// SPDX-License-Identifier: GPL-2.0
/*
 * cfg80211 scan result handling
 *
 * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
 * Copyright 2013-2014  Intel Mobile Communications GmbH
 * Copyright 2016       Intel Deutschland GmbH
 * Copyright (C) 2018-2025 Intel Corporation
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/wireless.h>
#include <linux/nl80211.h>
#include <linux/etherdevice.h>
#include <linux/crc32.h>
#include <linux/bitfield.h>
#include <net/arp.h>
#include <net/cfg80211.h>
#include <net/cfg80211-wext.h>
#include <net/iw_handler.h>
#include <kunit/visibility.h>
#include "core.h"
#include "nl80211.h"
#include "wext-compat.h"
#include "rdev-ops.h"

/**
 * DOC: BSS tree/list structure
 *
 * At the top level, the BSS list is kept in both a list in each
 * registered device (@bss_list) as well as an RB-tree for faster
 * lookup. In the RB-tree, entries can be looked up using their
 * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
 * for other BSSes.
 *
 * Due to the possibility of hidden SSIDs, there's a second level
 * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
 * The hidden_list connects all BSSes belonging to a single AP
 * that has a hidden SSID, and connects beacon and probe response
 * entries. For a probe response entry for a hidden SSID, the
 * hidden_beacon_bss pointer points to the BSS struct holding the
 * beacon's information.
 *
 * Reference counting is done for all these references except for
 * the hidden_list, so that a beacon BSS struct that is otherwise
 * not referenced has one reference for being on the bss_list and
 * one for each probe response entry that points to it using the
 * hidden_beacon_bss pointer. When a BSS struct that has such a
 * pointer is get/put, the refcount update is also propagated to
 * the referenced struct, this ensure that it cannot get removed
 * while somebody is using the probe response version.
 *
 * Note that the hidden_beacon_bss pointer never changes, due to
 * the reference counting. Therefore, no locking is needed for
 * it.
 *
 * Also note that the hidden_beacon_bss pointer is only relevant
 * if the driver uses something other than the IEs, e.g. private
 * data stored in the BSS struct, since the beacon IEs are
 * also linked into the probe response struct.
 */

/*
 * Limit the number of BSS entries stored in mac80211. Each one is
 * a bit over 4k at most, so this limits to roughly 4-5M of memory.
 * If somebody wants to really attack this though, they'd likely
 * use small beacons, and only one type of frame, limiting each of
 * the entries to a much smaller size (in order to generate more
 * entries in total, so overhead is bigger.)
 */
static int bss_entries_limit = 1000;
module_param(bss_entries_limit, int, 0644);
MODULE_PARM_DESC(bss_entries_limit,
                 "limit to number of scan BSS entries (per wiphy, default 1000)");

#define IEEE80211_SCAN_RESULT_EXPIRE    (30 * HZ)

static void bss_free(struct cfg80211_internal_bss *bss)
{
        struct cfg80211_bss_ies *ies;

        if (WARN_ON(atomic_read(&bss->hold)))
                return;

        ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
        if (ies && !bss->pub.hidden_beacon_bss)
                kfree_rcu(ies, rcu_head);
        ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
        if (ies)
                kfree_rcu(ies, rcu_head);

        /*
         * This happens when the module is removed, it doesn't
         * really matter any more save for completeness
         */
        if (!list_empty(&bss->hidden_list))
                list_del(&bss->hidden_list);

        kfree(bss);
}

static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
                               struct cfg80211_internal_bss *bss)
{
        lockdep_assert_held(&rdev->bss_lock);

        bss->refcount++;

        if (bss->pub.hidden_beacon_bss)
                bss_from_pub(bss->pub.hidden_beacon_bss)->refcount++;

        if (bss->pub.transmitted_bss)
                bss_from_pub(bss->pub.transmitted_bss)->refcount++;
}

static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
                               struct cfg80211_internal_bss *bss)
{
        lockdep_assert_held(&rdev->bss_lock);

        if (bss->pub.hidden_beacon_bss) {
                struct cfg80211_internal_bss *hbss;

                hbss = bss_from_pub(bss->pub.hidden_beacon_bss);
                hbss->refcount--;
                if (hbss->refcount == 0)
                        bss_free(hbss);
        }

        if (bss->pub.transmitted_bss) {
                struct cfg80211_internal_bss *tbss;

                tbss = bss_from_pub(bss->pub.transmitted_bss);
                tbss->refcount--;
                if (tbss->refcount == 0)
                        bss_free(tbss);
        }

        bss->refcount--;
        if (bss->refcount == 0)
                bss_free(bss);
}

static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
                                  struct cfg80211_internal_bss *bss)
{
        lockdep_assert_held(&rdev->bss_lock);

        if (!list_empty(&bss->hidden_list)) {
                /*
                 * don't remove the beacon entry if it has
                 * probe responses associated with it
                 */
                if (!bss->pub.hidden_beacon_bss)
                        return false;
                /*
                 * if it's a probe response entry break its
                 * link to the other entries in the group
                 */
                list_del_init(&bss->hidden_list);
        }

        list_del_init(&bss->list);
        list_del_init(&bss->pub.nontrans_list);
        rb_erase(&bss->rbn, &rdev->bss_tree);
        rdev->bss_entries--;
        WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list),
                  "rdev bss entries[%d]/list[empty:%d] corruption\n",
                  rdev->bss_entries, list_empty(&rdev->bss_list));
        bss_ref_put(rdev, bss);
        return true;
}

bool cfg80211_is_element_inherited(const struct element *elem,
                                   const struct element *non_inherit_elem)
{
        u8 id_len, ext_id_len, i, loop_len, id;
        const u8 *list;

        if (elem->id == WLAN_EID_MULTIPLE_BSSID)
                return false;

        if (elem->id == WLAN_EID_EXTENSION && elem->datalen > 1 &&
            elem->data[0] == WLAN_EID_EXT_EHT_MULTI_LINK)
                return false;

        if (!non_inherit_elem || non_inherit_elem->datalen < 2)
                return true;

        /*
         * non inheritance element format is:
         * ext ID (56) | IDs list len | list | extension IDs list len | list
         * Both lists are optional. Both lengths are mandatory.
         * This means valid length is:
         * elem_len = 1 (extension ID) + 2 (list len fields) + list lengths
         */
        id_len = non_inherit_elem->data[1];
        if (non_inherit_elem->datalen < 3 + id_len)
                return true;

        ext_id_len = non_inherit_elem->data[2 + id_len];
        if (non_inherit_elem->datalen < 3 + id_len + ext_id_len)
                return true;

        if (elem->id == WLAN_EID_EXTENSION) {
                if (!ext_id_len)
                        return true;
                loop_len = ext_id_len;
                list = &non_inherit_elem->data[3 + id_len];
                id = elem->data[0];
        } else {
                if (!id_len)
                        return true;
                loop_len = id_len;
                list = &non_inherit_elem->data[2];
                id = elem->id;
        }

        for (i = 0; i < loop_len; i++) {
                if (list[i] == id)
                        return false;
        }

        return true;
}
EXPORT_SYMBOL(cfg80211_is_element_inherited);

static size_t cfg80211_copy_elem_with_frags(const struct element *elem,
                                            const u8 *ie, size_t ie_len,
                                            u8 **pos, u8 *buf, size_t buf_len)
{
        if (WARN_ON((u8 *)elem < ie || elem->data > ie + ie_len ||
                    elem->data + elem->datalen > ie + ie_len))
                return 0;

        if (elem->datalen + 2 > buf + buf_len - *pos)
                return 0;

        memcpy(*pos, elem, elem->datalen + 2);
        *pos += elem->datalen + 2;

        /* Finish if it is not fragmented  */
        if (elem->datalen != 255)
                return *pos - buf;

        ie_len = ie + ie_len - elem->data - elem->datalen;
        ie = (const u8 *)elem->data + elem->datalen;

        for_each_element(elem, ie, ie_len) {
                if (elem->id != WLAN_EID_FRAGMENT)
                        break;

                if (elem->datalen + 2 > buf + buf_len - *pos)
                        return 0;

                memcpy(*pos, elem, elem->datalen + 2);
                *pos += elem->datalen + 2;

                if (elem->datalen != 255)
                        break;
        }

        return *pos - buf;
}

VISIBLE_IF_CFG80211_KUNIT size_t
cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
                    const u8 *subie, size_t subie_len,
                    u8 *new_ie, size_t new_ie_len)
{
        const struct element *non_inherit_elem, *parent, *sub;
        u8 *pos = new_ie;
        const u8 *mbssid_index_ie;
        u8 id, ext_id, bssid_index = 255;
        unsigned int match_len;

        non_inherit_elem = cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE,
                                                  subie, subie_len);

        mbssid_index_ie = cfg80211_find_ie(WLAN_EID_MULTI_BSSID_IDX, subie,
                                           subie_len);
        if (mbssid_index_ie && mbssid_index_ie[1] > 0 &&
            mbssid_index_ie[2] > 0 && mbssid_index_ie[2] <= 46)
                bssid_index = mbssid_index_ie[2];

        /* We copy the elements one by one from the parent to the generated
         * elements.
         * If they are not inherited (included in subie or in the non
         * inheritance element), then we copy all occurrences the first time
         * we see this element type.
         */
        for_each_element(parent, ie, ielen) {
                if (parent->id == WLAN_EID_FRAGMENT)
                        continue;

                if (parent->id == WLAN_EID_EXTENSION) {
                        if (parent->datalen < 1)
                                continue;

                        id = WLAN_EID_EXTENSION;
                        ext_id = parent->data[0];
                        match_len = 1;
                } else {
                        id = parent->id;
                        match_len = 0;
                }

                /* Find first occurrence in subie */
                sub = cfg80211_find_elem_match(id, subie, subie_len,
                                               &ext_id, match_len, 0);

                /* Copy from parent if not in subie and inherited */
                if (!sub &&
                    cfg80211_is_element_inherited(parent, non_inherit_elem)) {
                        if (!cfg80211_copy_elem_with_frags(parent,
                                                           ie, ielen,
                                                           &pos, new_ie,
                                                           new_ie_len))
                                return 0;

                        continue;
                }

                /* For ML probe response, match the MLE in the frame body with
                 * MLD id being 'bssid_index'
                 */
                if (parent->id == WLAN_EID_EXTENSION && parent->datalen > 1 &&
                    parent->data[0] == WLAN_EID_EXT_EHT_MULTI_LINK &&
                    bssid_index == ieee80211_mle_get_mld_id(parent->data + 1)) {
                        if (!cfg80211_copy_elem_with_frags(parent,
                                                           ie, ielen,
                                                           &pos, new_ie,
                                                           new_ie_len))
                                return 0;

                        /* Continue here to prevent processing the MLE in
                         * sub-element, which AP MLD should not carry
                         */
                        continue;
                }

                /* Already copied if an earlier element had the same type */
                if (cfg80211_find_elem_match(id, ie, (u8 *)parent - ie,
                                             &ext_id, match_len, 0))
                        continue;

                /* Not inheriting, copy all similar elements from subie */
                while (sub) {
                        if (!cfg80211_copy_elem_with_frags(sub,
                                                           subie, subie_len,
                                                           &pos, new_ie,
                                                           new_ie_len))
                                return 0;

                        sub = cfg80211_find_elem_match(id,
                                                       sub->data + sub->datalen,
                                                       subie_len + subie -
                                                       (sub->data +
                                                        sub->datalen),
                                                       &ext_id, match_len, 0);
                }
        }

        /* The above misses elements that are included in subie but not in the
         * parent, so do a pass over subie and append those.
         * Skip the non-tx BSSID caps and non-inheritance element.
         */
        for_each_element(sub, subie, subie_len) {
                if (sub->id == WLAN_EID_NON_TX_BSSID_CAP)
                        continue;

                if (sub->id == WLAN_EID_FRAGMENT)
                        continue;

                if (sub->id == WLAN_EID_EXTENSION) {
                        if (sub->datalen < 1)
                                continue;

                        id = WLAN_EID_EXTENSION;
                        ext_id = sub->data[0];
                        match_len = 1;

                        if (ext_id == WLAN_EID_EXT_NON_INHERITANCE)
                                continue;
                } else {
                        id = sub->id;
                        match_len = 0;
                }

                /* Processed if one was included in the parent */
                if (cfg80211_find_elem_match(id, ie, ielen,
                                             &ext_id, match_len, 0))
                        continue;

                if (!cfg80211_copy_elem_with_frags(sub, subie, subie_len,
                                                   &pos, new_ie, new_ie_len))
                        return 0;
        }

        return pos - new_ie;
}
EXPORT_SYMBOL_IF_CFG80211_KUNIT(cfg80211_gen_new_ie);

static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
                   const u8 *ssid, size_t ssid_len)
{
        const struct cfg80211_bss_ies *ies;
        const struct element *ssid_elem;

        if (bssid && !ether_addr_equal(a->bssid, bssid))
                return false;

        if (!ssid)
                return true;

        ies = rcu_access_pointer(a->ies);
        if (!ies)
                return false;
        ssid_elem = cfg80211_find_elem(WLAN_EID_SSID, ies->data, ies->len);
        if (!ssid_elem)
                return false;
        if (ssid_elem->datalen != ssid_len)
                return false;
        return memcmp(ssid_elem->data, ssid, ssid_len) == 0;
}

static int
cfg80211_add_nontrans_list(struct cfg80211_bss *trans_bss,
                           struct cfg80211_bss *nontrans_bss)
{
        const struct element *ssid_elem;
        struct cfg80211_bss *bss = NULL;

        rcu_read_lock();
        ssid_elem = ieee80211_bss_get_elem(nontrans_bss, WLAN_EID_SSID);
        if (!ssid_elem) {
                rcu_read_unlock();
                return -EINVAL;
        }

        /* check if nontrans_bss is in the list */
        list_for_each_entry(bss, &trans_bss->nontrans_list, nontrans_list) {
                if (is_bss(bss, nontrans_bss->bssid, ssid_elem->data,
                           ssid_elem->datalen)) {
                        rcu_read_unlock();
                        return 0;
                }
        }

        rcu_read_unlock();

        /*
         * This is a bit weird - it's not on the list, but already on another
         * one! The only way that could happen is if there's some BSSID/SSID
         * shared by multiple APs in their multi-BSSID profiles, potentially
         * with hidden SSID mixed in ... ignore it.
         */
        if (!list_empty(&nontrans_bss->nontrans_list))
                return -EINVAL;

        /* add to the list */
        list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list);
        return 0;
}

static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
                                  unsigned long expire_time)
{
        struct cfg80211_internal_bss *bss, *tmp;
        bool expired = false;

        lockdep_assert_held(&rdev->bss_lock);

        list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
                if (atomic_read(&bss->hold))
                        continue;
                if (!time_after(expire_time, bss->ts))
                        continue;

                if (__cfg80211_unlink_bss(rdev, bss))
                        expired = true;
        }

        if (expired)
                rdev->bss_generation++;
}

static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev)
{
        struct cfg80211_internal_bss *bss, *oldest = NULL;
        bool ret;

        lockdep_assert_held(&rdev->bss_lock);

        list_for_each_entry(bss, &rdev->bss_list, list) {
                if (atomic_read(&bss->hold))
                        continue;

                if (!list_empty(&bss->hidden_list) &&
                    !bss->pub.hidden_beacon_bss)
                        continue;

                if (oldest && time_before(oldest->ts, bss->ts))
                        continue;
                oldest = bss;
        }

        if (WARN_ON(!oldest))
                return false;

        /*
         * The callers make sure to increase rdev->bss_generation if anything
         * gets removed (and a new entry added), so there's no need to also do
         * it here.
         */

        ret = __cfg80211_unlink_bss(rdev, oldest);
        WARN_ON(!ret);
        return ret;
}

static u8 cfg80211_parse_bss_param(u8 data,
                                   struct cfg80211_colocated_ap *coloc_ap)
{
        coloc_ap->oct_recommended =
                u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_OCT_RECOMMENDED);
        coloc_ap->same_ssid =
                u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_SAME_SSID);
        coloc_ap->multi_bss =
                u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_MULTI_BSSID);
        coloc_ap->transmitted_bssid =
                u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_TRANSMITTED_BSSID);
        coloc_ap->unsolicited_probe =
                u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_PROBE_ACTIVE);
        coloc_ap->colocated_ess =
                u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_COLOC_ESS);

        return u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_COLOC_AP);
}

static int cfg80211_calc_short_ssid(const struct cfg80211_bss_ies *ies,
                                    const struct element **elem, u32 *s_ssid)
{

