text: /*
   * 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 <linux/module.h>
  #include <linux/init.h>
  #include <linux/netdevice.h>
  #include <linux/types.h>
  #include <linux/slab.h>
  #include <linux/skbuff.h>
  #include <linux/etherdevice.h>
  #include <linux/if_arp.h>
  #include <linux/rtnetlink.h>
  #include <linux/bitmap.h>
  #include <linux/pm_qos.h>
  #include <linux/inetdevice.h>
  #include <net/net_namespace.h>
  #include <net/cfg80211.h>
  #include <net/addrconf.h>
  
  #include "ieee80211_i.h"
  #include "driver-ops.h"
  #include "rate.h"
  #include "mesh.h"
  #include "wep.h"
  #include "led.h"
  #include "cfg.h"
  #include "debugfs.h"
  
  void ieee80211_configure_filter(struct ieee80211_local *local)
  {
  	u64 mc;
  	unsigned int changed_flags;
  	unsigned int new_flags = 0;
  
  	if (atomic_read(&local->iff_promiscs))
  		new_flags |= FIF_PROMISC_IN_BSS;
  
  	if (atomic_read(&local->iff_allmultis))
  		new_flags |= FIF_ALLMULTI;
  
  	if (local->monitors || test_bit(SCAN_SW_SCANNING, &local->scanning) ||
  	    test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning))
  		new_flags |= FIF_BCN_PRBRESP_PROMISC;
  
  	if (local->fif_probe_req || local->probe_req_reg)
  		new_flags |= FIF_PROBE_REQ;
  
  	if (local->fif_fcsfail)
  		new_flags |= FIF_FCSFAIL;
  
  	if (local->fif_plcpfail)
  		new_flags |= FIF_PLCPFAIL;
  
  	if (local->fif_control)
  		new_flags |= FIF_CONTROL;
  
  	if (local->fif_other_bss)
  		new_flags |= FIF_OTHER_BSS;
  
  	if (local->fif_pspoll)
  		new_flags |= FIF_PSPOLL;
  
  	spin_lock_bh(&local->filter_lock);
  	changed_flags = local->filter_flags ^ new_flags;
  
  	mc = drv_prepare_multicast(local, &local->mc_list);
  	spin_unlock_bh(&local->filter_lock);
  
  	/* be a bit nasty */
  	new_flags |= (1<<31);
  
  	drv_configure_filter(local, changed_flags, &new_flags, mc);
  
  	WARN_ON(new_flags & (1<<31));
  
  	local->filter_flags = new_flags & ~(1<<31);
  }
  
  static void ieee80211_reconfig_filter(struct work_struct *work)
  {
  	struct ieee80211_local *local =
  		container_of(work, struct ieee80211_local, reconfig_filter);
  
  	ieee80211_configure_filter(local);
  }
  
  static u32 ieee80211_hw_conf_chan(struct ieee80211_local *local)
  {
  	struct ieee80211_sub_if_data *sdata;
  	struct cfg80211_chan_def chandef = {};
  	u32 changed = 0;
  	int power;
  	u32 offchannel_flag;
  
  	offchannel_flag = local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
  
  	if (local->scan_chandef.chan) {
  		chandef = local->scan_chandef;
  	} else if (local->tmp_channel) {
  		chandef.chan = local->tmp_channel;
  		chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
  		chandef.center_freq1 = chandef.chan->center_freq;
  	} else
  		chandef = local->_oper_chandef;
  
  	WARN(!cfg80211_chandef_valid(&chandef),
  	     "control:%d MHz width:%d center: %d/%d MHz",
  	     chandef.chan->center_freq, chandef.width,
  	     chandef.center_freq1, chandef.center_freq2);
  
  	if (!cfg80211_chandef_identical(&chandef, &local->_oper_chandef))
  		local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
  	else
  		local->hw.conf.flags &= ~IEEE80211_CONF_OFFCHANNEL;
  
  	offchannel_flag ^= local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
  
  	if (offchannel_flag ||
  	    !cfg80211_chandef_identical(&local->hw.conf.chandef,
  					&local->_oper_chandef)) {
  		local->hw.conf.chandef = chandef;
  		changed |= IEEE80211_CONF_CHANGE_CHANNEL;
  	}
  
