mac80211: fix work race

[safe/jmp/linux-2.6] / net / mac80211 / main.c

/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
 *
 * 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 <net/ieee80211_radiotap.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/wireless.h>
#include <linux/rtnetlink.h>
#include <linux/bitmap.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>

#include "ieee80211_i.h"
#include "rate.h"
#include "mesh.h"
#include "wep.h"
#include "wme.h"
#include "aes_ccm.h"
#include "led.h"
#include "cfg.h"
#include "debugfs.h"
#include "debugfs_netdev.h"

/*
 * For seeing transmitted packets on monitor interfaces
 * we have a radiotap header too.
 */
struct ieee80211_tx_status_rtap_hdr {
        struct ieee80211_radiotap_header hdr;
        __le16 tx_flags;
        u8 data_retries;
} __attribute__ ((packed));

/* common interface routines */

static int header_parse_80211(const struct sk_buff *skb, unsigned char *haddr)
{
        memcpy(haddr, skb_mac_header(skb) + 10, ETH_ALEN); /* addr2 */
        return ETH_ALEN;
}

/* must be called under mdev tx lock */
static void ieee80211_configure_filter(struct ieee80211_local *local)
{
        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)
                new_flags |= FIF_BCN_PRBRESP_PROMISC;

        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;

        changed_flags = local->filter_flags ^ new_flags;

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

        local->ops->configure_filter(local_to_hw(local),
                                     changed_flags, &new_flags,
                                     local->mdev->mc_count,
                                     local->mdev->mc_list);

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

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

/* master interface */

static int ieee80211_master_open(struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_sub_if_data *sdata;
        int res = -EOPNOTSUPP;

        /* we hold the RTNL here so can safely walk the list */
        list_for_each_entry(sdata, &local->interfaces, list) {
                if (netif_running(sdata->dev)) {
                        res = 0;
                        break;
                }
        }

        if (res)
                return res;

        netif_tx_start_all_queues(local->mdev);

        return 0;
}

static int ieee80211_master_stop(struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_sub_if_data *sdata;

        /* we hold the RTNL here so can safely walk the list */
        list_for_each_entry(sdata, &local->interfaces, list)
                if (netif_running(sdata->dev))
                        dev_close(sdata->dev);

        return 0;
}

static void ieee80211_master_set_multicast_list(struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);

        ieee80211_configure_filter(local);
}

/* regular interfaces */

static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
{
        int meshhdrlen;
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

        meshhdrlen = (sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT) ? 5 : 0;

        /* FIX: what would be proper limits for MTU?
         * This interface uses 802.3 frames. */
        if (new_mtu < 256 ||
            new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6 - meshhdrlen) {
                return -EINVAL;
        }

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
        printk(KERN_DEBUG "%s: setting MTU %d\n", dev->name, new_mtu);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
        dev->mtu = new_mtu;
        return 0;
}

static inline int identical_mac_addr_allowed(int type1, int type2)
{
        return (type1 == IEEE80211_IF_TYPE_MNTR ||
                type2 == IEEE80211_IF_TYPE_MNTR ||
                (type1 == IEEE80211_IF_TYPE_AP &&
                 type2 == IEEE80211_IF_TYPE_WDS) ||
                (type1 == IEEE80211_IF_TYPE_WDS &&
                 (type2 == IEEE80211_IF_TYPE_WDS ||
                  type2 == IEEE80211_IF_TYPE_AP)) ||
                (type1 == IEEE80211_IF_TYPE_AP &&
                 type2 == IEEE80211_IF_TYPE_VLAN) ||
                (type1 == IEEE80211_IF_TYPE_VLAN &&
                 (type2 == IEEE80211_IF_TYPE_AP ||
                  type2 == IEEE80211_IF_TYPE_VLAN)));
}

static int ieee80211_open(struct net_device *dev)
{
        struct ieee80211_sub_if_data *sdata, *nsdata;
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct sta_info *sta;
        struct ieee80211_if_init_conf conf;
        u32 changed = 0;
        int res;
        bool need_hw_reconfig = 0;
        u8 null_addr[ETH_ALEN] = {0};

        sdata = IEEE80211_DEV_TO_SUB_IF(dev);

        /* fail early if user set an invalid address */
        if (compare_ether_addr(dev->dev_addr, null_addr) &&
            !is_valid_ether_addr(dev->dev_addr))
                return -EADDRNOTAVAIL;

        /* we hold the RTNL here so can safely walk the list */
        list_for_each_entry(nsdata, &local->interfaces, list) {
                struct net_device *ndev = nsdata->dev;

                if (ndev != dev && netif_running(ndev)) {
                        /*
                         * Allow only a single IBSS interface to be up at any
                         * time. This is restricted because beacon distribution
                         * cannot work properly if both are in the same IBSS.
                         *
                         * To remove this restriction we'd have to disallow them
                         * from setting the same SSID on different IBSS interfaces
                         * belonging to the same hardware. Then, however, we're
                         * faced with having to adopt two different TSF timers...
                         */
                        if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS &&
                            nsdata->vif.type == IEEE80211_IF_TYPE_IBSS)
                                return -EBUSY;

                        /*
                         * The remaining checks are only performed for interfaces
                         * with the same MAC address.
                         */
                        if (compare_ether_addr(dev->dev_addr, ndev->dev_addr))
                                continue;

                        /*
                         * check whether it may have the same address
                         */
                        if (!identical_mac_addr_allowed(sdata->vif.type,
                                                        nsdata->vif.type))
                                return -ENOTUNIQ;

