_KEYS
        x509_load_certificate_list(shipped_regdb_certs,
                                   shipped_regdb_certs_len,
                                   builtin_regdb_keys);
#endif
#ifdef CONFIG_CFG80211_EXTRA_REGDB_KEYDIR
        if (CONFIG_CFG80211_EXTRA_REGDB_KEYDIR[0] != '\0')
                x509_load_certificate_list(extra_regdb_certs,
                                           extra_regdb_certs_len,
                                           builtin_regdb_keys);
#endif

        return 0;
}

MODULE_FIRMWARE("regulatory.db.p7s");

static bool regdb_has_valid_signature(const u8 *data, unsigned int size)
{
        const struct firmware *sig;
        bool result;

        if (request_firmware(&sig, "regulatory.db.p7s", &reg_pdev->dev))
                return false;

        result = verify_pkcs7_signature(data, size, sig->data, sig->size,
                                        builtin_regdb_keys,
                                        VERIFYING_UNSPECIFIED_SIGNATURE,
                                        NULL, NULL) == 0;

        release_firmware(sig);

        return result;
}

static void free_regdb_keyring(void)
{
        key_put(builtin_regdb_keys);
}
#else
static int load_builtin_regdb_keys(void)
{
        return 0;
}

static bool regdb_has_valid_signature(const u8 *data, unsigned int size)
{
        return true;
}

static void free_regdb_keyring(void)
{
}
#endif /* CONFIG_CFG80211_REQUIRE_SIGNED_REGDB */

static bool valid_regdb(const u8 *data, unsigned int size)
{
        const struct fwdb_header *hdr = (void *)data;
        const struct fwdb_country *country;

        if (size < sizeof(*hdr))
                return false;

        if (hdr->magic != cpu_to_be32(FWDB_MAGIC))
                return false;

        if (hdr->version != cpu_to_be32(FWDB_VERSION))
                return false;

        if (!regdb_has_valid_signature(data, size))
                return false;

        country = &hdr->country[0];
        while ((u8 *)(country + 1) <= data + size) {
                if (!country->coll_ptr)
                        break;
                if (!valid_country(data, size, country))
                        return false;
                country++;
        }

        return true;
}

static void set_wmm_rule(const struct fwdb_header *db,
                         const struct fwdb_country *country,
                         const struct fwdb_rule *rule,
                         struct ieee80211_reg_rule *rrule)
{
        struct ieee80211_wmm_rule *wmm_rule = &rrule->wmm_rule;
        struct fwdb_wmm_rule *wmm;
        unsigned int i, wmm_ptr;

        wmm_ptr = be16_to_cpu(rule->wmm_ptr) << 2;
        wmm = (void *)((u8 *)db + wmm_ptr);

        if (!valid_wmm(wmm)) {
                pr_err("Invalid regulatory WMM rule %u-%u in domain %c%c\n",
                       be32_to_cpu(rule->start), be32_to_cpu(rule->end),
                       country->alpha2[0], country->alpha2[1]);
                return;
        }

        for (i = 0; i < IEEE80211_NUM_ACS; i++) {
                wmm_rule->client[i].cw_min =
                        ecw2cw((wmm->client[i].ecw & 0xf0) >> 4);
                wmm_rule->client[i].cw_max = ecw2cw(wmm->client[i].ecw & 0x0f);
                wmm_rule->client[i].aifsn =  wmm->client[i].aifsn;
                wmm_rule->client[i].cot =
                        1000 * be16_to_cpu(wmm->client[i].cot);
                wmm_rule->ap[i].cw_min = ecw2cw((wmm->ap[i].ecw & 0xf0) >> 4);
                wmm_rule->ap[i].cw_max = ecw2cw(wmm->ap[i].ecw & 0x0f);
                wmm_rule->ap[i].aifsn = wmm->ap[i].aifsn;
                wmm_rule->ap[i].cot = 1000 * be16_to_cpu(wmm->ap[i].cot);
        }

        rrule->has_wmm = true;
}

static int __regdb_query_wmm(const struct fwdb_header *db,
                             const struct fwdb_country *country, int freq,
                             struct ieee80211_reg_rule *rrule)
{
        unsigned int ptr = be16_to_cpu(country->coll_ptr) << 2;
        struct fwdb_collection *coll = (void *)((u8 *)db + ptr);
        int i;

        for (i = 0; i < coll->n_rules; i++) {
                __be16 *rules_ptr = (void *)((u8 *)coll + ALIGN(coll->len, 2));
                unsigned int rule_ptr = be16_to_cpu(rules_ptr[i]) << 2;
                struct fwdb_rule *rule = (void *)((u8 *)db + rule_ptr);

                if (rule->len < offsetofend(struct fwdb_rule, wmm_ptr))
                        continue;

                if (freq >= KHZ_TO_MHZ(be32_to_cpu(rule->start)) &&
                    freq <= KHZ_TO_MHZ(be32_to_cpu(rule->end))) {
                        set_wmm_rule(db, country, rule, rrule);
                        return 0;
                }
        }

        return -ENODATA;
}

int reg_query_regdb_wmm(char *alpha2, int freq, struct ieee80211_reg_rule *rule)
{
        const struct fwdb_header *hdr = regdb;
        const struct fwdb_country *country;

        if (!regdb)
                return -ENODATA;

        if (IS_ERR(regdb))
                return PTR_ERR(regdb);

        country = &hdr->country[0];
        while (country->coll_ptr) {
                if (alpha2_equal(alpha2, country->alpha2))
                        return __regdb_query_wmm(regdb, country, freq, rule);

                country++;
        }

        return -ENODATA;
}
EXPORT_SYMBOL(reg_query_regdb_wmm);

static int regdb_query_country(const struct fwdb_header *db,
                               const struct fwdb_country *country)
{
        unsigned int ptr = be16_to_cpu(country->coll_ptr) << 2;
        struct fwdb_collection *coll = (void *)((u8 *)db + ptr);
        struct ieee80211_regdomain *regdom;
        unsigned int i;

        regdom = kzalloc(struct_size(regdom, reg_rules, coll->n_rules),
                         GFP_KERNEL);
        if (!regdom)
                return -ENOMEM;

        regdom->n_reg_rules = coll->n_rules;
        regdom->alpha2[0] = country->alpha2[0];
        regdom->alpha2[1] = country->alpha2[1];
        regdom->dfs_region = coll->dfs_region;

        for (i = 0; i < regdom->n_reg_rules; i++) {
                __be16 *rules_ptr = (void *)((u8 *)coll + ALIGN(coll->len, 2));
                unsigned int rule_ptr = be16_to_cpu(rules_ptr[i]) << 2;
                struct fwdb_rule *rule = (void *)((u8 *)db + rule_ptr);
                struct ieee80211_reg_rule *rrule = &regdom->reg_rules[i];

                rrule->freq_range.start_freq_khz = be32_to_cpu(rule->start);
                rrule->freq_range.end_freq_khz = be32_to_cpu(rule->end);
                rrule->freq_range.max_bandwidth_khz = be32_to_cpu(rule->max_bw);

                rrule->power_rule.max_antenna_gain = 0;
                rrule->power_rule.max_eirp = be16_to_cpu(rule->max_eirp);

                rrule->flags = 0;
                if (rule->flags & FWDB_FLAG_NO_OFDM)
                        rrule->flags |= NL80211_RRF_NO_OFDM;
                if (rule->flags & FWDB_FLAG_NO_OUTDOOR)
                        rrule->flags |= NL80211_RRF_NO_OUTDOOR;
                if (rule->flags & FWDB_FLAG_DFS)
                        rrule->flags |= NL80211_RRF_DFS;
                if (rule->flags & FWDB_FLAG_NO_IR)
                        rrule->flags |= NL80211_RRF_NO_IR;
                if (rule->flags & FWDB_FLAG_AUTO_BW)
                        rrule->flags |= NL80211_RRF_AUTO_BW;

                rrule->dfs_cac_ms = 0;

                /* handle optional data */
                if (rule->len >= offsetofend(struct fwdb_rule, cac_timeout))
                        rrule->dfs_cac_ms =
                                1000 * be16_to_cpu(rule->cac_timeout);
                if (rule->len >= offsetofend(struct fwdb_rule, wmm_ptr))
                        set_wmm_rule(db, country, rule, rrule);
        }

        return reg_schedule_apply(regdom);
}

static int query_regdb(const char *alpha2)
{
        const struct fwdb_header *hdr = regdb;
        const struct fwdb_country *country;

        ASSERT_RTNL();

        if (IS_ERR(regdb))
                return PTR_ERR(regdb);

        country = &hdr->country[0];
        while (country->coll_ptr) {
                if (alpha2_equal(alpha2, country->alpha2))
                        return regdb_query_country(regdb, country);
                country++;
        }

        return -ENODATA;
}

static void regdb_fw_cb(const struct firmware *fw, void *context)
{
        int set_error = 0;
        bool restore = true;
        void *db;

        if (!fw) {
                pr_info("failed to load regulatory.db\n");
                set_error = -ENODATA;
        } else if (!valid_regdb(fw->data, fw->size)) {
                pr_info("loaded regulatory.db is malformed or signature is missing/invalid\n");
                set_error = -EINVAL;
        }

        rtnl_lock();
        if (regdb && !IS_ERR(regdb)) {
                /* negative case - a bug
                 * positive case - can happen due to race in case of multiple cb's in
                 * queue, due to usage of asynchronous callback
                 *
                 * Either case, just restore and free new db.
                 */
        } else if (set_error) {
                regdb = ERR_PTR(set_error);
        } else if (fw) {
                db = kmemdup(fw->data, fw->size, GFP_KERNEL);
                if (db) {
                        regdb = db;
                        restore = context && query_regdb(context);
                } else {
                        restore = true;
                }
        }

        if (restore)
                restore_regulatory_settings(true, false);

        rtnl_unlock();

        kfree(context);

        release_firmware(fw);
}

MODULE_FIRMWARE("regulatory.db");

static int query_regdb_file(const char *alpha2)
{
        int err;

        ASSERT_RTNL();

        if (regdb)
                return query_regdb(alpha2);

        alpha2 = kmemdup(alpha2, 2, GFP_KERNEL);
        if (!alpha2)
                return -ENOMEM;

        err = request_firmware_nowait(THIS_MODULE, true, "regulatory.db",
                                      &reg_pdev->dev, GFP_KERNEL,
                                      (void *)alpha2, regdb_fw_cb);
        if (err)
                kfree(alpha2);

        return err;
}

int reg_reload_regdb(void)
{
        const struct firmware *fw;
        void *db;
        int err;
        const struct ieee80211_regdomain *current_regdomain;
        struct regulatory_request *request;

        err = request_firmware(&fw, "regulatory.db", &reg_pdev->dev);
        if (err)
                return err;

        if (!valid_regdb(fw->data, fw->size)) {
                err = -ENODATA;
                goto out;
        }

        db = kmemdup(fw->data, fw->size, GFP_KERNEL);
        if (!db) {
                err = -ENOMEM;
                goto out;
        }

        rtnl_lock();
        if (!IS_ERR_OR_NULL(regdb))
                kfree(regdb);
        regdb = db;

        /* reset regulatory domain */
        current_regdomain = get_cfg80211_regdom();

        request = kzalloc(sizeof(*request), GFP_KERNEL);
        if (!request) {
                err = -ENOMEM;
                goto out_unlock;
        }

        request->wiphy_idx = WIPHY_IDX_INVALID;
        request->alpha2[0] = current_regdomain->alpha2[0];
        request->alpha2[1] = current_regdomain->alpha2[1];
        request->initiator = NL80211_REGDOM_SET_BY_CORE;
        request->user_reg_hint_type = NL80211_USER_REG_HINT_USER;

        reg_process_hint(request);

out_unlock:
        rtnl_unlock();
 out:
        release_firmware(fw);
        return err;
}

static bool reg_query_database(struct regulatory_request *request)
{
        if (query_regdb_file(request->alpha2) == 0)
                return true;

        if (call_crda(request->alpha2) == 0)
                return true;

        return false;
}

bool reg_is_valid_request(const char *alpha2)
{
        struct regulatory_request *lr = get_last_request();

        if (!lr || lr->processed)
                return false;

