main.c

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/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <net/mac80211.h>
#include <linux/module.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/pm_qos.h>
#include <linux/inetdevice.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>

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

static struct lock_class_key ieee80211_rx_skb_queue_class;

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

    if (atomic_read(&local->iff_promiscs))
        new_flags |= FIF_PROMISC_IN_BSS;

    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;

    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);
}

int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
{
    struct ieee80211_channel *chan;
    int ret = 0;
    int power;
    enum nl80211_channel_type channel_type;
    u32 offchannel_flag;

    might_sleep();

    offchannel_flag = local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
    if (local->scan_channel) {
        chan = local->scan_channel;
        /* If scanning on oper channel, use whatever channel-type
         * is currently in use.
         */
        if (chan == local->oper_channel)
            channel_type = local->_oper_channel_type;
        else
            channel_type = NL80211_CHAN_NO_HT;
    } else if (local->tmp_channel) {
        chan = local->tmp_channel;
        channel_type = local->tmp_channel_type;
    } else {
        chan = local->oper_channel;
        channel_type = local->_oper_channel_type;
    }

    if (chan != local->oper_channel ||
        channel_type != local->_oper_channel_type)
        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 || chan != local->hw.conf.channel ||
        channel_type != local->hw.conf.channel_type) {
        local->hw.conf.channel = chan;
        local->hw.conf.channel_type = channel_type;
        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;
    }

    if (test_bit(SCAN_SW_SCANNING, &local->scanning) ||
        test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning) ||
        test_bit(SCAN_HW_SCANNING, &local->scanning) ||
        !local->ap_power_level)
        power = chan->max_power;
    else
        power = min(chan->max_power, local->ap_power_level);

    if (local->user_power_level >= 0)
        power = min(power, local->user_power_level);

    if (local->hw.conf.power_level != power) {
        changed |= IEEE80211_CONF_CHANGE_POWER;
        local->hw.conf.power_level = 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;
    static const u8 zero[ETH_ALEN] = { 0 };

    if (!changed)
        return;

    if (sdata->vif.type == NL80211_IFTYPE_STATION) {
        sdata->vif.bss_conf.bssid = sdata->u.mgd.bssid;
    } else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
        sdata->vif.bss_conf.bssid = sdata->u.ibss.bssid;
    else if (sdata->vif.type == NL80211_IFTYPE_AP)
        sdata->vif.bss_conf.bssid = sdata->vif.addr;
    else if (sdata->vif.type == NL80211_IFTYPE_WDS)
        sdata->vif.bss_conf.bssid = NULL;
    else if (ieee80211_vif_is_mesh(&sdata->vif)) {
        sdata->vif.bss_conf.bssid = zero;
    } else if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) {
        sdata->vif.bss_conf.bssid = sdata->vif.addr;
        WARN_ONCE(changed & ~(BSS_CHANGED_IDLE),
              "P2P Device BSS changed %#x", changed);
    } else {
        WARN_ON(1);
        return;
    }

    switch (sdata->vif.type) {
    case NL80211_IFTYPE_AP:
    case NL80211_IFTYPE_ADHOC:
    case NL80211_IFTYPE_WDS:
    case NL80211_IFTYPE_MESH_POINT:
        break;
    default:
        /* do not warn to simplify caller in scan.c */
        changed &= ~BSS_CHANGED_BEACON_ENABLED;
        if (WARN_ON(changed & BSS_CHANGED_BEACON))
            return;
        break;
    }

    if (changed & BSS_CHANGED_BEACON_ENABLED) {
        if (local->quiescing || !ieee80211_sdata_running(sdata) ||
            test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state)) {
            sdata->vif.bss_conf.enable_beacon = false;
        } else {
            /*
             * Beacon should be enabled, but AP mode must
             * check whether there is a beacon configured.
             */
            switch (sdata->vif.type) {
            case NL80211_IFTYPE_AP:
                sdata->vif.bss_conf.enable_beacon =
                    !!sdata->u.ap.beacon;
                break;
            case NL80211_IFTYPE_ADHOC:
                sdata->vif.bss_conf.enable_beacon =
                    !!sdata->u.ibss.presp;
                break;
#ifdef CONFIG_MAC80211_MESH
            case NL80211_IFTYPE_MESH_POINT:
                sdata->vif.bss_conf.enable_beacon =
                    !!sdata->u.mesh.mesh_id_len;
                break;
#endif
            default:
                /* not reached */
                WARN_ON(1);
                break;
            }
        }
    }

