Linux 5.8.3

[linux/fpc-iii.git] / net / mac80211 / main.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
 * Copyright 2013-2014  Intel Mobile Communications GmbH
 * Copyright (C) 2017     Intel Deutschland GmbH
 * Copyright (C) 2018 - 2019 Intel Corporation
 */

#include <net/mac80211.h>
#include <linux/module.h>
#include <linux/fips.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/rtnetlink.h>
#include <linux/bitmap.h>
#include <linux/inetdevice.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>
#include <net/addrconf.h>

#include "ieee80211_i.h"
#include "driver-ops.h"
#include "rate.h"
#include "mesh.h"
#include "wep.h"
#include "led.h"
#include "debugfs.h"

void ieee80211_configure_filter(struct ieee80211_local *local)
{
        u64 mc;
        unsigned int changed_flags;
        unsigned int new_flags = 0;

        if (atomic_read(&local->iff_allmultis))
                new_flags |= FIF_ALLMULTI;

        if (local->monitors || test_bit(SCAN_SW_SCANNING, &local->scanning) ||
            test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning))
                new_flags |= FIF_BCN_PRBRESP_PROMISC;

        if (local->fif_probe_req || local->probe_req_reg)
                new_flags |= FIF_PROBE_REQ;

        if (local->fif_fcsfail)
                new_flags |= FIF_FCSFAIL;

        if (local->fif_plcpfail)
                new_flags |= FIF_PLCPFAIL;

        if (local->fif_control)
                new_flags |= FIF_CONTROL;

        if (local->fif_other_bss)
                new_flags |= FIF_OTHER_BSS;

        if (local->fif_pspoll)
                new_flags |= FIF_PSPOLL;

        if (local->rx_mcast_action_reg)
                new_flags |= FIF_MCAST_ACTION;

        spin_lock_bh(&local->filter_lock);
        changed_flags = local->filter_flags ^ new_flags;

        mc = drv_prepare_multicast(local, &local->mc_list);
        spin_unlock_bh(&local->filter_lock);

        /* be a bit nasty */
        new_flags |= (1<<31);

        drv_configure_filter(local, changed_flags, &new_flags, mc);

        WARN_ON(new_flags & (1<<31));

        local->filter_flags = new_flags & ~(1<<31);
}

static void ieee80211_reconfig_filter(struct work_struct *work)
{
        struct ieee80211_local *local =
                container_of(work, struct ieee80211_local, reconfig_filter);

        ieee80211_configure_filter(local);
}

static u32 ieee80211_hw_conf_chan(struct ieee80211_local *local)
{
        struct ieee80211_sub_if_data *sdata;
        struct cfg80211_chan_def chandef = {};
        u32 changed = 0;
        int power;
        u32 offchannel_flag;

        offchannel_flag = local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;

        if (local->scan_chandef.chan) {
                chandef = local->scan_chandef;
        } else if (local->tmp_channel) {
                chandef.chan = local->tmp_channel;
                chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
                chandef.center_freq1 = chandef.chan->center_freq;
                chandef.freq1_offset = chandef.chan->freq_offset;
        } else
                chandef = local->_oper_chandef;

        WARN(!cfg80211_chandef_valid(&chandef),
             "control:%d.%03d MHz width:%d center: %d.%03d/%d MHz",
             chandef.chan->center_freq, chandef.chan->freq_offset,
             chandef.width, chandef.center_freq1, chandef.freq1_offset,
             chandef.center_freq2);

        if (!cfg80211_chandef_identical(&chandef, &local->_oper_chandef))
                local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
        else
                local->hw.conf.flags &= ~IEEE80211_CONF_OFFCHANNEL;

        offchannel_flag ^= local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;

        if (offchannel_flag ||
            !cfg80211_chandef_identical(&local->hw.conf.chandef,
                                        &local->_oper_chandef)) {
                local->hw.conf.chandef = chandef;
                changed |= IEEE80211_CONF_CHANGE_CHANNEL;
        }

        if (!conf_is_ht(&local->hw.conf)) {
                /*
                 * mac80211.h documents that this is only valid
                 * when the channel is set to an HT type, and
                 * that otherwise STATIC is used.
                 */
                local->hw.conf.smps_mode = IEEE80211_SMPS_STATIC;
        } else if (local->hw.conf.smps_mode != local->smps_mode) {
                local->hw.conf.smps_mode = local->smps_mode;
                changed |= IEEE80211_CONF_CHANGE_SMPS;
        }

        power = ieee80211_chandef_max_power(&chandef);

        rcu_read_lock();
        list_for_each_entry_rcu(sdata, &local->interfaces, list) {
                if (!rcu_access_pointer(sdata->vif.chanctx_conf))
                        continue;
                if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
                        continue;
                if (sdata->vif.bss_conf.txpower == INT_MIN)
                        continue;
                power = min(power, sdata->vif.bss_conf.txpower);
        }
        rcu_read_unlock();

        if (local->hw.conf.power_level != power) {
                changed |= IEEE80211_CONF_CHANGE_POWER;
                local->hw.conf.power_level = power;
        }

        return changed;
}

int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
{
        int ret = 0;

        might_sleep();

        if (!local->use_chanctx)
                changed |= ieee80211_hw_conf_chan(local);
        else
                changed &= ~(IEEE80211_CONF_CHANGE_CHANNEL |
                             IEEE80211_CONF_CHANGE_POWER);

        if (changed && local->open_count) {
                ret = drv_config(local, changed);
                /*
                 * Goal:
                 * HW reconfiguration should never fail, the driver has told
                 * us what it can support so it should live up to that promise.
                 *
                 * Current status:
                 * rfkill is not integrated with mac80211 and a
                 * configuration command can thus fail if hardware rfkill
                 * is enabled
                 *
                 * FIXME: integrate rfkill with mac80211 and then add this
                 * WARN_ON() back
                 *
                 */
                /* WARN_ON(ret); */
        }

        return ret;
}

void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata,
                                      u32 changed)
{
        struct ieee80211_local *local = sdata->local;

        if (!changed || sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
                return;

        drv_bss_info_changed(local, sdata, &sdata->vif.bss_conf, changed);
}

u32 ieee80211_reset_erp_info(struct ieee80211_sub_if_data *sdata)
{
        sdata->vif.bss_conf.use_cts_prot = false;
        sdata->vif.bss_conf.use_short_preamble = false;
        sdata->vif.bss_conf.use_short_slot = false;
        return BSS_CHANGED_ERP_CTS_PROT |
               BSS_CHANGED_ERP_PREAMBLE |
               BSS_CHANGED_ERP_SLOT;
}

static void ieee80211_tasklet_handler(unsigned long data)
{
        struct ieee80211_local *local = (struct ieee80211_local *) data;
        struct sk_buff *skb;

        while ((skb = skb_dequeue(&local->skb_queue)) ||
               (skb = skb_dequeue(&local->skb_queue_unreliable))) {
                switch (skb->pkt_type) {
                case IEEE80211_RX_MSG:
                        /* Clear skb->pkt_type in order to not confuse kernel
                         * netstack. */
                        skb->pkt_type = 0;
                        ieee80211_rx(&local->hw, skb);
                        break;
                case IEEE80211_TX_STATUS_MSG:
                        skb->pkt_type = 0;
                        ieee80211_tx_status(&local->hw, skb);
                        break;
                default:
                        WARN(1, "mac80211: Packet is of unknown type %d\n",
                             skb->pkt_type);
                        dev_kfree_skb(skb);
                        break;
                }
        }
}

static void ieee80211_restart_work(struct work_struct *work)
{
        struct ieee80211_local *local =
                container_of(work, struct ieee80211_local, restart_work);
        struct ieee80211_sub_if_data *sdata;