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

static const struct ieee80211_regdomain *reg_get_regdomain(struct wiphy *wiphy)
{
        struct regulatory_request *lr = get_last_request();

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

        return get_cfg80211_regdom();
}

static unsigned int
reg_get_max_bandwidth_from_range(const struct ieee80211_regdomain *rd,
                                 const struct ieee80211_reg_rule *rule)
{
        const struct ieee80211_freq_range *freq_range = &rule->freq_range;
        const struct ieee80211_freq_range *freq_range_tmp;
        const struct ieee80211_reg_rule *tmp;
        u32 start_freq, end_freq, idx, no;

        for (idx = 0; idx < rd->n_reg_rules; idx++)
                if (rule == &rd->reg_rules[idx])
                        break;

        if (idx == rd->n_reg_rules)
                return 0;

        /* get start_freq */
        no = idx;

        while (no) {
                tmp = &rd->reg_rules[--no];
                freq_range_tmp = &tmp->freq_range;

                if (freq_range_tmp->end_freq_khz < freq_range->start_freq_khz)
                        break;

                freq_range = freq_range_tmp;
        }

        start_freq = freq_range->start_freq_khz;

        /* get end_freq */
        freq_range = &rule->freq_range;
        no = idx;

        while (no < rd->n_reg_rules - 1) {
                tmp = &rd->reg_rules[++no];
                freq_range_tmp = &tmp->freq_range;

                if (freq_range_tmp->start_freq_khz > freq_range->end_freq_khz)
                        break;

                freq_range = freq_range_tmp;
        }

        end_freq = freq_range->end_freq_khz;

        return end_freq - start_freq;
}

unsigned int reg_get_max_bandwidth(const struct ieee80211_regdomain *rd,
                                   const struct ieee80211_reg_rule *rule)
{
        unsigned int bw = reg_get_max_bandwidth_from_range(rd, rule);

        if (rule->flags & NL80211_RRF_NO_320MHZ)
                bw = min_t(unsigned int, bw, MHZ_TO_KHZ(160));
        if (rule->flags & NL80211_RRF_NO_160MHZ)
                bw = min_t(unsigned int, bw, MHZ_TO_KHZ(80));
        if (rule->flags & NL80211_RRF_NO_80MHZ)
                bw = min_t(unsigned int, bw, MHZ_TO_KHZ(40));

        /*
         * HT40+/HT40- limits are handled per-channel. Only limit BW if both
         * are not allowed.
         */
        if (rule->flags & NL80211_RRF_NO_HT40MINUS &&
            rule->flags & NL80211_RRF_NO_HT40PLUS)
                bw = min_t(unsigned int, bw, MHZ_TO_KHZ(20));

        return bw;
}

/* 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;
}

/**
 * freq_in_rule_band - tells us if a frequency is in a frequency band
 * @freq_range: frequency rule we want to query
 * @freq_khz: frequency we are inquiring about
 *
 * This lets us know if a specific frequency rule is or is not relevant to
 * a specific frequency's band. Bands are device specific and artificial
 * definitions (the "2.4 GHz band", the "5 GHz band" and the "60GHz band"),
 * however it is safe for now to assume that a frequency rule should not be
 * part of a frequency's band if the start freq or end freq are off by more
 * than 2 GHz for the 2.4 and 5 GHz bands, and by more than 20 GHz for the
 * 60 GHz band.
 * This resolution can be lowered and should be considered as we add
 * regulatory rule support for other "bands".
 *
 * Returns: whether or not the frequency is in the range
 */
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 ?
                        20 * 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
}

/*
 * Later on we can perhaps use the more restrictive DFS
 * region but we don't have information for that yet so
 * for now simply disallow conflicts.
 */
static enum nl80211_dfs_regions
reg_intersect_dfs_region(const enum nl80211_dfs_regions dfs_region1,
                         const enum nl80211_dfs_regions dfs_region2)
{
        if (dfs_region1 != dfs_region2)
                return NL80211_DFS_UNSET;
        return dfs_region1;
}

static void reg_wmm_rules_intersect(const struct ieee80211_wmm_ac *wmm_ac1,
                                    const struct ieee80211_wmm_ac *wmm_ac2,
                                    struct ieee80211_wmm_ac *intersect)
{
        intersect->cw_min = max_t(u16, wmm_ac1->cw_min, wmm_ac2->cw_min);
        intersect->cw_max = max_t(u16, wmm_ac1->cw_max, wmm_ac2->cw_max);
        intersect->cot = min_t(u16, wmm_ac1->cot, wmm_ac2->cot);
        intersect->aifsn = max_t(u8, wmm_ac1->aifsn, wmm_ac2->aifsn);
}

/*
 * Helper for regdom_intersect(), this does the real
 * mathematical intersection fun
 */
static int reg_rules_intersect(const struct ieee80211_regdomain *rd1,
                               const struct ieee80211_regdomain *rd2,
                               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;
        const struct ieee80211_wmm_rule *wmm_rule1, *wmm_rule2;
        struct ieee80211_wmm_rule *wmm_rule;
        u32 freq_diff, max_bandwidth1, max_bandwidth2;

        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;

        wmm_rule1 = &rule1->wmm_rule;
        wmm_rule2 = &rule2->wmm_rule;
        wmm_rule = &intersected_rule->wmm_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);

        max_bandwidth1 = freq_range1->max_bandwidth_khz;
        max_bandwidth2 = freq_range2->max_bandwidth_khz;

        if (rule1->flags & NL80211_RRF_AUTO_BW)
                max_bandwidth1 = reg_get_max_bandwidth(rd1, rule1);
        if (rule2->flags & NL80211_RRF_AUTO_BW)
                max_bandwidth2 = reg_get_max_bandwidth(rd2, rule2);

        freq_range->max_bandwidth_khz = min(max_bandwidth1, max_bandwidth2);

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

        /*
         * In case NL80211_RRF_AUTO_BW requested for both rules
         * set AUTO_BW in intersected rule also. Next we will
         * calculate BW correctly in handle_channel function.
         * In other case remove AUTO_BW flag while we calculate
         * maximum bandwidth correctly and auto calculation is
         * not required.
         */
        if ((rule1->flags & NL80211_RRF_AUTO_BW) &&
            (rule2->flags & NL80211_RRF_AUTO_BW))
                intersected_rule->flags |= NL80211_RRF_AUTO_BW;
        else
                intersected_rule->flags &= ~NL80211_RRF_AUTO_BW;

        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->dfs_cac_ms = max(rule1->dfs_cac_ms,
                                           rule2->dfs_cac_ms);

        if (rule1->has_wmm && rule2->has_wmm) {
                u8 ac;

                for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
                        reg_wmm_rules_intersect(&wmm_rule1->client[ac],
                                                &wmm_rule2->client[ac],
                                                &wmm_rule->client[ac]);
                        reg_wmm_rules_intersect(&wmm_rule1->ap[ac],
                                                &wmm_rule2->ap[ac],
                                                &wmm_rule->ap[ac]);
                }

                intersected_rule->has_wmm = true;
        } else if (rule1->has_wmm) {
                *wmm_rule = *wmm_rule1;
                intersected_rule->has_wmm = true;
        } else if (rule2->has_wmm) {
                *wmm_rule = *wmm_rule2;
                intersected_rule->has_wmm = true;
        } else {
                intersected_rule->has_wmm = false;
        }

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

        return 0;
}

/* check whether old rule contains new rule */
static bool rule_contains(struct ieee80211_reg_rule *r1,
                          struct ieee80211_reg_rule *r2)
{
        /* for simplicity, currently consider only same flags */
        if (r1->flags != r2->flags)
                return false;

        /* verify r1 is more restrictive */
        if ((r1->power_rule.max_antenna_gain >
             r2->power_rule.max_antenna_gain) ||
            r1->power_rule.max_eirp > r2->power_rule.max_eirp)
                return false;

        /* make sure r2's range is contained within r1 */
        if (r1->freq_range.start_freq_khz > r2->freq_range.start_freq_khz ||
            r1->freq_range.end_freq_khz < r2->freq_range.end_freq_khz)
                return false;

        /* and finally verify that r1.max_bw >= r2.max_bw */
        if (r1->freq_range.max_bandwidth_khz <
            r2->freq_range.max_bandwidth_khz)
                return false;

        return true;
}

/* add or extend current rules. do nothing if rule is already contained */
static void add_rule(struct ieee80211_reg_rule *rule,
                     struct ieee80211_reg_rule *reg_rules, u32 *n_rules)
{
        struct ieee80211_reg_rule *tmp_rule;
        int i;

        for (i = 0; i < *n_rules; i++) {
                tmp_rule = &reg_rules[i];
                /* rule is already contained - do nothing */
                if (rule_contains(tmp_rule, rule))
                        return;

                /* extend rule if possible */
                if (rule_contains(rule, tmp_rule)) {
                        memcpy(tmp_rule, rule, sizeof(*rule));
                        return;
                }
        }

        memcpy(&reg_rules[*n_rules], rule, sizeof(*rule));
        (*n_rules)++;
}

/**
 * regdom_intersect - do the intersection between two regulatory domains
 * @rd1: first regulatory domain
 * @rd2: second regulatory domain
 *
 * Use this function to get the intersection between two regulatory domains.
 * Once completed we will mark the alpha2 for the rd as intersected, "98",
 * as no one single alpha2 can represent this regulatory domain.
 *
 * Returns a pointer to the regulatory domain structure which will hold the
 * resulting intersection of rules between rd1 and rd2. We will
 * kzalloc() this structure for you.
 *
 * Returns: the intersected regdomain
 */
static struct ieee80211_regdomain *
regdom_intersect(const struct ieee80211_regdomain *rd1,
                 const struct ieee80211_regdomain *rd2)
{
        int r;
        unsigned int x, y;
        unsigned int num_rules = 0;
        const struct ieee80211_reg_rule *rule1, *rule2;
        struct ieee80211_reg_rule intersected_rule;
        struct ieee80211_regdomain *rd;

        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(rd1, rd2, rule1, rule2,
                                                 &intersected_rule))
                                num_rules++;
                }
        }

        if (!num_rules)
                return NULL;

        rd = kzalloc(struct_size(rd, reg_rules, num_rules), 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];
                        r = reg_rules_intersect(rd1, rd2, rule1, rule2,
                                                &intersected_rule);
                        /*
                         * No need to memset here the intersected rule here as
                         * we're not using the stack anymore
                         */
                        if (r)
                                continue;

                        add_rule(&intersected_rule, rd->reg_rules,
                                 &rd->n_reg_rules);
                }
        }

        rd->alpha2[0] = '9';
        rd->alpha2[1] = '8';
        rd->dfs_region = reg_intersect_dfs_region(rd1->dfs_region,
                                                  rd2->dfs_region);

        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_NO_IR_ALL)
                channel_flags |= IEEE80211_CHAN_NO_IR;
        if (rd_flags & NL80211_RRF_DFS)
                channel_flags |= IEEE80211_CHAN_RADAR;
        if (rd_flags & NL80211_RRF_NO_OFDM)
                channel_flags |= IEEE80211_CHAN_NO_OFDM;
        if (rd_flags & NL80211_RRF_NO_OUTDOOR)
                channel_flags |= IEEE80211_CHAN_INDOOR_ONLY;
        if (rd_flags & NL80211_RRF_IR_CONCURRENT)
                channel_flags |= IEEE80211_CHAN_IR_CONCURRENT;
        if (rd_flags & NL80211_RRF_NO_HT40MINUS)
                channel_flags |= IEEE80211_CHAN_NO_HT40MINUS;
        if (rd_flags & NL80211_RRF_NO_HT40PLUS)
                channel_flags |= IEEE80211_CHAN_NO_HT40PLUS;
        if (rd_flags & NL80211_RRF_NO_80MHZ)
                channel_flags |= IEEE80211_CHAN_NO_80MHZ;
        if (rd_flags & NL80211_RRF_NO_160MHZ)
                channel_flags |= IEEE80211_CHAN_NO_160MHZ;
        if (rd_flags & NL80211_RRF_NO_HE)
                channel_flags |= IEEE80211_CHAN_NO_HE;
        if (rd_flags & NL80211_RRF_NO_320MHZ)
                channel_flags |= IEEE80211_CHAN_NO_320MHZ;
        if (rd_flags & NL80211_RRF_NO_EHT)
                channel_flags |= IEEE80211_CHAN_NO_EHT;
        if (rd_flags & NL80211_RRF_DFS_CONCURRENT)
                channel_flags |= IEEE80211_CHAN_DFS_CONCURRENT;
        if (rd_flags & NL80211_RRF_NO_UHB_VLP_CLIENT)
                channel_flags |= IEEE80211_CHAN_NO_UHB_VLP_CLIENT;
        if (rd_flags & NL80211_RRF_NO_UHB_AFC_CLIENT)
                channel_flags |= IEEE80211_CHAN_NO_UHB_AFC_CLIENT;
        if (rd_flags & NL80211_RRF_PSD)
                channel_flags |= IEEE80211_CHAN_PSD;
        return channel_flags;
}