  	if (!conf_is_ht(&local->hw.conf)) {
  		/*
  		 * mac80211.h documents that this is only valid
  		 * when the channel is set to an HT type, and
  		 * that otherwise STATIC is used.
  		 */
  		local->hw.conf.smps_mode = IEEE80211_SMPS_STATIC;
  	} else if (local->hw.conf.smps_mode != local->smps_mode) {
  		local->hw.conf.smps_mode = local->smps_mode;
  		changed |= IEEE80211_CONF_CHANGE_SMPS;
  	}
  
  	power = ieee80211_chandef_max_power(&chandef);
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  		if (!rcu_access_pointer(sdata->vif.chanctx_conf))
  			continue;
  		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  			continue;
  		power = min(power, sdata->vif.bss_conf.txpower);
  	}
  	rcu_read_unlock();
  
  	if (local->hw.conf.power_level != power) {
  		changed |= IEEE80211_CONF_CHANGE_POWER;
  		local->hw.conf.power_level = power;
  	}
  
  	return changed;
  }
  
  int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
  {
  	int ret = 0;
  
  	might_sleep();
  
  	if (!local->use_chanctx)
  		changed |= ieee80211_hw_conf_chan(local);
  	else
  		changed &= ~(IEEE80211_CONF_CHANGE_CHANNEL |
  			     IEEE80211_CONF_CHANGE_POWER);
  
  	if (changed && local->open_count) {
  		ret = drv_config(local, changed);
  		/*
  		 * Goal:
  		 * HW reconfiguration should never fail, the driver has told
  		 * us what it can support so it should live up to that promise.
  		 *
  		 * Current status:
  		 * rfkill is not integrated with mac80211 and a
  		 * configuration command can thus fail if hardware rfkill
  		 * is enabled
  		 *
  		 * FIXME: integrate rfkill with mac80211 and then add this
  		 * WARN_ON() back
  		 *
  		 */
  		/* WARN_ON(ret); */
  	}
  
  	return ret;
  }
  
  void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata,
  				      u32 changed)
  {
  	struct ieee80211_local *local = sdata->local;
  
  	if (!changed || sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  		return;
  
  	drv_bss_info_changed(local, sdata, &sdata->vif.bss_conf, changed);
  }
  
  u32 ieee80211_reset_erp_info(struct ieee80211_sub_if_data *sdata)
  {
  	sdata->vif.bss_conf.use_cts_prot = false;
  	sdata->vif.bss_conf.use_short_preamble = false;
  	sdata->vif.bss_conf.use_short_slot = false;
  	return BSS_CHANGED_ERP_CTS_PROT |
  	       BSS_CHANGED_ERP_PREAMBLE |
  	       BSS_CHANGED_ERP_SLOT;
  }
  
  static void ieee80211_tasklet_handler(unsigned long data)
  {
  	struct ieee80211_local *local = (struct ieee80211_local *) data;
  	struct sk_buff *skb;
  
  	while ((skb = skb_dequeue(&local->skb_queue)) ||
  	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
  		switch (skb->pkt_type) {
  		case IEEE80211_RX_MSG:
  			/* Clear skb->pkt_type in order to not confuse kernel
  			 * netstack. */
  			skb->pkt_type = 0;
  			ieee80211_rx(&local->hw, skb);
  			break;
  		case IEEE80211_TX_STATUS_MSG:
  			skb->pkt_type = 0;
  			ieee80211_tx_status(&local->hw, skb);
  			break;
  		default:
  			WARN(1, "mac80211: Packet is of unknown type %d\n",
  			     skb->pkt_type);
  			dev_kfree_skb(skb);
  			break;
  		}
  	}
  }
  
  static void ieee80211_restart_work(struct work_struct *work)
  {
  	struct ieee80211_local *local =
  		container_of(work, struct ieee80211_local, restart_work);
  
  	/* wait for scan work complete */
  	flush_workqueue(local->workqueue);
  