        /* wait for scan work complete */
        flush_workqueue(local->workqueue);
        flush_work(&local->sched_scan_stopped_work);

        WARN(test_bit(SCAN_HW_SCANNING, &local->scanning),
             "%s called with hardware scan in progress\n", __func__);

        flush_work(&local->radar_detected_work);
        rtnl_lock();
        list_for_each_entry(sdata, &local->interfaces, list) {
                /*
                 * XXX: there may be more work for other vif types and even
                 * for station mode: a good thing would be to run most of
                 * the iface type's dependent _stop (ieee80211_mg_stop,
                 * ieee80211_ibss_stop) etc...
                 * For now, fix only the specific bug that was seen: race
                 * between csa_connection_drop_work and us.
                 */
                if (sdata->vif.type == NL80211_IFTYPE_STATION) {
                        /*
                         * This worker is scheduled from the iface worker that
                         * runs on mac80211's workqueue, so we can't be
                         * scheduling this worker after the cancel right here.
                         * The exception is ieee80211_chswitch_done.
                         * Then we can have a race...
                         */
                        cancel_work_sync(&sdata->u.mgd.csa_connection_drop_work);
                }
                flush_delayed_work(&sdata->dec_tailroom_needed_wk);
        }
        ieee80211_scan_cancel(local);

        /* make sure any new ROC will consider local->in_reconfig */
        flush_delayed_work(&local->roc_work);
        flush_work(&local->hw_roc_done);

        /* wait for all packet processing to be done */
        synchronize_net();

        ieee80211_reconfig(local);
        rtnl_unlock();
}

void ieee80211_restart_hw(struct ieee80211_hw *hw)
{
        struct ieee80211_local *local = hw_to_local(hw);

        trace_api_restart_hw(local);

        wiphy_info(hw->wiphy,
                   "Hardware restart was requested\n");

        /* use this reason, ieee80211_reconfig will unblock it */
        ieee80211_stop_queues_by_reason(hw, IEEE80211_MAX_QUEUE_MAP,
                                        IEEE80211_QUEUE_STOP_REASON_SUSPEND,
                                        false);

        /*
         * Stop all Rx during the reconfig. We don't want state changes
         * or driver callbacks while this is in progress.
         */
        local->in_reconfig = true;
        barrier();

        queue_work(system_freezable_wq, &local->restart_work);
}
EXPORT_SYMBOL(ieee80211_restart_hw);

#ifdef CONFIG_INET
static int ieee80211_ifa_changed(struct notifier_block *nb,
                                 unsigned long data, void *arg)
{
        struct in_ifaddr *ifa = arg;
        struct ieee80211_local *local =
                container_of(nb, struct ieee80211_local,
                             ifa_notifier);
        struct net_device *ndev = ifa->ifa_dev->dev;
        struct wireless_dev *wdev = ndev->ieee80211_ptr;
        struct in_device *idev;
        struct ieee80211_sub_if_data *sdata;
        struct ieee80211_bss_conf *bss_conf;
        struct ieee80211_if_managed *ifmgd;
        int c = 0;

        /* Make sure it's our interface that got changed */
        if (!wdev)
                return NOTIFY_DONE;

        if (wdev->wiphy != local->hw.wiphy)
                return NOTIFY_DONE;

        sdata = IEEE80211_DEV_TO_SUB_IF(ndev);
        bss_conf = &sdata->vif.bss_conf;

        /* ARP filtering is only supported in managed mode */
        if (sdata->vif.type != NL80211_IFTYPE_STATION)
                return NOTIFY_DONE;

        idev = __in_dev_get_rtnl(sdata->dev);
        if (!idev)
                return NOTIFY_DONE;

        ifmgd = &sdata->u.mgd;
        sdata_lock(sdata);

        /* Copy the addresses to the bss_conf list */
        ifa = rtnl_dereference(idev->ifa_list);
        while (ifa) {
                if (c < IEEE80211_BSS_ARP_ADDR_LIST_LEN)
                        bss_conf->arp_addr_list[c] = ifa->ifa_address;
                ifa = rtnl_dereference(ifa->ifa_next);
                c++;
        }

        bss_conf->arp_addr_cnt = c;

        /* Configure driver only if associated (which also implies it is up) */
        if (ifmgd->associated)
                ieee80211_bss_info_change_notify(sdata,
                                                 BSS_CHANGED_ARP_FILTER);

        sdata_unlock(sdata);

        return NOTIFY_OK;
}
#endif

#if IS_ENABLED(CONFIG_IPV6)
static int ieee80211_ifa6_changed(struct notifier_block *nb,
                                  unsigned long data, void *arg)
{
        struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)arg;
        struct inet6_dev *idev = ifa->idev;
        struct net_device *ndev = ifa->idev->dev;
        struct ieee80211_local *local =
                container_of(nb, struct ieee80211_local, ifa6_notifier);
        struct wireless_dev *wdev = ndev->ieee80211_ptr;
        struct ieee80211_sub_if_data *sdata;

        /* Make sure it's our interface that got changed */
        if (!wdev || wdev->wiphy != local->hw.wiphy)
                return NOTIFY_DONE;

        sdata = IEEE80211_DEV_TO_SUB_IF(ndev);