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

        if (!regd)
                return ERR_PTR(-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
                 * in center_freq's band, that's enough, so let's
                 * not overwrite it once found
                 */
                if (!band_rule_found)
                        band_rule_found = freq_in_rule_band(fr, center_freq);

                bw_fits = cfg80211_does_bw_fit_range(fr, center_freq, bw);

                if (band_rule_found && bw_fits)
                        return rr;
        }

        if (!band_rule_found)
                return ERR_PTR(-ERANGE);

        return ERR_PTR(-EINVAL);
}

static const struct ieee80211_reg_rule *
__freq_reg_info(struct wiphy *wiphy, u32 center_freq, u32 min_bw)
{
        const struct ieee80211_regdomain *regd = reg_get_regdomain(wiphy);
        static const u32 bws[] = {0, 1, 2, 4, 5, 8, 10, 16, 20};
        const struct ieee80211_reg_rule *reg_rule = ERR_PTR(-ERANGE);
        int i = ARRAY_SIZE(bws) - 1;
        u32 bw;

        for (bw = MHZ_TO_KHZ(bws[i]); bw >= min_bw; bw = MHZ_TO_KHZ(bws[i--])) {
                reg_rule = freq_reg_info_regd(center_freq, regd, bw);
                if (!IS_ERR(reg_rule))
                        return reg_rule;
        }

        return reg_rule;
}

const struct ieee80211_reg_rule *freq_reg_info(struct wiphy *wiphy,
                                               u32 center_freq)
{
        u32 min_bw = center_freq < MHZ_TO_KHZ(1000) ? 1 : 20;

        return __freq_reg_info(wiphy, center_freq, MHZ_TO_KHZ(min_bw));
}
EXPORT_SYMBOL(freq_reg_info);

const char *reg_initiator_name(enum nl80211_reg_initiator initiator)
{
        switch (initiator) {
        case NL80211_REGDOM_SET_BY_CORE:
                return "core";
        case NL80211_REGDOM_SET_BY_USER:
                return "user";
        case NL80211_REGDOM_SET_BY_DRIVER:
                return "driver";
        case NL80211_REGDOM_SET_BY_COUNTRY_IE:
                return "country element";
        default:
                WARN_ON(1);
                return "bug";
        }
}
EXPORT_SYMBOL(reg_initiator_name);

static uint32_t reg_rule_to_chan_bw_flags(const struct ieee80211_regdomain *regd,
                                          const struct ieee80211_reg_rule *reg_rule,
                                          const struct ieee80211_channel *chan)
{
        const struct ieee80211_freq_range *freq_range = NULL;
        u32 max_bandwidth_khz, center_freq_khz, bw_flags = 0;
        bool is_s1g = chan->band == NL80211_BAND_S1GHZ;

        freq_range = &reg_rule->freq_range;

        max_bandwidth_khz = freq_range->max_bandwidth_khz;
        center_freq_khz = ieee80211_channel_to_khz(chan);
        /* Check if auto calculation requested */
        if (reg_rule->flags & NL80211_RRF_AUTO_BW)
                max_bandwidth_khz = reg_get_max_bandwidth(regd, reg_rule);

        /* If we get a reg_rule we can assume that at least 5Mhz fit */
        if (!cfg80211_does_bw_fit_range(freq_range,
                                        center_freq_khz,
                                        MHZ_TO_KHZ(10)))
                bw_flags |= IEEE80211_CHAN_NO_10MHZ;
        if (!cfg80211_does_bw_fit_range(freq_range,
                                        center_freq_khz,
                                        MHZ_TO_KHZ(20)))
                bw_flags |= IEEE80211_CHAN_NO_20MHZ;

        if (is_s1g) {
                /* S1G is strict about non overlapping channels. We can
                 * calculate which bandwidth is allowed per channel by finding
                 * the largest bandwidth which cleanly divides the freq_range.
                 */
                int edge_offset;
                int ch_bw = max_bandwidth_khz;

                while (ch_bw) {
                        edge_offset = (center_freq_khz - ch_bw / 2) -
                                      freq_range->start_freq_khz;
                        if (edge_offset % ch_bw == 0) {
                                switch (KHZ_TO_MHZ(ch_bw)) {
                                case 1:
                                        bw_flags |= IEEE80211_CHAN_1MHZ;
                                        break;
                                case 2:
                                        bw_flags |= IEEE80211_CHAN_2MHZ;
                                        break;
                                case 4:
                                        bw_flags |= IEEE80211_CHAN_4MHZ;
                                        break;
                                case 8:
                                        bw_flags |= IEEE80211_CHAN_8MHZ;
                                        break;
                                case 16:
                                        bw_flags |= IEEE80211_CHAN_16MHZ;
                                        break;
                                default:
                                        /* If we got here, no bandwidths fit on
                                         * this frequency, ie. band edge.
                                         */
                                        bw_flags |= IEEE80211_CHAN_DISABLED;
                                        break;
                                }
                                break;
                        }
                        ch_bw /= 2;
                }
        } else {
                if (max_bandwidth_khz < MHZ_TO_KHZ(10))
                        bw_flags |= IEEE80211_CHAN_NO_10MHZ;
                if (max_bandwidth_khz < MHZ_TO_KHZ(20))
                        bw_flags |= IEEE80211_CHAN_NO_20MHZ;
                if (max_bandwidth_khz < MHZ_TO_KHZ(40))
                        bw_flags |= IEEE80211_CHAN_NO_HT40;
                if (max_bandwidth_khz < MHZ_TO_KHZ(80))
                        bw_flags |= IEEE80211_CHAN_NO_80MHZ;
                if (max_bandwidth_khz < MHZ_TO_KHZ(160))
                        bw_flags |= IEEE80211_CHAN_NO_160MHZ;
                if (max_bandwidth_khz < MHZ_TO_KHZ(320))
                        bw_flags |= IEEE80211_CHAN_NO_320MHZ;
        }
        return bw_flags;
}

static void handle_channel_single_rule(struct wiphy *wiphy,
                                       enum nl80211_reg_initiator initiator,
                                       struct ieee80211_channel *chan,
                                       u32 flags,
                                       struct regulatory_request *lr,
                                       struct wiphy *request_wiphy,
                                       const struct ieee80211_reg_rule *reg_rule)
{
        u32 bw_flags = 0;
        const struct ieee80211_power_rule *power_rule = NULL;
        const struct ieee80211_regdomain *regd;

        regd = reg_get_regdomain(wiphy);

        power_rule = &reg_rule->power_rule;
        bw_flags = reg_rule_to_chan_bw_flags(regd, reg_rule, chan);

        if (lr->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
            request_wiphy && request_wiphy == wiphy &&
            request_wiphy->regulatory_flags & REGULATORY_STRICT_REG) {
                /*
                 * 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);

                if (chan->flags & IEEE80211_CHAN_RADAR) {
                        chan->dfs_cac_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
                        if (reg_rule->dfs_cac_ms)
                                chan->dfs_cac_ms = reg_rule->dfs_cac_ms;
                }

                if (chan->flags & IEEE80211_CHAN_PSD)
                        chan->psd = reg_rule->psd;

                return;
        }

        chan->dfs_state = NL80211_DFS_USABLE;
        chan->dfs_state_entered = jiffies;

        chan->beacon_found = false;
        chan->flags = flags | bw_flags | map_regdom_flags(reg_rule->flags);
        chan->max_antenna_gain =
                min_t(int, chan->orig_mag,
                      MBI_TO_DBI(power_rule->max_antenna_gain));
        chan->max_reg_power = (int) MBM_TO_DBM(power_rule->max_eirp);

        if (chan->flags & IEEE80211_CHAN_RADAR) {
                if (reg_rule->dfs_cac_ms)
                        chan->dfs_cac_ms = reg_rule->dfs_cac_ms;
                else
                        chan->dfs_cac_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
        }

        if (chan->flags & IEEE80211_CHAN_PSD)
                chan->psd = reg_rule->psd;

        if (chan->orig_mpwr) {
                /*
                 * Devices that use REGULATORY_COUNTRY_IE_FOLLOW_POWER
                 * will always follow the passed country IE power settings.
                 */
                if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
                    wiphy->regulatory_flags & REGULATORY_COUNTRY_IE_FOLLOW_POWER)
                        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_channel_adjacent_rules(struct wiphy *wiphy,
                                          enum nl80211_reg_initiator initiator,
                                          struct ieee80211_channel *chan,
                                          u32 flags,
                                          struct regulatory_request *lr,
                                          struct wiphy *request_wiphy,
                                          const struct ieee80211_reg_rule *rrule1,
                                          const struct ieee80211_reg_rule *rrule2,
                                          struct ieee80211_freq_range *comb_range)
{
        u32 bw_flags1 = 0;
        u32 bw_flags2 = 0;
        const struct ieee80211_power_rule *power_rule1 = NULL;
        const struct ieee80211_power_rule *power_rule2 = NULL;
        const struct ieee80211_regdomain *regd;

        regd = reg_get_regdomain(wiphy);

        power_rule1 = &rrule1->power_rule;
        power_rule2 = &rrule2->power_rule;
        bw_flags1 = reg_rule_to_chan_bw_flags(regd, rrule1, chan);
        bw_flags2 = reg_rule_to_chan_bw_flags(regd, rrule2, chan);

        if (lr->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
            request_wiphy && request_wiphy == wiphy &&
            request_wiphy->regulatory_flags & REGULATORY_STRICT_REG) {
                /* This guarantees the driver's requested regulatory domain
                 * will always be used as a base for further regulatory
                 * settings
                 */
                chan->flags =
                        map_regdom_flags(rrule1->flags) |
                        map_regdom_flags(rrule2->flags) |
                        bw_flags1 |
                        bw_flags2;
                chan->orig_flags = chan->flags;
                chan->max_antenna_gain =
                        min_t(int, MBI_TO_DBI(power_rule1->max_antenna_gain),
                              MBI_TO_DBI(power_rule2->max_antenna_gain));
                chan->orig_mag = chan->max_antenna_gain;
                chan->max_reg_power =
                        min_t(int, MBM_TO_DBM(power_rule1->max_eirp),
                              MBM_TO_DBM(power_rule2->max_eirp));
                chan->max_power = chan->max_reg_power;
                chan->orig_mpwr = chan->max_reg_power;

                if (chan->flags & IEEE80211_CHAN_RADAR) {
                        chan->dfs_cac_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
                        if (rrule1->dfs_cac_ms || rrule2->dfs_cac_ms)
                                chan->dfs_cac_ms = max_t(unsigned int,
                                                         rrule1->dfs_cac_ms,
                                                         rrule2->dfs_cac_ms);
                }

                if ((rrule1->flags & NL80211_RRF_PSD) &&
                    (rrule2->flags & NL80211_RRF_PSD))
                        chan->psd = min_t(s8, rrule1->psd, rrule2->psd);
                else
                        chan->flags &= ~NL80211_RRF_PSD;

                return;
        }

        chan->dfs_state = NL80211_DFS_USABLE;
        chan->dfs_state_entered = jiffies;

        chan->beacon_found = false;
        chan->flags = flags | bw_flags1 | bw_flags2 |
                      map_regdom_flags(rrule1->flags) |
                      map_regdom_flags(rrule2->flags);