                        /*
                         * can only add VLANs to enabled APs
                         */
                        if (sdata->vif.type == IEEE80211_IF_TYPE_VLAN &&
                            nsdata->vif.type == IEEE80211_IF_TYPE_AP)
                                sdata->bss = &nsdata->u.ap;
                }
        }

        switch (sdata->vif.type) {
        case IEEE80211_IF_TYPE_WDS:
                if (!is_valid_ether_addr(sdata->u.wds.remote_addr))
                        return -ENOLINK;
                break;
        case IEEE80211_IF_TYPE_VLAN:
                if (!sdata->bss)
                        return -ENOLINK;
                list_add(&sdata->u.vlan.list, &sdata->bss->vlans);
                break;
        case IEEE80211_IF_TYPE_AP:
                sdata->bss = &sdata->u.ap;
                break;
        case IEEE80211_IF_TYPE_MESH_POINT:
                if (!ieee80211_vif_is_mesh(&sdata->vif))
                        break;
                /* mesh ifaces must set allmulti to forward mcast traffic */
                atomic_inc(&local->iff_allmultis);
                break;
        case IEEE80211_IF_TYPE_STA:
        case IEEE80211_IF_TYPE_MNTR:
        case IEEE80211_IF_TYPE_IBSS:
                /* no special treatment */
                break;
        case IEEE80211_IF_TYPE_INVALID:
                /* cannot happen */
                WARN_ON(1);
                break;
        }

        if (local->open_count == 0) {
                res = 0;
                if (local->ops->start)
                        res = local->ops->start(local_to_hw(local));
                if (res)
                        goto err_del_bss;
                need_hw_reconfig = 1;
                ieee80211_led_radio(local, local->hw.conf.radio_enabled);
        }

        /*
         * Check all interfaces and copy the hopefully now-present
         * MAC address to those that have the special null one.
         */
        list_for_each_entry(nsdata, &local->interfaces, list) {
                struct net_device *ndev = nsdata->dev;

                /*
                 * No need to check netif_running since we do not allow
                 * it to start up with this invalid address.
                 */
                if (compare_ether_addr(null_addr, ndev->dev_addr) == 0)
                        memcpy(ndev->dev_addr,
                               local->hw.wiphy->perm_addr,
                               ETH_ALEN);
        }

        if (compare_ether_addr(null_addr, local->mdev->dev_addr) == 0)
                memcpy(local->mdev->dev_addr, local->hw.wiphy->perm_addr,
                       ETH_ALEN);

        /*
         * Validate the MAC address for this device.
         */
        if (!is_valid_ether_addr(dev->dev_addr)) {
                if (!local->open_count && local->ops->stop)
                        local->ops->stop(local_to_hw(local));
                return -EADDRNOTAVAIL;
        }

        switch (sdata->vif.type) {
        case IEEE80211_IF_TYPE_VLAN:
                /* no need to tell driver */
                break;
        case IEEE80211_IF_TYPE_MNTR:
                if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
                        local->cooked_mntrs++;
                        break;
                }

                /* must be before the call to ieee80211_configure_filter */
                local->monitors++;
                if (local->monitors == 1)
                        local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;

                if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
                        local->fif_fcsfail++;
                if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
                        local->fif_plcpfail++;
                if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
                        local->fif_control++;
                if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
                        local->fif_other_bss++;

                netif_addr_lock_bh(local->mdev);
                ieee80211_configure_filter(local);
                netif_addr_unlock_bh(local->mdev);
                break;
        case IEEE80211_IF_TYPE_STA:
        case IEEE80211_IF_TYPE_IBSS:
                sdata->u.sta.flags &= ~IEEE80211_STA_PREV_BSSID_SET;
                /* fall through */
        default:
                conf.vif = &sdata->vif;
                conf.type = sdata->vif.type;
                conf.mac_addr = dev->dev_addr;
                res = local->ops->add_interface(local_to_hw(local), &conf);
                if (res)
                        goto err_stop;

                if (ieee80211_vif_is_mesh(&sdata->vif))
                        ieee80211_start_mesh(sdata);
                changed |= ieee80211_reset_erp_info(sdata);
                ieee80211_bss_info_change_notify(sdata, changed);
                ieee80211_enable_keys(sdata);

                if (sdata->vif.type == IEEE80211_IF_TYPE_STA &&
                    !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
                        netif_carrier_off(dev);
                else
                        netif_carrier_on(dev);
        }

        if (sdata->vif.type == IEEE80211_IF_TYPE_WDS) {
                /* Create STA entry for the WDS peer */
                sta = sta_info_alloc(sdata, sdata->u.wds.remote_addr,
                                     GFP_KERNEL);
                if (!sta) {
                        res = -ENOMEM;
                        goto err_del_interface;
                }

                /* no locking required since STA is not live yet */
                sta->flags |= WLAN_STA_AUTHORIZED;

                res = sta_info_insert(sta);
                if (res) {
                        /* STA has been freed */
                        goto err_del_interface;
                }
        }

        if (local->open_count == 0) {
                res = dev_open(local->mdev);
                WARN_ON(res);
                if (res)
                        goto err_del_interface;
                tasklet_enable(&local->tx_pending_tasklet);
                tasklet_enable(&local->tasklet);
        }

        /*
         * set_multicast_list will be invoked by the networking core
         * which will check whether any increments here were done in
         * error and sync them down to the hardware as filter flags.
         */
        if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
                atomic_inc(&local->iff_allmultis);

        if (sdata->flags & IEEE80211_SDATA_PROMISC)
                atomic_inc(&local->iff_promiscs);

        local->open_count++;
        if (need_hw_reconfig) {
                ieee80211_hw_config(local);
                /*
                 * set default queue parameters so drivers don't
                 * need to initialise the hardware if the hardware
                 * doesn't start up with sane defaults
                 */
                ieee80211_set_wmm_default(sdata);
        }