        *elem = cfg80211_find_elem(WLAN_EID_SSID, ies->data, ies->len);
        if (!*elem || (*elem)->datalen > IEEE80211_MAX_SSID_LEN)
                return -EINVAL;

        *s_ssid = ~crc32_le(~0, (*elem)->data, (*elem)->datalen);
        return 0;
}

VISIBLE_IF_CFG80211_KUNIT void
cfg80211_free_coloc_ap_list(struct list_head *coloc_ap_list)
{
        struct cfg80211_colocated_ap *ap, *tmp_ap;

        list_for_each_entry_safe(ap, tmp_ap, coloc_ap_list, list) {
                list_del(&ap->list);
                kfree(ap);
        }
}
EXPORT_SYMBOL_IF_CFG80211_KUNIT(cfg80211_free_coloc_ap_list);

static int cfg80211_parse_ap_info(struct cfg80211_colocated_ap *entry,
                                  const u8 *pos, u8 length,
                                  const struct element *ssid_elem,
                                  u32 s_ssid_tmp)
{
        u8 bss_params;

        entry->psd_20 = IEEE80211_RNR_TBTT_PARAMS_PSD_RESERVED;

        /* The length is already verified by the caller to contain bss_params */
        if (length > sizeof(struct ieee80211_tbtt_info_7_8_9)) {
                struct ieee80211_tbtt_info_ge_11 *tbtt_info = (void *)pos;

                memcpy(entry->bssid, tbtt_info->bssid, ETH_ALEN);
                entry->short_ssid = le32_to_cpu(tbtt_info->short_ssid);
                entry->short_ssid_valid = true;

                bss_params = tbtt_info->bss_params;

                /* Ignore disabled links */
                if (length >= offsetofend(typeof(*tbtt_info), mld_params)) {
                        if (le16_get_bits(tbtt_info->mld_params.params,
                                          IEEE80211_RNR_MLD_PARAMS_DISABLED_LINK))
                                return -EINVAL;
                }

                if (length >= offsetofend(struct ieee80211_tbtt_info_ge_11,
                                          psd_20))
                        entry->psd_20 = tbtt_info->psd_20;
        } else {
                struct ieee80211_tbtt_info_7_8_9 *tbtt_info = (void *)pos;

                memcpy(entry->bssid, tbtt_info->bssid, ETH_ALEN);

                bss_params = tbtt_info->bss_params;

                if (length == offsetofend(struct ieee80211_tbtt_info_7_8_9,
                                          psd_20))
                        entry->psd_20 = tbtt_info->psd_20;
        }

        /* ignore entries with invalid BSSID */
        if (!is_valid_ether_addr(entry->bssid))
                return -EINVAL;

        /* skip non colocated APs */
        if (!cfg80211_parse_bss_param(bss_params, entry))
                return -EINVAL;

        /* no information about the short ssid. Consider the entry valid
         * for now. It would later be dropped in case there are explicit
         * SSIDs that need to be matched
         */
        if (!entry->same_ssid && !entry->short_ssid_valid)
                return 0;

        if (entry->same_ssid) {
                entry->short_ssid = s_ssid_tmp;
                entry->short_ssid_valid = true;

                /*
                 * This is safe because we validate datalen in
                 * cfg80211_parse_colocated_ap(), before calling this
                 * function.
                 */
                memcpy(&entry->ssid, &ssid_elem->data, ssid_elem->datalen);
                entry->ssid_len = ssid_elem->datalen;
        }

        return 0;
}

bool cfg80211_iter_rnr(const u8 *elems, size_t elems_len,
                       enum cfg80211_rnr_iter_ret
                       (*iter)(void *data, u8 type,
                               const struct ieee80211_neighbor_ap_info *info,
                               const u8 *tbtt_info, u8 tbtt_info_len),
                       void *iter_data)
{
        const struct element *rnr;
        const u8 *pos, *end;

        for_each_element_id(rnr, WLAN_EID_REDUCED_NEIGHBOR_REPORT,
                            elems, elems_len) {
                const struct ieee80211_neighbor_ap_info *info;

                pos = rnr->data;
                end = rnr->data + rnr->datalen;

                /* RNR IE may contain more than one NEIGHBOR_AP_INFO */
                while (sizeof(*info) <= end - pos) {
                        u8 length, i, count;
                        u8 type;

                        info = (void *)pos;
                        count = u8_get_bits(info->tbtt_info_hdr,
                                            IEEE80211_AP_INFO_TBTT_HDR_COUNT) +
                                1;
                        length = info->tbtt_info_len;

                        pos += sizeof(*info);

                        if (count * length > end - pos)
                                return false;

                        type = u8_get_bits(info->tbtt_info_hdr,
                                           IEEE80211_AP_INFO_TBTT_HDR_TYPE);

                        for (i = 0; i < count; i++) {
                                switch (iter(iter_data, type, info,
                                             pos, length)) {
                                case RNR_ITER_CONTINUE:
                                        break;
                                case RNR_ITER_BREAK:
                                        return true;
                                case RNR_ITER_ERROR:
                                        return false;
                                }

                                pos += length;
                        }
                }

                if (pos != end)
                        return false;
        }

        return true;
}
EXPORT_SYMBOL_GPL(cfg80211_iter_rnr);

struct colocated_ap_data {
        const struct element *ssid_elem;
        struct list_head ap_list;
        u32 s_ssid_tmp;
        int n_coloc;
};

static enum cfg80211_rnr_iter_ret
cfg80211_parse_colocated_ap_iter(void *_data, u8 type,
                                 const struct ieee80211_neighbor_ap_info *info,
                                 const u8 *tbtt_info, u8 tbtt_info_len)
{
        struct colocated_ap_data *data = _data;
        struct cfg80211_colocated_ap *entry;
        enum nl80211_band band;

        if (type != IEEE80211_TBTT_INFO_TYPE_TBTT)
                return RNR_ITER_CONTINUE;

        if (!ieee80211_operating_class_to_band(info->op_class, &band))
                return RNR_ITER_CONTINUE;

        /* TBTT info must include bss param + BSSID + (short SSID or
         * same_ssid bit to be set). Ignore other options, and move to
         * the next AP info
         */
        if (band != NL80211_BAND_6GHZ ||
            !(tbtt_info_len == offsetofend(struct ieee80211_tbtt_info_7_8_9,
                                           bss_params) ||
              tbtt_info_len == sizeof(struct ieee80211_tbtt_info_7_8_9) ||
              tbtt_info_len >= offsetofend(struct ieee80211_tbtt_info_ge_11,
                                           bss_params)))
                return RNR_ITER_CONTINUE;

        entry = kzalloc_obj(*entry, GFP_ATOMIC);
        if (!entry)
                return RNR_ITER_ERROR;

        entry->center_freq =
                ieee80211_channel_to_frequency(info->channel, band);

        if (!cfg80211_parse_ap_info(entry, tbtt_info, tbtt_info_len,
                                    data->ssid_elem, data->s_ssid_tmp)) {
                struct cfg80211_colocated_ap *tmp;

                /* Don't add duplicate BSSIDs on the same channel. */
                list_for_each_entry(tmp, &data->ap_list, list) {
                        if (ether_addr_equal(tmp->bssid, entry->bssid) &&
                            tmp->center_freq == entry->center_freq) {
                                kfree(entry);
                                return RNR_ITER_CONTINUE;
                        }
                }

                data->n_coloc++;
                list_add_tail(&entry->list, &data->ap_list);
        } else {
                kfree(entry);
        }

        return RNR_ITER_CONTINUE;
}

VISIBLE_IF_CFG80211_KUNIT int
cfg80211_parse_colocated_ap(const struct cfg80211_bss_ies *ies,
                            struct list_head *list)
{
        struct colocated_ap_data data = {};
        int ret;

        INIT_LIST_HEAD(&data.ap_list);

        ret = cfg80211_calc_short_ssid(ies, &data.ssid_elem, &data.s_ssid_tmp);
        if (ret)
                return 0;

        if (!cfg80211_iter_rnr(ies->data, ies->len,
                               cfg80211_parse_colocated_ap_iter, &data)) {
                cfg80211_free_coloc_ap_list(&data.ap_list);
                return 0;
        }

        list_splice_tail(&data.ap_list, list);
        return data.n_coloc;
}
EXPORT_SYMBOL_IF_CFG80211_KUNIT(cfg80211_parse_colocated_ap);

static void cfg80211_scan_req_add_chan(struct cfg80211_scan_request *request,
                                       struct ieee80211_channel *chan,
                                       bool add_to_6ghz)
{
        int i;
        u32 n_channels = request->n_channels;
        struct cfg80211_scan_6ghz_params *params =
                &request->scan_6ghz_params[request->n_6ghz_params];

        for (i = 0; i < n_channels; i++) {
                if (request->channels[i] == chan) {
                        if (add_to_6ghz)
                                params->channel_idx = i;
                        return;
                }
        }

        request->n_channels++;
        request->channels[n_channels] = chan;
        if (add_to_6ghz)
                request->scan_6ghz_params[request->n_6ghz_params].channel_idx =
                        n_channels;
}

static bool cfg80211_find_ssid_match(struct cfg80211_colocated_ap *ap,
                                     struct cfg80211_scan_request *request)
{
        int i;
        u32 s_ssid;

        for (i = 0; i < request->n_ssids; i++) {
                /* wildcard ssid in the scan request */
                if (!request->ssids[i].ssid_len) {
                        if (ap->multi_bss && !ap->transmitted_bssid)
                                continue;

                        return true;
                }

                if (ap->ssid_len &&
                    ap->ssid_len == request->ssids[i].ssid_len) {
                        if (!memcmp(request->ssids[i].ssid, ap->ssid,
                                    ap->ssid_len))
                                return true;
                } else if (ap->short_ssid_valid) {
                        s_ssid = ~crc32_le(~0, request->ssids[i].ssid,
                                           request->ssids[i].ssid_len);

                        if (ap->short_ssid == s_ssid)
                                return true;
                }
        }

        return false;
}

static int cfg80211_scan_6ghz(struct cfg80211_registered_device *rdev,
                              bool first_part)
{
        u8 i;
        struct cfg80211_colocated_ap *ap;
        int n_channels, count = 0, err;
        struct cfg80211_scan_request_int *request, *rdev_req = rdev->scan_req;
        LIST_HEAD(coloc_ap_list);
        bool need_scan_psc = true;
        const struct ieee80211_sband_iftype_data *iftd;
        size_t size, offs_ssids, offs_6ghz_params, offs_ies;

        rdev_req->req.scan_6ghz = true;
        rdev_req->req.first_part = first_part;

        if (!rdev->wiphy.bands[NL80211_BAND_6GHZ])
                return -EOPNOTSUPP;

        iftd = ieee80211_get_sband_iftype_data(rdev->wiphy.bands[NL80211_BAND_6GHZ],
                                               rdev_req->req.wdev->iftype);
        if (!iftd || !iftd->he_cap.has_he)
                return -EOPNOTSUPP;

        n_channels = rdev->wiphy.bands[NL80211_BAND_6GHZ]->n_channels;

        if (rdev_req->req.flags & NL80211_SCAN_FLAG_COLOCATED_6GHZ) {
                struct cfg80211_internal_bss *intbss;

                spin_lock_bh(&rdev->bss_lock);
                list_for_each_entry(intbss, &rdev->bss_list, list) {
                        struct cfg80211_bss *res = &intbss->pub;
                        const struct cfg80211_bss_ies *ies;
                        const struct element *ssid_elem;
                        struct cfg80211_colocated_ap *entry;
                        u32 s_ssid_tmp;
                        int ret;

                        ies = rcu_access_pointer(res->ies);
                        count += cfg80211_parse_colocated_ap(ies,
                                                             &coloc_ap_list);

                        /* In case the scan request specified a specific BSSID
                         * and the BSS is found and operating on 6GHz band then
                         * add this AP to the collocated APs list.
                         * This is relevant for ML probe requests when the lower
                         * band APs have not been discovered.
                         */
                        if (is_broadcast_ether_addr(rdev_req->req.bssid) ||
                            !ether_addr_equal(rdev_req->req.bssid, res->bssid) ||
                            res->channel->band != NL80211_BAND_6GHZ)
                                continue;

                        ret = cfg80211_calc_short_ssid(ies, &ssid_elem,
                                                       &s_ssid_tmp);
                        if (ret)
                                continue;

                        entry = kzalloc_obj(*entry, GFP_ATOMIC);
                        if (!entry)
                                continue;

                        memcpy(entry->bssid, res->bssid, ETH_ALEN);
                        entry->short_ssid = s_ssid_tmp;
                        memcpy(entry->ssid, ssid_elem->data,
                               ssid_elem->datalen);
                        entry->ssid_len = ssid_elem->datalen;
                        entry->short_ssid_valid = true;
                        entry->center_freq = res->channel->center_freq;

                        list_add_tail(&entry->list, &coloc_ap_list);
                        count++;
                }
                spin_unlock_bh(&rdev->bss_lock);
        }

        size = struct_size(request, req.channels, n_channels);
        offs_ssids = size;
        size += sizeof(*request->req.ssids) * rdev_req->req.n_ssids;
        offs_6ghz_params = size;
        size += sizeof(*request->req.scan_6ghz_params) * count;
        offs_ies = size;
        size += rdev_req->req.ie_len;

        request = kzalloc(size, GFP_KERNEL);
        if (!request) {
                cfg80211_free_coloc_ap_list(&coloc_ap_list);
                return -ENOMEM;
        }

        *request = *rdev_req;
        request->req.n_channels = 0;
        request->req.n_6ghz_params = 0;
        if (rdev_req->req.n_ssids) {
                /*
                 * Add the ssids from the parent scan request to the new
                 * scan request, so the driver would be able to use them
                 * in its probe requests to discover hidden APs on PSC
                 * channels.
                 */
                request->req.ssids = (void *)request + offs_ssids;
                memcpy(request->req.ssids, rdev_req->req.ssids,
                       sizeof(*request->req.ssids) * request->req.n_ssids);
        }
        request->req.scan_6ghz_params = (void *)request + offs_6ghz_params;

        if (rdev_req->req.ie_len) {
                void *ie = (void *)request + offs_ies;

                memcpy(ie, rdev_req->req.ie, rdev_req->req.ie_len);
                request->req.ie = ie;
        }

        /*
         * PSC channels should not be scanned in case of direct scan with 1 SSID
         * and at least one of the reported co-located APs with same SSID
         * indicating that all APs in the same ESS are co-located
         */
        if (count &&
            request->req.n_ssids == 1 &&
            request->req.ssids[0].ssid_len) {
                list_for_each_entry(ap, &coloc_ap_list, list) {
                        if (ap->colocated_ess &&
                            cfg80211_find_ssid_match(ap, &request->req)) {
                                need_scan_psc = false;
                                break;
                        }
                }
        }

        /*
         * add to the scan request the channels that need to be scanned
         * regardless of the collocated APs (PSC channels or all channels
         * in case that NL80211_SCAN_FLAG_COLOCATED_6GHZ is not set)
         */
        for (i = 0; i < rdev_req->req.n_channels; i++) {
                if (rdev_req->req.channels[i]->band == NL80211_BAND_6GHZ &&
                    ((need_scan_psc &&
                      cfg80211_channel_is_psc(rdev_req->req.channels[i])) ||
                     !(rdev_req->req.flags & NL80211_SCAN_FLAG_COLOCATED_6GHZ))) {
                        cfg80211_scan_req_add_chan(&request->req,
                                                   rdev_req->req.channels[i],
                                                   false);
                }
        }

        if (!(rdev_req->req.flags & NL80211_SCAN_FLAG_COLOCATED_6GHZ))
                goto skip;

        list_for_each_entry(ap, &coloc_ap_list, list) {
                bool found = false;
                struct cfg80211_scan_6ghz_params *scan_6ghz_params =
                        &request->req.scan_6ghz_params[request->req.n_6ghz_params];
                struct ieee80211_channel *chan =
                        ieee80211_get_channel(&rdev->wiphy, ap->center_freq);

                if (!chan || chan->flags & IEEE80211_CHAN_DISABLED ||
                    !cfg80211_wdev_channel_allowed(rdev_req->req.wdev, chan))
                        continue;

                for (i = 0; i < rdev_req->req.n_channels; i++) {
                        if (rdev_req->req.channels[i] == chan)
                                found = true;
                }

                if (!found)
                        continue;

                if (request->req.n_ssids > 0 &&
                    !cfg80211_find_ssid_match(ap, &request->req))
                        continue;

                if (!is_broadcast_ether_addr(request->req.bssid) &&
                    !ether_addr_equal(request->req.bssid, ap->bssid))
                        continue;

                if (!request->req.n_ssids && ap->multi_bss &&
                    !ap->transmitted_bssid)
                        continue;

                cfg80211_scan_req_add_chan(&request->req, chan, true);
                memcpy(scan_6ghz_params->bssid, ap->bssid, ETH_ALEN);
                scan_6ghz_params->short_ssid = ap->short_ssid;
                scan_6ghz_params->short_ssid_valid = ap->short_ssid_valid;
                scan_6ghz_params->unsolicited_probe = ap->unsolicited_probe;
                scan_6ghz_params->psd_20 = ap->psd_20;