        /* reg_rule_to_chan_bw_flags may forbids 10 and forbids 20 MHz
         * (otherwise no adj. rule case), recheck therefore
         */
        if (cfg80211_does_bw_fit_range(comb_range,
                                       ieee80211_channel_to_khz(chan),
                                       MHZ_TO_KHZ(10)))
                chan->flags &= ~IEEE80211_CHAN_NO_10MHZ;
        if (cfg80211_does_bw_fit_range(comb_range,
                                       ieee80211_channel_to_khz(chan),
                                       MHZ_TO_KHZ(20)))
                chan->flags &= ~IEEE80211_CHAN_NO_20MHZ;

        chan->max_antenna_gain =
                min_t(int, chan->orig_mag,
                      min_t(int,
                            MBI_TO_DBI(power_rule1->max_antenna_gain),
                            MBI_TO_DBI(power_rule2->max_antenna_gain)));
        chan->max_reg_power = min_t(int,
                                    MBM_TO_DBM(power_rule1->max_eirp),
                                    MBM_TO_DBM(power_rule2->max_eirp));

        if (chan->flags & IEEE80211_CHAN_RADAR) {
                if (rrule1->dfs_cac_ms || rrule2->dfs_cac_ms)
                        chan->dfs_cac_ms = max_t(unsigned int,
                                                 rrule1->dfs_cac_ms,
                                                 rrule2->dfs_cac_ms);
                else
                        chan->dfs_cac_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
        }

        if (chan->orig_mpwr) {
                /* Devices that use REGULATORY_COUNTRY_IE_FOLLOW_POWER
                 * will always follow the passed country IE power settings.
                 */
                if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
                    wiphy->regulatory_flags & REGULATORY_COUNTRY_IE_FOLLOW_POWER)
                        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;
        }
}

/* 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).
 */
static void handle_channel(struct wiphy *wiphy,
                           enum nl80211_reg_initiator initiator,
                           struct ieee80211_channel *chan)
{
        const u32 orig_chan_freq = ieee80211_channel_to_khz(chan);
        struct regulatory_request *lr = get_last_request();
        struct wiphy *request_wiphy = wiphy_idx_to_wiphy(lr->wiphy_idx);
        const struct ieee80211_reg_rule *rrule = NULL;
        const struct ieee80211_reg_rule *rrule1 = NULL;
        const struct ieee80211_reg_rule *rrule2 = NULL;

        u32 flags = chan->orig_flags;

        rrule = freq_reg_info(wiphy, orig_chan_freq);
        if (IS_ERR(rrule)) {
                /* check for adjacent match, therefore get rules for
                 * chan - 20 MHz and chan + 20 MHz and test
                 * if reg rules are adjacent
                 */
                rrule1 = freq_reg_info(wiphy,
                                       orig_chan_freq - MHZ_TO_KHZ(20));
                rrule2 = freq_reg_info(wiphy,
                                       orig_chan_freq + MHZ_TO_KHZ(20));
                if (!IS_ERR(rrule1) && !IS_ERR(rrule2)) {
                        struct ieee80211_freq_range comb_range;

                        if (rrule1->freq_range.end_freq_khz !=
                            rrule2->freq_range.start_freq_khz)
                                goto disable_chan;

                        comb_range.start_freq_khz =
                                rrule1->freq_range.start_freq_khz;
                        comb_range.end_freq_khz =
                                rrule2->freq_range.end_freq_khz;
                        comb_range.max_bandwidth_khz =
                                min_t(u32,
                                      rrule1->freq_range.max_bandwidth_khz,
                                      rrule2->freq_range.max_bandwidth_khz);

                        if (!cfg80211_does_bw_fit_range(&comb_range,
                                                        orig_chan_freq,
                                                        MHZ_TO_KHZ(20)))
                                goto disable_chan;

                        handle_channel_adjacent_rules(wiphy, initiator, chan,
                                                      flags, lr, request_wiphy,
                                                      rrule1, rrule2,
                                                      &comb_range);
                        return;
                }

disable_chan:
                /* 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 &&
                    PTR_ERR(rrule) == -ERANGE)
                        return;

                if (lr->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
                    request_wiphy && request_wiphy == wiphy &&
                    request_wiphy->regulatory_flags & REGULATORY_STRICT_REG) {
                        pr_debug("Disabling freq %d.%03d MHz for good\n",
                                 chan->center_freq, chan->freq_offset);
                        chan->orig_flags |= IEEE80211_CHAN_DISABLED;
                        chan->flags = chan->orig_flags;
                } else {
                        pr_debug("Disabling freq %d.%03d MHz\n",
                                 chan->center_freq, chan->freq_offset);
                        chan->flags |= IEEE80211_CHAN_DISABLED;
                }
                return;
        }

        handle_channel_single_rule(wiphy, initiator, chan, flags, lr,
                                   request_wiphy, rrule);
}

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

        if (!sband)
                return;

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

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

bool reg_last_request_cell_base(void)
{
        return reg_request_cell_base(get_last_request());
}

#ifdef CONFIG_CFG80211_REG_CELLULAR_HINTS
/* Core specific check */
static enum reg_request_treatment
reg_ignore_cell_hint(struct regulatory_request *pending_request)
{
        struct regulatory_request *lr = get_last_request();

        if (!reg_num_devs_support_basehint)
                return REG_REQ_IGNORE;

        if (reg_request_cell_base(lr) &&
            !regdom_changes(pending_request->alpha2))
                return REG_REQ_ALREADY_SET;

        return REG_REQ_OK;
}

/* Device specific check */
static bool reg_dev_ignore_cell_hint(struct wiphy *wiphy)
{
        return !(wiphy->features & NL80211_FEATURE_CELL_BASE_REG_HINTS);
}
#else
static enum reg_request_treatment
reg_ignore_cell_hint(struct regulatory_request *pending_request)
{
        return REG_REQ_IGNORE;
}

static bool reg_dev_ignore_cell_hint(struct wiphy *wiphy)
{
        return true;
}
#endif

static bool wiphy_strict_alpha2_regd(struct wiphy *wiphy)
{
        if (wiphy->regulatory_flags & REGULATORY_STRICT_REG &&
            !(wiphy->regulatory_flags & REGULATORY_CUSTOM_REG))
                return true;
        return false;
}

static bool ignore_reg_update(struct wiphy *wiphy,
                              enum nl80211_reg_initiator initiator)
{
        struct regulatory_request *lr = get_last_request();

        if (wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED)
                return true;

        if (!lr) {
                pr_debug("Ignoring regulatory request set by %s since last_request is not set\n",
                         reg_initiator_name(initiator));
                return true;
        }

        if (initiator == NL80211_REGDOM_SET_BY_CORE &&
            wiphy->regulatory_flags & REGULATORY_CUSTOM_REG) {
                pr_debug("Ignoring regulatory request set by %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_strict_alpha2_regd(wiphy) && !wiphy->regd &&
            initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
            !is_world_regdom(lr->alpha2)) {
                pr_debug("Ignoring regulatory request set by %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(lr))
                return reg_dev_ignore_cell_hint(wiphy);

        return false;
}

static bool reg_is_world_roaming(struct wiphy *wiphy)
{
        const struct ieee80211_regdomain *cr = get_cfg80211_regdom();
        const struct ieee80211_regdomain *wr = get_wiphy_regdom(wiphy);
        struct regulatory_request *lr = get_last_request();

        if (is_world_regdom(cr->alpha2) || (wr && is_world_regdom(wr->alpha2)))
                return true;

        if (lr && lr->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
            wiphy->regulatory_flags & REGULATORY_CUSTOM_REG)
                return true;

        return false;
}

static void reg_call_notifier(struct wiphy *wiphy,
                              struct regulatory_request *request)
{
        if (wiphy->reg_notifier)
                wiphy->reg_notifier(wiphy, request);
}

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;
        struct regulatory_request *lr = get_last_request();

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

        if (likely(!ieee80211_channel_equal(chan, &reg_beacon->chan)))
                return;

        if (chan->beacon_found)
                return;

        chan->beacon_found = true;

        if (!reg_is_world_roaming(wiphy))
                return;

        if (wiphy->regulatory_flags & REGULATORY_DISABLE_BEACON_HINTS)
                return;

        chan_before = *chan;

        if (chan->flags & IEEE80211_CHAN_NO_IR) {
                chan->flags &= ~IEEE80211_CHAN_NO_IR;
                channel_changed = true;
        }

        if (channel_changed) {
                nl80211_send_beacon_hint_event(wiphy, &chan_before, chan);
                if (wiphy->flags & WIPHY_FLAG_CHANNEL_CHANGE_ON_BEACON)
                        reg_call_notifier(wiphy, lr);
        }
}

/*
 * 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;

        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;

        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);
        }
}

/* 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;
        wiphy_update_beacon_reg(wiphy);
}

static bool is_ht40_allowed(struct ieee80211_channel *chan)
{
        if (!chan)
                return false;
        if (chan->flags & IEEE80211_CHAN_DISABLED)
                return false;
        /* This would happen when regulatory rules disallow HT40 completely */
        if ((chan->flags & IEEE80211_CHAN_NO_HT40) == IEEE80211_CHAN_NO_HT40)
                return false;
        return true;
}

static void reg_process_ht_flags_channel(struct wiphy *wiphy,
                                         struct ieee80211_channel *channel)
{
        struct ieee80211_supported_band *sband = wiphy->bands[channel->band];
        struct ieee80211_channel *channel_before = NULL, *channel_after = NULL;
        const struct ieee80211_regdomain *regd;
        unsigned int i;
        u32 flags;

        if (!is_ht40_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;
        }

        flags = 0;
        regd = get_wiphy_regdom(wiphy);
        if (regd) {
                const struct ieee80211_reg_rule *reg_rule =
                        freq_reg_info_regd(MHZ_TO_KHZ(channel->center_freq),
                                           regd, MHZ_TO_KHZ(20));

                if (!IS_ERR(reg_rule))
                        flags = reg_rule->flags;
        }

        /*
         * 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_allowed(channel_before) ||
            flags & NL80211_RRF_NO_HT40MINUS)
                channel->flags |= IEEE80211_CHAN_NO_HT40MINUS;
        else
                channel->flags &= ~IEEE80211_CHAN_NO_HT40MINUS;

        if (!is_ht40_allowed(channel_after) ||
            flags & NL80211_RRF_NO_HT40PLUS)
                channel->flags |= IEEE80211_CHAN_NO_HT40PLUS;
        else
                channel->flags &= ~IEEE80211_CHAN_NO_HT40PLUS;
}

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

        if (!sband)
                return;

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

static void reg_process_ht_flags(struct wiphy *wiphy)
{
        enum nl80211_band band;

        if (!wiphy)
                return;

        for (band = 0; band < NUM_NL80211_BANDS; band++)
                reg_process_ht_flags_band(wiphy, wiphy->bands[band]);
}

static bool reg_wdev_chan_valid(struct wiphy *wiphy, struct wireless_dev *wdev)
{
        struct cfg80211_chan_def chandef = {};
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
        enum nl80211_iftype iftype;
        bool ret;
        int link;

        iftype = wdev->iftype;

        /* make sure the interface is active */
        if (!wdev->netdev || !netif_running(wdev->netdev))
                return true;

        for (link = 0; link < ARRAY_SIZE(wdev->links); link++) {
                struct ieee80211_channel *chan;

                if (!wdev->valid_links && link > 0)
                        break;
                if (wdev->valid_links && !(wdev->valid_links & BIT(link)))
                        continue;
                switch (iftype) {
                case NL80211_IFTYPE_AP:
                case NL80211_IFTYPE_P2P_GO:
                        if (!wdev->links[link].ap.beacon_interval)
                                continue;
                        chandef = wdev->links[link].ap.chandef;
                        break;
                case NL80211_IFTYPE_MESH_POINT:
                        if (!wdev->u.mesh.beacon_interval)
                                continue;
                        chandef = wdev->u.mesh.chandef;
                        break;
                case NL80211_IFTYPE_ADHOC:
                        if (!wdev->u.ibss.ssid_len)
                                continue;
                        chandef = wdev->u.ibss.chandef;
                        break;
                case NL80211_IFTYPE_STATION:
                case NL80211_IFTYPE_P2P_CLIENT:
                        /* Maybe we could consider disabling that link only? */
                        if (!wdev->links[link].client.current_bss)
                                continue;

                        chan = wdev->links[link].client.current_bss->pub.channel;
                        if (!chan)
                                continue;

