// SPDX-License-Identifier: GPL-2.0-only

  /*

   * Interface handling

   *

   * Copyright 2002-2005, Instant802 Networks, Inc.
   * Copyright 2005-2006, Devicescape Software, Inc.
   * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>

   * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>

   * Copyright 2013-2014  Intel Mobile Communications GmbH

   * Copyright (c) 2016        Intel Deutschland GmbH

   * Copyright (C) 2018-2020 Intel Corporation

   */

  #include <linux/slab.h>

  #include <linux/kernel.h>
  #include <linux/if_arp.h>
  #include <linux/netdevice.h>
  #include <linux/rtnetlink.h>
  #include <net/mac80211.h>

  #include <net/ieee80211_radiotap.h>

  #include "ieee80211_i.h"
  #include "sta_info.h"

  #include "debugfs_netdev.h"

  #include "mesh.h"

  #include "led.h"

  #include "driver-ops.h"

  #include "wme.h"

  #include "rate.h"

  /**
   * DOC: Interface list locking
   *
   * The interface list in each struct ieee80211_local is protected
   * three-fold:
   *
   * (1) modifications may only be done under the RTNL
   * (2) modifications and readers are protected against each other by
   *     the iflist_mtx.
   * (3) modifications are done in an RCU manner so atomic readers
   *     can traverse the list in RCU-safe blocks.
   *
   * As a consequence, reads (traversals) of the list can be protected
   * by either the RTNL, the iflist_mtx or RCU.
   */

  static void ieee80211_iface_work(struct work_struct *work);

  bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)
  {
  	struct ieee80211_chanctx_conf *chanctx_conf;
  	int power;
  
  	rcu_read_lock();
  	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
  	if (!chanctx_conf) {
  		rcu_read_unlock();
  		return false;
  	}

  	power = ieee80211_chandef_max_power(&chanctx_conf->def);

  	rcu_read_unlock();
  
  	if (sdata->user_power_level != IEEE80211_UNSET_POWER_LEVEL)
  		power = min(power, sdata->user_power_level);
  
  	if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL)
  		power = min(power, sdata->ap_power_level);
  
  	if (power != sdata->vif.bss_conf.txpower) {
  		sdata->vif.bss_conf.txpower = power;
  		ieee80211_hw_config(sdata->local, 0);
  		return true;
  	}
  
  	return false;
  }

  void ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata,
  			      bool update_bss)

  {

  	if (__ieee80211_recalc_txpower(sdata) ||
  	    (update_bss && ieee80211_sdata_running(sdata)))

  		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_TXPOWER);
  }

  static u32 __ieee80211_idle_off(struct ieee80211_local *local)

  {
  	if (!(local->hw.conf.flags & IEEE80211_CONF_IDLE))
  		return 0;
  
  	local->hw.conf.flags &= ~IEEE80211_CONF_IDLE;
  	return IEEE80211_CONF_CHANGE_IDLE;
  }

  static u32 __ieee80211_idle_on(struct ieee80211_local *local)

  {
  	if (local->hw.conf.flags & IEEE80211_CONF_IDLE)
  		return 0;

  	ieee80211_flush_queues(local, NULL, false);

  
  	local->hw.conf.flags |= IEEE80211_CONF_IDLE;
  	return IEEE80211_CONF_CHANGE_IDLE;
  }

  static u32 __ieee80211_recalc_idle(struct ieee80211_local *local,
  				   bool force_active)

  {

  	bool working, scanning, active;

  	unsigned int led_trig_start = 0, led_trig_stop = 0;

  	lockdep_assert_held(&local->mtx);

  	active = force_active ||
  		 !list_empty(&local->chanctx_list) ||
  		 local->monitors;

  	working = !local->ops->remain_on_channel &&
  		  !list_empty(&local->roc_list);

  	scanning = test_bit(SCAN_SW_SCANNING, &local->scanning) ||
  		   test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);

  	if (working || scanning)
  		led_trig_start |= IEEE80211_TPT_LEDTRIG_FL_WORK;
  	else
  		led_trig_stop |= IEEE80211_TPT_LEDTRIG_FL_WORK;

  	if (active)

  		led_trig_start |= IEEE80211_TPT_LEDTRIG_FL_CONNECTED;
  	else
  		led_trig_stop |= IEEE80211_TPT_LEDTRIG_FL_CONNECTED;
  
  	ieee80211_mod_tpt_led_trig(local, led_trig_start, led_trig_stop);

  	if (working || scanning || active)

  		return __ieee80211_idle_off(local);
  	return __ieee80211_idle_on(local);
  }
  
  u32 ieee80211_idle_off(struct ieee80211_local *local)
  {
  	return __ieee80211_recalc_idle(local, true);
  }
  
  void ieee80211_recalc_idle(struct ieee80211_local *local)
  {
  	u32 change = __ieee80211_recalc_idle(local, false);

  	if (change)
  		ieee80211_hw_config(local, change);

  }

  static int ieee80211_verify_mac(struct ieee80211_sub_if_data *sdata, u8 *addr,

  				bool check_dup)

  {

  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_sub_if_data *iter;

  	u64 new, mask, tmp;
  	u8 *m;
  	int ret = 0;
  
  	if (is_zero_ether_addr(local->hw.wiphy->addr_mask))
  		return 0;
  
  	m = addr;
  	new =	((u64)m[0] << 5*8) | ((u64)m[1] << 4*8) |
  		((u64)m[2] << 3*8) | ((u64)m[3] << 2*8) |
  		((u64)m[4] << 1*8) | ((u64)m[5] << 0*8);
  
  	m = local->hw.wiphy->addr_mask;
  	mask =	((u64)m[0] << 5*8) | ((u64)m[1] << 4*8) |
  		((u64)m[2] << 3*8) | ((u64)m[3] << 2*8) |
  		((u64)m[4] << 1*8) | ((u64)m[5] << 0*8);

  	if (!check_dup)
  		return ret;

  
  	mutex_lock(&local->iflist_mtx);

  	list_for_each_entry(iter, &local->interfaces, list) {
  		if (iter == sdata)

  			continue;

  		if (iter->vif.type == NL80211_IFTYPE_MONITOR &&

  		    !(iter->u.mntr.flags & MONITOR_FLAG_ACTIVE))

  			continue;

  		m = iter->vif.addr;

  		tmp =	((u64)m[0] << 5*8) | ((u64)m[1] << 4*8) |
  			((u64)m[2] << 3*8) | ((u64)m[3] << 2*8) |
  			((u64)m[4] << 1*8) | ((u64)m[5] << 0*8);
  
  		if ((new & ~mask) != (tmp & ~mask)) {
  			ret = -EINVAL;
  			break;
  		}
  	}
  	mutex_unlock(&local->iflist_mtx);
  
  	return ret;
  }

  static int ieee80211_change_mac(struct net_device *dev, void *addr)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

  	struct sockaddr *sa = addr;

  	bool check_dup = true;

  	int ret;

  	if (ieee80211_sdata_running(sdata))

  		return -EBUSY;

  	if (sdata->vif.type == NL80211_IFTYPE_MONITOR &&

  	    !(sdata->u.mntr.flags & MONITOR_FLAG_ACTIVE))

  		check_dup = false;

  	ret = ieee80211_verify_mac(sdata, sa->sa_data, check_dup);

  	if (ret)
  		return ret;

  	ret = eth_mac_addr(dev, sa);

  
  	if (ret == 0)

  		memcpy(sdata->vif.addr, sa->sa_data, ETH_ALEN);

  
  	return ret;
  }

  static inline int identical_mac_addr_allowed(int type1, int type2)
  {
  	return type1 == NL80211_IFTYPE_MONITOR ||
  		type2 == NL80211_IFTYPE_MONITOR ||

  		type1 == NL80211_IFTYPE_P2P_DEVICE ||
  		type2 == NL80211_IFTYPE_P2P_DEVICE ||

  		(type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_WDS) ||
  		(type1 == NL80211_IFTYPE_WDS &&
  			(type2 == NL80211_IFTYPE_WDS ||
  			 type2 == NL80211_IFTYPE_AP)) ||
  		(type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_AP_VLAN) ||
  		(type1 == NL80211_IFTYPE_AP_VLAN &&
  			(type2 == NL80211_IFTYPE_AP ||
  			 type2 == NL80211_IFTYPE_AP_VLAN));
  }

  static int ieee80211_check_concurrent_iface(struct ieee80211_sub_if_data *sdata,
  					    enum nl80211_iftype iftype)