                /*
                 * If a PSC channel is added to the scan and 'need_scan_psc' is
                 * set to false, then all the APs that the scan logic is
                 * interested with on the channel are collocated and thus there
                 * is no need to perform the initial PSC channel listen.
                 */
                if (cfg80211_channel_is_psc(chan) && !need_scan_psc)
                        scan_6ghz_params->psc_no_listen = true;

                request->req.n_6ghz_params++;
        }

skip:
        cfg80211_free_coloc_ap_list(&coloc_ap_list);

        if (request->req.n_channels) {
                struct cfg80211_scan_request_int *old = rdev->int_scan_req;

                rdev->int_scan_req = request;

                /*
                 * If this scan follows a previous scan, save the scan start
                 * info from the first part of the scan
                 */
                if (!first_part && !WARN_ON(!old))
                        rdev->int_scan_req->info = old->info;

                err = rdev_scan(rdev, request);
                if (err) {
                        rdev->int_scan_req = old;
                        kfree(request);
                } else {
                        kfree(old);
                }

                return err;
        }

        kfree(request);
        return -EINVAL;
}

int cfg80211_scan(struct cfg80211_registered_device *rdev)
{
        struct cfg80211_scan_request_int *request;
        struct cfg80211_scan_request_int *rdev_req = rdev->scan_req;
        u32 n_channels = 0, idx, i;

        if (!(rdev->wiphy.flags & WIPHY_FLAG_SPLIT_SCAN_6GHZ)) {
                rdev_req->req.first_part = true;
                return rdev_scan(rdev, rdev_req);
        }

        for (i = 0; i < rdev_req->req.n_channels; i++) {
                if (rdev_req->req.channels[i]->band != NL80211_BAND_6GHZ)
                        n_channels++;
        }

        if (!n_channels)
                return cfg80211_scan_6ghz(rdev, true);

        request = kzalloc_flex(*request, req.channels, n_channels);
        if (!request)
                return -ENOMEM;

        *request = *rdev_req;
        request->req.n_channels = n_channels;

        for (i = idx = 0; i < rdev_req->req.n_channels; i++) {
                if (rdev_req->req.channels[i]->band != NL80211_BAND_6GHZ)
                        request->req.channels[idx++] =
                                rdev_req->req.channels[i];
        }

        rdev_req->req.scan_6ghz = false;
        rdev_req->req.first_part = true;
        rdev->int_scan_req = request;
        return rdev_scan(rdev, request);
}

void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
                           bool send_message)
{
        struct cfg80211_scan_request_int *request, *rdev_req;
        struct wireless_dev *wdev;
        struct sk_buff *msg;
#ifdef CONFIG_CFG80211_WEXT
        union iwreq_data wrqu;
#endif

        lockdep_assert_held(&rdev->wiphy.mtx);

        if (rdev->scan_msg) {
                nl80211_send_scan_msg(rdev, rdev->scan_msg);
                rdev->scan_msg = NULL;
                return;
        }

        rdev_req = rdev->scan_req;
        if (!rdev_req)
                return;

        wdev = rdev_req->req.wdev;
        request = rdev->int_scan_req ? rdev->int_scan_req : rdev_req;

        if (wdev_running(wdev) &&
            (rdev->wiphy.flags & WIPHY_FLAG_SPLIT_SCAN_6GHZ) &&
            !rdev_req->req.scan_6ghz && !request->info.aborted &&
            !cfg80211_scan_6ghz(rdev, false))
                return;

        /*
         * This must be before sending the other events!
         * Otherwise, wpa_supplicant gets completely confused with
         * wext events.
         */
        if (wdev->netdev)
                cfg80211_sme_scan_done(wdev->netdev);

        if (!request->info.aborted &&
            request->req.flags & NL80211_SCAN_FLAG_FLUSH) {
                /* flush entries from previous scans */
                spin_lock_bh(&rdev->bss_lock);
                __cfg80211_bss_expire(rdev, request->req.scan_start);
                spin_unlock_bh(&rdev->bss_lock);
        }

        msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted);

#ifdef CONFIG_CFG80211_WEXT
        if (wdev->netdev && !request->info.aborted) {
                memset(&wrqu, 0, sizeof(wrqu));

                wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
        }
#endif

        dev_put(wdev->netdev);

        kfree(rdev->int_scan_req);
        rdev->int_scan_req = NULL;

        kfree(rdev->scan_req);
        rdev->scan_req = NULL;

        if (!send_message)
                rdev->scan_msg = msg;
        else
                nl80211_send_scan_msg(rdev, msg);
}

void __cfg80211_scan_done(struct wiphy *wiphy, struct wiphy_work *wk)
{
        ___cfg80211_scan_done(wiphy_to_rdev(wiphy), true);
}

void cfg80211_scan_done(struct cfg80211_scan_request *request,
                        struct cfg80211_scan_info *info)
{
        struct cfg80211_scan_request_int *intreq =
                container_of(request, struct cfg80211_scan_request_int, req);
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(request->wiphy);
        struct cfg80211_scan_info old_info = intreq->info;

        trace_cfg80211_scan_done(intreq, info);
        WARN_ON(intreq != rdev->scan_req &&
                intreq != rdev->int_scan_req);

        intreq->info = *info;

        /*
         * In case the scan is split, the scan_start_tsf and tsf_bssid should
         * be of the first part. In such a case old_info.scan_start_tsf should
         * be non zero.
         */
        if (request->scan_6ghz && old_info.scan_start_tsf) {
                intreq->info.scan_start_tsf = old_info.scan_start_tsf;
                memcpy(intreq->info.tsf_bssid, old_info.tsf_bssid,
                       sizeof(intreq->info.tsf_bssid));
        }

        intreq->notified = true;
        wiphy_work_queue(request->wiphy, &rdev->scan_done_wk);
}
EXPORT_SYMBOL(cfg80211_scan_done);

void cfg80211_add_sched_scan_req(struct cfg80211_registered_device *rdev,
                                 struct cfg80211_sched_scan_request *req)
{
        lockdep_assert_held(&rdev->wiphy.mtx);

        list_add_rcu(&req->list, &rdev->sched_scan_req_list);
}

static void cfg80211_del_sched_scan_req(struct cfg80211_registered_device *rdev,
                                        struct cfg80211_sched_scan_request *req)
{
        lockdep_assert_held(&rdev->wiphy.mtx);

        list_del_rcu(&req->list);
        kfree_rcu(req, rcu_head);
}

static struct cfg80211_sched_scan_request *
cfg80211_find_sched_scan_req(struct cfg80211_registered_device *rdev, u64 reqid)
{
        struct cfg80211_sched_scan_request *pos;

        list_for_each_entry_rcu(pos, &rdev->sched_scan_req_list, list,
                                lockdep_is_held(&rdev->wiphy.mtx)) {
                if (pos->reqid == reqid)
                        return pos;
        }
        return NULL;
}

/*
 * Determines if a scheduled scan request can be handled. When a legacy
 * scheduled scan is running no other scheduled scan is allowed regardless
 * whether the request is for legacy or multi-support scan. When a multi-support
 * scheduled scan is running a request for legacy scan is not allowed. In this
 * case a request for multi-support scan can be handled if resources are
 * available, ie. struct wiphy::max_sched_scan_reqs limit is not yet reached.
 */
int cfg80211_sched_scan_req_possible(struct cfg80211_registered_device *rdev,
                                     bool want_multi)
{
        struct cfg80211_sched_scan_request *pos;
        int i = 0;

        list_for_each_entry(pos, &rdev->sched_scan_req_list, list) {
                /* request id zero means legacy in progress */
                if (!i && !pos->reqid)
                        return -EINPROGRESS;
                i++;
        }

        if (i) {
                /* no legacy allowed when multi request(s) are active */
                if (!want_multi)
                        return -EINPROGRESS;

                /* resource limit reached */
                if (i == rdev->wiphy.max_sched_scan_reqs)
                        return -ENOSPC;
        }
        return 0;
}

void cfg80211_sched_scan_results_wk(struct work_struct *work)
{
        struct cfg80211_registered_device *rdev;
        struct cfg80211_sched_scan_request *req, *tmp;

        rdev = container_of(work, struct cfg80211_registered_device,
                           sched_scan_res_wk);

        guard(wiphy)(&rdev->wiphy);

        list_for_each_entry_safe(req, tmp, &rdev->sched_scan_req_list, list) {
                if (req->report_results) {
                        req->report_results = false;
                        if (req->flags & NL80211_SCAN_FLAG_FLUSH) {
                                /* flush entries from previous scans */
                                spin_lock_bh(&rdev->bss_lock);
                                __cfg80211_bss_expire(rdev, req->scan_start);
                                spin_unlock_bh(&rdev->bss_lock);
                                req->scan_start = jiffies;
                        }
                        nl80211_send_sched_scan(req,
                                                NL80211_CMD_SCHED_SCAN_RESULTS);
                }
        }
}

void cfg80211_sched_scan_results(struct wiphy *wiphy, u64 reqid)
{
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
        struct cfg80211_sched_scan_request *request;

        trace_cfg80211_sched_scan_results(wiphy, reqid);
        /* ignore if we're not scanning */

        rcu_read_lock();
        request = cfg80211_find_sched_scan_req(rdev, reqid);
        if (request) {
                request->report_results = true;
                queue_work(cfg80211_wq, &rdev->sched_scan_res_wk);
        }
        rcu_read_unlock();
}
EXPORT_SYMBOL(cfg80211_sched_scan_results);

void cfg80211_sched_scan_stopped_locked(struct wiphy *wiphy, u64 reqid)
{
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);

        lockdep_assert_held(&wiphy->mtx);

        trace_cfg80211_sched_scan_stopped(wiphy, reqid);

        __cfg80211_stop_sched_scan(rdev, reqid, true);
}
EXPORT_SYMBOL(cfg80211_sched_scan_stopped_locked);

void cfg80211_sched_scan_stopped(struct wiphy *wiphy, u64 reqid)
{
        guard(wiphy)(wiphy);

        cfg80211_sched_scan_stopped_locked(wiphy, reqid);
}
EXPORT_SYMBOL(cfg80211_sched_scan_stopped);

int cfg80211_stop_sched_scan_req(struct cfg80211_registered_device *rdev,
                                 struct cfg80211_sched_scan_request *req,
                                 bool driver_initiated)
{
        lockdep_assert_held(&rdev->wiphy.mtx);

        if (!driver_initiated) {
                int err = rdev_sched_scan_stop(rdev, req->dev, req->reqid);
                if (err)
                        return err;
        }

        nl80211_send_sched_scan(req, NL80211_CMD_SCHED_SCAN_STOPPED);

        cfg80211_del_sched_scan_req(rdev, req);

        return 0;
}

int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
                               u64 reqid, bool driver_initiated)
{
        struct cfg80211_sched_scan_request *sched_scan_req;

        lockdep_assert_held(&rdev->wiphy.mtx);

        sched_scan_req = cfg80211_find_sched_scan_req(rdev, reqid);
        if (!sched_scan_req)
                return -ENOENT;

        return cfg80211_stop_sched_scan_req(rdev, sched_scan_req,
                                            driver_initiated);
}

void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
                      unsigned long age_secs)
{
        struct cfg80211_internal_bss *bss;
        unsigned long age_jiffies = secs_to_jiffies(age_secs);

        spin_lock_bh(&rdev->bss_lock);
        list_for_each_entry(bss, &rdev->bss_list, list)
                bss->ts -= age_jiffies;
        spin_unlock_bh(&rdev->bss_lock);
}

void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
{
        __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
}

void cfg80211_bss_flush(struct wiphy *wiphy)
{
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);

        spin_lock_bh(&rdev->bss_lock);
        __cfg80211_bss_expire(rdev, jiffies);
        spin_unlock_bh(&rdev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_bss_flush);

const struct element *
cfg80211_find_elem_match(u8 eid, const u8 *ies, unsigned int len,
                         const u8 *match, unsigned int match_len,
                         unsigned int match_offset)
{
        const struct element *elem;

        for_each_element_id(elem, eid, ies, len) {
                if (elem->datalen >= match_offset + match_len &&
                    !memcmp(elem->data + match_offset, match, match_len))
                        return elem;
        }

        return NULL;
}
EXPORT_SYMBOL(cfg80211_find_elem_match);

const struct element *cfg80211_find_vendor_elem(unsigned int oui, int oui_type,
                                                const u8 *ies,
                                                unsigned int len)
{
        const struct element *elem;
        u8 match[] = { oui >> 16, oui >> 8, oui, oui_type };
        int match_len = (oui_type < 0) ? 3 : sizeof(match);

        if (WARN_ON(oui_type > 0xff))
                return NULL;

        elem = cfg80211_find_elem_match(WLAN_EID_VENDOR_SPECIFIC, ies, len,
                                        match, match_len, 0);

        if (!elem || elem->datalen < 4)
                return NULL;

        return elem;
}
EXPORT_SYMBOL(cfg80211_find_vendor_elem);

/**
 * enum bss_compare_mode - BSS compare mode
 * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 */
enum bss_compare_mode {
        BSS_CMP_REGULAR,
        BSS_CMP_HIDE_ZLEN,
        BSS_CMP_HIDE_NUL,
};

static int cmp_bss(struct cfg80211_bss *a,
                   struct cfg80211_bss *b,
                   enum bss_compare_mode mode)
{
        const struct cfg80211_bss_ies *a_ies, *b_ies;
        const u8 *ie1 = NULL;
        const u8 *ie2 = NULL;
        int i, r;

        if (a->channel != b->channel)
                return (b->channel->center_freq * 1000 + b->channel->freq_offset) -
                       (a->channel->center_freq * 1000 + a->channel->freq_offset);

        a_ies = rcu_access_pointer(a->ies);
        if (!a_ies)
                return -1;
        b_ies = rcu_access_pointer(b->ies);
        if (!b_ies)
                return 1;

        if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
                ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
                                       a_ies->data, a_ies->len);
        if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
                ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
                                       b_ies->data, b_ies->len);
        if (ie1 && ie2) {
                int mesh_id_cmp;

                if (ie1[1] == ie2[1])
                        mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
                else
                        mesh_id_cmp = ie2[1] - ie1[1];

                ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
                                       a_ies->data, a_ies->len);
                ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
                                       b_ies->data, b_ies->len);
                if (ie1 && ie2) {
                        if (mesh_id_cmp)
                                return mesh_id_cmp;
                        if (ie1[1] != ie2[1])
                                return ie2[1] - ie1[1];
                        return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
                }
        }

        r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
        if (r)
                return r;

        ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
        ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);

        if (!ie1 && !ie2)
                return 0;

        /*
         * Note that with "hide_ssid", the function returns a match if
         * the already-present BSS ("b") is a hidden SSID beacon for
         * the new BSS ("a").
         */