                        if (!rdev->ops->get_channel ||
                            rdev_get_channel(rdev, wdev, link, &chandef))
                                cfg80211_chandef_create(&chandef, chan,
                                                        NL80211_CHAN_NO_HT);
                        break;
                case NL80211_IFTYPE_MONITOR:
                case NL80211_IFTYPE_AP_VLAN:
                case NL80211_IFTYPE_P2P_DEVICE:
                        /* no enforcement required */
                        break;
                case NL80211_IFTYPE_OCB:
                        if (!wdev->u.ocb.chandef.chan)
                                continue;
                        chandef = wdev->u.ocb.chandef;
                        break;
                case NL80211_IFTYPE_NAN:
                        /* we have no info, but NAN is also pretty universal */
                        continue;
                default:
                        /* others not implemented for now */
                        WARN_ON_ONCE(1);
                        break;
                }

                switch (iftype) {
                case NL80211_IFTYPE_AP:
                case NL80211_IFTYPE_P2P_GO:
                case NL80211_IFTYPE_ADHOC:
                case NL80211_IFTYPE_MESH_POINT:
                        ret = cfg80211_reg_can_beacon_relax(wiphy, &chandef,
                                                            iftype);
                        if (!ret)
                                return ret;
                        break;
                case NL80211_IFTYPE_STATION:
                case NL80211_IFTYPE_P2P_CLIENT:
                        ret = cfg80211_chandef_usable(wiphy, &chandef,
                                                      IEEE80211_CHAN_DISABLED);
                        if (!ret)
                                return ret;
                        break;
                default:
                        break;
                }
        }

        return true;
}

static void reg_leave_invalid_chans(struct wiphy *wiphy)
{
        struct wireless_dev *wdev;
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);

        wiphy_lock(wiphy);
        list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list)
                if (!reg_wdev_chan_valid(wiphy, wdev))
                        cfg80211_leave(rdev, wdev);
        wiphy_unlock(wiphy);
}

static void reg_check_chans_work(struct work_struct *work)
{
        struct cfg80211_registered_device *rdev;

        pr_debug("Verifying active interfaces after reg change\n");
        rtnl_lock();

        for_each_rdev(rdev)
                reg_leave_invalid_chans(&rdev->wiphy);

        rtnl_unlock();
}

void reg_check_channels(void)
{
        /*
         * Give usermode a chance to do something nicer (move to another
         * channel, orderly disconnection), before forcing a disconnection.
         */
        mod_delayed_work(system_power_efficient_wq,
                         &reg_check_chans,
                         msecs_to_jiffies(REG_ENFORCE_GRACE_MS));
}

static void wiphy_update_regulatory(struct wiphy *wiphy,
                                    enum nl80211_reg_initiator initiator)
{
        enum nl80211_band band;
        struct regulatory_request *lr = get_last_request();

        if (ignore_reg_update(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->regulatory_flags & REGULATORY_CUSTOM_REG &&
                    !(wiphy->regulatory_flags &
                      REGULATORY_WIPHY_SELF_MANAGED))
                        reg_call_notifier(wiphy, lr);
                return;
        }

        lr->dfs_region = get_cfg80211_regdom()->dfs_region;

        for (band = 0; band < NUM_NL80211_BANDS; band++)
                handle_band(wiphy, initiator, wiphy->bands[band]);

        reg_process_beacons(wiphy);
        reg_process_ht_flags(wiphy);
        reg_call_notifier(wiphy, lr);
}

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

        ASSERT_RTNL();

        for_each_rdev(rdev) {
                wiphy = &rdev->wiphy;
                wiphy_update_regulatory(wiphy, initiator);
        }

        reg_check_channels();
}

static void handle_channel_custom(struct wiphy *wiphy,
                                  struct ieee80211_channel *chan,
                                  const struct ieee80211_regdomain *regd,
                                  u32 min_bw)
{
        u32 bw_flags = 0;
        const struct ieee80211_reg_rule *reg_rule = NULL;
        const struct ieee80211_power_rule *power_rule = NULL;
        u32 bw, center_freq_khz;

        center_freq_khz = ieee80211_channel_to_khz(chan);
        for (bw = MHZ_TO_KHZ(20); bw >= min_bw; bw = bw / 2) {
                reg_rule = freq_reg_info_regd(center_freq_khz, regd, bw);
                if (!IS_ERR(reg_rule))
                        break;
        }

        if (IS_ERR_OR_NULL(reg_rule)) {
                pr_debug("Disabling freq %d.%03d MHz as custom regd has no rule that fits it\n",
                         chan->center_freq, chan->freq_offset);
                if (wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED) {
                        chan->flags |= IEEE80211_CHAN_DISABLED;
                } else {
                        chan->orig_flags |= IEEE80211_CHAN_DISABLED;
                        chan->flags = chan->orig_flags;
                }
                return;
        }

        power_rule = &reg_rule->power_rule;
        bw_flags = reg_rule_to_chan_bw_flags(regd, reg_rule, chan);

        chan->dfs_state_entered = jiffies;
        chan->dfs_state = NL80211_DFS_USABLE;

        chan->beacon_found = false;

        if (wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED)
                chan->flags = chan->orig_flags | bw_flags |
                              map_regdom_flags(reg_rule->flags);
        else
                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);

        if (chan->flags & IEEE80211_CHAN_RADAR) {
                if (reg_rule->dfs_cac_ms)
                        chan->dfs_cac_ms = reg_rule->dfs_cac_ms;
                else
                        chan->dfs_cac_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
        }

        if (chan->flags & IEEE80211_CHAN_PSD)
                chan->psd = reg_rule->psd;

        chan->max_power = chan->max_reg_power;
}

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

        if (!sband)
                return;

        /*
         * We currently assume that you always want at least 20 MHz,
         * otherwise channel 12 might get enabled if this rule is
         * compatible to US, which permits 2402 - 2472 MHz.
         */
        for (i = 0; i < sband->n_channels; i++)
                handle_channel_custom(wiphy, &sband->channels[i], regd,
                                      MHZ_TO_KHZ(20));
}

/* Used by drivers prior to wiphy registration */
void wiphy_apply_custom_regulatory(struct wiphy *wiphy,
                                   const struct ieee80211_regdomain *regd)
{
        const struct ieee80211_regdomain *new_regd, *tmp;
        enum nl80211_band band;
        unsigned int bands_set = 0;

        WARN(!(wiphy->regulatory_flags & REGULATORY_CUSTOM_REG),
             "wiphy should have REGULATORY_CUSTOM_REG\n");
        wiphy->regulatory_flags |= REGULATORY_CUSTOM_REG;

        for (band = 0; band < NUM_NL80211_BANDS; band++) {
                if (!wiphy->bands[band])
                        continue;
                handle_band_custom(wiphy, wiphy->bands[band], regd);
                bands_set++;
        }

        /*
         * no point in calling this if it won't have any effect
         * on your device's supported bands.
         */
        WARN_ON(!bands_set);
        new_regd = reg_copy_regd(regd);
        if (IS_ERR(new_regd))
                return;

        rtnl_lock();
        wiphy_lock(wiphy);

        tmp = get_wiphy_regdom(wiphy);
        rcu_assign_pointer(wiphy->regd, new_regd);
        rcu_free_regdom(tmp);

        wiphy_unlock(wiphy);
        rtnl_unlock();
}
EXPORT_SYMBOL(wiphy_apply_custom_regulatory);

static void reg_set_request_processed(void)
{
        bool need_more_processing = false;
        struct regulatory_request *lr = get_last_request();

        lr->processed = true;

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

        cancel_crda_timeout();

        if (need_more_processing)
                schedule_work(&reg_work);
}

/**
 * reg_process_hint_core - process core regulatory requests
 * @core_request: a pending core regulatory request
 *
 * The wireless subsystem can use this function to process
 * a regulatory request issued by the regulatory core.
 *
 * Returns: %REG_REQ_OK or %REG_REQ_IGNORE, indicating if the
 *      hint was processed or ignored
 */
static enum reg_request_treatment
reg_process_hint_core(struct regulatory_request *core_request)
{
        if (reg_query_database(core_request)) {
                core_request->intersect = false;
                core_request->processed = false;
                reg_update_last_request(core_request);
                return REG_REQ_OK;
        }

        return REG_REQ_IGNORE;
}

static enum reg_request_treatment
__reg_process_hint_user(struct regulatory_request *user_request)
{
        struct regulatory_request *lr = get_last_request();

        if (reg_request_cell_base(user_request))
                return reg_ignore_cell_hint(user_request);

        if (reg_request_cell_base(lr))
                return REG_REQ_IGNORE;

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

        if (!regdom_changes(user_request->alpha2))
                return REG_REQ_ALREADY_SET;

        return REG_REQ_OK;
}

/**
 * reg_process_hint_user - process user regulatory requests
 * @user_request: a pending user regulatory request
 *
 * The wireless subsystem can use this function to process
 * a regulatory request initiated by userspace.
 *
 * Returns: %REG_REQ_OK or %REG_REQ_IGNORE, indicating if the
 *      hint was processed or ignored
 */
static enum reg_request_treatment
reg_process_hint_user(struct regulatory_request *user_request)
{
        enum reg_request_treatment treatment;

        treatment = __reg_process_hint_user(user_request);
        if (treatment == REG_REQ_IGNORE ||
            treatment == REG_REQ_ALREADY_SET)
                return REG_REQ_IGNORE;

        user_request->intersect = treatment == REG_REQ_INTERSECT;
        user_request->processed = false;

        if (reg_query_database(user_request)) {
                reg_update_last_request(user_request);
                user_alpha2[0] = user_request->alpha2[0];
                user_alpha2[1] = user_request->alpha2[1];
                return REG_REQ_OK;
        }

        return REG_REQ_IGNORE;
}

static enum reg_request_treatment
__reg_process_hint_driver(struct regulatory_request *driver_request)
{
        struct regulatory_request *lr = get_last_request();

        if (lr->initiator == NL80211_REGDOM_SET_BY_CORE) {
                if (regdom_changes(driver_request->alpha2))
                        return REG_REQ_OK;
                return REG_REQ_ALREADY_SET;
        }

        /*
         * 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 (lr->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
            !regdom_changes(driver_request->alpha2))
                return REG_REQ_ALREADY_SET;

        return REG_REQ_INTERSECT;
}

/**
 * reg_process_hint_driver - process driver regulatory requests
 * @wiphy: the wireless device for the regulatory request
 * @driver_request: a pending driver regulatory request
 *
 * The wireless subsystem can use this function to process
 * a regulatory request issued by an 802.11 driver.
 *
 * Returns: one of the different reg request treatment values.
 */
static enum reg_request_treatment
reg_process_hint_driver(struct wiphy *wiphy,
                        struct regulatory_request *driver_request)
{
        const struct ieee80211_regdomain *regd, *tmp;
        enum reg_request_treatment treatment;

        treatment = __reg_process_hint_driver(driver_request);

        switch (treatment) {
        case REG_REQ_OK:
                break;
        case REG_REQ_IGNORE:
                return REG_REQ_IGNORE;
        case REG_REQ_INTERSECT:
        case REG_REQ_ALREADY_SET:
                regd = reg_copy_regd(get_cfg80211_regdom());
                if (IS_ERR(regd))
                        return REG_REQ_IGNORE;

                tmp = get_wiphy_regdom(wiphy);
                ASSERT_RTNL();
                wiphy_lock(wiphy);
                rcu_assign_pointer(wiphy->regd, regd);
                wiphy_unlock(wiphy);
                rcu_free_regdom(tmp);
        }


        driver_request->intersect = treatment == REG_REQ_INTERSECT;
        driver_request->processed = false;