  {

  	struct ieee80211_local *local = sdata->local;

  	struct ieee80211_sub_if_data *nsdata;

  	int ret;

  	ASSERT_RTNL();

  
  	/* we hold the RTNL here so can safely walk the list */
  	list_for_each_entry(nsdata, &local->interfaces, list) {

  		if (nsdata != sdata && ieee80211_sdata_running(nsdata)) {

  			/*

  			 * Only OCB and monitor mode may coexist
  			 */
  			if ((sdata->vif.type == NL80211_IFTYPE_OCB &&
  			     nsdata->vif.type != NL80211_IFTYPE_MONITOR) ||
  			    (sdata->vif.type != NL80211_IFTYPE_MONITOR &&
  			     nsdata->vif.type == NL80211_IFTYPE_OCB))
  				return -EBUSY;
  
  			/*

  			 * 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 (iftype == NL80211_IFTYPE_ADHOC &&

  			    nsdata->vif.type == NL80211_IFTYPE_ADHOC)
  				return -EBUSY;

  			/*
  			 * will not add another interface while any channel
  			 * switch is active.
  			 */
  			if (nsdata->vif.csa_active)
  				return -EBUSY;

  
  			/*
  			 * The remaining checks are only performed for interfaces
  			 * with the same MAC address.
  			 */

  			if (!ether_addr_equal(sdata->vif.addr,
  					      nsdata->vif.addr))

  				continue;
  
  			/*
  			 * check whether it may have the same address
  			 */

  			if (!identical_mac_addr_allowed(iftype,

  							nsdata->vif.type))
  				return -ENOTUNIQ;
  
  			/*
  			 * can only add VLANs to enabled APs
  			 */

  			if (iftype == NL80211_IFTYPE_AP_VLAN &&

  			    nsdata->vif.type == NL80211_IFTYPE_AP)
  				sdata->bss = &nsdata->u.ap;
  		}
  	}

  	mutex_lock(&local->chanctx_mtx);
  	ret = ieee80211_check_combinations(sdata, NULL, 0, 0);
  	mutex_unlock(&local->chanctx_mtx);
  	return ret;

  }

  static int ieee80211_check_queues(struct ieee80211_sub_if_data *sdata,
  				  enum nl80211_iftype iftype)

  {
  	int n_queues = sdata->local->hw.queues;
  	int i;

  	if (iftype == NL80211_IFTYPE_NAN)
  		return 0;

  	if (iftype != NL80211_IFTYPE_P2P_DEVICE) {

  		for (i = 0; i < IEEE80211_NUM_ACS; i++) {
  			if (WARN_ON_ONCE(sdata->vif.hw_queue[i] ==
  					 IEEE80211_INVAL_HW_QUEUE))
  				return -EINVAL;
  			if (WARN_ON_ONCE(sdata->vif.hw_queue[i] >=
  					 n_queues))
  				return -EINVAL;
  		}

  	}

  	if ((iftype != NL80211_IFTYPE_AP &&
  	     iftype != NL80211_IFTYPE_P2P_GO &&
  	     iftype != NL80211_IFTYPE_MESH_POINT) ||

  	    !ieee80211_hw_check(&sdata->local->hw, QUEUE_CONTROL)) {

  		sdata->vif.cab_queue = IEEE80211_INVAL_HW_QUEUE;
  		return 0;
  	}
  
  	if (WARN_ON_ONCE(sdata->vif.cab_queue == IEEE80211_INVAL_HW_QUEUE))
  		return -EINVAL;
  
  	if (WARN_ON_ONCE(sdata->vif.cab_queue >= n_queues))
  		return -EINVAL;
  
  	return 0;
  }

  static int ieee80211_open(struct net_device *dev)

  {

  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	int err;
  
  	/* fail early if user set an invalid address */
  	if (!is_valid_ether_addr(dev->dev_addr))
  		return -EADDRNOTAVAIL;
  
  	err = ieee80211_check_concurrent_iface(sdata, sdata->vif.type);
  	if (err)
  		return err;
  
  	return ieee80211_do_open(&sdata->wdev, true);

  }

  static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
  			      bool going_down)

  {
  	struct ieee80211_local *local = sdata->local;

  	unsigned long flags;
  	struct sk_buff *skb, *tmp;
  	u32 hw_reconf_flags = 0;
  	int i, flushed;
  	struct ps_data *ps;
  	struct cfg80211_chan_def chandef;
  	bool cancel_scan;
  	struct cfg80211_nan_func *func;

  	clear_bit(SDATA_STATE_RUNNING, &sdata->state);

  	cancel_scan = rcu_access_pointer(local->scan_sdata) == sdata;
  	if (cancel_scan)
  		ieee80211_scan_cancel(local);

  	/*
  	 * Stop TX on this interface first.
  	 */
  	if (sdata->dev)
  		netif_tx_stop_all_queues(sdata->dev);

  	ieee80211_roc_purge(local, sdata);

  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_STATION:
  		ieee80211_mgd_stop(sdata);
  		break;
  	case NL80211_IFTYPE_ADHOC:
  		ieee80211_ibss_stop(sdata);
  		break;
  	case NL80211_IFTYPE_MONITOR:
  		if (sdata->u.mntr.flags & MONITOR_FLAG_COOK_FRAMES)
  			break;
  		list_del_rcu(&sdata->u.mntr.list);
  		break;
  	default:
  		break;
  	}

  	/*
  	 * 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!)
  	 *
  	 * In WDS mode a station must exist here and be flushed, for
  	 * AP_VLANs stations may exist since there's nothing else that
  	 * would have removed them, but in other modes there shouldn't
  	 * be any stations.
  	 */
  	flushed = sta_info_flush(sdata);
  	WARN_ON_ONCE(sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
  		     ((sdata->vif.type != NL80211_IFTYPE_WDS && flushed > 0) ||
  		      (sdata->vif.type == NL80211_IFTYPE_WDS && flushed != 1)));

  	/* don't count this interface for allmulti while it is down */
  	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
  		atomic_dec(&local->iff_allmultis);

  	if (sdata->vif.type == NL80211_IFTYPE_AP) {
  		local->fif_pspoll--;
  		local->fif_probe_req--;
  	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
  		local->fif_probe_req--;

  	}

  	if (sdata->dev) {
  		netif_addr_lock_bh(sdata->dev);
  		spin_lock_bh(&local->filter_lock);
  		__hw_addr_unsync(&local->mc_list, &sdata->dev->mc,
  				 sdata->dev->addr_len);
  		spin_unlock_bh(&local->filter_lock);
  		netif_addr_unlock_bh(sdata->dev);

  	}

  	del_timer_sync(&local->dynamic_ps_timer);
  	cancel_work_sync(&local->dynamic_ps_enable_work);

  	cancel_work_sync(&sdata->recalc_smps);
  	sdata_lock(sdata);
  	mutex_lock(&local->mtx);
  	sdata->vif.csa_active = false;
  	if (sdata->vif.type == NL80211_IFTYPE_STATION)
  		sdata->u.mgd.csa_waiting_bcn = false;
  	if (sdata->csa_block_tx) {
  		ieee80211_wake_vif_queues(local, sdata,
  					  IEEE80211_QUEUE_STOP_REASON_CSA);
  		sdata->csa_block_tx = false;

  	}

  	mutex_unlock(&local->mtx);
  	sdata_unlock(sdata);

  	cancel_work_sync(&sdata->csa_finalize_work);

  	cancel_delayed_work_sync(&sdata->dfs_cac_timer_work);

  	if (sdata->wdev.cac_started) {
  		chandef = sdata->vif.bss_conf.chandef;
  		WARN_ON(local->suspended);
  		mutex_lock(&local->mtx);
  		ieee80211_vif_release_channel(sdata);
  		mutex_unlock(&local->mtx);
  		cfg80211_cac_event(sdata->dev, &chandef,
  				   NL80211_RADAR_CAC_ABORTED,
  				   GFP_KERNEL);
  	}

  	/* APs need special treatment */
  	if (sdata->vif.type == NL80211_IFTYPE_AP) {
  		struct ieee80211_sub_if_data *vlan, *tmpsdata;

  		/* down all dependent devices, that is VLANs */
  		list_for_each_entry_safe(vlan, tmpsdata, &sdata->u.ap.vlans,
  					 u.vlan.list)
  			dev_close(vlan->dev);
  		WARN_ON(!list_empty(&sdata->u.ap.vlans));
  	} else if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
  		/* remove all packets in parent bc_buf pointing to this dev */
  		ps = &sdata->bss->ps;

  		spin_lock_irqsave(&ps->bc_buf.lock, flags);
  		skb_queue_walk_safe(&ps->bc_buf, skb, tmp) {
  			if (skb->dev == sdata->dev) {
  				__skb_unlink(skb, &ps->bc_buf);
  				local->total_ps_buffered--;
  				ieee80211_free_txskb(&local->hw, skb);
  			}
  		}
  		spin_unlock_irqrestore(&ps->bc_buf.lock, flags);