        /*
         * ieee80211_sta_work is disabled while network interface
         * is down. Therefore, some configuration changes may not
         * yet be effective. Trigger execution of ieee80211_sta_work
         * to fix this.
         */
        if (sdata->vif.type == IEEE80211_IF_TYPE_STA ||
            sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
                struct ieee80211_if_sta *ifsta = &sdata->u.sta;
                queue_work(local->hw.workqueue, &ifsta->work);
        }

        netif_tx_start_all_queues(dev);

        return 0;
 err_del_interface:
        local->ops->remove_interface(local_to_hw(local), &conf);
 err_stop:
        if (!local->open_count && local->ops->stop)
                local->ops->stop(local_to_hw(local));
 err_del_bss:
        sdata->bss = NULL;
        if (sdata->vif.type == IEEE80211_IF_TYPE_VLAN)
                list_del(&sdata->u.vlan.list);
        return res;
}

static int ieee80211_stop(struct net_device *dev)
{
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_init_conf conf;
        struct sta_info *sta;

        /*
         * Stop TX on this interface first.
         */
        netif_tx_stop_all_queues(dev);

        /*
         * Now delete all active aggregation sessions.
         */
        rcu_read_lock();

        list_for_each_entry_rcu(sta, &local->sta_list, list) {
                if (sta->sdata == sdata)
                        ieee80211_sta_tear_down_BA_sessions(sdata, sta->addr);
        }

        rcu_read_unlock();

        /*
         * Remove all stations associated with this interface.
         *
         * This must be done before calling ops->remove_interface()
         * because otherwise we can later invoke ops->sta_notify()
         * whenever the STAs are removed, and that invalidates driver
         * assumptions about always getting a vif pointer that is valid
         * (because if we remove a STA after ops->remove_interface()
         * the driver will have removed the vif info already!)
         *
         * We could relax this and only unlink the stations from the
         * hash table and list but keep them on a per-sdata list that
         * will be inserted back again when the interface is brought
         * up again, but I don't currently see a use case for that,
         * except with WDS which gets a STA entry created when it is
         * brought up.
         */
        sta_info_flush(local, sdata);

        /*
         * Don't count this interface for promisc/allmulti while it
         * is down. dev_mc_unsync() will invoke set_multicast_list
         * on the master interface which will sync these down to the
         * hardware as filter flags.
         */
        if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
                atomic_dec(&local->iff_allmultis);

        if (sdata->flags & IEEE80211_SDATA_PROMISC)
                atomic_dec(&local->iff_promiscs);

        dev_mc_unsync(local->mdev, dev);

        /* APs need special treatment */
        if (sdata->vif.type == IEEE80211_IF_TYPE_AP) {
                struct ieee80211_sub_if_data *vlan, *tmp;
                struct beacon_data *old_beacon = sdata->u.ap.beacon;

                /* remove beacon */
                rcu_assign_pointer(sdata->u.ap.beacon, NULL);
                synchronize_rcu();
                kfree(old_beacon);

                /* down all dependent devices, that is VLANs */
                list_for_each_entry_safe(vlan, tmp, &sdata->u.ap.vlans,
                                         u.vlan.list)
                        dev_close(vlan->dev);
                WARN_ON(!list_empty(&sdata->u.ap.vlans));
        }

        local->open_count--;

        switch (sdata->vif.type) {
        case IEEE80211_IF_TYPE_VLAN:
                list_del(&sdata->u.vlan.list);
                /* no need to tell driver */
                break;
        case IEEE80211_IF_TYPE_MNTR:
                if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
                        local->cooked_mntrs--;
                        break;
                }

                local->monitors--;
                if (local->monitors == 0)
                        local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;

                if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
                        local->fif_fcsfail--;
                if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
                        local->fif_plcpfail--;
                if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
                        local->fif_control--;
                if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
                        local->fif_other_bss--;

                netif_addr_lock_bh(local->mdev);
                ieee80211_configure_filter(local);
                netif_addr_unlock_bh(local->mdev);
                break;
        case IEEE80211_IF_TYPE_STA:
        case IEEE80211_IF_TYPE_IBSS:
                sdata->u.sta.state = IEEE80211_STA_MLME_DISABLED;
                memset(sdata->u.sta.bssid, 0, ETH_ALEN);
                del_timer_sync(&sdata->u.sta.timer);
                /*
                 * If the timer fired while we waited for it, it will have
                 * requeued the work. Now the work will be running again
                 * but will not rearm the timer again because it checks
                 * whether the interface is running, which, at this point,
                 * it no longer is.
                 */
                cancel_work_sync(&sdata->u.sta.work);
                /*
                 * When we get here, the interface is marked down.
                 * Call synchronize_rcu() to wait for the RX path
                 * should it be using the interface and enqueuing
                 * frames at this very time on another CPU.
                 */
                synchronize_rcu();
                skb_queue_purge(&sdata->u.sta.skb_queue);

                if (local->scan_sdata == sdata) {
                        if (!local->ops->hw_scan) {
                                local->sta_sw_scanning = 0;
                                cancel_delayed_work(&local->scan_work);
                        } else
                                local->sta_hw_scanning = 0;
                }

                sdata->u.sta.flags &= ~IEEE80211_STA_PRIVACY_INVOKED;
                kfree(sdata->u.sta.extra_ie);
                sdata->u.sta.extra_ie = NULL;
                sdata->u.sta.extra_ie_len = 0;
                /* fall through */
        case IEEE80211_IF_TYPE_MESH_POINT:
                if (ieee80211_vif_is_mesh(&sdata->vif)) {
                        /* allmulti is always set on mesh ifaces */
                        atomic_dec(&local->iff_allmultis);
                        ieee80211_stop_mesh(sdata);
                }
                /* fall through */
        default:
                conf.vif = &sdata->vif;
                conf.type = sdata->vif.type;
                conf.mac_addr = dev->dev_addr;
                /* disable all keys for as long as this netdev is down */
                ieee80211_disable_keys(sdata);
                local->ops->remove_interface(local_to_hw(local), &conf);
        }