        /*
         * 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 (treatment == REG_REQ_ALREADY_SET) {
                nl80211_send_reg_change_event(driver_request);
                reg_update_last_request(driver_request);
                reg_set_request_processed();
                return REG_REQ_ALREADY_SET;
        }

        if (reg_query_database(driver_request)) {
                reg_update_last_request(driver_request);
                return REG_REQ_OK;
        }

        return REG_REQ_IGNORE;
}

static enum reg_request_treatment
__reg_process_hint_country_ie(struct wiphy *wiphy,
                              struct regulatory_request *country_ie_request)
{
        struct wiphy *last_wiphy = NULL;
        struct regulatory_request *lr = get_last_request();

        if (reg_request_cell_base(lr)) {
                /* Trust a Cell base station over the AP's country IE */
                if (regdom_changes(country_ie_request->alpha2))
                        return REG_REQ_IGNORE;
                return REG_REQ_ALREADY_SET;
        } else {
                if (wiphy->regulatory_flags & REGULATORY_COUNTRY_IE_IGNORE)
                        return REG_REQ_IGNORE;
        }

        if (unlikely(!is_an_alpha2(country_ie_request->alpha2)))
                return -EINVAL;

        if (lr->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE)
                return REG_REQ_OK;

        last_wiphy = wiphy_idx_to_wiphy(lr->wiphy_idx);

        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(country_ie_request->alpha2))
                        return REG_REQ_IGNORE;
                return REG_REQ_ALREADY_SET;
        }

        if (regdom_changes(country_ie_request->alpha2))
                return REG_REQ_OK;
        return REG_REQ_ALREADY_SET;
}

/**
 * reg_process_hint_country_ie - process regulatory requests from country IEs
 * @wiphy: the wireless device for the regulatory request
 * @country_ie_request: a regulatory request from a country IE
 *
 * The wireless subsystem can use this function to process
 * a regulatory request issued by a country Information Element.
 *
 * Returns: one of the different reg request treatment values.
 */
static enum reg_request_treatment
reg_process_hint_country_ie(struct wiphy *wiphy,
                            struct regulatory_request *country_ie_request)
{
        enum reg_request_treatment treatment;

        treatment = __reg_process_hint_country_ie(wiphy, country_ie_request);

        switch (treatment) {
        case REG_REQ_OK:
                break;
        case REG_REQ_IGNORE:
                return REG_REQ_IGNORE;
        case REG_REQ_ALREADY_SET:
                reg_free_request(country_ie_request);
                return REG_REQ_ALREADY_SET;
        case REG_REQ_INTERSECT:
                /*
                 * This doesn't happen yet, not sure we
                 * ever want to support it for this case.
                 */
                WARN_ONCE(1, "Unexpected intersection for country elements");
                return REG_REQ_IGNORE;
        }

        country_ie_request->intersect = false;
        country_ie_request->processed = false;

        if (reg_query_database(country_ie_request)) {
                reg_update_last_request(country_ie_request);
                return REG_REQ_OK;
        }

        return REG_REQ_IGNORE;
}

bool reg_dfs_domain_same(struct wiphy *wiphy1, struct wiphy *wiphy2)
{
        const struct ieee80211_regdomain *wiphy1_regd = NULL;
        const struct ieee80211_regdomain *wiphy2_regd = NULL;
        const struct ieee80211_regdomain *cfg80211_regd = NULL;
        bool dfs_domain_same;

        rcu_read_lock();

        cfg80211_regd = rcu_dereference(cfg80211_regdomain);
        wiphy1_regd = rcu_dereference(wiphy1->regd);
        if (!wiphy1_regd)
                wiphy1_regd = cfg80211_regd;

        wiphy2_regd = rcu_dereference(wiphy2->regd);
        if (!wiphy2_regd)
                wiphy2_regd = cfg80211_regd;

        dfs_domain_same = wiphy1_regd->dfs_region == wiphy2_regd->dfs_region;

        rcu_read_unlock();

        return dfs_domain_same;
}

static void reg_copy_dfs_chan_state(struct ieee80211_channel *dst_chan,
                                    struct ieee80211_channel *src_chan)
{
        if (!(dst_chan->flags & IEEE80211_CHAN_RADAR) ||
            !(src_chan->flags & IEEE80211_CHAN_RADAR))
                return;

        if (dst_chan->flags & IEEE80211_CHAN_DISABLED ||
            src_chan->flags & IEEE80211_CHAN_DISABLED)
                return;

        if (src_chan->center_freq == dst_chan->center_freq &&
            dst_chan->dfs_state == NL80211_DFS_USABLE) {
                dst_chan->dfs_state = src_chan->dfs_state;
                dst_chan->dfs_state_entered = src_chan->dfs_state_entered;
        }
}

static void wiphy_share_dfs_chan_state(struct wiphy *dst_wiphy,
                                       struct wiphy *src_wiphy)
{
        struct ieee80211_supported_band *src_sband, *dst_sband;
        struct ieee80211_channel *src_chan, *dst_chan;
        int i, j, band;

        if (!reg_dfs_domain_same(dst_wiphy, src_wiphy))
                return;

        for (band = 0; band < NUM_NL80211_BANDS; band++) {
                dst_sband = dst_wiphy->bands[band];
                src_sband = src_wiphy->bands[band];
                if (!dst_sband || !src_sband)
                        continue;

                for (i = 0; i < dst_sband->n_channels; i++) {
                        dst_chan = &dst_sband->channels[i];
                        for (j = 0; j < src_sband->n_channels; j++) {
                                src_chan = &src_sband->channels[j];
                                reg_copy_dfs_chan_state(dst_chan, src_chan);
                        }
                }
        }
}

static void wiphy_all_share_dfs_chan_state(struct wiphy *wiphy)
{
        struct cfg80211_registered_device *rdev;

        ASSERT_RTNL();

        for_each_rdev(rdev) {
                if (wiphy == &rdev->wiphy)
                        continue;
                wiphy_share_dfs_chan_state(wiphy, &rdev->wiphy);
        }
}

/* This processes *all* regulatory hints */
static void reg_process_hint(struct regulatory_request *reg_request)
{
        struct wiphy *wiphy = NULL;
        enum reg_request_treatment treatment;
        enum nl80211_reg_initiator initiator = reg_request->initiator;

        if (reg_request->wiphy_idx != WIPHY_IDX_INVALID)
                wiphy = wiphy_idx_to_wiphy(reg_request->wiphy_idx);

        switch (initiator) {
        case NL80211_REGDOM_SET_BY_CORE:
                treatment = reg_process_hint_core(reg_request);
                break;
        case NL80211_REGDOM_SET_BY_USER:
                treatment = reg_process_hint_user(reg_request);
                break;
        case NL80211_REGDOM_SET_BY_DRIVER:
                if (!wiphy)
                        goto out_free;
                treatment = reg_process_hint_driver(wiphy, reg_request);
                break;
        case NL80211_REGDOM_SET_BY_COUNTRY_IE:
                if (!wiphy)
                        goto out_free;
                treatment = reg_process_hint_country_ie(wiphy, reg_request);
                break;
        default:
                WARN(1, "invalid initiator %d\n", initiator);
                goto out_free;
        }

        if (treatment == REG_REQ_IGNORE)
                goto out_free;

        WARN(treatment != REG_REQ_OK && treatment != REG_REQ_ALREADY_SET,
             "unexpected treatment value %d\n", treatment);

        /* This is required so that the orig_* parameters are saved.
         * NOTE: treatment must be set for any case that reaches here!
         */
        if (treatment == REG_REQ_ALREADY_SET && wiphy &&
            wiphy->regulatory_flags & REGULATORY_STRICT_REG) {
                wiphy_update_regulatory(wiphy, initiator);
                wiphy_all_share_dfs_chan_state(wiphy);
                reg_check_channels();
        }

        return;

out_free:
        reg_free_request(reg_request);
}

static void notify_self_managed_wiphys(struct regulatory_request *request)
{
        struct cfg80211_registered_device *rdev;
        struct wiphy *wiphy;

        for_each_rdev(rdev) {
                wiphy = &rdev->wiphy;
                if (wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED &&
                    request->initiator == NL80211_REGDOM_SET_BY_USER)
                        reg_call_notifier(wiphy, request);
        }
}

/*
 * 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, *lr;

        lr = get_last_request();

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

        spin_lock(&reg_requests_lock);

        if (list_empty(&reg_requests_list)) {
                spin_unlock(&reg_requests_lock);
                return;
        }

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

        spin_unlock(&reg_requests_lock);

        notify_self_managed_wiphys(reg_request);

        reg_process_hint(reg_request);

        lr = get_last_request();

        spin_lock(&reg_requests_lock);
        if (!list_empty(&reg_requests_list) && lr && lr->processed)
                schedule_work(&reg_work);
        spin_unlock(&reg_requests_lock);
}

/* 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;

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

        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 */
                for_each_rdev(rdev)
                        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);
}

static void reg_process_self_managed_hint(struct wiphy *wiphy)
{
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
        const struct ieee80211_regdomain *tmp;
        const struct ieee80211_regdomain *regd;
        enum nl80211_band band;
        struct regulatory_request request = {};

        ASSERT_RTNL();
        lockdep_assert_wiphy(wiphy);

        spin_lock(&reg_requests_lock);
        regd = rdev->requested_regd;
        rdev->requested_regd = NULL;
        spin_unlock(&reg_requests_lock);

        if (!regd)
                return;

        tmp = get_wiphy_regdom(wiphy);
        rcu_assign_pointer(wiphy->regd, regd);
        rcu_free_regdom(tmp);

        for (band = 0; band < NUM_NL80211_BANDS; band++)
                handle_band_custom(wiphy, wiphy->bands[band], regd);

        reg_process_ht_flags(wiphy);

        request.wiphy_idx = get_wiphy_idx(wiphy);
        request.alpha2[0] = regd->alpha2[0];
        request.alpha2[1] = regd->alpha2[1];
        request.initiator = NL80211_REGDOM_SET_BY_DRIVER;

        if (wiphy->flags & WIPHY_FLAG_NOTIFY_REGDOM_BY_DRIVER)
                reg_call_notifier(wiphy, &request);

        nl80211_send_wiphy_reg_change_event(&request);
}

static void reg_process_self_managed_hints(void)
{
        struct cfg80211_registered_device *rdev;

        ASSERT_RTNL();

        for_each_rdev(rdev) {
                wiphy_lock(&rdev->wiphy);
                reg_process_self_managed_hint(&rdev->wiphy);
                wiphy_unlock(&rdev->wiphy);
        }

        reg_check_channels();
}

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

static void queue_regulatory_request(struct regulatory_request *request)
{
        request->alpha2[0] = toupper(request->alpha2[0]);
        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;
        request->wiphy_idx = WIPHY_IDX_INVALID;

        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;

        if (WARN_ON(!alpha2))
                return -EINVAL;

        if (!is_world_regdom(alpha2) && !is_an_alpha2(alpha2))
                return -EINVAL;

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

        request->wiphy_idx = WIPHY_IDX_INVALID;
        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;

        /* Allow calling CRDA again */
        reset_crda_timeouts();

        queue_regulatory_request(request);

        return 0;
}

int regulatory_hint_indoor(bool is_indoor, u32 portid)
{
        spin_lock(&reg_indoor_lock);

        /* It is possible that more than one user space process is trying to
         * configure the indoor setting. To handle such cases, clear the indoor
         * setting in case that some process does not think that the device
         * is operating in an indoor environment. In addition, if a user space
         * process indicates that it is controlling the indoor setting, save its
         * portid, i.e., make it the owner.
         */
        reg_is_indoor = is_indoor;
        if (reg_is_indoor) {
                if (!reg_is_indoor_portid)
                        reg_is_indoor_portid = portid;
        } else {
                reg_is_indoor_portid = 0;
        }

        spin_unlock(&reg_indoor_lock);

        if (!is_indoor)
                reg_check_channels();

        return 0;
}

void regulatory_netlink_notify(u32 portid)
{
        spin_lock(&reg_indoor_lock);

        if (reg_is_indoor_portid != portid) {
                spin_unlock(&reg_indoor_lock);
                return;
        }

        reg_is_indoor = false;
        reg_is_indoor_portid = 0;

        spin_unlock(&reg_indoor_lock);

        reg_check_channels();
}

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

        if (WARN_ON(!alpha2 || !wiphy))
                return -EINVAL;

        wiphy->regulatory_flags &= ~REGULATORY_CUSTOM_REG;

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

        request->wiphy_idx = get_wiphy_idx(wiphy);

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

        /* Allow calling CRDA again */
        reset_crda_timeouts();

        queue_regulatory_request(request);

        return 0;
}
EXPORT_SYMBOL(regulatory_hint);

void regulatory_hint_country_ie(struct wiphy *wiphy, enum nl80211_band band,
                                const u8 *country_ie, u8 country_ie_len)
{
        char alpha2[2];
        enum environment_cap env = ENVIRON_ANY;
        struct regulatory_request *request = NULL, *lr;