  	}

  	if (going_down)
  		local->open_count--;

  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_AP_VLAN:
  		mutex_lock(&local->mtx);
  		list_del(&sdata->u.vlan.list);
  		mutex_unlock(&local->mtx);
  		RCU_INIT_POINTER(sdata->vif.chanctx_conf, NULL);
  		/* see comment in the default case below */
  		ieee80211_free_keys(sdata, true);
  		/* no need to tell driver */
  		break;
  	case NL80211_IFTYPE_MONITOR:
  		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_MONITOR;
  			hw_reconf_flags |= IEEE80211_CONF_CHANGE_MONITOR;
  		}

  		ieee80211_adjust_monitor_flags(sdata, -1);
  		break;
  	case NL80211_IFTYPE_NAN:
  		/* clean all the functions */
  		spin_lock_bh(&sdata->u.nan.func_lock);

  		idr_for_each_entry(&sdata->u.nan.function_inst_ids, func, i) {
  			idr_remove(&sdata->u.nan.function_inst_ids, i);
  			cfg80211_free_nan_func(func);
  		}
  		idr_destroy(&sdata->u.nan.function_inst_ids);

  		spin_unlock_bh(&sdata->u.nan.func_lock);
  		break;
  	case NL80211_IFTYPE_P2P_DEVICE:
  		/* relies on synchronize_rcu() below */
  		RCU_INIT_POINTER(local->p2p_sdata, NULL);
  		fallthrough;
  	default:
  		cancel_work_sync(&sdata->work);
  		/*
  		 * When we get here, the interface is marked down.
  		 * Free the remaining keys, if there are any
  		 * (which can happen in AP mode if userspace sets
  		 * keys before the interface is operating, and maybe
  		 * also in WDS mode)
  		 *
  		 * Force the key freeing to always synchronize_net()
  		 * to wait for the RX path in case it is using this
  		 * interface enqueuing frames at this very time on
  		 * another CPU.
  		 */
  		ieee80211_free_keys(sdata, true);
  		skb_queue_purge(&sdata->skb_queue);

  	}

  	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
  	for (i = 0; i < IEEE80211_MAX_QUEUES; i++) {
  		skb_queue_walk_safe(&local->pending[i], skb, tmp) {
  			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  			if (info->control.vif == &sdata->vif) {
  				__skb_unlink(skb, &local->pending[i]);
  				ieee80211_free_txskb(&local->hw, skb);
  			}
  		}

  	}

  	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);

  	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  		ieee80211_txq_remove_vlan(local, sdata);

  	sdata->bss = NULL;
  
  	if (local->open_count == 0)
  		ieee80211_clear_tx_pending(local);
  
  	sdata->vif.bss_conf.beacon_int = 0;
  
  	/*
  	 * If the interface goes down while suspended, presumably because
  	 * the device was unplugged and that happens before our resume,
  	 * then the driver is already unconfigured and the remainder of
  	 * this function isn't needed.
  	 * XXX: what about WoWLAN? If the device has software state, e.g.
  	 *	memory allocated, it might expect teardown commands from
  	 *	mac80211 here?
  	 */
  	if (local->suspended) {
  		WARN_ON(local->wowlan);
  		WARN_ON(rtnl_dereference(local->monitor_sdata));
  		return;

  	}

  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_AP_VLAN:
  		break;
  	case NL80211_IFTYPE_MONITOR:
  		if (local->monitors == 0)
  			ieee80211_del_virtual_monitor(local);

  		mutex_lock(&local->mtx);
  		ieee80211_recalc_idle(local);
  		mutex_unlock(&local->mtx);

  		if (!(sdata->u.mntr.flags & MONITOR_FLAG_ACTIVE))
  			break;

  		fallthrough;
  	default:
  		if (going_down)
  			drv_remove_interface(local, sdata);
  	}

  	ieee80211_recalc_ps(local);

  	if (cancel_scan)
  		flush_delayed_work(&local->scan_work);

  	if (local->open_count == 0) {
  		ieee80211_stop_device(local);
  
  		/* no reconfiguring after stop! */

  		return;
  	}

  	/* do after stop to avoid reconfiguring when we stop anyway */
  	ieee80211_configure_filter(local);
  	ieee80211_hw_config(local, hw_reconf_flags);

  	if (local->monitors == local->open_count)
  		ieee80211_add_virtual_monitor(local);
  }

  static int ieee80211_stop(struct net_device *dev)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

  	ieee80211_do_stop(sdata, true);

  	return 0;

  }

  static void ieee80211_set_multicast_list(struct net_device *dev)

  {

  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

  	struct ieee80211_local *local = sdata->local;

  	int allmulti, sdata_allmulti;

  	allmulti = !!(dev->flags & IFF_ALLMULTI);
  	sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);

  	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;
  	}

  	spin_lock_bh(&local->filter_lock);
  	__hw_addr_sync(&local->mc_list, &dev->mc, dev->addr_len);
  	spin_unlock_bh(&local->filter_lock);
  	ieee80211_queue_work(&local->hw, &local->reconfig_filter);
  }

  /*
   * Called when the netdev is removed or, by the code below, before
   * the interface type changes.
   */
  static void ieee80211_teardown_sdata(struct ieee80211_sub_if_data *sdata)
  {
  	int i;

  	/* free extra data */
  	ieee80211_free_keys(sdata, false);

  	ieee80211_debugfs_remove_netdev(sdata);

  	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
  		__skb_queue_purge(&sdata->fragments[i].skb_list);
  	sdata->fragment_next = 0;

  	if (ieee80211_vif_is_mesh(&sdata->vif))
  		ieee80211_mesh_teardown_sdata(sdata);
  }

  static void ieee80211_uninit(struct net_device *dev)
  {
  	ieee80211_teardown_sdata(IEEE80211_DEV_TO_SUB_IF(dev));
  }

  static u16 ieee80211_netdev_select_queue(struct net_device *dev,
  					 struct sk_buff *skb,
  					 struct net_device *sb_dev)
  {
  	return ieee80211_select_queue(IEEE80211_DEV_TO_SUB_IF(dev), skb);
  }

  static void
  ieee80211_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
  {

  	dev_fetch_sw_netstats(stats, dev->tstats);

  }

  static const struct net_device_ops ieee80211_dataif_ops = {
  	.ndo_open		= ieee80211_open,
  	.ndo_stop		= ieee80211_stop,
  	.ndo_uninit		= ieee80211_uninit,
  	.ndo_start_xmit		= ieee80211_subif_start_xmit,
  	.ndo_set_rx_mode	= ieee80211_set_multicast_list,
  	.ndo_set_mac_address 	= ieee80211_change_mac,
  	.ndo_select_queue	= ieee80211_netdev_select_queue,
  	.ndo_get_stats64	= ieee80211_get_stats64,
  };

  static u16 ieee80211_monitor_select_queue(struct net_device *dev,
  					  struct sk_buff *skb,
  					  struct net_device *sb_dev)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  	struct ieee80211_hdr *hdr;
  	int len_rthdr;

  	if (local->hw.queues < IEEE80211_NUM_ACS)
  		return 0;

  	/* reset flags and info before parsing radiotap header */
  	memset(info, 0, sizeof(*info));

  	if (!ieee80211_parse_tx_radiotap(skb, dev))
  		return 0; /* doesn't matter, frame will be dropped */

  	len_rthdr = ieee80211_get_radiotap_len(skb->data);
  	hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
  	if (skb->len < len_rthdr + 2 ||
  	    skb->len < len_rthdr + ieee80211_hdrlen(hdr->frame_control))
  		return 0; /* doesn't matter, frame will be dropped */

  	return ieee80211_select_queue_80211(sdata, skb, hdr);
  }

  static const struct net_device_ops ieee80211_monitorif_ops = {
  	.ndo_open		= ieee80211_open,
  	.ndo_stop		= ieee80211_stop,
  	.ndo_uninit		= ieee80211_uninit,
  	.ndo_start_xmit		= ieee80211_monitor_start_xmit,
  	.ndo_set_rx_mode	= ieee80211_set_multicast_list,
  	.ndo_set_mac_address 	= ieee80211_change_mac,
  	.ndo_select_queue	= ieee80211_monitor_select_queue,
  	.ndo_get_stats64	= ieee80211_get_stats64,
  };

  static const struct net_device_ops ieee80211_dataif_8023_ops = {
  	.ndo_open		= ieee80211_open,
  	.ndo_stop		= ieee80211_stop,
  	.ndo_uninit		= ieee80211_uninit,
  	.ndo_start_xmit		= ieee80211_subif_start_xmit_8023,
  	.ndo_set_rx_mode	= ieee80211_set_multicast_list,
  	.ndo_set_mac_address	= ieee80211_change_mac,
  	.ndo_select_queue	= ieee80211_netdev_select_queue,
  	.ndo_get_stats64	= ieee80211_get_stats64,
  };

  static bool ieee80211_iftype_supports_encap_offload(enum nl80211_iftype iftype)
  {
  	switch (iftype) {
  	/* P2P GO and client are mapped to AP/STATION types */
  	case NL80211_IFTYPE_AP:
  	case NL80211_IFTYPE_STATION:
  		return true;

  	default:

  		return false;