        /* sort missing IE before (left of) present IE */
        if (!ie1)
                return -1;
        if (!ie2)
                return 1;

        switch (mode) {
        case BSS_CMP_HIDE_ZLEN:
                /*
                 * In ZLEN mode we assume the BSS entry we're
                 * looking for has a zero-length SSID. So if
                 * the one we're looking at right now has that,
                 * return 0. Otherwise, return the difference
                 * in length, but since we're looking for the
                 * 0-length it's really equivalent to returning
                 * the length of the one we're looking at.
                 *
                 * No content comparison is needed as we assume
                 * the content length is zero.
                 */
                return ie2[1];
        case BSS_CMP_REGULAR:
        default:
                /* sort by length first, then by contents */
                if (ie1[1] != ie2[1])
                        return ie2[1] - ie1[1];
                return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
        case BSS_CMP_HIDE_NUL:
                if (ie1[1] != ie2[1])
                        return ie2[1] - ie1[1];
                /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
                for (i = 0; i < ie2[1]; i++)
                        if (ie2[i + 2])
                                return -1;
                return 0;
        }
}

static bool cfg80211_bss_type_match(u16 capability,
                                    enum nl80211_band band,
                                    enum ieee80211_bss_type bss_type)
{
        bool ret = true;
        u16 mask, val;

        if (bss_type == IEEE80211_BSS_TYPE_ANY)
                return ret;

        if (band == NL80211_BAND_60GHZ) {
                mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
                switch (bss_type) {
                case IEEE80211_BSS_TYPE_ESS:
                        val = WLAN_CAPABILITY_DMG_TYPE_AP;
                        break;
                case IEEE80211_BSS_TYPE_PBSS:
                        val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
                        break;
                case IEEE80211_BSS_TYPE_IBSS:
                        val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
                        break;
                default:
                        return false;
                }
        } else {
                mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
                switch (bss_type) {
                case IEEE80211_BSS_TYPE_ESS:
                        val = WLAN_CAPABILITY_ESS;
                        break;
                case IEEE80211_BSS_TYPE_IBSS:
                        val = WLAN_CAPABILITY_IBSS;
                        break;
                case IEEE80211_BSS_TYPE_MBSS:
                        val = 0;
                        break;
                default:
                        return false;
                }
        }

        ret = ((capability & mask) == val);
        return ret;
}

/* Returned bss is reference counted and must be cleaned up appropriately. */
struct cfg80211_bss *__cfg80211_get_bss(struct wiphy *wiphy,
                                        struct ieee80211_channel *channel,
                                        const u8 *bssid,
                                        const u8 *ssid, size_t ssid_len,
                                        enum ieee80211_bss_type bss_type,
                                        enum ieee80211_privacy privacy,
                                        u32 use_for)
{
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
        struct cfg80211_internal_bss *bss, *res = NULL;
        unsigned long now = jiffies;
        int bss_privacy;

        trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
                               privacy);

        spin_lock_bh(&rdev->bss_lock);

        list_for_each_entry(bss, &rdev->bss_list, list) {
                if (!cfg80211_bss_type_match(bss->pub.capability,
                                             bss->pub.channel->band, bss_type))
                        continue;

                bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
                if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
                    (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
                        continue;
                if (channel && bss->pub.channel != channel)
                        continue;
                if (!is_valid_ether_addr(bss->pub.bssid))
                        continue;
                if ((bss->pub.use_for & use_for) != use_for)
                        continue;
                /* Don't get expired BSS structs */
                if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
                    !atomic_read(&bss->hold))
                        continue;
                if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
                        res = bss;
                        bss_ref_get(rdev, res);
                        break;
                }
        }

        spin_unlock_bh(&rdev->bss_lock);
        if (!res)
                return NULL;
        trace_cfg80211_return_bss(&res->pub);
        return &res->pub;
}
EXPORT_SYMBOL(__cfg80211_get_bss);

static bool rb_insert_bss(struct cfg80211_registered_device *rdev,
                          struct cfg80211_internal_bss *bss)
{
        struct rb_node **p = &rdev->bss_tree.rb_node;
        struct rb_node *parent = NULL;
        struct cfg80211_internal_bss *tbss;
        int cmp;

        while (*p) {
                parent = *p;
                tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);

                cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);

                if (WARN_ON(!cmp)) {
                        /* will sort of leak this BSS */
                        return false;
                }

                if (cmp < 0)
                        p = &(*p)->rb_left;
                else
                        p = &(*p)->rb_right;
        }

        rb_link_node(&bss->rbn, parent, p);
        rb_insert_color(&bss->rbn, &rdev->bss_tree);
        return true;
}

static struct cfg80211_internal_bss *
rb_find_bss(struct cfg80211_registered_device *rdev,
            struct cfg80211_internal_bss *res,
            enum bss_compare_mode mode)
{
        struct rb_node *n = rdev->bss_tree.rb_node;
        struct cfg80211_internal_bss *bss;
        int r;

        while (n) {
                bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
                r = cmp_bss(&res->pub, &bss->pub, mode);

                if (r == 0)
                        return bss;
                else if (r < 0)
                        n = n->rb_left;
                else
                        n = n->rb_right;
        }

        return NULL;
}

static void cfg80211_insert_bss(struct cfg80211_registered_device *rdev,
                                struct cfg80211_internal_bss *bss)
{
        lockdep_assert_held(&rdev->bss_lock);

        if (!rb_insert_bss(rdev, bss))
                return;
        list_add_tail(&bss->list, &rdev->bss_list);
        rdev->bss_entries++;
}

static void cfg80211_rehash_bss(struct cfg80211_registered_device *rdev,
                                struct cfg80211_internal_bss *bss)
{
        lockdep_assert_held(&rdev->bss_lock);

        rb_erase(&bss->rbn, &rdev->bss_tree);
        if (!rb_insert_bss(rdev, bss)) {
                list_del(&bss->list);
                if (!list_empty(&bss->hidden_list))
                        list_del_init(&bss->hidden_list);
                if (!list_empty(&bss->pub.nontrans_list))
                        list_del_init(&bss->pub.nontrans_list);
                rdev->bss_entries--;
        }
        rdev->bss_generation++;
}

static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
                                   struct cfg80211_internal_bss *new)
{
        const struct cfg80211_bss_ies *ies;
        struct cfg80211_internal_bss *bss;
        const u8 *ie;
        int i, ssidlen;
        u8 fold = 0;
        u32 n_entries = 0;

        ies = rcu_access_pointer(new->pub.beacon_ies);
        if (WARN_ON(!ies))
                return false;

        ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
        if (!ie) {
                /* nothing to do */
                return true;
        }

        ssidlen = ie[1];
        for (i = 0; i < ssidlen; i++)
                fold |= ie[2 + i];

        if (fold) {
                /* not a hidden SSID */
                return true;
        }

        /* This is the bad part ... */

        list_for_each_entry(bss, &rdev->bss_list, list) {
                /*
                 * we're iterating all the entries anyway, so take the
                 * opportunity to validate the list length accounting
                 */
                n_entries++;

                if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
                        continue;
                if (bss->pub.channel != new->pub.channel)
                        continue;
                if (rcu_access_pointer(bss->pub.beacon_ies))
                        continue;
                ies = rcu_access_pointer(bss->pub.ies);
                if (!ies)
                        continue;
                ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
                if (!ie)
                        continue;
                if (ssidlen && ie[1] != ssidlen)
                        continue;
                if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
                        continue;
                if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
                        list_del(&bss->hidden_list);
                /* combine them */
                list_add(&bss->hidden_list, &new->hidden_list);
                bss->pub.hidden_beacon_bss = &new->pub;
                new->refcount += bss->refcount;
                rcu_assign_pointer(bss->pub.beacon_ies,
                                   new->pub.beacon_ies);
        }

        WARN_ONCE(n_entries != rdev->bss_entries,
                  "rdev bss entries[%d]/list[len:%d] corruption\n",
                  rdev->bss_entries, n_entries);

        return true;
}

static void cfg80211_update_hidden_bsses(struct cfg80211_internal_bss *known,
                                         const struct cfg80211_bss_ies *new_ies,
                                         const struct cfg80211_bss_ies *old_ies)
{
        struct cfg80211_internal_bss *bss;

        /* Assign beacon IEs to all sub entries */
        list_for_each_entry(bss, &known->hidden_list, hidden_list) {
                const struct cfg80211_bss_ies *ies;

                ies = rcu_access_pointer(bss->pub.beacon_ies);
                WARN_ON(ies != old_ies);

                rcu_assign_pointer(bss->pub.beacon_ies, new_ies);

                bss->ts = known->ts;
                bss->pub.ts_boottime = known->pub.ts_boottime;
        }
}

static void cfg80211_check_stuck_ecsa(struct cfg80211_registered_device *rdev,
                                      struct cfg80211_internal_bss *known,
                                      const struct cfg80211_bss_ies *old)
{
        const struct ieee80211_ext_chansw_ie *ecsa;
        const struct element *elem_new, *elem_old;
        const struct cfg80211_bss_ies *new, *bcn;

        if (known->pub.proberesp_ecsa_stuck)
                return;

        new = rcu_dereference_protected(known->pub.proberesp_ies,
                                        lockdep_is_held(&rdev->bss_lock));
        if (WARN_ON(!new))
                return;

        if (new->tsf - old->tsf < USEC_PER_SEC)
                return;

        elem_old = cfg80211_find_elem(WLAN_EID_EXT_CHANSWITCH_ANN,
                                      old->data, old->len);
        if (!elem_old)
                return;

        elem_new = cfg80211_find_elem(WLAN_EID_EXT_CHANSWITCH_ANN,
                                      new->data, new->len);
        if (!elem_new)
                return;

        bcn = rcu_dereference_protected(known->pub.beacon_ies,
                                        lockdep_is_held(&rdev->bss_lock));
        if (bcn &&
            cfg80211_find_elem(WLAN_EID_EXT_CHANSWITCH_ANN,
                               bcn->data, bcn->len))
                return;

        if (elem_new->datalen != elem_old->datalen)
                return;
        if (elem_new->datalen < sizeof(struct ieee80211_ext_chansw_ie))
                return;
        if (memcmp(elem_new->data, elem_old->data, elem_new->datalen))
                return;

        ecsa = (void *)elem_new->data;

        if (!ecsa->mode)
                return;

        if (ecsa->new_ch_num !=
            ieee80211_frequency_to_channel(known->pub.channel->center_freq))
                return;

        known->pub.proberesp_ecsa_stuck = 1;
}

static bool
cfg80211_update_known_bss(struct cfg80211_registered_device *rdev,
                          struct cfg80211_internal_bss *known,
                          struct cfg80211_internal_bss *new,
                          bool signal_valid)
{
        lockdep_assert_held(&rdev->bss_lock);

        /* Update time stamps */
        known->ts = new->ts;
        known->pub.ts_boottime = new->pub.ts_boottime;

        /* Update IEs */
        if (rcu_access_pointer(new->pub.proberesp_ies)) {
                const struct cfg80211_bss_ies *old;

                old = rcu_access_pointer(known->pub.proberesp_ies);

                rcu_assign_pointer(known->pub.proberesp_ies,
                                   new->pub.proberesp_ies);
                /* Override possible earlier Beacon frame IEs */
                rcu_assign_pointer(known->pub.ies,
                                   new->pub.proberesp_ies);
                if (old) {
                        cfg80211_check_stuck_ecsa(rdev, known, old);
                        kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head);
                }
        }

        if (rcu_access_pointer(new->pub.beacon_ies)) {
                const struct cfg80211_bss_ies *old;

                if (known->pub.hidden_beacon_bss &&
                    !list_empty(&known->hidden_list)) {
                        const struct cfg80211_bss_ies *f;

                        /* The known BSS struct is one of the probe
                         * response members of a group, but we're
                         * receiving a beacon (beacon_ies in the new
                         * bss is used). This can only mean that the
                         * AP changed its beacon from not having an
                         * SSID to showing it, which is confusing so
                         * drop this information.
                         */

                        f = rcu_access_pointer(new->pub.beacon_ies);
                        if (!new->pub.hidden_beacon_bss)
                                kfree_rcu((struct cfg80211_bss_ies *)f, rcu_head);
                        return false;
                }

                old = rcu_access_pointer(known->pub.beacon_ies);

                rcu_assign_pointer(known->pub.beacon_ies, new->pub.beacon_ies);

                /* Override IEs if they were from a beacon before */
                if (old == rcu_access_pointer(known->pub.ies))
                        rcu_assign_pointer(known->pub.ies, new->pub.beacon_ies);

                cfg80211_update_hidden_bsses(known,
                                             rcu_access_pointer(new->pub.beacon_ies),
                                             old);

                if (old)
                        kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head);
        }

        known->pub.beacon_interval = new->pub.beacon_interval;

        /* don't update the signal if beacon was heard on
         * adjacent channel.
         */
        if (signal_valid)
                known->pub.signal = new->pub.signal;
        known->pub.capability = new->pub.capability;
        known->parent_tsf = new->parent_tsf;
        known->pub.chains = new->pub.chains;
        memcpy(known->pub.chain_signal, new->pub.chain_signal,
               IEEE80211_MAX_CHAINS);
        ether_addr_copy(known->parent_bssid, new->parent_bssid);
        known->pub.max_bssid_indicator = new->pub.max_bssid_indicator;
        known->pub.bssid_index = new->pub.bssid_index;
        known->pub.use_for = new->pub.use_for;
        known->pub.cannot_use_reasons = new->pub.cannot_use_reasons;
        known->bss_source = new->bss_source;

        return true;
}

/* Returned bss is reference counted and must be cleaned up appropriately. */
static struct cfg80211_internal_bss *
__cfg80211_bss_update(struct cfg80211_registered_device *rdev,
                      struct cfg80211_internal_bss *tmp,
                      bool signal_valid, unsigned long ts)
{
        struct cfg80211_internal_bss *found = NULL;
        struct cfg80211_bss_ies *ies;

        if (WARN_ON(!tmp->pub.channel))
                goto free_ies;

        tmp->ts = ts;

        if (WARN_ON(!rcu_access_pointer(tmp->pub.ies)))
                goto free_ies;

        found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);

        if (found) {
                if (!cfg80211_update_known_bss(rdev, found, tmp, signal_valid))
                        return NULL;
        } else {
                struct cfg80211_internal_bss *new;
                struct cfg80211_internal_bss *hidden;

                /*
                 * create a copy -- the "res" variable that is passed in
                 * is allocated on the stack since it's not needed in the
                 * more common case of an update
                 */
                new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
                              GFP_ATOMIC);
                if (!new)
                        goto free_ies;
                memcpy(new, tmp, sizeof(*new));
                new->refcount = 1;
                INIT_LIST_HEAD(&new->hidden_list);
                INIT_LIST_HEAD(&new->pub.nontrans_list);
                /* we'll set this later if it was non-NULL */
                new->pub.transmitted_bss = NULL;

                if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
                        hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
                        if (!hidden)
                                hidden = rb_find_bss(rdev, tmp,
                                                     BSS_CMP_HIDE_NUL);
                        if (hidden) {
                                new->pub.hidden_beacon_bss = &hidden->pub;
                                list_add(&new->hidden_list,
                                         &hidden->hidden_list);
                                hidden->refcount++;

                                ies = (void *)rcu_access_pointer(new->pub.beacon_ies);
                                rcu_assign_pointer(new->pub.beacon_ies,
                                                   hidden->pub.beacon_ies);
                                if (ies)
                                        kfree_rcu(ies, rcu_head);
                        }
                } else {
                        /*
                         * Ok so we found a beacon, and don't have an entry. If
                         * it's a beacon with hidden SSID, we might be in for an
                         * expensive search for any probe responses that should
                         * be grouped with this beacon for updates ...
                         */
                        if (!cfg80211_combine_bsses(rdev, new)) {
                                bss_ref_put(rdev, new);
                                return NULL;
                        }
                }

                if (rdev->bss_entries >= bss_entries_limit &&
                    !cfg80211_bss_expire_oldest(rdev)) {
                        bss_ref_put(rdev, new);
                        return NULL;
                }