  	WARN(test_bit(SCAN_HW_SCANNING, &local->scanning),
  	     "%s called with hardware scan in progress\n", __func__);
  
  	rtnl_lock();
  	ieee80211_scan_cancel(local);
  	ieee80211_reconfig(local);
  	rtnl_unlock();
  }
  
  void ieee80211_restart_hw(struct ieee80211_hw *hw)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  
  	trace_api_restart_hw(local);
  
  	wiphy_info(hw->wiphy,
  		   "Hardware restart was requested\n");
  
  	/* use this reason, ieee80211_reconfig will unblock it */
  	ieee80211_stop_queues_by_reason(hw, IEEE80211_MAX_QUEUE_MAP,
  					IEEE80211_QUEUE_STOP_REASON_SUSPEND);
  
  	/*
  	 * Stop all Rx during the reconfig. We don't want state changes
  	 * or driver callbacks while this is in progress.
  	 */
  	local->in_reconfig = true;
  	barrier();
  
  	schedule_work(&local->restart_work);
  }
  EXPORT_SYMBOL(ieee80211_restart_hw);
  
  #ifdef CONFIG_INET
  static int ieee80211_ifa_changed(struct notifier_block *nb,
  				 unsigned long data, void *arg)
  {
  	struct in_ifaddr *ifa = arg;
  	struct ieee80211_local *local =
  		container_of(nb, struct ieee80211_local,
  			     ifa_notifier);
  	struct net_device *ndev = ifa->ifa_dev->dev;
  	struct wireless_dev *wdev = ndev->ieee80211_ptr;
  	struct in_device *idev;
  	struct ieee80211_sub_if_data *sdata;
  	struct ieee80211_bss_conf *bss_conf;
  	struct ieee80211_if_managed *ifmgd;
  	int c = 0;
  
  	/* Make sure it's our interface that got changed */
  	if (!wdev)
  		return NOTIFY_DONE;
  
  	if (wdev->wiphy != local->hw.wiphy)
  		return NOTIFY_DONE;
  
  	sdata = IEEE80211_DEV_TO_SUB_IF(ndev);
  	bss_conf = &sdata->vif.bss_conf;
  
  	/* ARP filtering is only supported in managed mode */
  	if (sdata->vif.type != NL80211_IFTYPE_STATION)
  		return NOTIFY_DONE;
  
  	idev = __in_dev_get_rtnl(sdata->dev);
  	if (!idev)
  		return NOTIFY_DONE;
  
  	ifmgd = &sdata->u.mgd;
  	sdata_lock(sdata);
  
  	/* Copy the addresses to the bss_conf list */
  	ifa = idev->ifa_list;
  	while (ifa) {
  		if (c < IEEE80211_BSS_ARP_ADDR_LIST_LEN)
  			bss_conf->arp_addr_list[c] = ifa->ifa_address;
  		ifa = ifa->ifa_next;
  		c++;
  	}
  
  	bss_conf->arp_addr_cnt = c;
  
  	/* Configure driver only if associated (which also implies it is up) */
  	if (ifmgd->associated)
  		ieee80211_bss_info_change_notify(sdata,
  						 BSS_CHANGED_ARP_FILTER);
  
  	sdata_unlock(sdata);
  
  	return NOTIFY_OK;
  }
  #endif
  
  #if IS_ENABLED(CONFIG_IPV6)
  static int ieee80211_ifa6_changed(struct notifier_block *nb,
  				  unsigned long data, void *arg)
  {
  	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)arg;
  	struct inet6_dev *idev = ifa->idev;
  	struct net_device *ndev = ifa->idev->dev;
  	struct ieee80211_local *local =
  		container_of(nb, struct ieee80211_local, ifa6_notifier);
  	struct wireless_dev *wdev = ndev->ieee80211_ptr;
  	struct ieee80211_sub_if_data *sdata;
  
  	/* Make sure it's our interface that got changed */
  	if (!wdev || wdev->wiphy != local->hw.wiphy)
  		return NOTIFY_DONE;
  
  	sdata = IEEE80211_DEV_TO_SUB_IF(ndev);
  