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

        if (country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN)
                return;

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

        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;

        rcu_read_lock();
        lr = get_last_request();

        if (unlikely(!lr))
                goto out;

        /*
         * We will run this only upon a successful connection on cfg80211.
         * We leave conflict resolution to the workqueue, where can hold
         * the RTNL.
         */
        if (lr->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
            lr->wiphy_idx != WIPHY_IDX_INVALID)
                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;

        /* Allow calling CRDA again */
        reset_crda_timeouts();

        queue_regulatory_request(request);
        request = NULL;
out:
        kfree(request);
        rcu_read_unlock();
}

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) {
                        pr_debug("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)) {
                                pr_debug("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 {
                        pr_debug("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)) {
                pr_debug("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
                pr_debug("Restoring regulatory settings\n");
}

static void restore_custom_reg_settings(struct wiphy *wiphy)
{
        struct ieee80211_supported_band *sband;
        enum nl80211_band band;
        struct ieee80211_channel *chan;
        int i;

        for (band = 0; band < NUM_NL80211_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 ignoring 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
 * not need to be remembered.
 */
static void restore_regulatory_settings(bool reset_user, bool cached)
{
        char alpha2[2];
        char world_alpha2[2];
        struct reg_beacon *reg_beacon, *btmp;
        LIST_HEAD(tmp_reg_req_list);
        struct cfg80211_registered_device *rdev;

        ASSERT_RTNL();

        /*
         * Clear the indoor setting in case that it is not controlled by user
         * space, as otherwise there is no guarantee that the device is still
         * operating in an indoor environment.
         */
        spin_lock(&reg_indoor_lock);
        if (reg_is_indoor && !reg_is_indoor_portid) {
                reg_is_indoor = false;
                reg_check_channels();
        }
        spin_unlock(&reg_indoor_lock);

        reset_regdomains(true, &world_regdom);
        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);
        list_splice_tail_init(&reg_requests_list, &tmp_reg_req_list);
        spin_unlock(&reg_requests_lock);

        /* Clear beacon hints */
        spin_lock_bh(&reg_pending_beacons_lock);
        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);

        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 */
        world_alpha2[0] = cfg80211_world_regdom->alpha2[0];
        world_alpha2[1] = cfg80211_world_regdom->alpha2[1];

        for_each_rdev(rdev) {
                if (rdev->wiphy.regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED)
                        continue;
                if (rdev->wiphy.regulatory_flags & REGULATORY_CUSTOM_REG)
                        restore_custom_reg_settings(&rdev->wiphy);
        }

        if (cached && (!is_an_alpha2(alpha2) ||
                       !IS_ERR_OR_NULL(cfg80211_user_regdom))) {
                reset_regdomains(false, cfg80211_world_regdom);
                update_all_wiphy_regulatory(NL80211_REGDOM_SET_BY_CORE);
                print_regdomain(get_cfg80211_regdom());
                nl80211_send_reg_change_event(&core_request_world);
                reg_set_request_processed();

                if (is_an_alpha2(alpha2) &&
                    !regulatory_hint_user(alpha2, NL80211_USER_REG_HINT_USER)) {
                        struct regulatory_request *ureq;

                        spin_lock(&reg_requests_lock);
                        ureq = list_last_entry(&reg_requests_list,
                                               struct regulatory_request,
                                               list);
                        list_del(&ureq->list);
                        spin_unlock(&reg_requests_lock);

                        notify_self_managed_wiphys(ureq);
                        reg_update_last_request(ureq);
                        set_regdom(reg_copy_regd(cfg80211_user_regdom),
                                   REGD_SOURCE_CACHED);
                }
        } else {
                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(alpha2, NL80211_USER_REG_HINT_USER);
        }

        spin_lock(&reg_requests_lock);
        list_splice_tail_init(&tmp_reg_req_list, &reg_requests_list);
        spin_unlock(&reg_requests_lock);

        pr_debug("Kicking the queue\n");

        schedule_work(&reg_work);
}

static bool is_wiphy_all_set_reg_flag(enum ieee80211_regulatory_flags flag)
{
        struct cfg80211_registered_device *rdev;
        struct wireless_dev *wdev;

        for_each_rdev(rdev) {
                wiphy_lock(&rdev->wiphy);
                list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
                        if (!(wdev->wiphy->regulatory_flags & flag)) {
                                wiphy_unlock(&rdev->wiphy);
                                return false;
                        }
                }
                wiphy_unlock(&rdev->wiphy);
        }

        return true;
}

void regulatory_hint_disconnect(void)
{
        /* Restore of regulatory settings is not required when wiphy(s)
         * ignore IE from connected access point but clearance of beacon hints
         * is required when wiphy(s) supports beacon hints.
         */
        if (is_wiphy_all_set_reg_flag(REGULATORY_COUNTRY_IE_IGNORE)) {
                struct reg_beacon *reg_beacon, *btmp;

                if (is_wiphy_all_set_reg_flag(REGULATORY_DISABLE_BEACON_HINTS))
                        return;

                spin_lock_bh(&reg_pending_beacons_lock);
                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);

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

                return;
        }

        pr_debug("All devices are disconnected, going to restore regulatory settings\n");
        restore_regulatory_settings(false, true);
}

static bool freq_is_chan_12_13_14(u32 freq)
{
        if (freq == ieee80211_channel_to_frequency(12, NL80211_BAND_2GHZ) ||
            freq == ieee80211_channel_to_frequency(13, NL80211_BAND_2GHZ) ||
            freq == ieee80211_channel_to_frequency(14, NL80211_BAND_2GHZ))
                return true;
        return false;
}

static bool pending_reg_beacon(struct ieee80211_channel *beacon_chan)
{
        struct reg_beacon *pending_beacon;

        list_for_each_entry(pending_beacon, &reg_pending_beacons, list)
                if (ieee80211_channel_equal(beacon_chan,
                                            &pending_beacon->chan))
                        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;
        bool processing;

        if (beacon_chan->beacon_found ||
            beacon_chan->flags & IEEE80211_CHAN_RADAR ||
            (beacon_chan->band == NL80211_BAND_2GHZ &&
             !freq_is_chan_12_13_14(beacon_chan->center_freq)))
                return 0;

        spin_lock_bh(&reg_pending_beacons_lock);
        processing = pending_reg_beacon(beacon_chan);
        spin_unlock_bh(&reg_pending_beacons_lock);

        if (processing)
                return 0;

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

        pr_debug("Found new beacon on frequency: %d.%03d MHz (Ch %d) on %s\n",
                 beacon_chan->center_freq, beacon_chan->freq_offset,
                 ieee80211_freq_khz_to_channel(
                         ieee80211_channel_to_khz(beacon_chan)),
                 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;
        char bw[32], cac_time[32];

        pr_debug("  (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)\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;

                if (reg_rule->flags & NL80211_RRF_AUTO_BW)
                        snprintf(bw, sizeof(bw), "%d KHz, %u KHz AUTO",
                                 freq_range->max_bandwidth_khz,
                                 reg_get_max_bandwidth(rd, reg_rule));
                else
                        snprintf(bw, sizeof(bw), "%d KHz",
                                 freq_range->max_bandwidth_khz);

                if (reg_rule->flags & NL80211_RRF_DFS)
                        scnprintf(cac_time, sizeof(cac_time), "%u s",
                                  reg_rule->dfs_cac_ms/1000);
                else
                        scnprintf(cac_time, sizeof(cac_time), "N/A");


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

bool reg_supported_dfs_region(enum nl80211_dfs_regions dfs_region)
{
        switch (dfs_region) {
        case NL80211_DFS_UNSET:
        case NL80211_DFS_FCC:
        case NL80211_DFS_ETSI:
        case NL80211_DFS_JP:
                return true;
        default:
                pr_debug("Ignoring unknown DFS master region: %d\n", dfs_region);
                return false;
        }
}

static void print_regdomain(const struct ieee80211_regdomain *rd)
{
        struct regulatory_request *lr = get_last_request();

        if (is_intersected_alpha2(rd->alpha2)) {
                if (lr->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
                        struct cfg80211_registered_device *rdev;
                        rdev = cfg80211_rdev_by_wiphy_idx(lr->wiphy_idx);
                        if (rdev) {
                                pr_debug("Current regulatory domain updated by AP to: %c%c\n",
                                        rdev->country_ie_alpha2[0],
                                        rdev->country_ie_alpha2[1]);
                        } else
                                pr_debug("Current regulatory domain intersected:\n");
                } else
                        pr_debug("Current regulatory domain intersected:\n");
        } else if (is_world_regdom(rd->alpha2)) {
                pr_debug("World regulatory domain updated:\n");
        } else {
                if (is_unknown_alpha2(rd->alpha2))
                        pr_debug("Regulatory domain changed to driver built-in settings (unknown country)\n");
                else {
                        if (reg_request_cell_base(lr))
                                pr_debug("Regulatory domain changed to country: %c%c by Cell Station\n",
                                        rd->alpha2[0], rd->alpha2[1]);
                        else
                                pr_debug("Regulatory domain changed to country: %c%c\n",
                                        rd->alpha2[0], rd->alpha2[1]);
                }
        }

        pr_debug(" DFS Master region: %s", reg_dfs_region_str(rd->dfs_region));
        print_rd_rules(rd);
}

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

static int reg_set_rd_core(const struct ieee80211_regdomain *rd)
{
        if (!is_world_regdom(rd->alpha2))
                return -EINVAL;
        update_world_regdomain(rd);
        return 0;
}

static int reg_set_rd_user(const struct ieee80211_regdomain *rd,
                           struct regulatory_request *user_request)
{
        const struct ieee80211_regdomain *intersected_rd = NULL;

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

        if (!is_valid_rd(rd)) {
                pr_err("Invalid regulatory domain detected: %c%c\n",
                       rd->alpha2[0], rd->alpha2[1]);
                print_regdomain_info(rd);
                return -EINVAL;
        }

        if (!user_request->intersect) {
                reset_regdomains(false, rd);
                return 0;
        }

        intersected_rd = regdom_intersect(rd, get_cfg80211_regdom());
        if (!intersected_rd)
                return -EINVAL;

        kfree(rd);
        rd = NULL;
        reset_regdomains(false, intersected_rd);

        return 0;
}

static int reg_set_rd_driver(const struct ieee80211_regdomain *rd,
                             struct regulatory_request *driver_request)
{
        const struct ieee80211_regdomain *regd;
        const struct ieee80211_regdomain *intersected_rd = NULL;
        const struct ieee80211_regdomain *tmp = NULL;
        struct wiphy *request_wiphy;

        if (is_world_regdom(rd->alpha2))
                return -EINVAL;

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

        if (!is_valid_rd(rd)) {
                pr_err("Invalid regulatory domain detected: %c%c\n",
                       rd->alpha2[0], rd->alpha2[1]);
                print_regdomain_info(rd);
                return -EINVAL;
        }

        request_wiphy = wiphy_idx_to_wiphy(driver_request->wiphy_idx);
        if (!request_wiphy)
                return -ENODEV;

        if (!driver_request->intersect) {
                ASSERT_RTNL();
                wiphy_lock(request_wiphy);
                if (request_wiphy->regd)
                        tmp = get_wiphy_regdom(request_wiphy);

                regd = reg_copy_regd(rd);
                if (IS_ERR(regd)) {
                        wiphy_unlock(request_wiphy);
                        return PTR_ERR(regd);
                }

                rcu_assign_pointer(request_wiphy->regd, regd);
                rcu_free_regdom(tmp);
                wiphy_unlock(request_wiphy);
                reset_regdomains(false, rd);
                return 0;
        }

        intersected_rd = regdom_intersect(rd, get_cfg80211_regdom());
        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
         */
        tmp = get_wiphy_regdom(request_wiphy);
        rcu_assign_pointer(request_wiphy->regd, rd);
        rcu_free_regdom(tmp);

        rd = NULL;

        reset_regdomains(false, intersected_rd);

        return 0;
}

static int reg_set_rd_country_ie(const struct ieee80211_regdomain *rd,
                                 struct regulatory_request *country_ie_request)
{
        struct wiphy *request_wiphy;

        if (!is_alpha2_set(rd->alpha2) && !is_an_alpha2(rd->alpha2) &&
            !is_unknown_alpha2(rd->alpha2))
                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 (!is_valid_rd(rd)) {
                pr_err("Invalid regulatory domain detected: %c%c\n",
                       rd->alpha2[0], rd->alpha2[1]);
                print_regdomain_info(rd);
                return -EINVAL;
        }

        request_wiphy = wiphy_idx_to_wiphy(country_ie_request->wiphy_idx);
        if (!request_wiphy)
                return -ENODEV;

        if (country_ie_request->intersect)
                return -EINVAL;

        reset_regdomains(false, 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.
 */
int set_regdom(const struct ieee80211_regdomain *rd,
               enum ieee80211_regd_source regd_src)
{
        struct regulatory_request *lr;
        bool user_reset = false;
        int r;

        if (IS_ERR_OR_NULL(rd))
                return -ENODATA;

        if (!reg_is_valid_request(rd->alpha2)) {
                kfree(rd);
                return -EINVAL;
        }

        if (regd_src == REGD_SOURCE_CRDA)
                reset_crda_timeouts();

        lr = get_last_request();