        sdata->bss = NULL;

        if (local->open_count == 0) {
                if (netif_running(local->mdev))
                        dev_close(local->mdev);

                if (local->ops->stop)
                        local->ops->stop(local_to_hw(local));

                ieee80211_led_radio(local, 0);

                flush_workqueue(local->hw.workqueue);

                tasklet_disable(&local->tx_pending_tasklet);
                tasklet_disable(&local->tasklet);
        }

        return 0;
}

static void ieee80211_set_multicast_list(struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        int allmulti, promisc, sdata_allmulti, sdata_promisc;

        allmulti = !!(dev->flags & IFF_ALLMULTI);
        promisc = !!(dev->flags & IFF_PROMISC);
        sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);
        sdata_promisc = !!(sdata->flags & IEEE80211_SDATA_PROMISC);

        if (allmulti != sdata_allmulti) {
                if (dev->flags & IFF_ALLMULTI)
                        atomic_inc(&local->iff_allmultis);
                else
                        atomic_dec(&local->iff_allmultis);
                sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
        }

        if (promisc != sdata_promisc) {
                if (dev->flags & IFF_PROMISC)
                        atomic_inc(&local->iff_promiscs);
                else
                        atomic_dec(&local->iff_promiscs);
                sdata->flags ^= IEEE80211_SDATA_PROMISC;
        }

        dev_mc_sync(local->mdev, dev);
}

static const struct header_ops ieee80211_header_ops = {
        .create         = eth_header,
        .parse          = header_parse_80211,
        .rebuild        = eth_rebuild_header,
        .cache          = eth_header_cache,
        .cache_update   = eth_header_cache_update,
};

void ieee80211_if_setup(struct net_device *dev)
{
        ether_setup(dev);
        dev->hard_start_xmit = ieee80211_subif_start_xmit;
        dev->wireless_handlers = &ieee80211_iw_handler_def;
        dev->set_multicast_list = ieee80211_set_multicast_list;
        dev->change_mtu = ieee80211_change_mtu;
        dev->open = ieee80211_open;
        dev->stop = ieee80211_stop;
        dev->destructor = free_netdev;
        /* we will validate the address ourselves in ->open */
        dev->validate_addr = NULL;
}

/* everything else */

int ieee80211_if_config(struct ieee80211_sub_if_data *sdata, u32 changed)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_conf conf;

        if (WARN_ON(!netif_running(sdata->dev)))
                return 0;

        if (!local->ops->config_interface)
                return 0;

        memset(&conf, 0, sizeof(conf));
        conf.changed = changed;

        if (sdata->vif.type == IEEE80211_IF_TYPE_STA ||
            sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
                conf.bssid = sdata->u.sta.bssid;
                conf.ssid = sdata->u.sta.ssid;
                conf.ssid_len = sdata->u.sta.ssid_len;
        } else if (sdata->vif.type == IEEE80211_IF_TYPE_AP) {
                conf.bssid = sdata->dev->dev_addr;
                conf.ssid = sdata->u.ap.ssid;
                conf.ssid_len = sdata->u.ap.ssid_len;
        } else if (ieee80211_vif_is_mesh(&sdata->vif)) {
                u8 zero[ETH_ALEN] = { 0 };
                conf.bssid = zero;
                conf.ssid = zero;
                conf.ssid_len = 0;
        } else {
                WARN_ON(1);
                return -EINVAL;
        }

        if (WARN_ON(!conf.bssid && (changed & IEEE80211_IFCC_BSSID)))
                return -EINVAL;

        if (WARN_ON(!conf.ssid && (changed & IEEE80211_IFCC_SSID)))
                return -EINVAL;

        return local->ops->config_interface(local_to_hw(local),
                                            &sdata->vif, &conf);
}

int ieee80211_hw_config(struct ieee80211_local *local)
{
        struct ieee80211_channel *chan;
        int ret = 0;

        if (local->sta_sw_scanning)
                chan = local->scan_channel;
        else
                chan = local->oper_channel;

        local->hw.conf.channel = chan;

        if (!local->hw.conf.power_level)
                local->hw.conf.power_level = chan->max_power;
        else
                local->hw.conf.power_level = min(chan->max_power,
                                               local->hw.conf.power_level);

        local->hw.conf.max_antenna_gain = chan->max_antenna_gain;

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
        printk(KERN_DEBUG "%s: HW CONFIG: freq=%d\n",
               wiphy_name(local->hw.wiphy), chan->center_freq);
#endif

        if (local->open_count)
                ret = local->ops->config(local_to_hw(local), &local->hw.conf);

        return ret;
}

/**
 * ieee80211_handle_ht should be used only after legacy configuration
 * has been determined namely band, as ht configuration depends upon
 * the hardware's HT abilities for a _specific_ band.
 */
u32 ieee80211_handle_ht(struct ieee80211_local *local, int enable_ht,
                           struct ieee80211_ht_info *req_ht_cap,
                           struct ieee80211_ht_bss_info *req_bss_cap)
{
        struct ieee80211_conf *conf = &local->hw.conf;
        struct ieee80211_supported_band *sband;
        struct ieee80211_ht_info ht_conf;
        struct ieee80211_ht_bss_info ht_bss_conf;
        u32 changed = 0;
        int i;
        u8 max_tx_streams = IEEE80211_HT_CAP_MAX_STREAMS;
        u8 tx_mcs_set_cap;

        sband = local->hw.wiphy->bands[conf->channel->band];

        memset(&ht_conf, 0, sizeof(struct ieee80211_ht_info));
        memset(&ht_bss_conf, 0, sizeof(struct ieee80211_ht_bss_info));