  	/*
  	 * For now only support station mode. This is mostly because
  	 * doing AP would have to handle AP_VLAN in some way ...
  	 */
  	if (sdata->vif.type != NL80211_IFTYPE_STATION)
  		return NOTIFY_DONE;
  
  	drv_ipv6_addr_change(local, sdata, idev);
  
  	return NOTIFY_OK;
  }
  #endif
  
  /* There isn't a lot of sense in it, but you can transmit anything you like */
  static const struct ieee80211_txrx_stypes
  ieee80211_default_mgmt_stypes[NUM_NL80211_IFTYPES] = {
  	[NL80211_IFTYPE_ADHOC] = {
  		.tx = 0xffff,
  		.rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
  			BIT(IEEE80211_STYPE_AUTH >> 4) |
  			BIT(IEEE80211_STYPE_DEAUTH >> 4) |
  			BIT(IEEE80211_STYPE_PROBE_REQ >> 4),
  	},
  	[NL80211_IFTYPE_STATION] = {
  		.tx = 0xffff,
  		.rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
  			BIT(IEEE80211_STYPE_PROBE_REQ >> 4),
  	},
  	[NL80211_IFTYPE_AP] = {
  		.tx = 0xffff,
  		.rx = BIT(IEEE80211_STYPE_ASSOC_REQ >> 4) |
  			BIT(IEEE80211_STYPE_REASSOC_REQ >> 4) |
  			BIT(IEEE80211_STYPE_PROBE_REQ >> 4) |
  			BIT(IEEE80211_STYPE_DISASSOC >> 4) |
  			BIT(IEEE80211_STYPE_AUTH >> 4) |
  			BIT(IEEE80211_STYPE_DEAUTH >> 4) |
  			BIT(IEEE80211_STYPE_ACTION >> 4),
  	},
  	[NL80211_IFTYPE_AP_VLAN] = {
  		/* copy AP */
  		.tx = 0xffff,
  		.rx = BIT(IEEE80211_STYPE_ASSOC_REQ >> 4) |
  			BIT(IEEE80211_STYPE_REASSOC_REQ >> 4) |
  			BIT(IEEE80211_STYPE_PROBE_REQ >> 4) |
  			BIT(IEEE80211_STYPE_DISASSOC >> 4) |
  			BIT(IEEE80211_STYPE_AUTH >> 4) |
  			BIT(IEEE80211_STYPE_DEAUTH >> 4) |
  			BIT(IEEE80211_STYPE_ACTION >> 4),
  	},
  	[NL80211_IFTYPE_P2P_CLIENT] = {
  		.tx = 0xffff,
  		.rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
  			BIT(IEEE80211_STYPE_PROBE_REQ >> 4),
  	},
  	[NL80211_IFTYPE_P2P_GO] = {
  		.tx = 0xffff,
  		.rx = BIT(IEEE80211_STYPE_ASSOC_REQ >> 4) |
  			BIT(IEEE80211_STYPE_REASSOC_REQ >> 4) |
  			BIT(IEEE80211_STYPE_PROBE_REQ >> 4) |
  			BIT(IEEE80211_STYPE_DISASSOC >> 4) |
  			BIT(IEEE80211_STYPE_AUTH >> 4) |
  			BIT(IEEE80211_STYPE_DEAUTH >> 4) |
  			BIT(IEEE80211_STYPE_ACTION >> 4),
  	},
  	[NL80211_IFTYPE_MESH_POINT] = {
  		.tx = 0xffff,
  		.rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
  			BIT(IEEE80211_STYPE_AUTH >> 4) |
  			BIT(IEEE80211_STYPE_DEAUTH >> 4),
  	},
  	[NL80211_IFTYPE_P2P_DEVICE] = {
  		.tx = 0xffff,
  		.rx = BIT(IEEE80211_STYPE_ACTION >> 4) |
  			BIT(IEEE80211_STYPE_PROBE_REQ >> 4),
  	},
  };
  
  static const struct ieee80211_ht_cap mac80211_ht_capa_mod_mask = {
  	.ampdu_params_info = IEEE80211_HT_AMPDU_PARM_FACTOR |
  			     IEEE80211_HT_AMPDU_PARM_DENSITY,
  