                /* This must be before the call to bss_ref_get */
                if (tmp->pub.transmitted_bss) {
                        new->pub.transmitted_bss = tmp->pub.transmitted_bss;
                        bss_ref_get(rdev, bss_from_pub(tmp->pub.transmitted_bss));
                }

                cfg80211_insert_bss(rdev, new);
                found = new;
        }

        rdev->bss_generation++;
        bss_ref_get(rdev, found);

        return found;

free_ies:
        ies = (void *)rcu_access_pointer(tmp->pub.beacon_ies);
        if (ies)
                kfree_rcu(ies, rcu_head);
        ies = (void *)rcu_access_pointer(tmp->pub.proberesp_ies);
        if (ies)
                kfree_rcu(ies, rcu_head);

        return NULL;
}

struct cfg80211_internal_bss *
cfg80211_bss_update(struct cfg80211_registered_device *rdev,
                    struct cfg80211_internal_bss *tmp,
                    bool signal_valid, unsigned long ts)
{
        struct cfg80211_internal_bss *res;

        spin_lock_bh(&rdev->bss_lock);
        res = __cfg80211_bss_update(rdev, tmp, signal_valid, ts);
        spin_unlock_bh(&rdev->bss_lock);

        return res;
}

int cfg80211_get_ies_channel_number(const u8 *ie, size_t ielen,
                                    enum nl80211_band band)
{
        const struct element *tmp;

        if (band == NL80211_BAND_6GHZ) {
                struct ieee80211_he_operation *he_oper;

                tmp = cfg80211_find_ext_elem(WLAN_EID_EXT_HE_OPERATION, ie,
                                             ielen);
                if (tmp && tmp->datalen >= sizeof(*he_oper) &&
                    tmp->datalen >= ieee80211_he_oper_size(&tmp->data[1])) {
                        const struct ieee80211_he_6ghz_oper *he_6ghz_oper;

                        he_oper = (void *)&tmp->data[1];

                        he_6ghz_oper = ieee80211_he_6ghz_oper(he_oper);
                        if (!he_6ghz_oper)
                                return -1;

                        return he_6ghz_oper->primary;
                }
        } else if (band == NL80211_BAND_S1GHZ) {
                tmp = cfg80211_find_elem(WLAN_EID_S1G_OPERATION, ie, ielen);
                if (tmp && tmp->datalen >= sizeof(struct ieee80211_s1g_oper_ie)) {
                        struct ieee80211_s1g_oper_ie *s1gop = (void *)tmp->data;

                        return s1gop->oper_ch;
                }
        } else {
                tmp = cfg80211_find_elem(WLAN_EID_DS_PARAMS, ie, ielen);
                if (tmp && tmp->datalen == 1)
                        return tmp->data[0];

                tmp = cfg80211_find_elem(WLAN_EID_HT_OPERATION, ie, ielen);
                if (tmp &&
                    tmp->datalen >= sizeof(struct ieee80211_ht_operation)) {
                        struct ieee80211_ht_operation *htop = (void *)tmp->data;

                        return htop->primary_chan;
                }
        }

        return -1;
}
EXPORT_SYMBOL(cfg80211_get_ies_channel_number);

/*
 * Update RX channel information based on the available frame payload
 * information. This is mainly for the 2.4 GHz band where frames can be received
 * from neighboring channels and the Beacon frames use the DSSS Parameter Set
 * element to indicate the current (transmitting) channel, but this might also
 * be needed on other bands if RX frequency does not match with the actual
 * operating channel of a BSS, or if the AP reports a different primary channel.
 */
static struct ieee80211_channel *
cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
                         struct ieee80211_channel *channel)
{
        u32 freq;
        int channel_number;
        struct ieee80211_channel *alt_channel;

        channel_number = cfg80211_get_ies_channel_number(ie, ielen,
                                                         channel->band);

        if (channel_number < 0) {
                /* No channel information in frame payload */
                return channel;
        }

        freq = ieee80211_channel_to_freq_khz(channel_number, channel->band);

        /*
         * Frame info (beacon/prob res) is the same as received channel,
         * no need for further processing.
         */
        if (freq == ieee80211_channel_to_khz(channel))
                return channel;

        alt_channel = ieee80211_get_channel_khz(wiphy, freq);
        if (!alt_channel) {
                if (channel->band == NL80211_BAND_2GHZ ||
                    channel->band == NL80211_BAND_6GHZ) {
                        /*
                         * Better not allow unexpected channels when that could
                         * be going beyond the 1-11 range (e.g., discovering
                         * BSS on channel 12 when radio is configured for
                         * channel 11) or beyond the 6 GHz channel range.
                         */
                        return NULL;
                }

                /* No match for the payload channel number - ignore it */
                return channel;
        }

        /*
         * Use the channel determined through the payload channel number
         * instead of the RX channel reported by the driver.
         */
        if (alt_channel->flags & IEEE80211_CHAN_DISABLED)
                return NULL;
        return alt_channel;
}

struct cfg80211_inform_single_bss_data {
        struct cfg80211_inform_bss *drv_data;
        enum cfg80211_bss_frame_type ftype;
        struct ieee80211_channel *channel;
        u8 bssid[ETH_ALEN];
        u64 tsf;
        u16 capability;
        u16 beacon_interval;
        const u8 *ie;
        size_t ielen;

        enum bss_source_type bss_source;
        /* Set if reporting bss_source != BSS_SOURCE_DIRECT */
        struct cfg80211_bss *source_bss;
        u8 max_bssid_indicator;
        u8 bssid_index;

        u8 use_for;
        u64 cannot_use_reasons;
};

enum ieee80211_ap_reg_power
cfg80211_get_6ghz_power_type(const u8 *elems, size_t elems_len,
                             u32 client_flags)
{
        const struct ieee80211_he_6ghz_oper *he_6ghz_oper;
        struct ieee80211_he_operation *he_oper;
        const struct element *tmp;

        tmp = cfg80211_find_ext_elem(WLAN_EID_EXT_HE_OPERATION,
                                     elems, elems_len);
        if (!tmp || tmp->datalen < sizeof(*he_oper) + 1 ||
            tmp->datalen < ieee80211_he_oper_size(tmp->data + 1))
                return IEEE80211_REG_UNSET_AP;

        he_oper = (void *)&tmp->data[1];
        he_6ghz_oper = ieee80211_he_6ghz_oper(he_oper);

        if (!he_6ghz_oper)
                return IEEE80211_REG_UNSET_AP;

        return cfg80211_6ghz_power_type(he_6ghz_oper->control, client_flags);
}

static bool cfg80211_6ghz_power_type_valid(const u8 *elems, size_t elems_len,
                                           const u32 flags)
{
        switch (cfg80211_get_6ghz_power_type(elems, elems_len, flags)) {
        case IEEE80211_REG_LPI_AP:
                return true;
        case IEEE80211_REG_SP_AP:
                return !(flags & IEEE80211_CHAN_NO_6GHZ_AFC_CLIENT);
        case IEEE80211_REG_VLP_AP:
                return !(flags & IEEE80211_CHAN_NO_6GHZ_VLP_CLIENT);
        default:
                return false;
        }
}

/* Returned bss is reference counted and must be cleaned up appropriately. */
static struct cfg80211_bss *
cfg80211_inform_single_bss_data(struct wiphy *wiphy,
                                struct cfg80211_inform_single_bss_data *data,
                                gfp_t gfp)
{
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
        struct cfg80211_inform_bss *drv_data = data->drv_data;
        struct cfg80211_bss_ies *ies;
        struct ieee80211_channel *channel;
        struct cfg80211_internal_bss tmp = {}, *res;
        int bss_type;
        bool signal_valid;
        unsigned long ts;

        if (WARN_ON(!wiphy))
                return NULL;

        if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
                    (drv_data->signal < 0 || drv_data->signal > 100)))
                return NULL;

        if (WARN_ON(data->bss_source != BSS_SOURCE_DIRECT && !data->source_bss))
                return NULL;

        channel = data->channel;
        if (!channel)
                channel = cfg80211_get_bss_channel(wiphy, data->ie, data->ielen,
                                                   drv_data->chan);
        if (!channel)
                return NULL;

        if (channel->band == NL80211_BAND_6GHZ &&
            !cfg80211_6ghz_power_type_valid(data->ie, data->ielen,
                                            channel->flags)) {
                data->use_for = 0;
                data->cannot_use_reasons =
                        NL80211_BSS_CANNOT_USE_6GHZ_PWR_MISMATCH;
        }

        memcpy(tmp.pub.bssid, data->bssid, ETH_ALEN);
        tmp.pub.channel = channel;
        if (data->bss_source != BSS_SOURCE_STA_PROFILE)
                tmp.pub.signal = drv_data->signal;
        else
                tmp.pub.signal = 0;
        tmp.pub.beacon_interval = data->beacon_interval;
        tmp.pub.capability = data->capability;
        tmp.pub.ts_boottime = drv_data->boottime_ns;
        tmp.parent_tsf = drv_data->parent_tsf;
        ether_addr_copy(tmp.parent_bssid, drv_data->parent_bssid);
        tmp.pub.chains = drv_data->chains;
        memcpy(tmp.pub.chain_signal, drv_data->chain_signal,
               IEEE80211_MAX_CHAINS);
        tmp.pub.use_for = data->use_for;
        tmp.pub.cannot_use_reasons = data->cannot_use_reasons;
        tmp.bss_source = data->bss_source;

        switch (data->bss_source) {
        case BSS_SOURCE_MBSSID:
                tmp.pub.transmitted_bss = data->source_bss;
                fallthrough;
        case BSS_SOURCE_STA_PROFILE:
                ts = bss_from_pub(data->source_bss)->ts;
                tmp.pub.bssid_index = data->bssid_index;
                tmp.pub.max_bssid_indicator = data->max_bssid_indicator;
                break;
        case BSS_SOURCE_DIRECT:
                ts = jiffies;

                if (channel->band == NL80211_BAND_60GHZ) {
                        bss_type = data->capability &
                                   WLAN_CAPABILITY_DMG_TYPE_MASK;
                        if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
                            bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
                                regulatory_hint_found_beacon(wiphy, channel,
                                                             gfp);
                } else {
                        if (data->capability & WLAN_CAPABILITY_ESS)
                                regulatory_hint_found_beacon(wiphy, channel,
                                                             gfp);
                }
                break;
        }

        /*
         * If we do not know here whether the IEs are from a Beacon or Probe
         * Response frame, we need to pick one of the options and only use it
         * with the driver that does not provide the full Beacon/Probe Response
         * frame. Use Beacon frame pointer to avoid indicating that this should
         * override the IEs pointer should we have received an earlier
         * indication of Probe Response data.
         */
        ies = kzalloc(sizeof(*ies) + data->ielen, gfp);
        if (!ies)
                return NULL;
        ies->len = data->ielen;
        ies->tsf = data->tsf;
        ies->from_beacon = false;
        memcpy(ies->data, data->ie, data->ielen);

        switch (data->ftype) {
        case CFG80211_BSS_FTYPE_BEACON:
        case CFG80211_BSS_FTYPE_S1G_BEACON:
                ies->from_beacon = true;
                fallthrough;
        case CFG80211_BSS_FTYPE_UNKNOWN:
                rcu_assign_pointer(tmp.pub.beacon_ies, ies);
                break;
        case CFG80211_BSS_FTYPE_PRESP:
                rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
                break;
        }
        rcu_assign_pointer(tmp.pub.ies, ies);

        signal_valid = drv_data->chan == channel;
        spin_lock_bh(&rdev->bss_lock);
        res = __cfg80211_bss_update(rdev, &tmp, signal_valid, ts);
        if (!res)
                goto drop;

        rdev_inform_bss(rdev, &res->pub, ies, drv_data->drv_data);

        if (data->bss_source == BSS_SOURCE_MBSSID) {
                /* this is a nontransmitting bss, we need to add it to
                 * transmitting bss' list if it is not there
                 */
                if (cfg80211_add_nontrans_list(data->source_bss, &res->pub)) {
                        if (__cfg80211_unlink_bss(rdev, res)) {
                                rdev->bss_generation++;
                                res = NULL;
                        }
                }

                if (!res)
                        goto drop;
        }
        spin_unlock_bh(&rdev->bss_lock);

        trace_cfg80211_return_bss(&res->pub);
        /* __cfg80211_bss_update gives us a referenced result */
        return &res->pub;

drop:
        spin_unlock_bh(&rdev->bss_lock);
        return NULL;
}

static const struct element
*cfg80211_get_profile_continuation(const u8 *ie, size_t ielen,
                                   const struct element *mbssid_elem,
                                   const struct element *sub_elem)
{
        const u8 *mbssid_end = mbssid_elem->data + mbssid_elem->datalen;
        const struct element *next_mbssid;
        const struct element *next_sub;

        next_mbssid = cfg80211_find_elem(WLAN_EID_MULTIPLE_BSSID,
                                         mbssid_end,
                                         ielen - (mbssid_end - ie));

        /*
         * If it is not the last subelement in current MBSSID IE or there isn't
         * a next MBSSID IE - profile is complete.
        */
        if ((sub_elem->data + sub_elem->datalen < mbssid_end - 1) ||
            !next_mbssid)
                return NULL;

        /* For any length error, just return NULL */

        if (next_mbssid->datalen < 4)
                return NULL;

        next_sub = (void *)&next_mbssid->data[1];

        if (next_mbssid->data + next_mbssid->datalen <
            next_sub->data + next_sub->datalen)
                return NULL;

        if (next_sub->id != 0 || next_sub->datalen < 2)
                return NULL;

        /*
         * Check if the first element in the next sub element is a start
         * of a new profile
         */
        return next_sub->data[0] == WLAN_EID_NON_TX_BSSID_CAP ?
               NULL : next_mbssid;
}

size_t cfg80211_merge_profile(const u8 *ie, size_t ielen,
                              const struct element *mbssid_elem,
                              const struct element *sub_elem,
                              u8 *merged_ie, size_t max_copy_len)
{
        size_t copied_len = sub_elem->datalen;
        const struct element *next_mbssid;

        if (sub_elem->datalen > max_copy_len)
                return 0;

        memcpy(merged_ie, sub_elem->data, sub_elem->datalen);

        while ((next_mbssid = cfg80211_get_profile_continuation(ie, ielen,
                                                                mbssid_elem,
                                                                sub_elem))) {
                const struct element *next_sub = (void *)&next_mbssid->data[1];

                if (copied_len + next_sub->datalen > max_copy_len)
                        break;
                memcpy(merged_ie + copied_len, next_sub->data,
                       next_sub->datalen);
                copied_len += next_sub->datalen;
        }

        return copied_len;
}
EXPORT_SYMBOL(cfg80211_merge_profile);

static void
cfg80211_parse_mbssid_data(struct wiphy *wiphy,
                           struct cfg80211_inform_single_bss_data *tx_data,
                           struct cfg80211_bss *source_bss,
                           gfp_t gfp)
{
        struct cfg80211_inform_single_bss_data data = {
                .drv_data = tx_data->drv_data,
                .ftype = tx_data->ftype,
                .tsf = tx_data->tsf,
                .beacon_interval = tx_data->beacon_interval,
                .source_bss = source_bss,
                .bss_source = BSS_SOURCE_MBSSID,
                .use_for = tx_data->use_for,
                .cannot_use_reasons = tx_data->cannot_use_reasons,
        };
        const u8 *mbssid_index_ie;
        const struct element *elem, *sub;
        u8 *new_ie, *profile;
        u64 seen_indices = 0;
        struct cfg80211_bss *bss;

        if (!source_bss)
                return;
        if (!cfg80211_find_elem(WLAN_EID_MULTIPLE_BSSID,
                                tx_data->ie, tx_data->ielen))
                return;
        if (!wiphy->support_mbssid)
                return;
        if (wiphy->support_only_he_mbssid &&
            !cfg80211_find_ext_elem(WLAN_EID_EXT_HE_CAPABILITY,
                                    tx_data->ie, tx_data->ielen))
                return;

        new_ie = kmalloc(IEEE80211_MAX_DATA_LEN, gfp);
        if (!new_ie)
                return;

        profile = kmalloc(tx_data->ielen, gfp);
        if (!profile)
                goto out;

        for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID,
                            tx_data->ie, tx_data->ielen) {
                if (elem->datalen < 4)
                        continue;
                if (elem->data[0] < 1 || (int)elem->data[0] > 8)
                        continue;
                for_each_element(sub, elem->data + 1, elem->datalen - 1) {
                        u8 profile_len;

                        if (sub->id != 0 || sub->datalen < 4) {
                                /* not a valid BSS profile */
                                continue;
                        }

                        if (sub->data[0] != WLAN_EID_NON_TX_BSSID_CAP ||
                            sub->data[1] != 2) {
                                /* The first element within the Nontransmitted
                                 * BSSID Profile is not the Nontransmitted
                                 * BSSID Capability element.
                                 */
                                continue;
                        }