        /*
         * For now only support station mode. This is mostly because
         * doing AP would have to handle AP_VLAN in some way ...
         */
        if (sdata->vif.type != NL80211_IFTYPE_STATION)
                return NOTIFY_DONE;

        drv_ipv6_addr_change(local, sdata, idev);

        return NOTIFY_OK;
}
#endif

/* There isn't a lot of sense in it, but you can transmit anything you like */
static const struct ieee80211_txrx_stypes
ieee80211_default_mgmt_stypes[NUM_NL80211_IFTYPES] = {
        [NL80211_IFTYPE_ADHOC] = {
                .tx = 0xffff,
                .rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
                        BIT(IEEE80211_STYPE_AUTH >> 4) |
                        BIT(IEEE80211_STYPE_DEAUTH >> 4) |
                        BIT(IEEE80211_STYPE_PROBE_REQ >> 4),
        },
        [NL80211_IFTYPE_STATION] = {
                .tx = 0xffff,
                /*
                 * To support Pre Association Security Negotiation (PASN) while
                 * already associated to one AP, allow user space to register to
                 * Rx authentication frames, so that the user space logic would
                 * be able to receive/handle authentication frames from a
                 * different AP as part of PASN.
                 * It is expected that user space would intelligently register
                 * for Rx authentication frames, i.e., only when PASN is used
                 * and configure a match filter only for PASN authentication
                 * algorithm, as otherwise the MLME functionality of mac80211
                 * would be broken.
                 */
                .rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
                        BIT(IEEE80211_STYPE_AUTH >> 4) |
                        BIT(IEEE80211_STYPE_PROBE_REQ >> 4),
        },
        [NL80211_IFTYPE_AP] = {
                .tx = 0xffff,
                .rx = BIT(IEEE80211_STYPE_ASSOC_REQ >> 4) |
                        BIT(IEEE80211_STYPE_REASSOC_REQ >> 4) |
                        BIT(IEEE80211_STYPE_PROBE_REQ >> 4) |
                        BIT(IEEE80211_STYPE_DISASSOC >> 4) |
                        BIT(IEEE80211_STYPE_AUTH >> 4) |
                        BIT(IEEE80211_STYPE_DEAUTH >> 4) |
                        BIT(IEEE80211_STYPE_ACTION >> 4),
        },
        [NL80211_IFTYPE_AP_VLAN] = {
                /* copy AP */
                .tx = 0xffff,
                .rx = BIT(IEEE80211_STYPE_ASSOC_REQ >> 4) |
                        BIT(IEEE80211_STYPE_REASSOC_REQ >> 4) |
                        BIT(IEEE80211_STYPE_PROBE_REQ >> 4) |
                        BIT(IEEE80211_STYPE_DISASSOC >> 4) |
                        BIT(IEEE80211_STYPE_AUTH >> 4) |
                        BIT(IEEE80211_STYPE_DEAUTH >> 4) |
                        BIT(IEEE80211_STYPE_ACTION >> 4),
        },
        [NL80211_IFTYPE_P2P_CLIENT] = {
                .tx = 0xffff,
                .rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
                        BIT(IEEE80211_STYPE_PROBE_REQ >> 4),
        },
        [NL80211_IFTYPE_P2P_GO] = {
                .tx = 0xffff,
                .rx = BIT(IEEE80211_STYPE_ASSOC_REQ >> 4) |
                        BIT(IEEE80211_STYPE_REASSOC_REQ >> 4) |
                        BIT(IEEE80211_STYPE_PROBE_REQ >> 4) |
                        BIT(IEEE80211_STYPE_DISASSOC >> 4) |
                        BIT(IEEE80211_STYPE_AUTH >> 4) |
                        BIT(IEEE80211_STYPE_DEAUTH >> 4) |
                        BIT(IEEE80211_STYPE_ACTION >> 4),
        },
        [NL80211_IFTYPE_MESH_POINT] = {
                .tx = 0xffff,
                .rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
                        BIT(IEEE80211_STYPE_AUTH >> 4) |
                        BIT(IEEE80211_STYPE_DEAUTH >> 4),
        },
        [NL80211_IFTYPE_P2P_DEVICE] = {
                .tx = 0xffff,
                .rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
                        BIT(IEEE80211_STYPE_PROBE_REQ >> 4),
        },
};

static const struct ieee80211_ht_cap mac80211_ht_capa_mod_mask = {
        .ampdu_params_info = IEEE80211_HT_AMPDU_PARM_FACTOR |
                             IEEE80211_HT_AMPDU_PARM_DENSITY,

        .cap_info = cpu_to_le16(IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
                                IEEE80211_HT_CAP_MAX_AMSDU |
                                IEEE80211_HT_CAP_SGI_20 |
                                IEEE80211_HT_CAP_SGI_40 |
                                IEEE80211_HT_CAP_TX_STBC |
                                IEEE80211_HT_CAP_RX_STBC |
                                IEEE80211_HT_CAP_LDPC_CODING |
                                IEEE80211_HT_CAP_40MHZ_INTOLERANT),
        .mcs = {
                .rx_mask = { 0xff, 0xff, 0xff, 0xff, 0xff,
                             0xff, 0xff, 0xff, 0xff, 0xff, },
        },
};

static const struct ieee80211_vht_cap mac80211_vht_capa_mod_mask = {
        .vht_cap_info =
                cpu_to_le32(IEEE80211_VHT_CAP_RXLDPC |
                            IEEE80211_VHT_CAP_SHORT_GI_80 |
                            IEEE80211_VHT_CAP_SHORT_GI_160 |
                            IEEE80211_VHT_CAP_RXSTBC_MASK |
                            IEEE80211_VHT_CAP_TXSTBC |
                            IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE |
                            IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE |
                            IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN |
                            IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN |
                            IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK),
        .supp_mcs = {
                .rx_mcs_map = cpu_to_le16(~0),
                .tx_mcs_map = cpu_to_le16(~0),
        },
};

struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
                                           const struct ieee80211_ops *ops,
                                           const char *requested_name)
{
        struct ieee80211_local *local;
        int priv_size, i;
        struct wiphy *wiphy;
        bool use_chanctx;

        if (WARN_ON(!ops->tx || !ops->start || !ops->stop || !ops->config ||
                    !ops->add_interface || !ops->remove_interface ||
                    !ops->configure_filter))
                return NULL;

        if (WARN_ON(ops->sta_state && (ops->sta_add || ops->sta_remove)))
                return NULL;

        /* check all or no channel context operations exist */
        i = !!ops->add_chanctx + !!ops->remove_chanctx +
            !!ops->change_chanctx + !!ops->assign_vif_chanctx +
            !!ops->unassign_vif_chanctx;
        if (WARN_ON(i != 0 && i != 5))
                return NULL;
        use_chanctx = i == 5;