    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 sta_info *sta, *tmp;
    struct skb_eosp_msg_data *eosp_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;
        case IEEE80211_EOSP_MSG:
            eosp_data = (void *)skb->cb;
            for_each_sta_info(local, eosp_data->sta, sta, tmp) {
                /* skip wrong virtual interface */
                if (memcmp(eosp_data->iface,
                       sta->sdata->vif.addr, ETH_ALEN))
                    continue;
                clear_sta_flag(sta, WLAN_STA_SP);
                break;
            }
            dev_kfree_skb(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);

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

    mutex_lock(&local->mtx);
    WARN(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
         rcu_dereference_protected(local->sched_scan_sdata,
                       lockdep_is_held(&local->mtx)),
        "%s called with hardware scan in progress\n", __func__);
    mutex_unlock(&local->mtx);

    rtnl_lock();
    ieee80211_scan_cancel(local);
    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_QUEUE_STOP_REASON_SUSPEND);

    /*
     * 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();

    schedule_work(&local->restart_work);
}
EXPORT_SYMBOL(ieee80211_restart_hw);

static void ieee80211_recalc_smps_work(struct work_struct *work)
{
    struct ieee80211_local *local =
        container_of(work, struct ieee80211_local, recalc_smps);

    ieee80211_recalc_smps(local);
}

#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;
    mutex_lock(&ifmgd->mtx);

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

    /* If not all addresses fit the list, disable filtering */
    if (ifa) {
        sdata->arp_filter_state = false;
        c = 0;
    } else {
        sdata->arp_filter_state = true;
    }
    bss_conf->arp_addr_cnt = c;

    /* Configure driver only if associated (which also implies it is up) */
    if (ifmgd->associated) {
        bss_conf->arp_filter_enabled = sdata->arp_filter_state;
        ieee80211_bss_info_change_notify(sdata,
                         BSS_CHANGED_ARP_FILTER);
    }

    mutex_unlock(&ifmgd->mtx);

    return NOTIFY_DONE;
}
#endif

static int ieee80211_napi_poll(struct napi_struct *napi, int budget)
{
    struct ieee80211_local *local =
        container_of(napi, struct ieee80211_local, napi);

    return local->ops->napi_poll(&local->hw, budget);
}

void ieee80211_napi_schedule(struct ieee80211_hw *hw)
{
    struct ieee80211_local *local = hw_to_local(hw);

    napi_schedule(&local->napi);
}
EXPORT_SYMBOL(ieee80211_napi_schedule);

void ieee80211_napi_complete(struct ieee80211_hw *hw)
{
    struct ieee80211_local *local = hw_to_local(hw);

    napi_complete(&local->napi);
}
EXPORT_SYMBOL(ieee80211_napi_complete);

/* 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),
    },
    [NL80211_IFTYPE_STATION] = {
        .tx = 0xffff,
        .rx = BIT(IEEE80211_STYPE_ACTION >> 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_40),
    .mcs = {
        .rx_mask = { 0xff, 0xff, 0xff, 0xff, 0xff,
                 0xff, 0xff, 0xff, 0xff, 0xff, },
    },
};

struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
                    const struct ieee80211_ops *ops)
{
    struct ieee80211_local *local;
    int priv_size, i;
    struct wiphy *wiphy;

    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;

    /* 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(&mac80211_config_ops, priv_size);

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

    wiphy->features = NL80211_FEATURE_SK_TX_STATUS |
              NL80211_FEATURE_HT_IBSS;

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

    wiphy->bss_priv_size = sizeof(struct ieee80211_bss);

    local = wiphy_priv(wiphy);

    local->hw.wiphy = wiphy;

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

    local->ops = ops;

    /* 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;
    local->hw.max_tx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF;
    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->user_power_level = -1;
    wiphy->ht_capa_mod_mask = &mac80211_ht_capa_mod_mask;

    INIT_LIST_HEAD(&local->interfaces);