  	}

  }

  static bool ieee80211_set_sdata_offload_flags(struct ieee80211_sub_if_data *sdata)
  {
  	struct ieee80211_local *local = sdata->local;
  	u32 flags;

  	flags = sdata->vif.offload_flags;

  	if (ieee80211_hw_check(&local->hw, SUPPORTS_TX_ENCAP_OFFLOAD) &&
  	    ieee80211_iftype_supports_encap_offload(sdata->vif.type)) {
  		flags |= IEEE80211_OFFLOAD_ENCAP_ENABLED;

  		if (!ieee80211_hw_check(&local->hw, SUPPORTS_TX_FRAG) &&
  		    local->hw.wiphy->frag_threshold != (u32)-1)
  			flags &= ~IEEE80211_OFFLOAD_ENCAP_ENABLED;

  		if (local->monitors)
  			flags &= ~IEEE80211_OFFLOAD_ENCAP_ENABLED;
  	} else {
  		flags &= ~IEEE80211_OFFLOAD_ENCAP_ENABLED;

  	}

  	if (sdata->vif.offload_flags == flags)
  		return false;
  
  	sdata->vif.offload_flags = flags;
  	return true;

  }

  static void ieee80211_set_vif_encap_ops(struct ieee80211_sub_if_data *sdata)

  {

  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_sub_if_data *bss = sdata;
  	bool enabled;

  	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
  		if (!sdata->bss)
  			return;

  		bss = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
  	}

  	if (!ieee80211_hw_check(&local->hw, SUPPORTS_TX_ENCAP_OFFLOAD) ||
  	    !ieee80211_iftype_supports_encap_offload(bss->vif.type))
  		return;

  	enabled = bss->vif.offload_flags & IEEE80211_OFFLOAD_ENCAP_ENABLED;
  	if (sdata->wdev.use_4addr &&
  	    !(bss->vif.offload_flags & IEEE80211_OFFLOAD_ENCAP_4ADDR))
  		enabled = false;

  	sdata->dev->netdev_ops = enabled ? &ieee80211_dataif_8023_ops :
  					   &ieee80211_dataif_ops;
  }

  static void ieee80211_recalc_sdata_offload(struct ieee80211_sub_if_data *sdata)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_sub_if_data *vsdata;

  	if (ieee80211_set_sdata_offload_flags(sdata)) {
  		drv_update_vif_offload(local, sdata);
  		ieee80211_set_vif_encap_ops(sdata);
  	}

  	list_for_each_entry(vsdata, &local->interfaces, list) {
  		if (vsdata->vif.type != NL80211_IFTYPE_AP_VLAN ||
  		    vsdata->bss != &sdata->u.ap)
  			continue;

  		ieee80211_set_vif_encap_ops(vsdata);

  	}

  }

  void ieee80211_recalc_offload(struct ieee80211_local *local)
  {
  	struct ieee80211_sub_if_data *sdata;

  	if (!ieee80211_hw_check(&local->hw, SUPPORTS_TX_ENCAP_OFFLOAD))
  		return;

  	mutex_lock(&local->iflist_mtx);

  	list_for_each_entry(sdata, &local->interfaces, list) {
  		if (!ieee80211_sdata_running(sdata))
  			continue;
  
  		ieee80211_recalc_sdata_offload(sdata);

  	}

  	mutex_unlock(&local->iflist_mtx);
  }

  void ieee80211_adjust_monitor_flags(struct ieee80211_sub_if_data *sdata,
  				    const int offset)
  {
  	struct ieee80211_local *local = sdata->local;
  	u32 flags = sdata->u.mntr.flags;

  #define ADJUST(_f, _s)	do {					\
  	if (flags & MONITOR_FLAG_##_f)				\
  		local->fif_##_s += offset;			\
  	} while (0)

  	ADJUST(FCSFAIL, fcsfail);
  	ADJUST(PLCPFAIL, plcpfail);
  	ADJUST(CONTROL, control);
  	ADJUST(CONTROL, pspoll);
  	ADJUST(OTHER_BSS, other_bss);

  #undef ADJUST
  }
  
  static void ieee80211_set_default_queues(struct ieee80211_sub_if_data *sdata)
  {
  	struct ieee80211_local *local = sdata->local;
  	int i;
  
  	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
  		if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
  			sdata->vif.hw_queue[i] = IEEE80211_INVAL_HW_QUEUE;
  		else if (local->hw.queues >= IEEE80211_NUM_ACS)
  			sdata->vif.hw_queue[i] = i;
  		else
  			sdata->vif.hw_queue[i] = 0;

  	}

  	sdata->vif.cab_queue = IEEE80211_INVAL_HW_QUEUE;
  }

  int ieee80211_add_virtual_monitor(struct ieee80211_local *local)
  {
  	struct ieee80211_sub_if_data *sdata;
  	int ret;

  	if (!ieee80211_hw_check(&local->hw, WANT_MONITOR_VIF))
  		return 0;

  	ASSERT_RTNL();

  	if (local->monitor_sdata)
  		return 0;

  	sdata = kzalloc(sizeof(*sdata) + local->hw.vif_data_size, GFP_KERNEL);
  	if (!sdata)
  		return -ENOMEM;

  	/* set up data */
  	sdata->local = local;
  	sdata->vif.type = NL80211_IFTYPE_MONITOR;
  	snprintf(sdata->name, IFNAMSIZ, "%s-monitor",
  		 wiphy_name(local->hw.wiphy));
  	sdata->wdev.iftype = NL80211_IFTYPE_MONITOR;

  	sdata->encrypt_headroom = IEEE80211_ENCRYPT_HEADROOM;

  	ieee80211_set_default_queues(sdata);

  	ret = drv_add_interface(local, sdata);
  	if (WARN_ON(ret)) {
  		/* ok .. stupid driver, it asked for this! */
  		kfree(sdata);
  		return ret;
  	}

  	set_bit(SDATA_STATE_RUNNING, &sdata->state);

  	ret = ieee80211_check_queues(sdata, NL80211_IFTYPE_MONITOR);
  	if (ret) {
  		kfree(sdata);
  		return ret;

  	}

  	mutex_lock(&local->iflist_mtx);
  	rcu_assign_pointer(local->monitor_sdata, sdata);
  	mutex_unlock(&local->iflist_mtx);
  
  	mutex_lock(&local->mtx);
  	ret = ieee80211_vif_use_channel(sdata, &local->monitor_chandef,
  					IEEE80211_CHANCTX_EXCLUSIVE);
  	mutex_unlock(&local->mtx);
  	if (ret) {
  		mutex_lock(&local->iflist_mtx);
  		RCU_INIT_POINTER(local->monitor_sdata, NULL);
  		mutex_unlock(&local->iflist_mtx);
  		synchronize_net();
  		drv_remove_interface(local, sdata);
  		kfree(sdata);
  		return ret;

  	}

  	skb_queue_head_init(&sdata->skb_queue);
  	INIT_WORK(&sdata->work, ieee80211_iface_work);

  	return 0;
  }

  void ieee80211_del_virtual_monitor(struct ieee80211_local *local)
  {
  	struct ieee80211_sub_if_data *sdata;

  	if (!ieee80211_hw_check(&local->hw, WANT_MONITOR_VIF))
  		return;