        /* Ensure 32-byte alignment of our private data and hw private data.
         * We use the wiphy priv data for both our ieee80211_local and for
         * the driver's private data
         *
         * In memory it'll be like this:
         *
         * +-------------------------+
         * | struct wiphy           |
         * +-------------------------+
         * | struct ieee80211_local  |
         * +-------------------------+
         * | driver's private data   |
         * +-------------------------+
         *
         */
        priv_size = ALIGN(sizeof(*local), NETDEV_ALIGN) + priv_data_len;

        wiphy = wiphy_new_nm(&mac80211_config_ops, priv_size, requested_name);

        if (!wiphy)
                return NULL;

        wiphy->mgmt_stypes = ieee80211_default_mgmt_stypes;

        wiphy->privid = mac80211_wiphy_privid;

        wiphy->flags |= WIPHY_FLAG_NETNS_OK |
                        WIPHY_FLAG_4ADDR_AP |
                        WIPHY_FLAG_4ADDR_STATION |
                        WIPHY_FLAG_REPORTS_OBSS |
                        WIPHY_FLAG_OFFCHAN_TX;

        if (!use_chanctx || ops->remain_on_channel)
                wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;

        wiphy->features |= NL80211_FEATURE_SK_TX_STATUS |
                           NL80211_FEATURE_SAE |
                           NL80211_FEATURE_HT_IBSS |
                           NL80211_FEATURE_VIF_TXPOWER |
                           NL80211_FEATURE_MAC_ON_CREATE |
                           NL80211_FEATURE_USERSPACE_MPM |
                           NL80211_FEATURE_FULL_AP_CLIENT_STATE;
        wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_FILS_STA);
        wiphy_ext_feature_set(wiphy,
                              NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211);
        wiphy_ext_feature_set(wiphy,
                              NL80211_EXT_FEATURE_CONTROL_PORT_NO_PREAUTH);
        wiphy_ext_feature_set(wiphy,
                              NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211_TX_STATUS);
        wiphy_ext_feature_set(wiphy,
                              NL80211_EXT_FEATURE_SCAN_FREQ_KHZ);

        if (!ops->hw_scan) {
                wiphy->features |= NL80211_FEATURE_LOW_PRIORITY_SCAN |
                                   NL80211_FEATURE_AP_SCAN;
                /*
                 * if the driver behaves correctly using the probe request
                 * (template) from mac80211, then both of these should be
                 * supported even with hw scan - but let drivers opt in.
                 */
                wiphy_ext_feature_set(wiphy,
                                      NL80211_EXT_FEATURE_SCAN_RANDOM_SN);
                wiphy_ext_feature_set(wiphy,
                                      NL80211_EXT_FEATURE_SCAN_MIN_PREQ_CONTENT);
        }

        if (!ops->set_key)
                wiphy->flags |= WIPHY_FLAG_IBSS_RSN;

        if (ops->wake_tx_queue)
                wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_TXQS);

        wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_RRM);

        wiphy->bss_priv_size = sizeof(struct ieee80211_bss);

        local = wiphy_priv(wiphy);

        if (sta_info_init(local))
                goto err_free;

        local->hw.wiphy = wiphy;

        local->hw.priv = (char *)local + ALIGN(sizeof(*local), NETDEV_ALIGN);

        local->ops = ops;
        local->use_chanctx = use_chanctx;

        /*
         * We need a bit of data queued to build aggregates properly, so
         * instruct the TCP stack to allow more than a single ms of data
         * to be queued in the stack. The value is a bit-shift of 1
         * second, so 7 is ~8ms of queued data. Only affects local TCP
         * sockets.
         * This is the default, anyhow - drivers may need to override it
         * for local reasons (longer buffers, longer completion time, or
         * similar).
         */
        local->hw.tx_sk_pacing_shift = 7;

        /* set up some defaults */
        local->hw.queues = 1;
        local->hw.max_rates = 1;
        local->hw.max_report_rates = 0;
        local->hw.max_rx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF_HT;
        local->hw.max_tx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF_HT;
        local->hw.offchannel_tx_hw_queue = IEEE80211_INVAL_HW_QUEUE;
        local->hw.conf.long_frame_max_tx_count = wiphy->retry_long;
        local->hw.conf.short_frame_max_tx_count = wiphy->retry_short;
        local->hw.radiotap_mcs_details = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
                                         IEEE80211_RADIOTAP_MCS_HAVE_GI |
                                         IEEE80211_RADIOTAP_MCS_HAVE_BW;
        local->hw.radiotap_vht_details = IEEE80211_RADIOTAP_VHT_KNOWN_GI |
                                         IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
        local->hw.uapsd_queues = IEEE80211_DEFAULT_UAPSD_QUEUES;
        local->hw.uapsd_max_sp_len = IEEE80211_DEFAULT_MAX_SP_LEN;
        local->hw.max_mtu = IEEE80211_MAX_DATA_LEN;
        local->user_power_level = IEEE80211_UNSET_POWER_LEVEL;
        wiphy->ht_capa_mod_mask = &mac80211_ht_capa_mod_mask;
        wiphy->vht_capa_mod_mask = &mac80211_vht_capa_mod_mask;

        local->ext_capa[7] = WLAN_EXT_CAPA8_OPMODE_NOTIF;

        wiphy->extended_capabilities = local->ext_capa;
        wiphy->extended_capabilities_mask = local->ext_capa;
        wiphy->extended_capabilities_len =
                ARRAY_SIZE(local->ext_capa);

        INIT_LIST_HEAD(&local->interfaces);
        INIT_LIST_HEAD(&local->mon_list);

        __hw_addr_init(&local->mc_list);

        mutex_init(&local->iflist_mtx);
        mutex_init(&local->mtx);

        mutex_init(&local->key_mtx);
        spin_lock_init(&local->filter_lock);
        spin_lock_init(&local->rx_path_lock);
        spin_lock_init(&local->queue_stop_reason_lock);

        for (i = 0; i < IEEE80211_NUM_ACS; i++) {
                INIT_LIST_HEAD(&local->active_txqs[i]);
                spin_lock_init(&local->active_txq_lock[i]);
                local->aql_txq_limit_low[i] = IEEE80211_DEFAULT_AQL_TXQ_LIMIT_L;
                local->aql_txq_limit_high[i] =
                        IEEE80211_DEFAULT_AQL_TXQ_LIMIT_H;
        }

        local->airtime_flags = AIRTIME_USE_TX | AIRTIME_USE_RX;
        local->aql_threshold = IEEE80211_AQL_THRESHOLD;
        atomic_set(&local->aql_total_pending_airtime, 0);

        INIT_LIST_HEAD(&local->chanctx_list);
        mutex_init(&local->chanctx_mtx);

        INIT_DELAYED_WORK(&local->scan_work, ieee80211_scan_work);

        INIT_WORK(&local->restart_work, ieee80211_restart_work);

        INIT_WORK(&local->radar_detected_work,
                  ieee80211_dfs_radar_detected_work);

        INIT_WORK(&local->reconfig_filter, ieee80211_reconfig_filter);
        local->smps_mode = IEEE80211_SMPS_OFF;

        INIT_WORK(&local->dynamic_ps_enable_work,
                  ieee80211_dynamic_ps_enable_work);
        INIT_WORK(&local->dynamic_ps_disable_work,
                  ieee80211_dynamic_ps_disable_work);
        timer_setup(&local->dynamic_ps_timer, ieee80211_dynamic_ps_timer, 0);

        INIT_WORK(&local->sched_scan_stopped_work,
                  ieee80211_sched_scan_stopped_work);