    __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->queue_stop_reason_lock);

    /*
     * The rx_skb_queue is only accessed from tasklets,
     * but other SKB queues are used from within IRQ
     * context. Therefore, this one needs a different
     * locking class so our direct, non-irq-safe use of
     * the queue's lock doesn't throw lockdep warnings.
     */
    skb_queue_head_init_class(&local->rx_skb_queue,
                  &ieee80211_rx_skb_queue_class);

    INIT_DELAYED_WORK(&local->scan_work, ieee80211_scan_work);

    INIT_WORK(&local->restart_work, ieee80211_restart_work);

    INIT_WORK(&local->reconfig_filter, ieee80211_reconfig_filter);
    INIT_WORK(&local->recalc_smps, ieee80211_recalc_smps_work);
    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);
    setup_timer(&local->dynamic_ps_timer,
            ieee80211_dynamic_ps_timer, (unsigned long) local);

    INIT_WORK(&local->sched_scan_stopped_work,
          ieee80211_sched_scan_stopped_work);

    spin_lock_init(&local->ack_status_lock);
    idr_init(&local->ack_status_frames);
    /* preallocate at least one entry */
    idr_pre_get(&local->ack_status_frames, GFP_KERNEL);

    sta_info_init(local);

    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);

    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);

    /* init dummy netdev for use w/ NAPI */
    init_dummy_netdev(&local->napi_dev);

    ieee80211_led_names(local);

    ieee80211_roc_setup(local);

    return &local->hw;
}
EXPORT_SYMBOL(ieee80211_alloc_hw);

int ieee80211_register_hw(struct ieee80211_hw *hw)
{
    struct ieee80211_local *local = hw_to_local(hw);
    int result, i;
    enum ieee80211_band band;
    int channels, max_bitrates;
    bool supp_ht, supp_vht;
    netdev_features_t feature_whitelist;
    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,

        /* keep last -- depends on hw flags! */
        WLAN_CIPHER_SUITE_AES_CMAC
    };

    if (hw->flags & IEEE80211_HW_QUEUE_CONTROL &&
        (local->hw.offchannel_tx_hw_queue == IEEE80211_INVAL_HW_QUEUE ||
         local->hw.offchannel_tx_hw_queue >= local->hw.queues))
        return -EINVAL;

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

    if ((hw->flags & IEEE80211_HW_SCAN_WHILE_IDLE) && !local->ops->hw_scan)
        return -EINVAL;

    /* Only HW csum features are currently compatible with mac80211 */
    feature_whitelist = NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
                NETIF_F_HW_CSUM;
    if (WARN_ON(hw->netdev_features & ~feature_whitelist))
        return -EINVAL;

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

    /*
     * 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;
    for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
        struct ieee80211_supported_band *sband;

        sband = local->hw.wiphy->bands[band];
        if (!sband)
            continue;
        if (!local->oper_channel) {
            /* init channel we're on */
            local->hw.conf.channel =
            local->oper_channel = &sband->channels[0];
            local->hw.conf.channel_type = NL80211_CHAN_NO_HT;
        }
        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;
    }

    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 < IEEE80211_NUM_BANDS; band++) {
        if (!local->hw.wiphy->bands[band])
            continue;
        local->int_scan_req->rates[band] = (u32) -1;
    }

    /* if low-level driver supports AP, we also support VLAN */
    if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP)) {
        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 1 channel, and also not more
     * than one IBSS interface
     */
    for (i = 0; i < hw->wiphy->n_iface_combinations; i++) {
        const struct ieee80211_iface_combination *c;
        int j;

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

        if (c->num_different_channels > 1)
            return -EINVAL;

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

#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 (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
        local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_MBM;
    else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
        local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_UNSPEC;

    WARN((local->hw.flags & IEEE80211_HW_SUPPORTS_UAPSD)
         && (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK),
         "U-APSD not supported with HW_PS_NULLFUNC_STACK\n");

    /*
     * 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_capabilities);

    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;