  	ASSERT_RTNL();
  
  	mutex_lock(&local->iflist_mtx);
  
  	sdata = rcu_dereference_protected(local->monitor_sdata,
  					  lockdep_is_held(&local->iflist_mtx));
  	if (!sdata) {
  		mutex_unlock(&local->iflist_mtx);

  		return;
  	}

  	RCU_INIT_POINTER(local->monitor_sdata, NULL);
  	mutex_unlock(&local->iflist_mtx);
  
  	synchronize_net();
  
  	mutex_lock(&local->mtx);
  	ieee80211_vif_release_channel(sdata);
  	mutex_unlock(&local->mtx);
  
  	drv_remove_interface(local, sdata);
  
  	kfree(sdata);
  }
  
  /*
   * NOTE: Be very careful when changing this function, it must NOT return
   * an error on interface type changes that have been pre-checked, so most
   * checks should be in ieee80211_check_concurrent_iface.
   */
  int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
  	struct net_device *dev = wdev->netdev;
  	struct ieee80211_local *local = sdata->local;
  	struct sta_info *sta;
  	u32 changed = 0;
  	int res;
  	u32 hw_reconf_flags = 0;

  	switch (sdata->vif.type) {

  	case NL80211_IFTYPE_WDS:
  		if (!is_valid_ether_addr(sdata->u.wds.remote_addr))
  			return -ENOLINK;

  		break;

  	case NL80211_IFTYPE_AP_VLAN: {
  		struct ieee80211_sub_if_data *master;
  
  		if (!sdata->bss)
  			return -ENOLINK;

  
  		mutex_lock(&local->mtx);

  		list_add(&sdata->u.vlan.list, &sdata->bss->vlans);

  		mutex_unlock(&local->mtx);

  		master = container_of(sdata->bss,
  				      struct ieee80211_sub_if_data, u.ap);
  		sdata->control_port_protocol =
  			master->control_port_protocol;
  		sdata->control_port_no_encrypt =
  			master->control_port_no_encrypt;
  		sdata->control_port_over_nl80211 =
  			master->control_port_over_nl80211;
  		sdata->control_port_no_preauth =
  			master->control_port_no_preauth;
  		sdata->vif.cab_queue = master->vif.cab_queue;
  		memcpy(sdata->vif.hw_queue, master->vif.hw_queue,
  		       sizeof(sdata->vif.hw_queue));
  		sdata->vif.bss_conf.chandef = master->vif.bss_conf.chandef;

  		mutex_lock(&local->key_mtx);
  		sdata->crypto_tx_tailroom_needed_cnt +=
  			master->crypto_tx_tailroom_needed_cnt;
  		mutex_unlock(&local->key_mtx);

  		break;
  		}
  	case NL80211_IFTYPE_AP:
  		sdata->bss = &sdata->u.ap;
  		break;
  	case NL80211_IFTYPE_MESH_POINT:
  	case NL80211_IFTYPE_STATION:
  	case NL80211_IFTYPE_MONITOR:
  	case NL80211_IFTYPE_ADHOC:
  	case NL80211_IFTYPE_P2P_DEVICE:
  	case NL80211_IFTYPE_OCB:
  	case NL80211_IFTYPE_NAN:
  		/* no special treatment */
  		break;
  	case NL80211_IFTYPE_UNSPECIFIED:
  	case NUM_NL80211_IFTYPES:
  	case NL80211_IFTYPE_P2P_CLIENT:
  	case NL80211_IFTYPE_P2P_GO:
  		/* cannot happen */
  		WARN_ON(1);
  		break;
  	}

  	if (local->open_count == 0) {

  		res = drv_start(local);
  		if (res)
  			goto err_del_bss;
  		/* we're brought up, everything changes */
  		hw_reconf_flags = ~0;
  		ieee80211_led_radio(local, true);
  		ieee80211_mod_tpt_led_trig(local,
  					   IEEE80211_TPT_LEDTRIG_FL_RADIO, 0);

  	}

  	/*
  	 * Copy the hopefully now-present MAC address to
  	 * this interface, if it has the special null one.
  	 */
  	if (dev && is_zero_ether_addr(dev->dev_addr)) {
  		memcpy(dev->dev_addr,
  		       local->hw.wiphy->perm_addr,
  		       ETH_ALEN);
  		memcpy(dev->perm_addr, dev->dev_addr, ETH_ALEN);

  		if (!is_valid_ether_addr(dev->dev_addr)) {
  			res = -EADDRNOTAVAIL;
  			goto err_stop;
  		}
  	}

  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_AP_VLAN:
  		/* no need to tell driver, but set carrier and chanctx */
  		if (rtnl_dereference(sdata->bss->beacon)) {
  			ieee80211_vif_vlan_copy_chanctx(sdata);
  			netif_carrier_on(dev);
  			ieee80211_set_vif_encap_ops(sdata);
  		} else {
  			netif_carrier_off(dev);
  		}
  		break;
  	case NL80211_IFTYPE_MONITOR:
  		if (sdata->u.mntr.flags & MONITOR_FLAG_COOK_FRAMES) {
  			local->cooked_mntrs++;
  			break;
  		}

  		if (sdata->u.mntr.flags & MONITOR_FLAG_ACTIVE) {
  			res = drv_add_interface(local, sdata);
  			if (res)
  				goto err_stop;
  		} else if (local->monitors == 0 && local->open_count == 0) {
  			res = ieee80211_add_virtual_monitor(local);
  			if (res)
  				goto err_stop;
  		}

  		/* must be before the call to ieee80211_configure_filter */
  		local->monitors++;
  		if (local->monitors == 1) {
  			local->hw.conf.flags |= IEEE80211_CONF_MONITOR;
  			hw_reconf_flags |= IEEE80211_CONF_CHANGE_MONITOR;
  		}

  		ieee80211_adjust_monitor_flags(sdata, 1);
  		ieee80211_configure_filter(local);
  		ieee80211_recalc_offload(local);
  		mutex_lock(&local->mtx);
  		ieee80211_recalc_idle(local);
  		mutex_unlock(&local->mtx);

  		netif_carrier_on(dev);
  		break;
  	default:
  		if (coming_up) {
  			ieee80211_del_virtual_monitor(local);
  			ieee80211_set_sdata_offload_flags(sdata);

  			res = drv_add_interface(local, sdata);
  			if (res)
  				goto err_stop;

  			ieee80211_set_vif_encap_ops(sdata);
  			res = ieee80211_check_queues(sdata,
  				ieee80211_vif_type_p2p(&sdata->vif));
  			if (res)
  				goto err_del_interface;
  		}

  		if (sdata->vif.type == NL80211_IFTYPE_AP) {
  			local->fif_pspoll++;
  			local->fif_probe_req++;

  			ieee80211_configure_filter(local);
  		} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
  			local->fif_probe_req++;
  		}

  		if (sdata->vif.probe_req_reg)
  			drv_config_iface_filter(local, sdata,
  						FIF_PROBE_REQ,
  						FIF_PROBE_REQ);

  		if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
  		    sdata->vif.type != NL80211_IFTYPE_NAN)
  			changed |= ieee80211_reset_erp_info(sdata);
  		ieee80211_bss_info_change_notify(sdata, changed);

  		switch (sdata->vif.type) {
  		case NL80211_IFTYPE_STATION:
  		case NL80211_IFTYPE_ADHOC:
  		case NL80211_IFTYPE_AP:
  		case NL80211_IFTYPE_MESH_POINT:
  		case NL80211_IFTYPE_OCB:
  			netif_carrier_off(dev);
  			break;
  		case NL80211_IFTYPE_WDS:
  		case NL80211_IFTYPE_P2P_DEVICE:
  		case NL80211_IFTYPE_NAN:
  			break;
  		default:
  			/* not reached */
  			WARN_ON(1);
  		}

  		/*
  		 * Set default queue parameters so drivers don't
  		 * need to initialise the hardware if the hardware
  		 * doesn't start up with sane defaults.
  		 * Enable QoS for anything but station interfaces.
  		 */
  		ieee80211_set_wmm_default(sdata, true,
  			sdata->vif.type != NL80211_IFTYPE_STATION);
  	}

  	set_bit(SDATA_STATE_RUNNING, &sdata->state);

  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_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;
  		}

  		sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
  		sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
  		sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);

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

  		rate_control_rate_init(sta);
  		netif_carrier_on(dev);
  		break;
  	case NL80211_IFTYPE_P2P_DEVICE:
  		rcu_assign_pointer(local->p2p_sdata, sdata);
  		break;
  	case NL80211_IFTYPE_MONITOR:
  		if (sdata->u.mntr.flags & MONITOR_FLAG_COOK_FRAMES)
  			break;
  		list_add_tail_rcu(&sdata->u.mntr.list, &local->mon_list);
  		break;
  	default:
  		break;