        INIT_WORK(&local->tdls_chsw_work, ieee80211_tdls_chsw_work);

        spin_lock_init(&local->ack_status_lock);
        idr_init(&local->ack_status_frames);

        for (i = 0; i < IEEE80211_MAX_QUEUES; i++) {
                skb_queue_head_init(&local->pending[i]);
                atomic_set(&local->agg_queue_stop[i], 0);
        }
        tasklet_init(&local->tx_pending_tasklet, ieee80211_tx_pending,
                     (unsigned long)local);

        if (ops->wake_tx_queue)
                tasklet_init(&local->wake_txqs_tasklet, ieee80211_wake_txqs,
                             (unsigned long)local);

        tasklet_init(&local->tasklet,
                     ieee80211_tasklet_handler,
                     (unsigned long) local);

        skb_queue_head_init(&local->skb_queue);
        skb_queue_head_init(&local->skb_queue_unreliable);
        skb_queue_head_init(&local->skb_queue_tdls_chsw);

        ieee80211_alloc_led_names(local);

        ieee80211_roc_setup(local);

        local->hw.radiotap_timestamp.units_pos = -1;
        local->hw.radiotap_timestamp.accuracy = -1;

        return &local->hw;
 err_free:
        wiphy_free(wiphy);
        return NULL;
}
EXPORT_SYMBOL(ieee80211_alloc_hw_nm);

static int ieee80211_init_cipher_suites(struct ieee80211_local *local)
{
        bool have_wep = !fips_enabled; /* FIPS does not permit the use of RC4 */
        bool have_mfp = ieee80211_hw_check(&local->hw, MFP_CAPABLE);
        int n_suites = 0, r = 0, w = 0;
        u32 *suites;
        static const u32 cipher_suites[] = {
                /* keep WEP first, it may be removed below */
                WLAN_CIPHER_SUITE_WEP40,
                WLAN_CIPHER_SUITE_WEP104,
                WLAN_CIPHER_SUITE_TKIP,
                WLAN_CIPHER_SUITE_CCMP,
                WLAN_CIPHER_SUITE_CCMP_256,
                WLAN_CIPHER_SUITE_GCMP,
                WLAN_CIPHER_SUITE_GCMP_256,

                /* keep last -- depends on hw flags! */
                WLAN_CIPHER_SUITE_AES_CMAC,
                WLAN_CIPHER_SUITE_BIP_CMAC_256,
                WLAN_CIPHER_SUITE_BIP_GMAC_128,
                WLAN_CIPHER_SUITE_BIP_GMAC_256,
        };

        if (ieee80211_hw_check(&local->hw, SW_CRYPTO_CONTROL) ||
            local->hw.wiphy->cipher_suites) {
                /* If the driver advertises, or doesn't support SW crypto,
                 * we only need to remove WEP if necessary.
                 */
                if (have_wep)
                        return 0;

                /* well if it has _no_ ciphers ... fine */
                if (!local->hw.wiphy->n_cipher_suites)
                        return 0;

                /* Driver provides cipher suites, but we need to exclude WEP */
                suites = kmemdup(local->hw.wiphy->cipher_suites,
                                 sizeof(u32) * local->hw.wiphy->n_cipher_suites,
                                 GFP_KERNEL);
                if (!suites)
                        return -ENOMEM;

                for (r = 0; r < local->hw.wiphy->n_cipher_suites; r++) {
                        u32 suite = local->hw.wiphy->cipher_suites[r];

                        if (suite == WLAN_CIPHER_SUITE_WEP40 ||
                            suite == WLAN_CIPHER_SUITE_WEP104)
                                continue;
                        suites[w++] = suite;
                }
        } else if (!local->hw.cipher_schemes) {
                /* If the driver doesn't have cipher schemes, there's nothing
                 * else to do other than assign the (software supported and
                 * perhaps offloaded) cipher suites.
                 */
                local->hw.wiphy->cipher_suites = cipher_suites;
                local->hw.wiphy->n_cipher_suites = ARRAY_SIZE(cipher_suites);

                if (!have_mfp)
                        local->hw.wiphy->n_cipher_suites -= 4;

                if (!have_wep) {
                        local->hw.wiphy->cipher_suites += 2;
                        local->hw.wiphy->n_cipher_suites -= 2;
                }

                /* not dynamically allocated, so just return */
                return 0;
        } else {
                const struct ieee80211_cipher_scheme *cs;

                cs = local->hw.cipher_schemes;

                /* Driver specifies cipher schemes only (but not cipher suites
                 * including the schemes)
                 *
                 * We start counting ciphers defined by schemes, TKIP, CCMP,
                 * CCMP-256, GCMP, and GCMP-256
                 */
                n_suites = local->hw.n_cipher_schemes + 5;

                /* check if we have WEP40 and WEP104 */
                if (have_wep)
                        n_suites += 2;

                /* check if we have AES_CMAC, BIP-CMAC-256, BIP-GMAC-128,
                 * BIP-GMAC-256
                 */
                if (have_mfp)
                        n_suites += 4;

                suites = kmalloc_array(n_suites, sizeof(u32), GFP_KERNEL);
                if (!suites)
                        return -ENOMEM;

                suites[w++] = WLAN_CIPHER_SUITE_CCMP;
                suites[w++] = WLAN_CIPHER_SUITE_CCMP_256;
                suites[w++] = WLAN_CIPHER_SUITE_TKIP;
                suites[w++] = WLAN_CIPHER_SUITE_GCMP;
                suites[w++] = WLAN_CIPHER_SUITE_GCMP_256;

                if (have_wep) {
                        suites[w++] = WLAN_CIPHER_SUITE_WEP40;
                        suites[w++] = WLAN_CIPHER_SUITE_WEP104;
                }

                if (have_mfp) {
                        suites[w++] = WLAN_CIPHER_SUITE_AES_CMAC;
                        suites[w++] = WLAN_CIPHER_SUITE_BIP_CMAC_256;
                        suites[w++] = WLAN_CIPHER_SUITE_BIP_GMAC_128;
                        suites[w++] = WLAN_CIPHER_SUITE_BIP_GMAC_256;
                }

                for (r = 0; r < local->hw.n_cipher_schemes; r++) {
                        suites[w++] = cs[r].cipher;
                        if (WARN_ON(cs[r].pn_len > IEEE80211_MAX_PN_LEN)) {
                                kfree(suites);
                                return -EINVAL;
                        }
                }
        }

        local->hw.wiphy->cipher_suites = suites;
        local->hw.wiphy->n_cipher_suites = w;
        local->wiphy_ciphers_allocated = true;

        return 0;
}

int ieee80211_register_hw(struct ieee80211_hw *hw)
{
        struct ieee80211_local *local = hw_to_local(hw);
        int result, i;
        enum nl80211_band band;
        int channels, max_bitrates;
        bool supp_ht, supp_vht, supp_he;
        struct cfg80211_chan_def dflt_chandef = {};

        if (ieee80211_hw_check(hw, QUEUE_CONTROL) &&
            (local->hw.offchannel_tx_hw_queue == IEEE80211_INVAL_HW_QUEUE ||
             local->hw.offchannel_tx_hw_queue >= local->hw.queues))
                return -EINVAL;

        if ((hw->wiphy->features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH) &&
            (!local->ops->tdls_channel_switch ||
             !local->ops->tdls_cancel_channel_switch ||
             !local->ops->tdls_recv_channel_switch))
                return -EOPNOTSUPP;

        if (WARN_ON(ieee80211_hw_check(hw, SUPPORTS_TX_FRAG) &&
                    !local->ops->set_frag_threshold))
                return -EINVAL;

        if (WARN_ON(local->hw.wiphy->interface_modes &
                        BIT(NL80211_IFTYPE_NAN) &&
                    (!local->ops->start_nan || !local->ops->stop_nan)))
                return -EINVAL;