                        memset(profile, 0, tx_data->ielen);
                        profile_len = cfg80211_merge_profile(tx_data->ie,
                                                             tx_data->ielen,
                                                             elem,
                                                             sub,
                                                             profile,
                                                             tx_data->ielen);

                        /* found a Nontransmitted BSSID Profile */
                        mbssid_index_ie = cfg80211_find_ie
                                (WLAN_EID_MULTI_BSSID_IDX,
                                 profile, profile_len);
                        if (!mbssid_index_ie || mbssid_index_ie[1] < 1 ||
                            mbssid_index_ie[2] == 0 ||
                            mbssid_index_ie[2] > 46 ||
                            mbssid_index_ie[2] >= (1 << elem->data[0])) {
                                /* No valid Multiple BSSID-Index element */
                                continue;
                        }

                        if (seen_indices & BIT_ULL(mbssid_index_ie[2]))
                                /* We don't support legacy split of a profile */
                                net_dbg_ratelimited("Partial info for BSSID index %d\n",
                                                    mbssid_index_ie[2]);

                        seen_indices |= BIT_ULL(mbssid_index_ie[2]);

                        data.bssid_index = mbssid_index_ie[2];
                        data.max_bssid_indicator = elem->data[0];

                        cfg80211_gen_new_bssid(tx_data->bssid,
                                               data.max_bssid_indicator,
                                               data.bssid_index,
                                               data.bssid);

                        memset(new_ie, 0, IEEE80211_MAX_DATA_LEN);
                        data.ie = new_ie;
                        data.ielen = cfg80211_gen_new_ie(tx_data->ie,
                                                         tx_data->ielen,
                                                         profile,
                                                         profile_len,
                                                         new_ie,
                                                         IEEE80211_MAX_DATA_LEN);
                        if (!data.ielen)
                                continue;

                        data.capability = get_unaligned_le16(profile + 2);
                        bss = cfg80211_inform_single_bss_data(wiphy, &data, gfp);
                        if (!bss)
                                break;
                        cfg80211_put_bss(wiphy, bss);
                }
        }

out:
        kfree(new_ie);
        kfree(profile);
}

ssize_t cfg80211_defragment_element(const struct element *elem, const u8 *ies,
                                    size_t ieslen, u8 *data, size_t data_len,
                                    u8 frag_id)
{
        const struct element *next;
        ssize_t copied;
        u8 elem_datalen;

        if (!elem)
                return -EINVAL;

        /* elem might be invalid after the memmove */
        next = (void *)(elem->data + elem->datalen);
        elem_datalen = elem->datalen;

        if (elem->id == WLAN_EID_EXTENSION) {
                copied = elem->datalen - 1;

                if (data) {
                        if (copied > data_len)
                                return -ENOSPC;

                        memmove(data, elem->data + 1, copied);
                }
        } else {
                copied = elem->datalen;

                if (data) {
                        if (copied > data_len)
                                return -ENOSPC;

                        memmove(data, elem->data, copied);
                }
        }

        /* Fragmented elements must have 255 bytes */
        if (elem_datalen < 255)
                return copied;

        for (elem = next;
             elem->data < ies + ieslen &&
                elem->data + elem->datalen <= ies + ieslen;
             elem = next) {
                /* elem might be invalid after the memmove */
                next = (void *)(elem->data + elem->datalen);

                if (elem->id != frag_id)
                        break;

                elem_datalen = elem->datalen;

                if (data) {
                        if (copied + elem_datalen > data_len)
                                return -ENOSPC;

                        memmove(data + copied, elem->data, elem_datalen);
                }

                copied += elem_datalen;

                /* Only the last fragment may be short */
                if (elem_datalen != 255)
                        break;
        }

        return copied;
}
EXPORT_SYMBOL(cfg80211_defragment_element);

struct cfg80211_mle {
        struct ieee80211_multi_link_elem *mle;
        struct ieee80211_mle_per_sta_profile
                *sta_prof[IEEE80211_MLD_MAX_NUM_LINKS];
        ssize_t sta_prof_len[IEEE80211_MLD_MAX_NUM_LINKS];

        u8 data[];
};

static struct cfg80211_mle *
cfg80211_defrag_mle(const struct element *mle, const u8 *ie, size_t ielen,
                    gfp_t gfp)
{
        const struct element *elem;
        struct cfg80211_mle *res;
        size_t buf_len;
        ssize_t mle_len;
        u8 common_size, idx;

        if (!mle || !ieee80211_mle_size_ok(mle->data + 1, mle->datalen - 1))
                return NULL;

        /* Required length for first defragmentation */
        buf_len = mle->datalen - 1;
        for_each_element(elem, mle->data + mle->datalen,
                         ie + ielen - mle->data - mle->datalen) {
                if (elem->id != WLAN_EID_FRAGMENT)
                        break;

                buf_len += elem->datalen;
        }

        res = kzalloc_flex(*res, data, buf_len, gfp);
        if (!res)
                return NULL;

        mle_len = cfg80211_defragment_element(mle, ie, ielen,
                                              res->data, buf_len,
                                              WLAN_EID_FRAGMENT);
        if (mle_len < 0)
                goto error;

        res->mle = (void *)res->data;

        /* Find the sub-element area in the buffer */
        common_size = ieee80211_mle_common_size((u8 *)res->mle);
        ie = res->data + common_size;
        ielen = mle_len - common_size;

        idx = 0;
        for_each_element_id(elem, IEEE80211_MLE_SUBELEM_PER_STA_PROFILE,
                            ie, ielen) {
                res->sta_prof[idx] = (void *)elem->data;
                res->sta_prof_len[idx] = elem->datalen;

                idx++;
                if (idx >= IEEE80211_MLD_MAX_NUM_LINKS)
                        break;
        }
        if (!for_each_element_completed(elem, ie, ielen))
                goto error;

        /* Defragment sta_info in-place */
        for (idx = 0; idx < IEEE80211_MLD_MAX_NUM_LINKS && res->sta_prof[idx];
             idx++) {
                if (res->sta_prof_len[idx] < 255)
                        continue;

                elem = (void *)res->sta_prof[idx] - 2;

                if (idx + 1 < ARRAY_SIZE(res->sta_prof) &&
                    res->sta_prof[idx + 1])
                        buf_len = (u8 *)res->sta_prof[idx + 1] -
                                  (u8 *)res->sta_prof[idx];
                else
                        buf_len = ielen + ie - (u8 *)elem;

                res->sta_prof_len[idx] =
                        cfg80211_defragment_element(elem,
                                                    (u8 *)elem, buf_len,
                                                    (u8 *)res->sta_prof[idx],
                                                    buf_len,
                                                    IEEE80211_MLE_SUBELEM_FRAGMENT);
                if (res->sta_prof_len[idx] < 0)
                        goto error;
        }

        return res;

error:
        kfree(res);
        return NULL;
}

struct tbtt_info_iter_data {
        const struct ieee80211_neighbor_ap_info *ap_info;
        u8 param_ch_count;
        u32 use_for;
        u8 mld_id, link_id;
        bool non_tx;
};

static enum cfg80211_rnr_iter_ret
cfg802121_mld_ap_rnr_iter(void *_data, u8 type,
                          const struct ieee80211_neighbor_ap_info *info,
                          const u8 *tbtt_info, u8 tbtt_info_len)
{
        const struct ieee80211_rnr_mld_params *mld_params;
        struct tbtt_info_iter_data *data = _data;
        u8 link_id;
        bool non_tx = false;

        if (type == IEEE80211_TBTT_INFO_TYPE_TBTT &&
            tbtt_info_len >= offsetofend(struct ieee80211_tbtt_info_ge_11,
                                         mld_params)) {
                const struct ieee80211_tbtt_info_ge_11 *tbtt_info_ge_11 =
                        (void *)tbtt_info;

                non_tx = (tbtt_info_ge_11->bss_params &
                          (IEEE80211_RNR_TBTT_PARAMS_MULTI_BSSID |
                           IEEE80211_RNR_TBTT_PARAMS_TRANSMITTED_BSSID)) ==
                         IEEE80211_RNR_TBTT_PARAMS_MULTI_BSSID;
                mld_params = &tbtt_info_ge_11->mld_params;
        } else if (type == IEEE80211_TBTT_INFO_TYPE_MLD &&
                 tbtt_info_len >= sizeof(struct ieee80211_rnr_mld_params))
                mld_params = (void *)tbtt_info;
        else
                return RNR_ITER_CONTINUE;

        link_id = le16_get_bits(mld_params->params,
                                IEEE80211_RNR_MLD_PARAMS_LINK_ID);

        if (data->mld_id != mld_params->mld_id)
                return RNR_ITER_CONTINUE;

        if (data->link_id != link_id)
                return RNR_ITER_CONTINUE;

        data->ap_info = info;
        data->param_ch_count =
                le16_get_bits(mld_params->params,
                              IEEE80211_RNR_MLD_PARAMS_BSS_CHANGE_COUNT);
        data->non_tx = non_tx;

        if (type == IEEE80211_TBTT_INFO_TYPE_TBTT)
                data->use_for = NL80211_BSS_USE_FOR_ALL;
        else
                data->use_for = NL80211_BSS_USE_FOR_MLD_LINK;
        return RNR_ITER_BREAK;
}

static u8
cfg80211_rnr_info_for_mld_ap(const u8 *ie, size_t ielen, u8 mld_id, u8 link_id,
                             const struct ieee80211_neighbor_ap_info **ap_info,
                             u8 *param_ch_count, bool *non_tx)
{
        struct tbtt_info_iter_data data = {
                .mld_id = mld_id,
                .link_id = link_id,
        };

        cfg80211_iter_rnr(ie, ielen, cfg802121_mld_ap_rnr_iter, &data);

        *ap_info = data.ap_info;
        *param_ch_count = data.param_ch_count;
        *non_tx = data.non_tx;

        return data.use_for;
}

static struct element *
cfg80211_gen_reporter_rnr(struct cfg80211_bss *source_bss, bool is_mbssid,
                          bool same_mld, u8 link_id, u8 bss_change_count,
                          gfp_t gfp)
{
        const struct cfg80211_bss_ies *ies;
        struct ieee80211_neighbor_ap_info ap_info;
        struct ieee80211_tbtt_info_ge_11 tbtt_info;
        u32 short_ssid;
        const struct element *elem;
        struct element *res;

        /*
         * We only generate the RNR to permit ML lookups. For that we do not
         * need an entry for the corresponding transmitting BSS, lets just skip
         * it even though it would be easy to add.
         */
        if (!same_mld)
                return NULL;

        /* We could use tx_data->ies if we change cfg80211_calc_short_ssid */
        rcu_read_lock();
        ies = rcu_dereference(source_bss->ies);

        ap_info.tbtt_info_len = offsetofend(typeof(tbtt_info), mld_params);
        ap_info.tbtt_info_hdr =
                        u8_encode_bits(IEEE80211_TBTT_INFO_TYPE_TBTT,
                                       IEEE80211_AP_INFO_TBTT_HDR_TYPE) |
                        u8_encode_bits(0, IEEE80211_AP_INFO_TBTT_HDR_COUNT);

        ap_info.channel = ieee80211_frequency_to_channel(source_bss->channel->center_freq);

        /* operating class */
        elem = cfg80211_find_elem(WLAN_EID_SUPPORTED_REGULATORY_CLASSES,
                                  ies->data, ies->len);
        if (elem && elem->datalen >= 1) {
                ap_info.op_class = elem->data[0];
        } else {
                struct cfg80211_chan_def chandef;

                /* The AP is not providing us with anything to work with. So
                 * make up a somewhat reasonable operating class, but don't
                 * bother with it too much as no one will ever use the
                 * information.
                 */
                cfg80211_chandef_create(&chandef, source_bss->channel,
                                        NL80211_CHAN_NO_HT);

                if (!ieee80211_chandef_to_operating_class(&chandef,
                                                          &ap_info.op_class))
                        goto out_unlock;
        }

        /* Just set TBTT offset and PSD 20 to invalid/unknown */
        tbtt_info.tbtt_offset = 255;
        tbtt_info.psd_20 = IEEE80211_RNR_TBTT_PARAMS_PSD_RESERVED;

        memcpy(tbtt_info.bssid, source_bss->bssid, ETH_ALEN);
        if (cfg80211_calc_short_ssid(ies, &elem, &short_ssid))
                goto out_unlock;

        rcu_read_unlock();

        tbtt_info.short_ssid = cpu_to_le32(short_ssid);

        tbtt_info.bss_params = IEEE80211_RNR_TBTT_PARAMS_SAME_SSID;

        if (is_mbssid) {
                tbtt_info.bss_params |= IEEE80211_RNR_TBTT_PARAMS_MULTI_BSSID;
                tbtt_info.bss_params |= IEEE80211_RNR_TBTT_PARAMS_TRANSMITTED_BSSID;
        }

        tbtt_info.mld_params.mld_id = 0;
        tbtt_info.mld_params.params =
                le16_encode_bits(link_id, IEEE80211_RNR_MLD_PARAMS_LINK_ID) |
                le16_encode_bits(bss_change_count,
                                 IEEE80211_RNR_MLD_PARAMS_BSS_CHANGE_COUNT);

        res = kzalloc_flex(*res, data, sizeof(ap_info) + ap_info.tbtt_info_len,
                           gfp);
        if (!res)
                return NULL;

        /* Copy the data */
        res->id = WLAN_EID_REDUCED_NEIGHBOR_REPORT;
        res->datalen = sizeof(ap_info) + ap_info.tbtt_info_len;
        memcpy(res->data, &ap_info, sizeof(ap_info));
        memcpy(res->data + sizeof(ap_info), &tbtt_info, ap_info.tbtt_info_len);

        return res;

out_unlock:
        rcu_read_unlock();
        return NULL;
}

static void
cfg80211_parse_ml_elem_sta_data(struct wiphy *wiphy,
                                struct cfg80211_inform_single_bss_data *tx_data,
                                struct cfg80211_bss *source_bss,
                                const struct element *elem,
                                gfp_t gfp)
{
        struct cfg80211_inform_single_bss_data data = {
                .drv_data = tx_data->drv_data,
                .ftype = tx_data->ftype,
                .source_bss = source_bss,
                .bss_source = BSS_SOURCE_STA_PROFILE,
        };
        struct element *reporter_rnr = NULL;
        struct ieee80211_multi_link_elem *ml_elem;
        struct cfg80211_mle *mle;
        const struct element *ssid_elem;
        const u8 *ssid = NULL;
        size_t ssid_len = 0;
        u16 control;
        u8 ml_common_len;
        u8 *new_ie = NULL;
        struct cfg80211_bss *bss;
        u8 mld_id, reporter_link_id, bss_change_count;
        u16 seen_links = 0;
        u8 i;

        if (!ieee80211_mle_type_ok(elem->data + 1,
                                   IEEE80211_ML_CONTROL_TYPE_BASIC,
                                   elem->datalen - 1))
                return;

        ml_elem = (void *)(elem->data + 1);
        control = le16_to_cpu(ml_elem->control);
        ml_common_len = ml_elem->variable[0];

        /* Must be present when transmitted by an AP (in a probe response) */
        if (!(control & IEEE80211_MLC_BASIC_PRES_BSS_PARAM_CH_CNT) ||
            !(control & IEEE80211_MLC_BASIC_PRES_LINK_ID) ||
            !(control & IEEE80211_MLC_BASIC_PRES_MLD_CAPA_OP))
                return;

        reporter_link_id = ieee80211_mle_get_link_id(elem->data + 1);
        bss_change_count = ieee80211_mle_get_bss_param_ch_cnt(elem->data + 1);

        /*
         * The MLD ID of the reporting AP is always zero. It is set if the AP
         * is part of an MBSSID set and will be non-zero for ML Elements
         * relating to a nontransmitted BSS (matching the Multi-BSSID Index,
         * Draft P802.11be_D3.2, 35.3.4.2)
         */
        mld_id = ieee80211_mle_get_mld_id(elem->data + 1);

        /* Fully defrag the ML element for sta information/profile iteration */
        mle = cfg80211_defrag_mle(elem, tx_data->ie, tx_data->ielen, gfp);
        if (!mle)
                return;