  	}

  	/*
  	 * 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 (coming_up)
  		local->open_count++;

  	if (hw_reconf_flags)
  		ieee80211_hw_config(local, hw_reconf_flags);

  	ieee80211_recalc_ps(local);

  	if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
  	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
  	    local->ops->wake_tx_queue) {
  		/* XXX: for AP_VLAN, actually track AP queues */
  		if (dev)
  			netif_tx_start_all_queues(dev);
  	} else if (dev) {
  		unsigned long flags;
  		int n_acs = IEEE80211_NUM_ACS;
  		int ac;

  		if (local->hw.queues < IEEE80211_NUM_ACS)
  			n_acs = 1;

  		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
  		if (sdata->vif.cab_queue == IEEE80211_INVAL_HW_QUEUE ||
  		    (local->queue_stop_reasons[sdata->vif.cab_queue] == 0 &&
  		     skb_queue_empty(&local->pending[sdata->vif.cab_queue]))) {
  			for (ac = 0; ac < n_acs; ac++) {
  				int ac_queue = sdata->vif.hw_queue[ac];

  				if (local->queue_stop_reasons[ac_queue] == 0 &&
  				    skb_queue_empty(&local->pending[ac_queue]))
  					netif_start_subqueue(dev, ac);
  			}
  		}
  		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
  	}

  	return 0;
   err_del_interface:
  	drv_remove_interface(local, sdata);
   err_stop:
  	if (!local->open_count)
  		drv_stop(local);
   err_del_bss:
  	sdata->bss = NULL;
  	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
  		mutex_lock(&local->mtx);
  		list_del(&sdata->u.vlan.list);
  		mutex_unlock(&local->mtx);
  	}
  	/* might already be clear but that doesn't matter */
  	clear_bit(SDATA_STATE_RUNNING, &sdata->state);
  	return res;
  }

  static void ieee80211_if_free(struct net_device *dev)
  {
  	free_percpu(dev->tstats);

  }

  static void ieee80211_if_setup(struct net_device *dev)
  {
  	ether_setup(dev);

  	dev->priv_flags &= ~IFF_TX_SKB_SHARING;

  	dev->netdev_ops = &ieee80211_dataif_ops;

  	dev->needs_free_netdev = true;
  	dev->priv_destructor = ieee80211_if_free;

  }

  static void ieee80211_if_setup_no_queue(struct net_device *dev)
  {
  	ieee80211_if_setup(dev);
  	dev->priv_flags |= IFF_NO_QUEUE;
  }

  static void ieee80211_iface_work(struct work_struct *work)
  {
  	struct ieee80211_sub_if_data *sdata =
  		container_of(work, struct ieee80211_sub_if_data, work);
  	struct ieee80211_local *local = sdata->local;
  	struct sk_buff *skb;

  	struct sta_info *sta;

  
  	if (!ieee80211_sdata_running(sdata))
  		return;

  	if (test_bit(SCAN_SW_SCANNING, &local->scanning))

  		return;

  	if (!ieee80211_can_run_worker(local))

  		return;
  
  	/* first process frames */
  	while ((skb = skb_dequeue(&sdata->skb_queue))) {

  		struct ieee80211_mgmt *mgmt = (void *)skb->data;

  		if (ieee80211_is_action(mgmt->frame_control) &&
  		    mgmt->u.action.category == WLAN_CATEGORY_BACK) {

  			int len = skb->len;

  			mutex_lock(&local->sta_mtx);

  			sta = sta_info_get_bss(sdata, mgmt->sa);

  			if (sta) {
  				switch (mgmt->u.action.u.addba_req.action_code) {
  				case WLAN_ACTION_ADDBA_REQ:
  					ieee80211_process_addba_request(
  							local, sta, mgmt, len);
  					break;
  				case WLAN_ACTION_ADDBA_RESP:
  					ieee80211_process_addba_resp(local, sta,
  								     mgmt, len);
  					break;
  				case WLAN_ACTION_DELBA:
  					ieee80211_process_delba(sdata, sta,
  								mgmt, len);
  					break;
  				default:
  					WARN_ON(1);
  					break;
  				}
  			}

  			mutex_unlock(&local->sta_mtx);

  		} else if (ieee80211_is_action(mgmt->frame_control) &&
  			   mgmt->u.action.category == WLAN_CATEGORY_VHT) {
  			switch (mgmt->u.action.u.vht_group_notif.action_code) {

  			case WLAN_VHT_ACTION_OPMODE_NOTIF: {
  				struct ieee80211_rx_status *status;
  				enum nl80211_band band;
  				u8 opmode;
  
  				status = IEEE80211_SKB_RXCB(skb);
  				band = status->band;
  				opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
  
  				mutex_lock(&local->sta_mtx);
  				sta = sta_info_get_bss(sdata, mgmt->sa);
  
  				if (sta)
  					ieee80211_vht_handle_opmode(sdata, sta,
  								    opmode,
  								    band);
  
  				mutex_unlock(&local->sta_mtx);
  				break;
  			}

  			case WLAN_VHT_ACTION_GROUPID_MGMT:
  				ieee80211_process_mu_groups(sdata, mgmt);
  				break;
  			default:
  				WARN_ON(1);
  				break;
  			}

  		} else if (ieee80211_is_ext(mgmt->frame_control)) {
  			if (sdata->vif.type == NL80211_IFTYPE_STATION)
  				ieee80211_sta_rx_queued_ext(sdata, skb);
  			else
  				WARN_ON(1);

  		} else if (ieee80211_is_data_qos(mgmt->frame_control)) {
  			struct ieee80211_hdr *hdr = (void *)mgmt;
  			/*
  			 * So the frame isn't mgmt, but frame_control
  			 * is at the right place anyway, of course, so
  			 * the if statement is correct.
  			 *
  			 * Warn if we have other data frame types here,
  			 * they must not get here.
  			 */
  			WARN_ON(hdr->frame_control &
  					cpu_to_le16(IEEE80211_STYPE_NULLFUNC));
  			WARN_ON(!(hdr->seq_ctrl &
  					cpu_to_le16(IEEE80211_SCTL_FRAG)));
  			/*
  			 * This was a fragment of a frame, received while
  			 * a block-ack session was active. That cannot be
  			 * right, so terminate the session.
  			 */

  			mutex_lock(&local->sta_mtx);

  			sta = sta_info_get_bss(sdata, mgmt->sa);

  			if (sta) {

  				u16 tid = ieee80211_get_tid(hdr);

  
  				__ieee80211_stop_rx_ba_session(
  					sta, tid, WLAN_BACK_RECIPIENT,

  					WLAN_REASON_QSTA_REQUIRE_SETUP,
  					true);

  			}

  			mutex_unlock(&local->sta_mtx);

  		} else switch (sdata->vif.type) {

  		case NL80211_IFTYPE_STATION:
  			ieee80211_sta_rx_queued_mgmt(sdata, skb);
  			break;
  		case NL80211_IFTYPE_ADHOC:
  			ieee80211_ibss_rx_queued_mgmt(sdata, skb);
  			break;
  		case NL80211_IFTYPE_MESH_POINT:
  			if (!ieee80211_vif_is_mesh(&sdata->vif))
  				break;
  			ieee80211_mesh_rx_queued_mgmt(sdata, skb);
  			break;
  		default:
  			WARN(1, "frame for unexpected interface type");

  			break;
  		}

  
  		kfree_skb(skb);

  	}
  
  	/* then other type-dependent work */
  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_STATION:
  		ieee80211_sta_work(sdata);
  		break;
  	case NL80211_IFTYPE_ADHOC:
  		ieee80211_ibss_work(sdata);
  		break;
  	case NL80211_IFTYPE_MESH_POINT:
  		if (!ieee80211_vif_is_mesh(&sdata->vif))
  			break;
  		ieee80211_mesh_work(sdata);
  		break;

  	case NL80211_IFTYPE_OCB:
  		ieee80211_ocb_work(sdata);
  		break;

  	default:
  		break;
  	}
  }

  static void ieee80211_recalc_smps_work(struct work_struct *work)
  {
  	struct ieee80211_sub_if_data *sdata =
  		container_of(work, struct ieee80211_sub_if_data, recalc_smps);
  
  	ieee80211_recalc_smps(sdata);
  }

  /*
   * Helper function to initialise an interface to a specific type.
   */
  static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,

  				  enum nl80211_iftype type)

  {

  	static const u8 bssid_wildcard[ETH_ALEN] = {0xff, 0xff, 0xff,
  						    0xff, 0xff, 0xff};