#ifdef CONFIG_PM
        if (hw->wiphy->wowlan && (!local->ops->suspend || !local->ops->resume))
                return -EINVAL;
#endif

        if (!local->use_chanctx) {
                for (i = 0; i < local->hw.wiphy->n_iface_combinations; i++) {
                        const struct ieee80211_iface_combination *comb;

                        comb = &local->hw.wiphy->iface_combinations[i];

                        if (comb->num_different_channels > 1)
                                return -EINVAL;
                }
        } else {
                /*
                 * WDS is currently prohibited when channel contexts are used
                 * because there's no clear definition of which channel WDS
                 * type interfaces use
                 */
                if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_WDS))
                        return -EINVAL;

                /* DFS is not supported with multi-channel combinations yet */
                for (i = 0; i < local->hw.wiphy->n_iface_combinations; i++) {
                        const struct ieee80211_iface_combination *comb;

                        comb = &local->hw.wiphy->iface_combinations[i];

                        if (comb->radar_detect_widths &&
                            comb->num_different_channels > 1)
                                return -EINVAL;
                }
        }

        /* Only HW csum features are currently compatible with mac80211 */
        if (WARN_ON(hw->netdev_features & ~MAC80211_SUPPORTED_FEATURES))
                return -EINVAL;

        if (hw->max_report_rates == 0)
                hw->max_report_rates = hw->max_rates;

        local->rx_chains = 1;

        /*
         * generic code guarantees at least one band,
         * set this very early because much code assumes
         * that hw.conf.channel is assigned
         */
        channels = 0;
        max_bitrates = 0;
        supp_ht = false;
        supp_vht = false;
        supp_he = false;
        for (band = 0; band < NUM_NL80211_BANDS; band++) {
                struct ieee80211_supported_band *sband;

                sband = local->hw.wiphy->bands[band];
                if (!sband)
                        continue;

                if (!dflt_chandef.chan) {
                        cfg80211_chandef_create(&dflt_chandef,
                                                &sband->channels[0],
                                                NL80211_CHAN_NO_HT);
                        /* init channel we're on */
                        if (!local->use_chanctx && !local->_oper_chandef.chan) {
                                local->hw.conf.chandef = dflt_chandef;
                                local->_oper_chandef = dflt_chandef;
                        }
                        local->monitor_chandef = dflt_chandef;
                }

                channels += sband->n_channels;

                if (max_bitrates < sband->n_bitrates)
                        max_bitrates = sband->n_bitrates;
                supp_ht = supp_ht || sband->ht_cap.ht_supported;
                supp_vht = supp_vht || sband->vht_cap.vht_supported;

                if (!supp_he)
                        supp_he = !!ieee80211_get_he_sta_cap(sband);

                /* HT, VHT, HE require QoS, thus >= 4 queues */
                if (WARN_ON(local->hw.queues < IEEE80211_NUM_ACS &&
                            (supp_ht || supp_vht || supp_he)))
                        return -EINVAL;

                if (!sband->ht_cap.ht_supported)
                        continue;

                /* TODO: consider VHT for RX chains, hopefully it's the same */
                local->rx_chains =
                        max(ieee80211_mcs_to_chains(&sband->ht_cap.mcs),
                            local->rx_chains);

                /* no need to mask, SM_PS_DISABLED has all bits set */
                sband->ht_cap.cap |= WLAN_HT_CAP_SM_PS_DISABLED <<
                                     IEEE80211_HT_CAP_SM_PS_SHIFT;
        }

        /* if low-level driver supports AP, we also support VLAN.
         * drivers advertising SW_CRYPTO_CONTROL should enable AP_VLAN
         * based on their support to transmit SW encrypted packets.
         */
        if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP) &&
            !ieee80211_hw_check(&local->hw, SW_CRYPTO_CONTROL)) {
                hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_AP_VLAN);
                hw->wiphy->software_iftypes |= BIT(NL80211_IFTYPE_AP_VLAN);
        }

        /* mac80211 always supports monitor */
        hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_MONITOR);
        hw->wiphy->software_iftypes |= BIT(NL80211_IFTYPE_MONITOR);

        /* mac80211 doesn't support more than one IBSS interface right now */
        for (i = 0; i < hw->wiphy->n_iface_combinations; i++) {
                const struct ieee80211_iface_combination *c;
                int j;

                c = &hw->wiphy->iface_combinations[i];

                for (j = 0; j < c->n_limits; j++)
                        if ((c->limits[j].types & BIT(NL80211_IFTYPE_ADHOC)) &&
                            c->limits[j].max > 1)
                                return -EINVAL;
        }

        local->int_scan_req = kzalloc(sizeof(*local->int_scan_req) +
                                      sizeof(void *) * channels, GFP_KERNEL);
        if (!local->int_scan_req)
                return -ENOMEM;

        for (band = 0; band < NUM_NL80211_BANDS; band++) {
                if (!local->hw.wiphy->bands[band])
                        continue;
                local->int_scan_req->rates[band] = (u32) -1;
        }

#ifndef CONFIG_MAC80211_MESH
        /* mesh depends on Kconfig, but drivers should set it if they want */
        local->hw.wiphy->interface_modes &= ~BIT(NL80211_IFTYPE_MESH_POINT);
#endif

        /* if the underlying driver supports mesh, mac80211 will (at least)
         * provide routing of mesh authentication frames to userspace */
        if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_MESH_POINT))
                local->hw.wiphy->flags |= WIPHY_FLAG_MESH_AUTH;

        /* mac80211 supports control port protocol changing */
        local->hw.wiphy->flags |= WIPHY_FLAG_CONTROL_PORT_PROTOCOL;

        if (ieee80211_hw_check(&local->hw, SIGNAL_DBM)) {
                local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_MBM;
        } else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC)) {
                local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_UNSPEC;
                if (hw->max_signal <= 0) {
                        result = -EINVAL;
                        goto fail_workqueue;
                }
        }