        /* Note that this doesn't update the wiphys, this is done below */
        switch (lr->initiator) {
        case NL80211_REGDOM_SET_BY_CORE:
                r = reg_set_rd_core(rd);
                break;
        case NL80211_REGDOM_SET_BY_USER:
                cfg80211_save_user_regdom(rd);
                r = reg_set_rd_user(rd, lr);
                user_reset = true;
                break;
        case NL80211_REGDOM_SET_BY_DRIVER:
                r = reg_set_rd_driver(rd, lr);
                break;
        case NL80211_REGDOM_SET_BY_COUNTRY_IE:
                r = reg_set_rd_country_ie(rd, lr);
                break;
        default:
                WARN(1, "invalid initiator %d\n", lr->initiator);
                kfree(rd);
                return -EINVAL;
        }

        if (r) {
                switch (r) {
                case -EALREADY:
                        reg_set_request_processed();
                        break;
                default:
                        /* Back to world regulatory in case of errors */
                        restore_regulatory_settings(user_reset, false);
                }

                kfree(rd);
                return r;
        }

        /* This would make this whole thing pointless */
        if (WARN_ON(!lr->intersect && rd != get_cfg80211_regdom()))
                return -EINVAL;

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

        print_regdomain(get_cfg80211_regdom());

        nl80211_send_reg_change_event(lr);

        reg_set_request_processed();

        return 0;
}

static int __regulatory_set_wiphy_regd(struct wiphy *wiphy,
                                       struct ieee80211_regdomain *rd)
{
        const struct ieee80211_regdomain *regd;
        const struct ieee80211_regdomain *prev_regd;
        struct cfg80211_registered_device *rdev;

        if (WARN_ON(!wiphy || !rd))
                return -EINVAL;

        if (WARN(!(wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED),
                 "wiphy should have REGULATORY_WIPHY_SELF_MANAGED\n"))
                return -EPERM;

        if (WARN(!is_valid_rd(rd),
                 "Invalid regulatory domain detected: %c%c\n",
                 rd->alpha2[0], rd->alpha2[1])) {
                print_regdomain_info(rd);
                return -EINVAL;
        }

        regd = reg_copy_regd(rd);
        if (IS_ERR(regd))
                return PTR_ERR(regd);

        rdev = wiphy_to_rdev(wiphy);

        spin_lock(&reg_requests_lock);
        prev_regd = rdev->requested_regd;
        rdev->requested_regd = regd;
        spin_unlock(&reg_requests_lock);

        kfree(prev_regd);
        return 0;
}

int regulatory_set_wiphy_regd(struct wiphy *wiphy,
                              struct ieee80211_regdomain *rd)
{
        int ret = __regulatory_set_wiphy_regd(wiphy, rd);

        if (ret)
                return ret;

        schedule_work(&reg_work);
        return 0;
}
EXPORT_SYMBOL(regulatory_set_wiphy_regd);

int regulatory_set_wiphy_regd_sync(struct wiphy *wiphy,
                                   struct ieee80211_regdomain *rd)
{
        int ret;

        ASSERT_RTNL();

        ret = __regulatory_set_wiphy_regd(wiphy, rd);
        if (ret)
                return ret;

        /* process the request immediately */
        reg_process_self_managed_hint(wiphy);
        reg_check_channels();
        return 0;
}
EXPORT_SYMBOL(regulatory_set_wiphy_regd_sync);

void wiphy_regulatory_register(struct wiphy *wiphy)
{
        struct regulatory_request *lr = get_last_request();

        /* self-managed devices ignore beacon hints and country IE */
        if (wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED) {
                wiphy->regulatory_flags |= REGULATORY_DISABLE_BEACON_HINTS |
                                           REGULATORY_COUNTRY_IE_IGNORE;

                /*
                 * The last request may have been received before this
                 * registration call. Call the driver notifier if
                 * initiator is USER.
                 */
                if (lr->initiator == NL80211_REGDOM_SET_BY_USER)
                        reg_call_notifier(wiphy, lr);
        }

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

        wiphy_update_regulatory(wiphy, lr->initiator);
        wiphy_all_share_dfs_chan_state(wiphy);
        reg_process_self_managed_hints();
}

void wiphy_regulatory_deregister(struct wiphy *wiphy)
{
        struct wiphy *request_wiphy = NULL;
        struct regulatory_request *lr;

        lr = get_last_request();

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

        rcu_free_regdom(get_wiphy_regdom(wiphy));
        RCU_INIT_POINTER(wiphy->regd, NULL);

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

        if (!request_wiphy || request_wiphy != wiphy)
                return;

        lr->wiphy_idx = WIPHY_IDX_INVALID;
        lr->country_ie_env = ENVIRON_ANY;
}

/*
 * See FCC notices for UNII band definitions
 *  5GHz: https://www.fcc.gov/document/5-ghz-unlicensed-spectrum-unii
 *  6GHz: https://www.fcc.gov/document/fcc-proposes-more-spectrum-unlicensed-use-0
 */
int cfg80211_get_unii(int freq)
{
        /* UNII-1 */
        if (freq >= 5150 && freq <= 5250)
                return 0;

        /* UNII-2A */
        if (freq > 5250 && freq <= 5350)
                return 1;

        /* UNII-2B */
        if (freq > 5350 && freq <= 5470)
                return 2;

        /* UNII-2C */
        if (freq > 5470 && freq <= 5725)
                return 3;

        /* UNII-3 */
        if (freq > 5725 && freq <= 5825)
                return 4;

        /* UNII-5 */
        if (freq > 5925 && freq <= 6425)
                return 5;

        /* UNII-6 */
        if (freq > 6425 && freq <= 6525)
                return 6;

        /* UNII-7 */
        if (freq > 6525 && freq <= 6875)
                return 7;

        /* UNII-8 */
        if (freq > 6875 && freq <= 7125)
                return 8;

        return -EINVAL;
}

bool regulatory_indoor_allowed(void)
{
        return reg_is_indoor;
}

bool regulatory_pre_cac_allowed(struct wiphy *wiphy)
{
        const struct ieee80211_regdomain *regd = NULL;
        const struct ieee80211_regdomain *wiphy_regd = NULL;
        bool pre_cac_allowed = false;

        rcu_read_lock();

        regd = rcu_dereference(cfg80211_regdomain);
        wiphy_regd = rcu_dereference(wiphy->regd);
        if (!wiphy_regd) {
                if (regd->dfs_region == NL80211_DFS_ETSI)
                        pre_cac_allowed = true;

                rcu_read_unlock();

                return pre_cac_allowed;
        }

        if (regd->dfs_region == wiphy_regd->dfs_region &&
            wiphy_regd->dfs_region == NL80211_DFS_ETSI)
                pre_cac_allowed = true;

        rcu_read_unlock();

        return pre_cac_allowed;
}
EXPORT_SYMBOL(regulatory_pre_cac_allowed);

static void cfg80211_check_and_end_cac(struct cfg80211_registered_device *rdev)
{
        struct wireless_dev *wdev;
        /* If we finished CAC or received radar, we should end any
         * CAC running on the same channels.
         * the check !cfg80211_chandef_dfs_usable contain 2 options:
         * either all channels are available - those the CAC_FINISHED
         * event has effected another wdev state, or there is a channel
         * in unavailable state in wdev chandef - those the RADAR_DETECTED
         * event has effected another wdev state.
         * In both cases we should end the CAC on the wdev.
         */
        list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
                struct cfg80211_chan_def *chandef;

                if (!wdev->cac_started)
                        continue;

                /* FIXME: radar detection is tied to link 0 for now */
                chandef = wdev_chandef(wdev, 0);
                if (!chandef)
                        continue;

                if (!cfg80211_chandef_dfs_usable(&rdev->wiphy, chandef))
                        rdev_end_cac(rdev, wdev->netdev);
        }
}

void regulatory_propagate_dfs_state(struct wiphy *wiphy,
                                    struct cfg80211_chan_def *chandef,
                                    enum nl80211_dfs_state dfs_state,
                                    enum nl80211_radar_event event)
{
        struct cfg80211_registered_device *rdev;

        ASSERT_RTNL();

        if (WARN_ON(!cfg80211_chandef_valid(chandef)))
                return;

        for_each_rdev(rdev) {
                if (wiphy == &rdev->wiphy)
                        continue;

                if (!reg_dfs_domain_same(wiphy, &rdev->wiphy))
                        continue;

                if (!ieee80211_get_channel(&rdev->wiphy,
                                           chandef->chan->center_freq))
                        continue;

                cfg80211_set_dfs_state(&rdev->wiphy, chandef, dfs_state);

                if (event == NL80211_RADAR_DETECTED ||
                    event == NL80211_RADAR_CAC_FINISHED) {
                        cfg80211_sched_dfs_chan_update(rdev);
                        cfg80211_check_and_end_cac(rdev);
                }

                nl80211_radar_notify(rdev, chandef, event, NULL, GFP_KERNEL);
        }
}

static int __init regulatory_init_db(void)
{
        int err;

        /*
         * It's possible that - due to other bugs/issues - cfg80211
         * never called regulatory_init() below, or that it failed;
         * in that case, don't try to do any further work here as
         * it's doomed to lead to crashes.
         */
        if (IS_ERR_OR_NULL(reg_pdev))
                return -EINVAL;

        err = load_builtin_regdb_keys();
        if (err) {
                platform_device_unregister(reg_pdev);
                return err;
        }

        /* We always try to get an update for the static regdomain */
        err = regulatory_hint_core(cfg80211_world_regdom->alpha2);
        if (err) {
                if (err == -ENOMEM) {
                        platform_device_unregister(reg_pdev);
                        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");
        }

        /*
         * 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;
}
#ifndef MODULE
late_initcall(regulatory_init_db);
#endif

int __init regulatory_init(void)
{
        reg_pdev = platform_device_register_simple("regulatory", 0, NULL, 0);
        if (IS_ERR(reg_pdev))
                return PTR_ERR(reg_pdev);

        rcu_assign_pointer(cfg80211_regdomain, cfg80211_world_regdom);

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

#ifdef MODULE
        return regulatory_init_db();
#else
        return 0;
#endif
}

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

        cancel_work_sync(&reg_work);
        cancel_crda_timeout_sync();
        cancel_delayed_work_sync(&reg_check_chans);

        /* Lock to suppress warnings */
        rtnl_lock();
        reset_regdomains(true, NULL);
        rtnl_unlock();

        dev_set_uevent_suppress(&reg_pdev->dev, true);

        platform_device_unregister(reg_pdev);

        list_for_each_entry_safe(reg_beacon, btmp, &reg_pending_beacons, list) {
                list_del(&reg_beacon->list);
                kfree(reg_beacon);
        }

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

        list_for_each_entry_safe(reg_request, tmp, &reg_requests_list, list) {
                list_del(&reg_request->list);
                kfree(reg_request);
        }

        if (!IS_ERR_OR_NULL(regdb))
                kfree(regdb);
        if (!IS_ERR_OR_NULL(cfg80211_user_regdom))
                kfree(cfg80211_user_regdom);

        free_regdb_keyring();
}