  	/* clear type-dependent union */
  	memset(&sdata->u, 0, sizeof(sdata->u));
  
  	/* and set some type-dependent values */
  	sdata->vif.type = type;

  	sdata->vif.p2p = false;

  	sdata->wdev.iftype = type;

  	sdata->control_port_protocol = cpu_to_be16(ETH_P_PAE);
  	sdata->control_port_no_encrypt = false;

  	sdata->control_port_over_nl80211 = false;
  	sdata->control_port_no_preauth = false;

  	sdata->encrypt_headroom = IEEE80211_ENCRYPT_HEADROOM;

  	sdata->vif.bss_conf.idle = true;

  	sdata->vif.bss_conf.txpower = INT_MIN; /* unset */

  	sdata->noack_map = 0;

  	/* only monitor/p2p-device differ */
  	if (sdata->dev) {
  		sdata->dev->netdev_ops = &ieee80211_dataif_ops;
  		sdata->dev->type = ARPHRD_ETHER;
  	}

  	skb_queue_head_init(&sdata->skb_queue);

  	INIT_WORK(&sdata->work, ieee80211_iface_work);

  	INIT_WORK(&sdata->recalc_smps, ieee80211_recalc_smps_work);

  	INIT_WORK(&sdata->csa_finalize_work, ieee80211_csa_finalize_work);

  	INIT_LIST_HEAD(&sdata->assigned_chanctx_list);

  	INIT_LIST_HEAD(&sdata->reserved_chanctx_list);

  	switch (type) {

  	case NL80211_IFTYPE_P2P_GO:
  		type = NL80211_IFTYPE_AP;
  		sdata->vif.type = type;
  		sdata->vif.p2p = true;

  		fallthrough;

  	case NL80211_IFTYPE_AP:

  		skb_queue_head_init(&sdata->u.ap.ps.bc_buf);

  		INIT_LIST_HEAD(&sdata->u.ap.vlans);

  		sdata->vif.bss_conf.bssid = sdata->vif.addr;

  		break;

  	case NL80211_IFTYPE_P2P_CLIENT:
  		type = NL80211_IFTYPE_STATION;
  		sdata->vif.type = type;
  		sdata->vif.p2p = true;

  		fallthrough;

  	case NL80211_IFTYPE_STATION:

  		sdata->vif.bss_conf.bssid = sdata->u.mgd.bssid;

  		ieee80211_sta_setup_sdata(sdata);

  		break;

  	case NL80211_IFTYPE_OCB:

  		sdata->vif.bss_conf.bssid = bssid_wildcard;
  		ieee80211_ocb_setup_sdata(sdata);

  		break;

  	case NL80211_IFTYPE_ADHOC:

  		sdata->vif.bss_conf.bssid = sdata->u.ibss.bssid;

  		ieee80211_ibss_setup_sdata(sdata);
  		break;

  	case NL80211_IFTYPE_MESH_POINT:

  		if (ieee80211_vif_is_mesh(&sdata->vif))
  			ieee80211_mesh_init_sdata(sdata);
  		break;

  	case NL80211_IFTYPE_MONITOR:

  		sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;

  		sdata->dev->netdev_ops = &ieee80211_monitorif_ops;

  		sdata->u.mntr.flags = MONITOR_FLAG_CONTROL |

  				      MONITOR_FLAG_OTHER_BSS;
  		break;

  	case NL80211_IFTYPE_WDS:

  		sdata->vif.bss_conf.bssid = NULL;
  		break;

  	case NL80211_IFTYPE_NAN:
  		idr_init(&sdata->u.nan.function_inst_ids);
  		spin_lock_init(&sdata->u.nan.func_lock);
  		sdata->vif.bss_conf.bssid = sdata->vif.addr;
  		break;

  	case NL80211_IFTYPE_AP_VLAN:

  	case NL80211_IFTYPE_P2P_DEVICE:

  		sdata->vif.bss_conf.bssid = sdata->vif.addr;

  		break;

  	case NL80211_IFTYPE_UNSPECIFIED:

  	case NUM_NL80211_IFTYPES:

  		WARN_ON(1);

  		break;
  	}
  
  	ieee80211_debugfs_add_netdev(sdata);
  }

  static int ieee80211_runtime_change_iftype(struct ieee80211_sub_if_data *sdata,
  					   enum nl80211_iftype type)
  {
  	struct ieee80211_local *local = sdata->local;
  	int ret, err;

  	enum nl80211_iftype internal_type = type;
  	bool p2p = false;

  
  	ASSERT_RTNL();
  
  	if (!local->ops->change_interface)
  		return -EBUSY;
  
  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_AP:
  	case NL80211_IFTYPE_STATION:
  	case NL80211_IFTYPE_ADHOC:

  	case NL80211_IFTYPE_OCB:

  		/*
  		 * Could maybe also all others here?
  		 * Just not sure how that interacts
  		 * with the RX/config path e.g. for
  		 * mesh.
  		 */
  		break;
  	default:
  		return -EBUSY;
  	}
  
  	switch (type) {
  	case NL80211_IFTYPE_AP:
  	case NL80211_IFTYPE_STATION:
  	case NL80211_IFTYPE_ADHOC:

  	case NL80211_IFTYPE_OCB:

  		/*
  		 * Could probably support everything
  		 * but WDS here (WDS do_open can fail
  		 * under memory pressure, which this
  		 * code isn't prepared to handle).
  		 */
  		break;

  	case NL80211_IFTYPE_P2P_CLIENT:
  		p2p = true;
  		internal_type = NL80211_IFTYPE_STATION;
  		break;
  	case NL80211_IFTYPE_P2P_GO:
  		p2p = true;
  		internal_type = NL80211_IFTYPE_AP;
  		break;

  	default:
  		return -EBUSY;
  	}

  	ret = ieee80211_check_concurrent_iface(sdata, internal_type);

  	if (ret)
  		return ret;
  
  	ieee80211_do_stop(sdata, false);

  	ieee80211_teardown_sdata(sdata);

  	ieee80211_set_sdata_offload_flags(sdata);

  	ret = drv_change_interface(local, sdata, internal_type, p2p);

  	if (ret)

  		type = ieee80211_vif_type_p2p(&sdata->vif);

  	/*
  	 * Ignore return value here, there's not much we can do since
  	 * the driver changed the interface type internally already.
  	 * The warnings will hopefully make driver authors fix it :-)
  	 */

  	ieee80211_check_queues(sdata, type);

  	ieee80211_setup_sdata(sdata, type);

  	ieee80211_set_vif_encap_ops(sdata);

  	err = ieee80211_do_open(&sdata->wdev, false);

  	WARN(err, "type change: do_open returned %d", err);
  
  	return ret;
  }

  int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,

  			     enum nl80211_iftype type)

  {

  	int ret;

  	ASSERT_RTNL();

  	if (type == ieee80211_vif_type_p2p(&sdata->vif))

  		return 0;

  	if (ieee80211_sdata_running(sdata)) {
  		ret = ieee80211_runtime_change_iftype(sdata, type);
  		if (ret)
  			return ret;
  	} else {
  		/* Purge and reset type-dependent state. */

  		ieee80211_teardown_sdata(sdata);

  		ieee80211_setup_sdata(sdata, type);
  	}

  
  	/* reset some values that shouldn't be kept across type changes */

  	if (type == NL80211_IFTYPE_STATION)
  		sdata->u.mgd.use_4addr = false;

  
  	return 0;

  }

  static void ieee80211_assign_perm_addr(struct ieee80211_local *local,

  				       u8 *perm_addr, enum nl80211_iftype type)

  {
  	struct ieee80211_sub_if_data *sdata;
  	u64 mask, start, addr, val, inc;
  	u8 *m;
  	u8 tmp_addr[ETH_ALEN];
  	int i;
  