        /* Mac80211 and therefore all drivers using SW crypto only
         * are able to handle PTK rekeys and Extended Key ID.
         */
        if (!local->ops->set_key) {
                wiphy_ext_feature_set(local->hw.wiphy,
                                      NL80211_EXT_FEATURE_CAN_REPLACE_PTK0);
                wiphy_ext_feature_set(local->hw.wiphy,
                                      NL80211_EXT_FEATURE_EXT_KEY_ID);
        }

        if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_ADHOC))
                wiphy_ext_feature_set(local->hw.wiphy,
                                      NL80211_EXT_FEATURE_DEL_IBSS_STA);

        /*
         * Calculate scan IE length -- we need this to alloc
         * memory and to subtract from the driver limit. It
         * includes the DS Params, (extended) supported rates, and HT
         * information -- SSID is the driver's responsibility.
         */
        local->scan_ies_len = 4 + max_bitrates /* (ext) supp rates */ +
                3 /* DS Params */;
        if (supp_ht)
                local->scan_ies_len += 2 + sizeof(struct ieee80211_ht_cap);

        if (supp_vht)
                local->scan_ies_len +=
                        2 + sizeof(struct ieee80211_vht_cap);

        /* HE cap element is variable in size - set len to allow max size */
        /*
         * TODO: 1 is added at the end of the calculation to accommodate for
         *      the temporary placing of the HE capabilities IE under EXT.
         *      Remove it once it is placed in the final place.
         */
        if (supp_he)
                local->scan_ies_len +=
                        2 + sizeof(struct ieee80211_he_cap_elem) +
                        sizeof(struct ieee80211_he_mcs_nss_supp) +
                        IEEE80211_HE_PPE_THRES_MAX_LEN + 1;

        if (!local->ops->hw_scan) {
                /* For hw_scan, driver needs to set these up. */
                local->hw.wiphy->max_scan_ssids = 4;
                local->hw.wiphy->max_scan_ie_len = IEEE80211_MAX_DATA_LEN;
        }

        /*
         * If the driver supports any scan IEs, then assume the
         * limit includes the IEs mac80211 will add, otherwise
         * leave it at zero and let the driver sort it out; we
         * still pass our IEs to the driver but userspace will
         * not be allowed to in that case.
         */
        if (local->hw.wiphy->max_scan_ie_len)
                local->hw.wiphy->max_scan_ie_len -= local->scan_ies_len;

        WARN_ON(!ieee80211_cs_list_valid(local->hw.cipher_schemes,
                                         local->hw.n_cipher_schemes));

        result = ieee80211_init_cipher_suites(local);
        if (result < 0)
                goto fail_workqueue;

        if (!local->ops->remain_on_channel)
                local->hw.wiphy->max_remain_on_channel_duration = 5000;

        /* mac80211 based drivers don't support internal TDLS setup */
        if (local->hw.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS)
                local->hw.wiphy->flags |= WIPHY_FLAG_TDLS_EXTERNAL_SETUP;

        /* mac80211 supports eCSA, if the driver supports STA CSA at all */
        if (ieee80211_hw_check(&local->hw, CHANCTX_STA_CSA))
                local->ext_capa[0] |= WLAN_EXT_CAPA1_EXT_CHANNEL_SWITCHING;

        /* mac80211 supports multi BSSID, if the driver supports it */
        if (ieee80211_hw_check(&local->hw, SUPPORTS_MULTI_BSSID)) {
                local->hw.wiphy->support_mbssid = true;
                if (ieee80211_hw_check(&local->hw,
                                       SUPPORTS_ONLY_HE_MULTI_BSSID))
                        local->hw.wiphy->support_only_he_mbssid = true;
                else
                        local->ext_capa[2] |=
                                WLAN_EXT_CAPA3_MULTI_BSSID_SUPPORT;
        }

        local->hw.wiphy->max_num_csa_counters = IEEE80211_MAX_CSA_COUNTERS_NUM;

        /*
         * We use the number of queues for feature tests (QoS, HT) internally
         * so restrict them appropriately.
         */
        if (hw->queues > IEEE80211_MAX_QUEUES)
                hw->queues = IEEE80211_MAX_QUEUES;

        local->workqueue =
                alloc_ordered_workqueue("%s", 0, wiphy_name(local->hw.wiphy));
        if (!local->workqueue) {
                result = -ENOMEM;
                goto fail_workqueue;
        }

        /*
         * The hardware needs headroom for sending the frame,
         * and we need some headroom for passing the frame to monitor
         * interfaces, but never both at the same time.
         */
        local->tx_headroom = max_t(unsigned int , local->hw.extra_tx_headroom,
                                   IEEE80211_TX_STATUS_HEADROOM);

        /*
         * if the driver doesn't specify a max listen interval we
         * use 5 which should be a safe default
         */
        if (local->hw.max_listen_interval == 0)
                local->hw.max_listen_interval = 5;

        local->hw.conf.listen_interval = local->hw.max_listen_interval;

        local->dynamic_ps_forced_timeout = -1;

        if (!local->hw.max_nan_de_entries)
                local->hw.max_nan_de_entries = IEEE80211_MAX_NAN_INSTANCE_ID;

        if (!local->hw.weight_multiplier)
                local->hw.weight_multiplier = 1;

        ieee80211_wep_init(local);

        local->hw.conf.flags = IEEE80211_CONF_IDLE;

        ieee80211_led_init(local);

        result = ieee80211_txq_setup_flows(local);
        if (result)
                goto fail_flows;

        rtnl_lock();
        result = ieee80211_init_rate_ctrl_alg(local,
                                              hw->rate_control_algorithm);
        rtnl_unlock();
        if (result < 0) {
                wiphy_debug(local->hw.wiphy,
                            "Failed to initialize rate control algorithm\n");
                goto fail_rate;
        }

        if (local->rate_ctrl) {
                clear_bit(IEEE80211_HW_SUPPORTS_VHT_EXT_NSS_BW, hw->flags);
                if (local->rate_ctrl->ops->capa & RATE_CTRL_CAPA_VHT_EXT_NSS_BW)
                        ieee80211_hw_set(hw, SUPPORTS_VHT_EXT_NSS_BW);
        }