    /* Set up cipher suites unless driver already did */
    if (!local->hw.wiphy->cipher_suites) {
        local->hw.wiphy->cipher_suites = cipher_suites;
        local->hw.wiphy->n_cipher_suites = ARRAY_SIZE(cipher_suites);
        if (!(local->hw.flags & IEEE80211_HW_MFP_CAPABLE))
            local->hw.wiphy->n_cipher_suites--;
    }
    if (IS_ERR(local->wep_tx_tfm) || IS_ERR(local->wep_rx_tfm)) {
        if (local->hw.wiphy->cipher_suites == cipher_suites) {
            local->hw.wiphy->cipher_suites += 2;
            local->hw.wiphy->n_cipher_suites -= 2;
        } else {
            u32 *suites;
            int r, w = 0;

            /* Filter out WEP */

            suites = kmemdup(
                local->hw.wiphy->cipher_suites,
                sizeof(u32) * local->hw.wiphy->n_cipher_suites,
                GFP_KERNEL);
            if (!suites) {
                result = -ENOMEM;
                goto fail_wiphy_register;
            }
            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;
            }
            local->hw.wiphy->cipher_suites = suites;
            local->hw.wiphy->n_cipher_suites = w;
            local->wiphy_ciphers_allocated = true;
        }
    }

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

    if (local->ops->sched_scan_start)
        local->hw.wiphy->flags |= WIPHY_FLAG_SUPPORTS_SCHED_SCAN;

    /* 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;

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

    /*
     * 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(wiphy_name(local->hw.wiphy), 0);
    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);

    debugfs_hw_add(local);

    /*
     * 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;

    result = ieee80211_wep_init(local);
    if (result < 0)
        wiphy_debug(local->hw.wiphy, "Failed to initialize wep: %d\n",
                result);

    ieee80211_led_init(local);

    rtnl_lock();

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

    /* add one default STA interface if supported */
    if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION)) {
        result = ieee80211_if_add(local, "wlan%d", NULL,
                      NL80211_IFTYPE_STATION, NULL);
        if (result)
            wiphy_warn(local->hw.wiphy,
                   "Failed to add default virtual iface\n");
    }

    rtnl_unlock();

    local->network_latency_notifier.notifier_call =
        ieee80211_max_network_latency;
    result = pm_qos_add_notifier(PM_QOS_NETWORK_LATENCY,
                     &local->network_latency_notifier);
    if (result) {
        rtnl_lock();
        goto fail_pm_qos;
    }

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

    netif_napi_add(&local->napi_dev, &local->napi, ieee80211_napi_poll,
            local->hw.napi_weight);

    return 0;

#ifdef CONFIG_INET
 fail_ifa:
    pm_qos_remove_notifier(PM_QOS_NETWORK_LATENCY,
                   &local->network_latency_notifier);
    rtnl_lock();
#endif
 fail_pm_qos:
    ieee80211_led_exit(local);
    ieee80211_remove_interfaces(local);
 fail_rate:
    rtnl_unlock();
    ieee80211_wep_free(local);
    sta_info_stop(local);
    destroy_workqueue(local->workqueue);
 fail_workqueue:
    wiphy_unregister(local->hw.wiphy);
 fail_wiphy_register:
    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);

    pm_qos_remove_notifier(PM_QOS_NETWORK_LATENCY,
                   &local->network_latency_notifier);
#ifdef CONFIG_INET
    unregister_inetaddr_notifier(&local->ifa_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_work_sync(&local->restart_work);
    cancel_work_sync(&local->reconfig_filter);

    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->rx_skb_queue);

    destroy_workqueue(local->workqueue);
    wiphy_unregister(local->hw.wiphy);
    sta_info_stop(local);
    ieee80211_wep_free(local);
    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);

    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);

    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 = rc80211_minstrel_ht_init();
    if (ret)
        goto err_minstrel;

    ret = rc80211_pid_init();
    if (ret)
        goto err_pid;

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

    return 0;
 err_netdev:
    rc80211_pid_exit();
 err_pid:
    rc80211_minstrel_ht_exit();
 err_minstrel:
    rc80211_minstrel_exit();

    return ret;
}

static void __exit ieee80211_exit(void)
{
    rc80211_pid_exit();
    rc80211_minstrel_ht_exit();
    rc80211_minstrel_exit();

    if (mesh_allocated)
        ieee80211s_stop();

    ieee80211_iface_exit();

    rcu_barrier();
}


subsys_initcall(ieee80211_init);
module_exit(ieee80211_exit);

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