  	.cap_info = cpu_to_le16(IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
  				IEEE80211_HT_CAP_MAX_AMSDU |
  				IEEE80211_HT_CAP_SGI_20 |
  				IEEE80211_HT_CAP_SGI_40 |
  				IEEE80211_HT_CAP_LDPC_CODING |
  				IEEE80211_HT_CAP_40MHZ_INTOLERANT),
  	.mcs = {
  		.rx_mask = { 0xff, 0xff, 0xff, 0xff, 0xff,
  			     0xff, 0xff, 0xff, 0xff, 0xff, },
  	},
  };
  
  static const struct ieee80211_vht_cap mac80211_vht_capa_mod_mask = {
  	.vht_cap_info =
  		cpu_to_le32(IEEE80211_VHT_CAP_RXLDPC |
  			    IEEE80211_VHT_CAP_SHORT_GI_80 |
  			    IEEE80211_VHT_CAP_SHORT_GI_160 |
  			    IEEE80211_VHT_CAP_RXSTBC_1 |
  			    IEEE80211_VHT_CAP_RXSTBC_2 |
  			    IEEE80211_VHT_CAP_RXSTBC_3 |
  			    IEEE80211_VHT_CAP_RXSTBC_4 |
  			    IEEE80211_VHT_CAP_TXSTBC |
  			    IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE |
  			    IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE |
  			    IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN |
  			    IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN |
  			    IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK),
  	.supp_mcs = {
  		.rx_mcs_map = cpu_to_le16(~0),
  		.tx_mcs_map = cpu_to_le16(~0),
  	},
  };
  
  static const u8 extended_capabilities[] = {
  	0, 0, 0, 0, 0, 0, 0,
  	WLAN_EXT_CAPA8_OPMODE_NOTIF,
  };
  
  struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
  					const struct ieee80211_ops *ops)
  {
  	struct ieee80211_local *local;
  	int priv_size, i;
  	struct wiphy *wiphy;
  	bool use_chanctx;
  
  	if (WARN_ON(!ops->tx || !ops->start || !ops->stop || !ops->config ||
  		    !ops->add_interface || !ops->remove_interface ||
  		    !ops->configure_filter))
  		return NULL;
  
  	if (WARN_ON(ops->sta_state && (ops->sta_add || ops->sta_remove)))
  		return NULL;
  
  	/* check all or no channel context operations exist */
  	i = !!ops->add_chanctx + !!ops->remove_chanctx +
  	    !!ops->change_chanctx + !!ops->assign_vif_chanctx +
  	    !!ops->unassign_vif_chanctx;
  	if (WARN_ON(i != 0 && i != 5))
  		return NULL;
  	use_chanctx = i == 5;
  
  	/* Ensure 32-byte alignment of our private data and hw private data.
  	 * We use the wiphy priv data for both our ieee80211_local and for
  	 * the driver's private data
  	 *
  	 * In memory it'll be like this:
  	 *
  	 * +-------------------------+
  	 * | struct wiphy	    |
  	 * +-------------------------+
  	 * | struct ieee80211_local  |
  	 * +-------------------------+
  	 * | driver's private data   |
  	 * +-------------------------+
  	 *
  	 */
  	priv_size = ALIGN(sizeof(*local), NETDEV_ALIGN) + priv_data_len;
  
  	wiphy = wiphy_new(&mac80211_config_ops, priv_size);
  
  	if (!wiphy)
  		return NULL;
  
  	wiphy->mgmt_stypes = ieee80211_default_mgmt_stypes;
  
  	wiphy->privid = mac80211_wiphy_privid;
  
  	wiphy->flags |= WIPHY_FLAG_NETNS_OK |
  			WIPHY_FLAG_4ADDR_AP |
  			WIPHY_FLAG_4ADDR_STATION |
  			WIPHY_FLAG_REPORTS_OBSS |
  			WIPHY_FLAG_OFFCHAN_TX;
  