        /*
         * If the VHT capabilities don't have IEEE80211_VHT_EXT_NSS_BW_CAPABLE,
         * or have it when we don't, copy the sband structure and set/clear it.
         * This is necessary because rate scaling algorithms could be switched
         * and have different support values.
         * Print a message so that in the common case the reallocation can be
         * avoided.
         */
        BUILD_BUG_ON(NUM_NL80211_BANDS > 8 * sizeof(local->sband_allocated));
        for (band = 0; band < NUM_NL80211_BANDS; band++) {
                struct ieee80211_supported_band *sband;
                bool local_cap, ie_cap;

                local_cap = ieee80211_hw_check(hw, SUPPORTS_VHT_EXT_NSS_BW);

                sband = local->hw.wiphy->bands[band];
                if (!sband || !sband->vht_cap.vht_supported)
                        continue;

                ie_cap = !!(sband->vht_cap.vht_mcs.tx_highest &
                            cpu_to_le16(IEEE80211_VHT_EXT_NSS_BW_CAPABLE));

                if (local_cap == ie_cap)
                        continue;

                sband = kmemdup(sband, sizeof(*sband), GFP_KERNEL);
                if (!sband) {
                        result = -ENOMEM;
                        goto fail_rate;
                }

                wiphy_dbg(hw->wiphy, "copying sband (band %d) due to VHT EXT NSS BW flag\n",
                          band);

                sband->vht_cap.vht_mcs.tx_highest ^=
                        cpu_to_le16(IEEE80211_VHT_EXT_NSS_BW_CAPABLE);

                local->hw.wiphy->bands[band] = sband;
                local->sband_allocated |= BIT(band);
        }

        result = wiphy_register(local->hw.wiphy);
        if (result < 0)
                goto fail_wiphy_register;

        debugfs_hw_add(local);
        rate_control_add_debugfs(local);

        rtnl_lock();

        /* add one default STA interface if supported */
        if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION) &&
            !ieee80211_hw_check(hw, NO_AUTO_VIF)) {
                struct vif_params params = {0};

                result = ieee80211_if_add(local, "wlan%d", NET_NAME_ENUM, NULL,
                                          NL80211_IFTYPE_STATION, &params);
                if (result)
                        wiphy_warn(local->hw.wiphy,
                                   "Failed to add default virtual iface\n");
        }

        rtnl_unlock();

#ifdef CONFIG_INET
        local->ifa_notifier.notifier_call = ieee80211_ifa_changed;
        result = register_inetaddr_notifier(&local->ifa_notifier);
        if (result)
                goto fail_ifa;
#endif

#if IS_ENABLED(CONFIG_IPV6)
        local->ifa6_notifier.notifier_call = ieee80211_ifa6_changed;
        result = register_inet6addr_notifier(&local->ifa6_notifier);
        if (result)
                goto fail_ifa6;
#endif

        return 0;

#if IS_ENABLED(CONFIG_IPV6)
 fail_ifa6:
#ifdef CONFIG_INET
        unregister_inetaddr_notifier(&local->ifa_notifier);
#endif
#endif
#if defined(CONFIG_INET) || defined(CONFIG_IPV6)
 fail_ifa:
#endif
        wiphy_unregister(local->hw.wiphy);
 fail_wiphy_register:
        rtnl_lock();
        rate_control_deinitialize(local);
        ieee80211_remove_interfaces(local);
        rtnl_unlock();
 fail_rate:
 fail_flows:
        ieee80211_led_exit(local);
        destroy_workqueue(local->workqueue);
 fail_workqueue:
        if (local->wiphy_ciphers_allocated)
                kfree(local->hw.wiphy->cipher_suites);
        kfree(local->int_scan_req);
        return result;
}
EXPORT_SYMBOL(ieee80211_register_hw);

void ieee80211_unregister_hw(struct ieee80211_hw *hw)
{
        struct ieee80211_local *local = hw_to_local(hw);

        tasklet_kill(&local->tx_pending_tasklet);
        tasklet_kill(&local->tasklet);

#ifdef CONFIG_INET
        unregister_inetaddr_notifier(&local->ifa_notifier);
#endif
#if IS_ENABLED(CONFIG_IPV6)
        unregister_inet6addr_notifier(&local->ifa6_notifier);
#endif

        rtnl_lock();

        /*
         * At this point, interface list manipulations are fine
         * because the driver cannot be handing us frames any
         * more and the tasklet is killed.
         */
        ieee80211_remove_interfaces(local);

        rtnl_unlock();

        cancel_delayed_work_sync(&local->roc_work);
        cancel_work_sync(&local->restart_work);
        cancel_work_sync(&local->reconfig_filter);
        cancel_work_sync(&local->tdls_chsw_work);
        flush_work(&local->sched_scan_stopped_work);
        flush_work(&local->radar_detected_work);

        ieee80211_clear_tx_pending(local);
        rate_control_deinitialize(local);

        if (skb_queue_len(&local->skb_queue) ||
            skb_queue_len(&local->skb_queue_unreliable))
                wiphy_warn(local->hw.wiphy, "skb_queue not empty\n");
        skb_queue_purge(&local->skb_queue);
        skb_queue_purge(&local->skb_queue_unreliable);
        skb_queue_purge(&local->skb_queue_tdls_chsw);

        wiphy_unregister(local->hw.wiphy);
        destroy_workqueue(local->workqueue);
        ieee80211_led_exit(local);
        kfree(local->int_scan_req);
}
EXPORT_SYMBOL(ieee80211_unregister_hw);

static int ieee80211_free_ack_frame(int id, void *p, void *data)
{
        WARN_ONCE(1, "Have pending ack frames!\n");
        kfree_skb(p);
        return 0;
}

void ieee80211_free_hw(struct ieee80211_hw *hw)
{
        struct ieee80211_local *local = hw_to_local(hw);
        enum nl80211_band band;

        mutex_destroy(&local->iflist_mtx);
        mutex_destroy(&local->mtx);

        if (local->wiphy_ciphers_allocated)
                kfree(local->hw.wiphy->cipher_suites);

        idr_for_each(&local->ack_status_frames,
                     ieee80211_free_ack_frame, NULL);
        idr_destroy(&local->ack_status_frames);

        sta_info_stop(local);

        ieee80211_free_led_names(local);

        for (band = 0; band < NUM_NL80211_BANDS; band++) {
                if (!(local->sband_allocated & BIT(band)))
                        continue;
                kfree(local->hw.wiphy->bands[band]);
        }

        wiphy_free(local->hw.wiphy);
}
EXPORT_SYMBOL(ieee80211_free_hw);

static int __init ieee80211_init(void)
{
        struct sk_buff *skb;
        int ret;

        BUILD_BUG_ON(sizeof(struct ieee80211_tx_info) > sizeof(skb->cb));
        BUILD_BUG_ON(offsetof(struct ieee80211_tx_info, driver_data) +
                     IEEE80211_TX_INFO_DRIVER_DATA_SIZE > sizeof(skb->cb));

        ret = rc80211_minstrel_init();
        if (ret)
                return ret;

        ret = ieee80211_iface_init();
        if (ret)
                goto err_netdev;

        return 0;
 err_netdev:
        rc80211_minstrel_exit();

        return ret;
}

static void __exit ieee80211_exit(void)
{
        rc80211_minstrel_exit();

        ieee80211s_stop();

        ieee80211_iface_exit();

        rcu_barrier();
}


subsys_initcall(ieee80211_init);
module_exit(ieee80211_exit);

MODULE_DESCRIPTION("IEEE 802.11 subsystem");
MODULE_LICENSE("GPL");