        /* No point in doing anything if there is no per-STA profile */
        if (!mle->sta_prof[0])
                goto out;

        new_ie = kmalloc(IEEE80211_MAX_DATA_LEN, gfp);
        if (!new_ie)
                goto out;

        reporter_rnr = cfg80211_gen_reporter_rnr(source_bss,
                                                 u16_get_bits(control,
                                                              IEEE80211_MLC_BASIC_PRES_MLD_ID),
                                                 mld_id == 0, reporter_link_id,
                                                 bss_change_count,
                                                 gfp);

        ssid_elem = cfg80211_find_elem(WLAN_EID_SSID, tx_data->ie,
                                       tx_data->ielen);
        if (ssid_elem) {
                ssid = ssid_elem->data;
                ssid_len = ssid_elem->datalen;
        }

        for (i = 0; i < ARRAY_SIZE(mle->sta_prof) && mle->sta_prof[i]; i++) {
                const struct ieee80211_neighbor_ap_info *ap_info;
                enum nl80211_band band;
                u32 freq;
                const u8 *profile;
                ssize_t profile_len;
                u8 param_ch_count;
                u8 link_id, use_for;
                bool non_tx;

                if (!ieee80211_mle_basic_sta_prof_size_ok((u8 *)mle->sta_prof[i],
                                                          mle->sta_prof_len[i]))
                        continue;

                control = le16_to_cpu(mle->sta_prof[i]->control);

                if (!(control & IEEE80211_MLE_STA_CONTROL_COMPLETE_PROFILE))
                        continue;

                link_id = u16_get_bits(control,
                                       IEEE80211_MLE_STA_CONTROL_LINK_ID);
                if (seen_links & BIT(link_id))
                        break;
                seen_links |= BIT(link_id);

                if (!(control & IEEE80211_MLE_STA_CONTROL_BEACON_INT_PRESENT) ||
                    !(control & IEEE80211_MLE_STA_CONTROL_TSF_OFFS_PRESENT) ||
                    !(control & IEEE80211_MLE_STA_CONTROL_STA_MAC_ADDR_PRESENT))
                        continue;

                memcpy(data.bssid, mle->sta_prof[i]->variable, ETH_ALEN);
                data.beacon_interval =
                        get_unaligned_le16(mle->sta_prof[i]->variable + 6);
                data.tsf = tx_data->tsf +
                           get_unaligned_le64(mle->sta_prof[i]->variable + 8);

                /* sta_info_len counts itself */
                profile = mle->sta_prof[i]->variable +
                          mle->sta_prof[i]->sta_info_len - 1;
                profile_len = (u8 *)mle->sta_prof[i] + mle->sta_prof_len[i] -
                              profile;

                if (profile_len < 2)
                        continue;

                data.capability = get_unaligned_le16(profile);
                profile += 2;
                profile_len -= 2;

                /* Find in RNR to look up channel information */
                use_for = cfg80211_rnr_info_for_mld_ap(tx_data->ie,
                                                       tx_data->ielen,
                                                       mld_id, link_id,
                                                       &ap_info,
                                                       &param_ch_count,
                                                       &non_tx);
                if (!use_for)
                        continue;

                /*
                 * As of 802.11be_D5.0, the specification does not give us any
                 * way of discovering both the MaxBSSID and the Multiple-BSSID
                 * Index. It does seem like the Multiple-BSSID Index element
                 * may be provided, but section 9.4.2.45 explicitly forbids
                 * including a Multiple-BSSID Element (in this case without any
                 * subelements).
                 * Without both pieces of information we cannot calculate the
                 * reference BSSID, so simply ignore the BSS.
                 */
                if (non_tx)
                        continue;

                /* We could sanity check the BSSID is included */

                if (!ieee80211_operating_class_to_band(ap_info->op_class,
                                                       &band))
                        continue;

                freq = ieee80211_channel_to_freq_khz(ap_info->channel, band);
                data.channel = ieee80211_get_channel_khz(wiphy, freq);

                /* Skip if RNR element specifies an unsupported channel */
                if (!data.channel)
                        continue;

                /* Skip if BSS entry generated from MBSSID or DIRECT source
                 * frame data available already.
                 */
                bss = cfg80211_get_bss(wiphy, data.channel, data.bssid, ssid,
                                       ssid_len, IEEE80211_BSS_TYPE_ANY,
                                       IEEE80211_PRIVACY_ANY);
                if (bss) {
                        struct cfg80211_internal_bss *ibss = bss_from_pub(bss);

                        if (data.capability == bss->capability &&
                            ibss->bss_source != BSS_SOURCE_STA_PROFILE) {
                                cfg80211_put_bss(wiphy, bss);
                                continue;
                        }
                        cfg80211_put_bss(wiphy, bss);
                }

                if (use_for == NL80211_BSS_USE_FOR_MLD_LINK &&
                    !(wiphy->flags & WIPHY_FLAG_SUPPORTS_NSTR_NONPRIMARY)) {
                        use_for = 0;
                        data.cannot_use_reasons =
                                NL80211_BSS_CANNOT_USE_NSTR_NONPRIMARY;
                }
                data.use_for = use_for;

                /* Generate new elements */
                memset(new_ie, 0, IEEE80211_MAX_DATA_LEN);
                data.ie = new_ie;
                data.ielen = cfg80211_gen_new_ie(tx_data->ie, tx_data->ielen,
                                                 profile, profile_len,
                                                 new_ie,
                                                 IEEE80211_MAX_DATA_LEN);
                if (!data.ielen)
                        continue;

                /* The generated elements do not contain:
                 *  - Basic ML element
                 *  - A TBTT entry in the RNR for the transmitting AP
                 *
                 * This information is needed both internally and in userspace
                 * as such, we should append it here.
                 */
                if (data.ielen + 3 + sizeof(*ml_elem) + ml_common_len >
                    IEEE80211_MAX_DATA_LEN)
                        continue;

                /* Copy the Basic Multi-Link element including the common
                 * information, and then fix up the link ID and BSS param
                 * change count.
                 * Note that the ML element length has been verified and we
                 * also checked that it contains the link ID.
                 */
                new_ie[data.ielen++] = WLAN_EID_EXTENSION;
                new_ie[data.ielen++] = 1 + sizeof(*ml_elem) + ml_common_len;
                new_ie[data.ielen++] = WLAN_EID_EXT_EHT_MULTI_LINK;
                memcpy(new_ie + data.ielen, ml_elem,
                       sizeof(*ml_elem) + ml_common_len);

                new_ie[data.ielen + sizeof(*ml_elem) + 1 + ETH_ALEN] = link_id;
                new_ie[data.ielen + sizeof(*ml_elem) + 1 + ETH_ALEN + 1] =
                        param_ch_count;

                data.ielen += sizeof(*ml_elem) + ml_common_len;

                if (reporter_rnr && (use_for & NL80211_BSS_USE_FOR_NORMAL)) {
                        if (data.ielen + sizeof(struct element) +
                            reporter_rnr->datalen > IEEE80211_MAX_DATA_LEN)
                                continue;

                        memcpy(new_ie + data.ielen, reporter_rnr,
                               sizeof(struct element) + reporter_rnr->datalen);
                        data.ielen += sizeof(struct element) +
                                      reporter_rnr->datalen;
                }

                bss = cfg80211_inform_single_bss_data(wiphy, &data, gfp);
                if (!bss)
                        break;
                cfg80211_put_bss(wiphy, bss);
        }

out:
        kfree(reporter_rnr);
        kfree(new_ie);
        kfree(mle);
}

static void cfg80211_parse_ml_sta_data(struct wiphy *wiphy,
                                       struct cfg80211_inform_single_bss_data *tx_data,
                                       struct cfg80211_bss *source_bss,
                                       gfp_t gfp)
{
        const struct element *elem;

        if (!source_bss)
                return;

        if (tx_data->ftype != CFG80211_BSS_FTYPE_PRESP)
                return;

        for_each_element_extid(elem, WLAN_EID_EXT_EHT_MULTI_LINK,
                               tx_data->ie, tx_data->ielen)
                cfg80211_parse_ml_elem_sta_data(wiphy, tx_data, source_bss,
                                                elem, gfp);
}

struct cfg80211_bss *
cfg80211_inform_bss_data(struct wiphy *wiphy,
                         struct cfg80211_inform_bss *data,
                         enum cfg80211_bss_frame_type ftype,
                         const u8 *bssid, u64 tsf, u16 capability,
                         u16 beacon_interval, const u8 *ie, size_t ielen,
                         gfp_t gfp)
{
        struct cfg80211_inform_single_bss_data inform_data = {
                .drv_data = data,
                .ftype = ftype,
                .tsf = tsf,
                .capability = capability,
                .beacon_interval = beacon_interval,
                .ie = ie,
                .ielen = ielen,
                .use_for = data->restrict_use ?
                                data->use_for :
                                NL80211_BSS_USE_FOR_ALL,
                .cannot_use_reasons = data->cannot_use_reasons,
        };
        struct cfg80211_bss *res;

        memcpy(inform_data.bssid, bssid, ETH_ALEN);

        res = cfg80211_inform_single_bss_data(wiphy, &inform_data, gfp);
        if (!res)
                return NULL;

        /* don't do any further MBSSID/ML handling for S1G */
        if (ftype == CFG80211_BSS_FTYPE_S1G_BEACON)
                return res;

        cfg80211_parse_mbssid_data(wiphy, &inform_data, res, gfp);

        cfg80211_parse_ml_sta_data(wiphy, &inform_data, res, gfp);

        return res;
}
EXPORT_SYMBOL(cfg80211_inform_bss_data);

struct cfg80211_bss *
cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
                               struct cfg80211_inform_bss *data,
                               struct ieee80211_mgmt *mgmt, size_t len,
                               gfp_t gfp)
{
        size_t min_hdr_len;
        struct ieee80211_ext *ext = NULL;
        enum cfg80211_bss_frame_type ftype;
        u16 beacon_interval;
        const u8 *bssid;
        u16 capability;
        const u8 *ie;
        size_t ielen;
        u64 tsf;
        size_t s1g_optional_len;

        if (WARN_ON(!mgmt))
                return NULL;

        if (WARN_ON(!wiphy))
                return NULL;

        BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
                     offsetof(struct ieee80211_mgmt, u.beacon.variable));

        trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);

        if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
                ext = (void *) mgmt;
                s1g_optional_len =
                        ieee80211_s1g_optional_len(ext->frame_control);
                min_hdr_len =
                        offsetof(struct ieee80211_ext, u.s1g_beacon.variable) +
                        s1g_optional_len;
        } else {
                /* same for beacons */
                min_hdr_len = offsetof(struct ieee80211_mgmt,
                                       u.probe_resp.variable);
        }

        if (WARN_ON(len < min_hdr_len))
                return NULL;

        ielen = len - min_hdr_len;
        ie = mgmt->u.probe_resp.variable;
        if (ext) {
                const struct ieee80211_s1g_bcn_compat_ie *compat;
                const struct element *elem;

                ie = ext->u.s1g_beacon.variable + s1g_optional_len;
                elem = cfg80211_find_elem(WLAN_EID_S1G_BCN_COMPAT, ie, ielen);
                if (!elem)
                        return NULL;
                if (elem->datalen < sizeof(*compat))
                        return NULL;
                compat = (void *)elem->data;
                bssid = ext->u.s1g_beacon.sa;
                capability = le16_to_cpu(compat->compat_info);
                beacon_interval = le16_to_cpu(compat->beacon_int);
        } else {
                bssid = mgmt->bssid;
                beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
                capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
        }

        tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);

        if (ieee80211_is_probe_resp(mgmt->frame_control))
                ftype = CFG80211_BSS_FTYPE_PRESP;
        else if (ext)
                ftype = CFG80211_BSS_FTYPE_S1G_BEACON;
        else
                ftype = CFG80211_BSS_FTYPE_BEACON;

        return cfg80211_inform_bss_data(wiphy, data, ftype,
                                        bssid, tsf, capability,
                                        beacon_interval, ie, ielen,
                                        gfp);
}
EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);

void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
{
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);

        if (!pub)
                return;

        spin_lock_bh(&rdev->bss_lock);
        bss_ref_get(rdev, bss_from_pub(pub));
        spin_unlock_bh(&rdev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_ref_bss);

void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
{
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);

        if (!pub)
                return;

        spin_lock_bh(&rdev->bss_lock);
        bss_ref_put(rdev, bss_from_pub(pub));
        spin_unlock_bh(&rdev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_put_bss);

void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
{
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
        struct cfg80211_internal_bss *bss, *tmp1;
        struct cfg80211_bss *nontrans_bss, *tmp;

        if (WARN_ON(!pub))
                return;

        bss = bss_from_pub(pub);

        spin_lock_bh(&rdev->bss_lock);
        if (list_empty(&bss->list))
                goto out;

        list_for_each_entry_safe(nontrans_bss, tmp,
                                 &pub->nontrans_list,
                                 nontrans_list) {
                tmp1 = bss_from_pub(nontrans_bss);
                if (__cfg80211_unlink_bss(rdev, tmp1))
                        rdev->bss_generation++;
        }

        if (__cfg80211_unlink_bss(rdev, bss))
                rdev->bss_generation++;
out:
        spin_unlock_bh(&rdev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_unlink_bss);

void cfg80211_bss_iter(struct wiphy *wiphy,
                       struct cfg80211_chan_def *chandef,
                       void (*iter)(struct wiphy *wiphy,
                                    struct cfg80211_bss *bss,
                                    void *data),
                       void *iter_data)
{
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
        struct cfg80211_internal_bss *bss;

        spin_lock_bh(&rdev->bss_lock);

        list_for_each_entry(bss, &rdev->bss_list, list) {
                if (!chandef || cfg80211_is_sub_chan(chandef, bss->pub.channel,
                                                     false))
                        iter(wiphy, &bss->pub, iter_data);
        }

        spin_unlock_bh(&rdev->bss_lock);
}
EXPORT_SYMBOL(cfg80211_bss_iter);

void cfg80211_update_assoc_bss_entry(struct wireless_dev *wdev,
                                     unsigned int link_id,
                                     struct ieee80211_channel *chan)
{
        struct wiphy *wiphy = wdev->wiphy;
        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
        struct cfg80211_internal_bss *cbss = wdev->links[link_id].client.current_bss;
        struct cfg80211_internal_bss *new = NULL;
        struct cfg80211_internal_bss *bss;
        struct cfg80211_bss *nontrans_bss;
        struct cfg80211_bss *tmp;

        spin_lock_bh(&rdev->bss_lock);

        /*
         * Some APs use CSA also for bandwidth changes, i.e., without actually
         * changing the control channel, so no need to update in such a case.
         */
        if (cbss->pub.channel == chan)
                goto done;

        /* use transmitting bss */
        if (cbss->pub.transmitted_bss)
                cbss = bss_from_pub(cbss->pub.transmitted_bss);

        cbss->pub.channel = chan;

        list_for_each_entry(bss, &rdev->bss_list, list) {
                if (!cfg80211_bss_type_match(bss->pub.capability,
                                             bss->pub.channel->band,
                                             wdev->conn_bss_type))
                        continue;

                if (bss == cbss)
                        continue;

                if (!cmp_bss(&bss->pub, &cbss->pub, BSS_CMP_REGULAR)) {
                        new = bss;
                        break;
                }
        }

        if (new) {
                /* to save time, update IEs for transmitting bss only */
                cfg80211_update_known_bss(rdev, cbss, new, false);
                new->pub.proberesp_ies = NULL;
                new->pub.beacon_ies = NULL;

                list_for_each_entry_safe(nontrans_bss, tmp,
                                         &new->pub.nontrans_list,
                                         nontrans_list) {
                        bss = bss_from_pub(nontrans_bss);
                        if (__cfg80211_unlink_bss(rdev, bss))
                                rdev->bss_generation++;
                }

                WARN_ON(atomic_read(&new->hold));
                if (!WARN_ON(!__cfg80211_unlink_bss(rdev, new)))
                        rdev->bss_generation++;
        }
        cfg80211_rehash_bss(rdev, cbss);

        list_for_each_entry_safe(nontrans_bss, tmp,
                                 &cbss->pub.nontrans_list,
                                 nontrans_list) {
                bss = bss_from_pub(nontrans_bss);
                bss->pub.channel = chan;
                cfg80211_rehash_bss(rdev, bss);
        }

done:
        spin_unlock_bh(&rdev->bss_lock);
}

#ifdef CONFIG_CFG80211_WEXT
static struct cfg80211_registered_device *
cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
{
        struct cfg80211_registered_device *rdev;
        struct net_device *dev;