        /* HT is not supported */
        if (!sband->ht_info.ht_supported) {
                conf->flags &= ~IEEE80211_CONF_SUPPORT_HT_MODE;
                goto out;
        }

        /* disable HT */
        if (!enable_ht) {
                if (conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE)
                        changed |= BSS_CHANGED_HT;
                conf->flags &= ~IEEE80211_CONF_SUPPORT_HT_MODE;
                conf->ht_conf.ht_supported = 0;
                goto out;
        }


        if (!(conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE))
                changed |= BSS_CHANGED_HT;

        conf->flags |= IEEE80211_CONF_SUPPORT_HT_MODE;
        ht_conf.ht_supported = 1;

        ht_conf.cap = req_ht_cap->cap & sband->ht_info.cap;
        ht_conf.cap &= ~(IEEE80211_HT_CAP_SM_PS);
        ht_conf.cap |= sband->ht_info.cap & IEEE80211_HT_CAP_SM_PS;
        ht_bss_conf.primary_channel = req_bss_cap->primary_channel;
        ht_bss_conf.bss_cap = req_bss_cap->bss_cap;
        ht_bss_conf.bss_op_mode = req_bss_cap->bss_op_mode;

        ht_conf.ampdu_factor = req_ht_cap->ampdu_factor;
        ht_conf.ampdu_density = req_ht_cap->ampdu_density;

        /* Bits 96-100 */
        tx_mcs_set_cap = sband->ht_info.supp_mcs_set[12];

        /* configure suppoerted Tx MCS according to requested MCS
         * (based in most cases on Rx capabilities of peer) and self
         * Tx MCS capabilities (as defined by low level driver HW
         * Tx capabilities) */
        if (!(tx_mcs_set_cap & IEEE80211_HT_CAP_MCS_TX_DEFINED))
                goto check_changed;

        /* Counting from 0 therfore + 1 */
        if (tx_mcs_set_cap & IEEE80211_HT_CAP_MCS_TX_RX_DIFF)
                max_tx_streams = ((tx_mcs_set_cap &
                                IEEE80211_HT_CAP_MCS_TX_STREAMS) >> 2) + 1;

        for (i = 0; i < max_tx_streams; i++)
                ht_conf.supp_mcs_set[i] =
                        sband->ht_info.supp_mcs_set[i] &
                                        req_ht_cap->supp_mcs_set[i];

        if (tx_mcs_set_cap & IEEE80211_HT_CAP_MCS_TX_UEQM)
                for (i = IEEE80211_SUPP_MCS_SET_UEQM;
                     i < IEEE80211_SUPP_MCS_SET_LEN; i++)
                        ht_conf.supp_mcs_set[i] =
                                sband->ht_info.supp_mcs_set[i] &
                                        req_ht_cap->supp_mcs_set[i];

check_changed:
        /* if bss configuration changed store the new one */
        if (memcmp(&conf->ht_conf, &ht_conf, sizeof(ht_conf)) ||
            memcmp(&conf->ht_bss_conf, &ht_bss_conf, sizeof(ht_bss_conf))) {
                changed |= BSS_CHANGED_HT;
                memcpy(&conf->ht_conf, &ht_conf, sizeof(ht_conf));
                memcpy(&conf->ht_bss_conf, &ht_bss_conf, sizeof(ht_bss_conf));
        }
out:
        return changed;
}

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

        if (!changed)
                return;

        if (local->ops->bss_info_changed)
                local->ops->bss_info_changed(local_to_hw(local),
                                             &sdata->vif,
                                             &sdata->bss_conf,
                                             changed);
}

u32 ieee80211_reset_erp_info(struct ieee80211_sub_if_data *sdata)
{
        sdata->bss_conf.use_cts_prot = 0;
        sdata->bss_conf.use_short_preamble = 0;
        return BSS_CHANGED_ERP_CTS_PROT | BSS_CHANGED_ERP_PREAMBLE;
}

void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
                                 struct sk_buff *skb)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
        int tmp;

        skb->dev = local->mdev;
        skb->pkt_type = IEEE80211_TX_STATUS_MSG;
        skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
                       &local->skb_queue : &local->skb_queue_unreliable, skb);
        tmp = skb_queue_len(&local->skb_queue) +
                skb_queue_len(&local->skb_queue_unreliable);
        while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
               (skb = skb_dequeue(&local->skb_queue_unreliable))) {
                dev_kfree_skb_irq(skb);
                tmp--;
                I802_DEBUG_INC(local->tx_status_drop);
        }
        tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);

static void ieee80211_tasklet_handler(unsigned long data)
{
        struct ieee80211_local *local = (struct ieee80211_local *) data;
        struct sk_buff *skb;
        struct ieee80211_rx_status rx_status;
        struct ieee80211_ra_tid *ra_tid;

        while ((skb = skb_dequeue(&local->skb_queue)) ||
               (skb = skb_dequeue(&local->skb_queue_unreliable))) {
                switch (skb->pkt_type) {
                case IEEE80211_RX_MSG:
                        /* status is in skb->cb */
                        memcpy(&rx_status, skb->cb, sizeof(rx_status));
                        /* Clear skb->pkt_type in order to not confuse kernel
                         * netstack. */
                        skb->pkt_type = 0;
                        __ieee80211_rx(local_to_hw(local), skb, &rx_status);
                        break;
                case IEEE80211_TX_STATUS_MSG:
                        skb->pkt_type = 0;
                        ieee80211_tx_status(local_to_hw(local), skb);
                        break;
                case IEEE80211_DELBA_MSG:
                        ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
                        ieee80211_stop_tx_ba_cb(local_to_hw(local),
                                                ra_tid->ra, ra_tid->tid);
                        dev_kfree_skb(skb);
                        break;
                case IEEE80211_ADDBA_MSG:
                        ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
                        ieee80211_start_tx_ba_cb(local_to_hw(local),
                                                 ra_tid->ra, ra_tid->tid);
                        dev_kfree_skb(skb);
                        break ;
                default:
                        WARN_ON(1);
                        dev_kfree_skb(skb);
                        break;
                }
        }
}