  	/* default ... something at least */

  	memcpy(perm_addr, local->hw.wiphy->perm_addr, ETH_ALEN);

  
  	if (is_zero_ether_addr(local->hw.wiphy->addr_mask) &&
  	    local->hw.wiphy->n_addresses <= 1)
  		return;

  	mutex_lock(&local->iflist_mtx);
  
  	switch (type) {
  	case NL80211_IFTYPE_MONITOR:
  		/* doesn't matter */
  		break;
  	case NL80211_IFTYPE_WDS:
  	case NL80211_IFTYPE_AP_VLAN:
  		/* match up with an AP interface */
  		list_for_each_entry(sdata, &local->interfaces, list) {
  			if (sdata->vif.type != NL80211_IFTYPE_AP)
  				continue;

  			memcpy(perm_addr, sdata->vif.addr, ETH_ALEN);

  			break;
  		}
  		/* keep default if no AP interface present */
  		break;

  	case NL80211_IFTYPE_P2P_CLIENT:
  	case NL80211_IFTYPE_P2P_GO:

  		if (ieee80211_hw_check(&local->hw, P2P_DEV_ADDR_FOR_INTF)) {

  			list_for_each_entry(sdata, &local->interfaces, list) {
  				if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE)
  					continue;
  				if (!ieee80211_sdata_running(sdata))
  					continue;
  				memcpy(perm_addr, sdata->vif.addr, ETH_ALEN);
  				goto out_unlock;
  			}
  		}

  		fallthrough;

  	default:
  		/* assign a new address if possible -- try n_addresses first */
  		for (i = 0; i < local->hw.wiphy->n_addresses; i++) {
  			bool used = false;
  
  			list_for_each_entry(sdata, &local->interfaces, list) {

  				if (ether_addr_equal(local->hw.wiphy->addresses[i].addr,
  						     sdata->vif.addr)) {

  					used = true;
  					break;
  				}
  			}
  
  			if (!used) {

  				memcpy(perm_addr,

  				       local->hw.wiphy->addresses[i].addr,
  				       ETH_ALEN);
  				break;
  			}
  		}
  
  		/* try mask if available */
  		if (is_zero_ether_addr(local->hw.wiphy->addr_mask))
  			break;
  
  		m = local->hw.wiphy->addr_mask;
  		mask =	((u64)m[0] << 5*8) | ((u64)m[1] << 4*8) |
  			((u64)m[2] << 3*8) | ((u64)m[3] << 2*8) |
  			((u64)m[4] << 1*8) | ((u64)m[5] << 0*8);
  
  		if (__ffs64(mask) + hweight64(mask) != fls64(mask)) {
  			/* not a contiguous mask ... not handled now! */

  			pr_info("not contiguous
  ");

  			break;
  		}

  		/*
  		 * Pick address of existing interface in case user changed
  		 * MAC address manually, default to perm_addr.
  		 */

  		m = local->hw.wiphy->perm_addr;

  		list_for_each_entry(sdata, &local->interfaces, list) {
  			if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
  				continue;
  			m = sdata->vif.addr;
  			break;
  		}

  		start = ((u64)m[0] << 5*8) | ((u64)m[1] << 4*8) |
  			((u64)m[2] << 3*8) | ((u64)m[3] << 2*8) |
  			((u64)m[4] << 1*8) | ((u64)m[5] << 0*8);
  
  		inc = 1ULL<<__ffs64(mask);
  		val = (start & mask);
  		addr = (start & ~mask) | (val & mask);
  		do {
  			bool used = false;
  
  			tmp_addr[5] = addr >> 0*8;
  			tmp_addr[4] = addr >> 1*8;
  			tmp_addr[3] = addr >> 2*8;
  			tmp_addr[2] = addr >> 3*8;
  			tmp_addr[1] = addr >> 4*8;
  			tmp_addr[0] = addr >> 5*8;
  
  			val += inc;
  
  			list_for_each_entry(sdata, &local->interfaces, list) {

  				if (ether_addr_equal(tmp_addr, sdata->vif.addr)) {

  					used = true;
  					break;
  				}
  			}
  
  			if (!used) {

  				memcpy(perm_addr, tmp_addr, ETH_ALEN);

  				break;
  			}
  			addr = (start & ~mask) | (val & mask);
  		} while (addr != start);
  
  		break;
  	}

   out_unlock:

  	mutex_unlock(&local->iflist_mtx);
  }

  int ieee80211_if_add(struct ieee80211_local *local, const char *name,

  		     unsigned char name_assign_type,

  		     struct wireless_dev **new_wdev, enum nl80211_iftype type,

  		     struct vif_params *params)

  {

  	struct net_device *ndev = NULL;

  	struct ieee80211_sub_if_data *sdata = NULL;

  	struct txq_info *txqi;

  	void (*if_setup)(struct net_device *dev);

  	int ret, i;

  	int txqs = 1;

  
  	ASSERT_RTNL();

  	if (type == NL80211_IFTYPE_P2P_DEVICE || type == NL80211_IFTYPE_NAN) {

  		struct wireless_dev *wdev;
  
  		sdata = kzalloc(sizeof(*sdata) + local->hw.vif_data_size,
  				GFP_KERNEL);
  		if (!sdata)
  			return -ENOMEM;
  		wdev = &sdata->wdev;
  
  		sdata->dev = NULL;
  		strlcpy(sdata->name, name, IFNAMSIZ);
  		ieee80211_assign_perm_addr(local, wdev->address, type);
  		memcpy(sdata->vif.addr, wdev->address, ETH_ALEN);
  	} else {

  		int size = ALIGN(sizeof(*sdata) + local->hw.vif_data_size,
  				 sizeof(void *));
  		int txq_size = 0;

  		if (local->ops->wake_tx_queue &&
  		    type != NL80211_IFTYPE_AP_VLAN &&

  		    (type != NL80211_IFTYPE_MONITOR ||
  		     (params->flags & MONITOR_FLAG_ACTIVE)))

  			txq_size += sizeof(struct txq_info) +
  				    local->hw.txq_data_size;

  		if (local->ops->wake_tx_queue) {

  			if_setup = ieee80211_if_setup_no_queue;

  		} else {

  			if_setup = ieee80211_if_setup;

  			if (local->hw.queues >= IEEE80211_NUM_ACS)
  				txqs = IEEE80211_NUM_ACS;
  		}

  		ndev = alloc_netdev_mqs(size + txq_size,

  					name, name_assign_type,

  					if_setup, txqs, 1);

  		if (!ndev)
  			return -ENOMEM;

  
  		if (!local->ops->wake_tx_queue && local->hw.wiphy->tx_queue_len)
  			ndev->tx_queue_len = local->hw.wiphy->tx_queue_len;

  		dev_net_set(ndev, wiphy_net(local->hw.wiphy));

  		ndev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
  		if (!ndev->tstats) {
  			free_netdev(ndev);
  			return -ENOMEM;
  		}

  		ndev->needed_headroom = local->tx_headroom +
  					4*6 /* four MAC addresses */
  					+ 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
  					+ 6 /* mesh */
  					+ 8 /* rfc1042/bridge tunnel */
  					- ETH_HLEN /* ethernet hard_header_len */
  					+ IEEE80211_ENCRYPT_HEADROOM;
  		ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;
  
  		ret = dev_alloc_name(ndev, ndev->name);
  		if (ret < 0) {

  			ieee80211_if_free(ndev);

  			free_netdev(ndev);

  			return ret;
  		}
  
  		ieee80211_assign_perm_addr(local, ndev->perm_addr, type);

  		if (is_valid_ether_addr(params->macaddr))

  			memcpy(ndev->dev_addr, params->macaddr, ETH_ALEN);
  		else
  			memcpy(ndev->dev_addr, ndev->perm_addr, ETH_ALEN);

  		SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
  
  		/* don't use IEEE80211_DEV_TO_SUB_IF -- it checks too much */
  		sdata = netdev_priv(ndev);
  		ndev->ieee80211_ptr = &sdata->wdev;
  		memcpy(sdata->vif.addr, ndev->dev_addr, ETH_ALEN);
  		memcpy(sdata->name, ndev->name, IFNAMSIZ);

  		if (txq_size) {
  			txqi = netdev_priv(ndev) + size;

  			ieee80211_txq_init(sdata, NULL, txqi, 0);

  		}

  		sdata->dev = ndev;
  	}

  
  	/* initialise type-independent data */

  	sdata->wdev.wiphy = local->hw.wiphy;

  	sdata->local = local;

  
  	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
  		skb_queue_head_init(&sdata->fragments[i].skb_list);
  
  	INIT_LIST_HEAD(&sdata->key_list);

  	INIT_DELAYED_WORK(&sdata->dfs_cac_timer_work,
  			  ieee80211_dfs_cac_timer_work);

  	INIT_DELAYED_WORK(&sdata->dec_tailroom_needed_wk,
  			  ieee80211_delayed_tailroom_dec);

  	for (i = 0; i < NUM_NL80211_BANDS; i++) {

  		struct ieee80211_supported_band *sband;
  		sband = local->hw.wiphy->bands[i];
  		sdata->rc_rateidx_mask[i] =
  			sband ? (1 << sband->n_bitrates) - 1 : 0;

  		if (sband) {
  			__le16 cap;
  			u16 *vht_rate_mask;