        ASSERT_RTNL();

        dev = dev_get_by_index(net, ifindex);
        if (!dev)
                return ERR_PTR(-ENODEV);
        if (dev->ieee80211_ptr)
                rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
        else
                rdev = ERR_PTR(-ENODEV);
        dev_put(dev);
        return rdev;
}

int cfg80211_wext_siwscan(struct net_device *dev,
                          struct iw_request_info *info,
                          union iwreq_data *wrqu, char *extra)
{
        struct cfg80211_registered_device *rdev;
        struct wiphy *wiphy;
        struct iw_scan_req *wreq = NULL;
        struct cfg80211_scan_request_int *creq;
        int i, err, n_channels = 0;
        enum nl80211_band band;

        if (!netif_running(dev))
                return -ENETDOWN;

        if (wrqu->data.length == sizeof(struct iw_scan_req))
                wreq = (struct iw_scan_req *)extra;

        rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);

        if (IS_ERR(rdev))
                return PTR_ERR(rdev);

        if (rdev->scan_req || rdev->scan_msg)
                return -EBUSY;

        wiphy = &rdev->wiphy;

        /* Determine number of channels, needed to allocate creq */
        if (wreq && wreq->num_channels) {
                /* Passed from userspace so should be checked */
                if (unlikely(wreq->num_channels > IW_MAX_FREQUENCIES))
                        return -EINVAL;
                n_channels = wreq->num_channels;
        } else {
                n_channels = ieee80211_get_num_supported_channels(wiphy);
        }

        creq = kzalloc(struct_size(creq, req.channels, n_channels) +
                       sizeof(struct cfg80211_ssid),
                       GFP_ATOMIC);
        if (!creq)
                return -ENOMEM;

        creq->req.wiphy = wiphy;
        creq->req.wdev = dev->ieee80211_ptr;
        /* SSIDs come after channels */
        creq->req.ssids = (void *)creq +
                          struct_size(creq, req.channels, n_channels);
        creq->req.n_channels = n_channels;
        creq->req.n_ssids = 1;
        creq->req.scan_start = jiffies;

        /* translate "Scan on frequencies" request */
        i = 0;
        for (band = 0; band < NUM_NL80211_BANDS; band++) {
                int j;

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

                for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
                        struct ieee80211_channel *chan;

                        /* ignore disabled channels */
                        chan = &wiphy->bands[band]->channels[j];
                        if (chan->flags & IEEE80211_CHAN_DISABLED ||
                            !cfg80211_wdev_channel_allowed(creq->req.wdev, chan))
                                continue;

                        /* If we have a wireless request structure and the
                         * wireless request specifies frequencies, then search
                         * for the matching hardware channel.
                         */
                        if (wreq && wreq->num_channels) {
                                int k;
                                int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
                                for (k = 0; k < wreq->num_channels; k++) {
                                        struct iw_freq *freq =
                                                &wreq->channel_list[k];
                                        int wext_freq =
                                                cfg80211_wext_freq(freq);

                                        if (wext_freq == wiphy_freq)
                                                goto wext_freq_found;
                                }
                                goto wext_freq_not_found;
                        }

                wext_freq_found:
                        creq->req.channels[i] =
                                &wiphy->bands[band]->channels[j];
                        i++;
                wext_freq_not_found: ;
                }
        }
        /* No channels found? */
        if (!i) {
                err = -EINVAL;
                goto out;
        }

        /* Set real number of channels specified in creq->req.channels[] */
        creq->req.n_channels = i;

        /* translate "Scan for SSID" request */
        if (wreq) {
                if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
                        if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
                                return -EINVAL;
                        memcpy(creq->req.ssids[0].ssid, wreq->essid,
                               wreq->essid_len);
                        creq->req.ssids[0].ssid_len = wreq->essid_len;
                }
                if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE) {
                        creq->req.ssids = NULL;
                        creq->req.n_ssids = 0;
                }
        }

        for (i = 0; i < NUM_NL80211_BANDS; i++)
                if (wiphy->bands[i])
                        creq->req.rates[i] =
                                (1 << wiphy->bands[i]->n_bitrates) - 1;

        eth_broadcast_addr(creq->req.bssid);

        scoped_guard(wiphy, &rdev->wiphy) {
                rdev->scan_req = creq;
                err = rdev_scan(rdev, creq);
                if (err) {
                        rdev->scan_req = NULL;
                        /* creq will be freed below */
                } else {
                        nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
                        /* creq now owned by driver */
                        creq = NULL;
                        dev_hold(dev);
                }
        }

 out:
        kfree(creq);
        return err;
}

static char *ieee80211_scan_add_ies(struct iw_request_info *info,
                                    const struct cfg80211_bss_ies *ies,
                                    char *current_ev, char *end_buf)
{
        const u8 *pos, *end, *next;
        struct iw_event iwe;

        if (!ies)
                return current_ev;

        /*
         * If needed, fragment the IEs buffer (at IE boundaries) into short
         * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
         */
        pos = ies->data;
        end = pos + ies->len;

        while (end - pos > IW_GENERIC_IE_MAX) {
                next = pos + 2 + pos[1];
                while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
                        next = next + 2 + next[1];

                memset(&iwe, 0, sizeof(iwe));
                iwe.cmd = IWEVGENIE;
                iwe.u.data.length = next - pos;
                current_ev = iwe_stream_add_point_check(info, current_ev,
                                                        end_buf, &iwe,
                                                        (void *)pos);
                if (IS_ERR(current_ev))
                        return current_ev;
                pos = next;
        }

        if (end > pos) {
                memset(&iwe, 0, sizeof(iwe));
                iwe.cmd = IWEVGENIE;
                iwe.u.data.length = end - pos;
                current_ev = iwe_stream_add_point_check(info, current_ev,
                                                        end_buf, &iwe,
                                                        (void *)pos);
                if (IS_ERR(current_ev))
                        return current_ev;
        }

        return current_ev;
}

static char *
ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
              struct cfg80211_internal_bss *bss, char *current_ev,
              char *end_buf)
{
        const struct cfg80211_bss_ies *ies;
        struct iw_event iwe;
        const u8 *ie;
        u8 buf[50];
        u8 *cfg, *p, *tmp;
        int rem, i, sig;
        bool ismesh = false;

        memset(&iwe, 0, sizeof(iwe));
        iwe.cmd = SIOCGIWAP;
        iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
        memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
        current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
                                                IW_EV_ADDR_LEN);
        if (IS_ERR(current_ev))
                return current_ev;

        memset(&iwe, 0, sizeof(iwe));
        iwe.cmd = SIOCGIWFREQ;
        iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
        iwe.u.freq.e = 0;
        current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
                                                IW_EV_FREQ_LEN);
        if (IS_ERR(current_ev))
                return current_ev;

        memset(&iwe, 0, sizeof(iwe));
        iwe.cmd = SIOCGIWFREQ;
        iwe.u.freq.m = bss->pub.channel->center_freq;
        iwe.u.freq.e = 6;
        current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
                                                IW_EV_FREQ_LEN);
        if (IS_ERR(current_ev))
                return current_ev;

        if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
                memset(&iwe, 0, sizeof(iwe));
                iwe.cmd = IWEVQUAL;
                iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
                                     IW_QUAL_NOISE_INVALID |
                                     IW_QUAL_QUAL_UPDATED;
                switch (wiphy->signal_type) {
                case CFG80211_SIGNAL_TYPE_MBM:
                        sig = bss->pub.signal / 100;
                        iwe.u.qual.level = sig;
                        iwe.u.qual.updated |= IW_QUAL_DBM;
                        if (sig < -110)         /* rather bad */
                                sig = -110;
                        else if (sig > -40)     /* perfect */
                                sig = -40;
                        /* will give a range of 0 .. 70 */
                        iwe.u.qual.qual = sig + 110;
                        break;
                case CFG80211_SIGNAL_TYPE_UNSPEC:
                        iwe.u.qual.level = bss->pub.signal;
                        /* will give range 0 .. 100 */
                        iwe.u.qual.qual = bss->pub.signal;
                        break;
                default:
                        /* not reached */
                        break;
                }
                current_ev = iwe_stream_add_event_check(info, current_ev,
                                                        end_buf, &iwe,
                                                        IW_EV_QUAL_LEN);
                if (IS_ERR(current_ev))
                        return current_ev;
        }

        memset(&iwe, 0, sizeof(iwe));
        iwe.cmd = SIOCGIWENCODE;
        if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
                iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
        else
                iwe.u.data.flags = IW_ENCODE_DISABLED;
        iwe.u.data.length = 0;
        current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
                                                &iwe, "");
        if (IS_ERR(current_ev))
                return current_ev;

        rcu_read_lock();
        ies = rcu_dereference(bss->pub.ies);
        rem = ies->len;
        ie = ies->data;

        while (rem >= 2) {
                /* invalid data */
                if (ie[1] > rem - 2)
                        break;

                switch (ie[0]) {
                case WLAN_EID_SSID:
                        memset(&iwe, 0, sizeof(iwe));
                        iwe.cmd = SIOCGIWESSID;
                        iwe.u.data.length = ie[1];
                        iwe.u.data.flags = 1;
                        current_ev = iwe_stream_add_point_check(info,
                                                                current_ev,
                                                                end_buf, &iwe,
                                                                (u8 *)ie + 2);
                        if (IS_ERR(current_ev))
                                goto unlock;
                        break;
                case WLAN_EID_MESH_ID:
                        memset(&iwe, 0, sizeof(iwe));
                        iwe.cmd = SIOCGIWESSID;
                        iwe.u.data.length = ie[1];
                        iwe.u.data.flags = 1;
                        current_ev = iwe_stream_add_point_check(info,
                                                                current_ev,
                                                                end_buf, &iwe,
                                                                (u8 *)ie + 2);
                        if (IS_ERR(current_ev))
                                goto unlock;
                        break;
                case WLAN_EID_MESH_CONFIG:
                        ismesh = true;
                        if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
                                break;
                        cfg = (u8 *)ie + 2;
                        memset(&iwe, 0, sizeof(iwe));
                        iwe.cmd = IWEVCUSTOM;
                        iwe.u.data.length = sprintf(buf,
                                                    "Mesh Network Path Selection Protocol ID: 0x%02X",
                                                    cfg[0]);
                        current_ev = iwe_stream_add_point_check(info,
                                                                current_ev,
                                                                end_buf,
                                                                &iwe, buf);
                        if (IS_ERR(current_ev))
                                goto unlock;
                        iwe.u.data.length = sprintf(buf,
                                                    "Path Selection Metric ID: 0x%02X",
                                                    cfg[1]);
                        current_ev = iwe_stream_add_point_check(info,
                                                                current_ev,
                                                                end_buf,
                                                                &iwe, buf);
                        if (IS_ERR(current_ev))
                                goto unlock;
                        iwe.u.data.length = sprintf(buf,
                                                    "Congestion Control Mode ID: 0x%02X",
                                                    cfg[2]);
                        current_ev = iwe_stream_add_point_check(info,
                                                                current_ev,
                                                                end_buf,
                                                                &iwe, buf);
                        if (IS_ERR(current_ev))
                                goto unlock;
                        iwe.u.data.length = sprintf(buf,
                                                    "Synchronization ID: 0x%02X",
                                                    cfg[3]);
                        current_ev = iwe_stream_add_point_check(info,
                                                                current_ev,
                                                                end_buf,
                                                                &iwe, buf);
                        if (IS_ERR(current_ev))
                                goto unlock;
                        iwe.u.data.length = sprintf(buf,
                                                    "Authentication ID: 0x%02X",
                                                    cfg[4]);
                        current_ev = iwe_stream_add_point_check(info,
                                                                current_ev,
                                                                end_buf,
                                                                &iwe, buf);
                        if (IS_ERR(current_ev))
                                goto unlock;
                        iwe.u.data.length = sprintf(buf,
                                                    "Formation Info: 0x%02X",
                                                    cfg[5]);
                        current_ev = iwe_stream_add_point_check(info,
                                                                current_ev,
                                                                end_buf,
                                                                &iwe, buf);
                        if (IS_ERR(current_ev))
                                goto unlock;
                        iwe.u.data.length = sprintf(buf,
                                                    "Capabilities: 0x%02X",
                                                    cfg[6]);
                        current_ev = iwe_stream_add_point_check(info,
                                                                current_ev,
                                                                end_buf,
                                                                &iwe, buf);
                        if (IS_ERR(current_ev))
                                goto unlock;
                        break;
                case WLAN_EID_SUPP_RATES:
                case WLAN_EID_EXT_SUPP_RATES:
                        /* display all supported rates in readable format */
                        p = current_ev + iwe_stream_lcp_len(info);

                        memset(&iwe, 0, sizeof(iwe));
                        iwe.cmd = SIOCGIWRATE;
                        /* Those two flags are ignored... */
                        iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;

                        for (i = 0; i < ie[1]; i++) {
                                iwe.u.bitrate.value =
                                        ((ie[i + 2] & 0x7f) * 500000);
                                tmp = p;
                                p = iwe_stream_add_value(info, current_ev, p,
                                                         end_buf, &iwe,
                                                         IW_EV_PARAM_LEN);
                                if (p == tmp) {
                                        current_ev = ERR_PTR(-E2BIG);
                                        goto unlock;
                                }
                        }
                        current_ev = p;
                        break;
                }
                rem -= ie[1] + 2;
                ie += ie[1] + 2;
        }

        if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
            ismesh) {
                memset(&iwe, 0, sizeof(iwe));
                iwe.cmd = SIOCGIWMODE;
                if (ismesh)
                        iwe.u.mode = IW_MODE_MESH;
                else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
                        iwe.u.mode = IW_MODE_MASTER;
                else
                        iwe.u.mode = IW_MODE_ADHOC;
                current_ev = iwe_stream_add_event_check(info, current_ev,
                                                        end_buf, &iwe,
                                                        IW_EV_UINT_LEN);
                if (IS_ERR(current_ev))
                        goto unlock;
        }

        memset(&iwe, 0, sizeof(iwe));
        iwe.cmd = IWEVCUSTOM;
        iwe.u.data.length = sprintf(buf, "tsf=%016llx",
                                    (unsigned long long)(ies->tsf));
        current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
                                                &iwe, buf);
        if (IS_ERR(current_ev))
                goto unlock;
        memset(&iwe, 0, sizeof(iwe));
        iwe.cmd = IWEVCUSTOM;
        iwe.u.data.length = sprintf(buf, " Last beacon: %ums ago",
                                    elapsed_jiffies_msecs(bss->ts));
        current_ev = iwe_stream_add_point_check(info, current_ev,
                                                end_buf, &iwe, buf);
        if (IS_ERR(current_ev))
                goto unlock;

        current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);

 unlock:
        rcu_read_unlock();
        return current_ev;
}


static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
                                  struct iw_request_info *info,
                                  char *buf, size_t len)
{
        char *current_ev = buf;
        char *end_buf = buf + len;
        struct cfg80211_internal_bss *bss;
        int err = 0;

        spin_lock_bh(&rdev->bss_lock);
        cfg80211_bss_expire(rdev);

        list_for_each_entry(bss, &rdev->bss_list, list) {
                if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
                        err = -E2BIG;
                        break;
                }
                current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
                                           current_ev, end_buf);
                if (IS_ERR(current_ev)) {
                        err = PTR_ERR(current_ev);
                        break;
                }
        }
        spin_unlock_bh(&rdev->bss_lock);

        if (err)
                return err;
        return current_ev - buf;
}


int cfg80211_wext_giwscan(struct net_device *dev,
                          struct iw_request_info *info,
                          union iwreq_data *wrqu, char *extra)
{
        struct iw_point *data = &wrqu->data;
        struct cfg80211_registered_device *rdev;
        int res;

        if (!netif_running(dev))
                return -ENETDOWN;

        rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);

        if (IS_ERR(rdev))
                return PTR_ERR(rdev);

        if (rdev->scan_req || rdev->scan_msg)
                return -EAGAIN;

        res = ieee80211_scan_results(rdev, info, extra, data->length);
        data->length = 0;
        if (res >= 0) {
                data->length = res;
                res = 0;
        }

        return res;
}
#endif