/* Remove added headers (e.g., QoS control), encryption header/MIC, etc. to
 * make a prepared TX frame (one that has been given to hw) to look like brand
 * new IEEE 802.11 frame that is ready to go through TX processing again.
 */
static void ieee80211_remove_tx_extra(struct ieee80211_local *local,
                                      struct ieee80211_key *key,
                                      struct sk_buff *skb)
{
        unsigned int hdrlen, iv_len, mic_len;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;

        hdrlen = ieee80211_hdrlen(hdr->frame_control);

        if (!key)
                goto no_key;

        switch (key->conf.alg) {
        case ALG_WEP:
                iv_len = WEP_IV_LEN;
                mic_len = WEP_ICV_LEN;
                break;
        case ALG_TKIP:
                iv_len = TKIP_IV_LEN;
                mic_len = TKIP_ICV_LEN;
                break;
        case ALG_CCMP:
                iv_len = CCMP_HDR_LEN;
                mic_len = CCMP_MIC_LEN;
                break;
        default:
                goto no_key;
        }

        if (skb->len >= hdrlen + mic_len &&
            !(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
                skb_trim(skb, skb->len - mic_len);
        if (skb->len >= hdrlen + iv_len) {
                memmove(skb->data + iv_len, skb->data, hdrlen);
                hdr = (struct ieee80211_hdr *)skb_pull(skb, iv_len);
        }

no_key:
        if (ieee80211_is_data_qos(hdr->frame_control)) {
                hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
                memmove(skb->data + IEEE80211_QOS_CTL_LEN, skb->data,
                        hdrlen - IEEE80211_QOS_CTL_LEN);
                skb_pull(skb, IEEE80211_QOS_CTL_LEN);
        }
}

static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
                                            struct sta_info *sta,
                                            struct sk_buff *skb)
{
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

        sta->tx_filtered_count++;

        /*
         * Clear the TX filter mask for this STA when sending the next
         * packet. If the STA went to power save mode, this will happen
         * when it wakes up for the next time.
         */
        set_sta_flags(sta, WLAN_STA_CLEAR_PS_FILT);

        /*
         * This code races in the following way:
         *
         *  (1) STA sends frame indicating it will go to sleep and does so
         *  (2) hardware/firmware adds STA to filter list, passes frame up
         *  (3) hardware/firmware processes TX fifo and suppresses a frame
         *  (4) we get TX status before having processed the frame and
         *      knowing that the STA has gone to sleep.
         *
         * This is actually quite unlikely even when both those events are
         * processed from interrupts coming in quickly after one another or
         * even at the same time because we queue both TX status events and
         * RX frames to be processed by a tasklet and process them in the
         * same order that they were received or TX status last. Hence, there
         * is no race as long as the frame RX is processed before the next TX
         * status, which drivers can ensure, see below.
         *
         * Note that this can only happen if the hardware or firmware can
         * actually add STAs to the filter list, if this is done by the
         * driver in response to set_tim() (which will only reduce the race
         * this whole filtering tries to solve, not completely solve it)
         * this situation cannot happen.
         *
         * To completely solve this race drivers need to make sure that they
         *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
         *      functions and
         *  (b) always process RX events before TX status events if ordering
         *      can be unknown, for example with different interrupt status
         *      bits.
         */
        if (test_sta_flags(sta, WLAN_STA_PS) &&
            skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) {
                ieee80211_remove_tx_extra(local, sta->key, skb);
                skb_queue_tail(&sta->tx_filtered, skb);
                return;
        }

        if (!test_sta_flags(sta, WLAN_STA_PS) &&
            !(info->flags & IEEE80211_TX_CTL_REQUEUE)) {
                /* Software retry the packet once */
                info->flags |= IEEE80211_TX_CTL_REQUEUE;
                ieee80211_remove_tx_extra(local, sta->key, skb);
                dev_queue_xmit(skb);
                return;
        }

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
        if (net_ratelimit())
                printk(KERN_DEBUG "%s: dropped TX filtered frame, "
                       "queue_len=%d PS=%d @%lu\n",
                       wiphy_name(local->hw.wiphy),
                       skb_queue_len(&sta->tx_filtered),
                       !!test_sta_flags(sta, WLAN_STA_PS), jiffies);
#endif
        dev_kfree_skb(skb);
}

void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
{
        struct sk_buff *skb2;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
        u16 frag, type;
        __le16 fc;
        struct ieee80211_tx_status_rtap_hdr *rthdr;
        struct ieee80211_sub_if_data *sdata;
        struct net_device *prev_dev = NULL;
        struct sta_info *sta;

        rcu_read_lock();

        if (info->status.excessive_retries) {
                sta = sta_info_get(local, hdr->addr1);
                if (sta) {
                        if (test_sta_flags(sta, WLAN_STA_PS)) {
                                /*
                                 * The STA is in power save mode, so assume
                                 * that this TX packet failed because of that.
                                 */
                                ieee80211_handle_filtered_frame(local, sta, skb);
                                rcu_read_unlock();
                                return;
                        }
                }
        }

        fc = hdr->frame_control;

        if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
            (ieee80211_is_data_qos(fc))) {
                u16 tid, ssn;
                u8 *qc;
                sta = sta_info_get(local, hdr->addr1);
                if (sta) {
                        qc = ieee80211_get_qos_ctl(hdr);
                        tid = qc[0] & 0xf;
                        ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
                                                & IEEE80211_SCTL_SEQ);
                        ieee80211_send_bar(sta->sdata, hdr->addr1,
                                           tid, ssn);
                }
        }

        if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
                sta = sta_info_get(local, hdr->addr1);
                if (sta) {
                        ieee80211_handle_filtered_frame(local, sta, skb);
                        rcu_read_unlock();
                        return;
                }
        } else
                rate_control_tx_status(local->mdev, skb);

        rcu_read_unlock();

        ieee80211_led_tx(local, 0);

        /* SNMP counters
         * Fragments are passed to low-level drivers as separate skbs, so these
         * are actually fragments, not frames. Update frame counters only for
         * the first fragment of the frame. */

        frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
        type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE;

        if (info->flags & IEEE80211_TX_STAT_ACK) {
                if (frag == 0) {
                        local->dot11TransmittedFrameCount++;
                        if (is_multicast_ether_addr(hdr->addr1))
                                local->dot11MulticastTransmittedFrameCount++;
                        if (info->status.retry_count > 0)
                                local->dot11RetryCount++;
                        if (info->status.retry_count > 1)
                                local->dot11MultipleRetryCount++;
                }

                /* This counter shall be incremented for an acknowledged MPDU
                 * with an individual address in the address 1 field or an MPDU
                 * with a multicast address in the address 1 field of type Data
                 * or Management. */
                if (!is_multicast_ether_addr(hdr->addr1) ||
                    type == IEEE80211_FTYPE_DATA ||
                    type == IEEE80211_FTYPE_MGMT)
                        local->dot11TransmittedFragmentCount++;
        } else {
                if (frag == 0)
                        local->dot11FailedCount++;
        }

        /* this was a transmitted frame, but now we want to reuse it */
        skb_orphan(skb);

        /*
         * This is a bit racy but we can avoid a lot of work
         * with this test...
         */
        if (!local->monitors && !local->cooked_mntrs) {
                dev_kfree_skb(skb);
                return;
        }

        /* send frame to monitor interfaces now */

        if (skb_headroom(skb) < sizeof(*rthdr)) {
                printk(KERN_ERR "ieee80211_tx_status: headroom too small\n");
                dev_kfree_skb(skb);
                return;
        }

        rthdr = (struct ieee80211_tx_status_rtap_hdr *)
                                skb_push(skb, sizeof(*rthdr));

        memset(rthdr, 0, sizeof(*rthdr));
        rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
        rthdr->hdr.it_present =
                cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
                            (1 << IEEE80211_RADIOTAP_DATA_RETRIES));

        if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
            !is_multicast_ether_addr(hdr->addr1))
                rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL);

        if ((info->flags & IEEE80211_TX_CTL_USE_RTS_CTS) &&
            (info->flags & IEEE80211_TX_CTL_USE_CTS_PROTECT))
                rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS);
        else if (info->flags & IEEE80211_TX_CTL_USE_RTS_CTS)
                rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS);

        rthdr->data_retries = info->status.retry_count;

        /* XXX: is this sufficient for BPF? */
        skb_set_mac_header(skb, 0);
        skb->ip_summed = CHECKSUM_UNNECESSARY;
        skb->pkt_type = PACKET_OTHERHOST;
        skb->protocol = htons(ETH_P_802_2);
        memset(skb->cb, 0, sizeof(skb->cb));

        rcu_read_lock();
        list_for_each_entry_rcu(sdata, &local->interfaces, list) {
                if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR) {
                        if (!netif_running(sdata->dev))
                                continue;

                        if (prev_dev) {
                                skb2 = skb_clone(skb, GFP_ATOMIC);
                                if (skb2) {
                                        skb2->dev = prev_dev;
                                        netif_rx(skb2);
                                }
                        }

                        prev_dev = sdata->dev;
                }
        }
        if (prev_dev) {
                skb->dev = prev_dev;
                netif_rx(skb);
                skb = NULL;
        }
        rcu_read_unlock();
        dev_kfree_skb(skb);
}
EXPORT_SYMBOL(ieee80211_tx_status);

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

        /* 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 = ((sizeof(struct ieee80211_local) +
                      NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST) +
                    priv_data_len;

        wiphy = wiphy_new(&mac80211_config_ops, priv_size);

        if (!wiphy)
                return NULL;

        wiphy->privid = mac80211_wiphy_privid;

        local = wiphy_priv(wiphy);
        local->hw.wiphy = wiphy;

        local->hw.priv = (char *)local +
                         ((sizeof(struct ieee80211_local) +
                           NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);

        BUG_ON(!ops->tx);
        BUG_ON(!ops->start);
        BUG_ON(!ops->stop);
        BUG_ON(!ops->config);
        BUG_ON(!ops->add_interface);
        BUG_ON(!ops->remove_interface);
        BUG_ON(!ops->configure_filter);
        local->ops = ops;

        local->hw.queues = 1; /* default */

        local->bridge_packets = 1;

        local->rts_threshold = IEEE80211_MAX_RTS_THRESHOLD;
        local->fragmentation_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
        local->short_retry_limit = 7;
        local->long_retry_limit = 4;
        local->hw.conf.radio_enabled = 1;

        INIT_LIST_HEAD(&local->interfaces);

        spin_lock_init(&local->key_lock);

        INIT_DELAYED_WORK(&local->scan_work, ieee80211_sta_scan_work);

        sta_info_init(local);

        tasklet_init(&local->tx_pending_tasklet, ieee80211_tx_pending,
                     (unsigned long)local);
        tasklet_disable(&local->tx_pending_tasklet);

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

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

        return local_to_hw(local);
}
EXPORT_SYMBOL(ieee80211_alloc_hw);

int ieee80211_register_hw(struct ieee80211_hw *hw)
{
        struct ieee80211_local *local = hw_to_local(hw);
        const char *name;
        int result;
        enum ieee80211_band band;
        struct net_device *mdev;
        struct wireless_dev *mwdev;

        /*
         * generic code guarantees at least one band,
         * set this very early because much code assumes
         * that hw.conf.channel is assigned
         */
        for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
                struct ieee80211_supported_band *sband;

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

        /* if low-level driver supports AP, we also support VLAN */
        if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP))
                local->hw.wiphy->interface_modes |= BIT(NL80211_IFTYPE_AP_VLAN);

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

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

        /*
         * 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;
        if (hw->ampdu_queues > IEEE80211_MAX_AMPDU_QUEUES)
                hw->ampdu_queues = IEEE80211_MAX_AMPDU_QUEUES;
        if (hw->queues < 4)
                hw->ampdu_queues = 0;

        mdev = alloc_netdev_mq(sizeof(struct wireless_dev),
                               "wmaster%d", ether_setup,
                               ieee80211_num_queues(hw));
        if (!mdev)
                goto fail_mdev_alloc;

        mwdev = netdev_priv(mdev);
        mdev->ieee80211_ptr = mwdev;
        mwdev->wiphy = local->hw.wiphy;

        local->mdev = mdev;

        ieee80211_rx_bss_list_init(local);

        mdev->hard_start_xmit = ieee80211_master_start_xmit;
        mdev->open = ieee80211_master_open;
        mdev->stop = ieee80211_master_stop;
        mdev->type = ARPHRD_IEEE80211;
        mdev->header_ops = &ieee80211_header_ops;
        mdev->set_multicast_list = ieee80211_master_set_multicast_list;

        name = wiphy_dev(local->hw.wiphy)->driver->name;
        local->hw.workqueue = create_freezeable_workqueue(name);
        if (!local->hw.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,
                                   sizeof(struct ieee80211_tx_status_rtap_hdr));

        debugfs_hw_add(local);

        if (local->hw.conf.beacon_int < 10)
                local->hw.conf.beacon_int = 100;

        if (local->hw.max_listen_interval == 0)
                local->hw.max_listen_interval = 1;

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

        local->wstats_flags |= local->hw.flags & (IEEE80211_HW_SIGNAL_UNSPEC |
                                                  IEEE80211_HW_SIGNAL_DB |
                                                  IEEE80211_HW_SIGNAL_DBM) ?
                               IW_QUAL_QUAL_UPDATED : IW_QUAL_QUAL_INVALID;
        local->wstats_flags |= local->hw.flags & IEEE80211_HW_NOISE_DBM ?
                               IW_QUAL_NOISE_UPDATED : IW_QUAL_NOISE_INVALID;
        if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
                local->wstats_flags |= IW_QUAL_DBM;

        result = sta_info_start(local);
        if (result < 0)
                goto fail_sta_info;

        rtnl_lock();
        result = dev_alloc_name(local->mdev, local->mdev->name);
        if (result < 0)
                goto fail_dev;

        memcpy(local->mdev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
        SET_NETDEV_DEV(local->mdev, wiphy_dev(local->hw.wiphy));

        result = register_netdevice(local->mdev);
        if (result < 0)
                goto fail_dev;

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

        result = ieee80211_wep_init(local);

        if (result < 0) {
                printk(KERN_DEBUG "%s: Failed to initialize wep: %d\n",
                       wiphy_name(local->hw.wiphy), result);
                goto fail_wep;
        }

        local->mdev->select_queue = ieee80211_select_queue;

        /* add one default STA interface */
        result = ieee80211_if_add(local, "wlan%d", NULL,
                                  IEEE80211_IF_TYPE_STA, NULL);
        if (result)
                printk(KERN_WARNING "%s: Failed to add default virtual iface\n",
                       wiphy_name(local->hw.wiphy));

        rtnl_unlock();

        ieee80211_led_init(local);

        return 0;

fail_wep:
        rate_control_deinitialize(local);
fail_rate:
        unregister_netdevice(local->mdev);
        local->mdev = NULL;
fail_dev:
        rtnl_unlock();
        sta_info_stop(local);
fail_sta_info:
        debugfs_hw_del(local);
        destroy_workqueue(local->hw.workqueue);
fail_workqueue:
        if (local->mdev)
                free_netdev(local->mdev);
fail_mdev_alloc:
        wiphy_unregister(local->hw.wiphy);
        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);

        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.
         */

        /* First, we remove all virtual interfaces. */
        ieee80211_remove_interfaces(local);

        /* then, finally, remove the master interface */
        unregister_netdevice(local->mdev);

        rtnl_unlock();

        ieee80211_rx_bss_list_deinit(local);
        ieee80211_clear_tx_pending(local);
        sta_info_stop(local);
        rate_control_deinitialize(local);
        debugfs_hw_del(local);

        if (skb_queue_len(&local->skb_queue)
                        || skb_queue_len(&local->skb_queue_unreliable))
                printk(KERN_WARNING "%s: skb_queue not empty\n",
                       wiphy_name(local->hw.wiphy));
        skb_queue_purge(&local->skb_queue);
        skb_queue_purge(&local->skb_queue_unreliable);

        destroy_workqueue(local->hw.workqueue);
        wiphy_unregister(local->hw.wiphy);
        ieee80211_wep_free(local);
        ieee80211_led_exit(local);
        free_netdev(local->mdev);
}
EXPORT_SYMBOL(ieee80211_unregister_hw);

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

        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_pid_init();
        if (ret)
                return ret;

        ieee80211_debugfs_netdev_init();

        return 0;
}

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

        /*
         * For key todo, it'll be empty by now but the work
         * might still be scheduled.
         */
        flush_scheduled_work();

        if (mesh_allocated)
                ieee80211s_stop();

        ieee80211_debugfs_netdev_exit();
}


subsys_initcall(ieee80211_init);
module_exit(ieee80211_exit);

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