  	wiphy->extended_capabilities = extended_capabilities;
  	wiphy->extended_capabilities_mask = extended_capabilities;
  	wiphy->extended_capabilities_len = ARRAY_SIZE(extended_capabilities);
  
  	if (ops->remain_on_channel)
  		wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
  
  	wiphy->features |= NL80211_FEATURE_SK_TX_STATUS |
  			   NL80211_FEATURE_SAE |
  			   NL80211_FEATURE_HT_IBSS |
  			   NL80211_FEATURE_VIF_TXPOWER |
  			   NL80211_FEATURE_USERSPACE_MPM;
  
  	if (!ops->hw_scan)
  		wiphy->features |= NL80211_FEATURE_LOW_PRIORITY_SCAN |
  				   NL80211_FEATURE_AP_SCAN;
  
  
  	if (!ops->set_key)
  		wiphy->flags |= WIPHY_FLAG_IBSS_RSN;
  
  	wiphy->bss_priv_size = sizeof(struct ieee80211_bss);
  
  	local = wiphy_priv(wiphy);
  
  	local->hw.wiphy = wiphy;
  
  	local->hw.priv = (char *)local + ALIGN(sizeof(*local), NETDEV_ALIGN);
  
  	local->ops = ops;
  	local->use_chanctx = use_chanctx;
  
  	/* set up some defaults */
  	local->hw.queues = 1;
  	local->hw.max_rates = 1;
  	local->hw.max_report_rates = 0;
  	local->hw.max_rx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF;
  	local->hw.max_tx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF;
  	local->hw.offchannel_tx_hw_queue = IEEE80211_INVAL_HW_QUEUE;
  	local->hw.conf.long_frame_max_tx_count = wiphy->retry_long;
  	local->hw.conf.short_frame_max_tx_count = wiphy->retry_short;
  	local->hw.radiotap_mcs_details = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
  					 IEEE80211_RADIOTAP_MCS_HAVE_GI |
  					 IEEE80211_RADIOTAP_MCS_HAVE_BW;
  	local->hw.radiotap_vht_details = IEEE80211_RADIOTAP_VHT_KNOWN_GI |
  					 IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
  	local->hw.uapsd_queues = IEEE80211_DEFAULT_UAPSD_QUEUES;
  	local->hw.uapsd_max_sp_len = IEEE80211_DEFAULT_MAX_SP_LEN;
  	local->user_power_level = IEEE80211_UNSET_POWER_LEVEL;
  	wiphy->ht_capa_mod_mask = &mac80211_ht_capa_mod_mask;
  	wiphy->vht_capa_mod_mask = &mac80211_vht_capa_mod_mask;
  
  	INIT_LIST_HEAD(&local->interfaces);
  
  	__hw_addr_init(&local->mc_list);
  
  	mutex_init(&local->iflist_mtx);
  	mutex_init(&local->mtx);
  
  	mutex_init(&local->key_mtx);
  	spin_lock_init(&local->filter_lock);
  	spin_lock_init(&local->rx_path_lock);
  	spin_lock_init(&local->queue_stop_reason_lock);
  
  	INIT_LIST_HEAD(&local->chanctx_list);
  	mutex_init(&local->chanctx_mtx);
  
  	INIT_DELAYED_WORK(&local->scan_work, ieee80211_scan_work);
  
  	INIT_WORK(&local->restart_work, ieee80211_restart_work);
  
  	INIT_WORK(&local->radar_detected_work,
  		  ieee80211_dfs_radar_detected_work);
  
  	INIT_WORK(&local->reconfig_filter, ieee80211_reconfig_filter);
  	local->smps_mode = IEEE80211_SMPS_OFF;
  
  	INIT_WORK(&local->dynamic_ps_enable_work,
  		  ieee80211_dynamic_ps_enable_work);
  	INIT_WORK(&local->dynamic_ps_disable_work,
  		  ieee80211_dynamic_ps_disable_work);
  	setup_timer(&local->dynamic_ps_timer,
  		    ieee80211_dynamic_ps_timer, (unsigned long) local);
  
  	INIT_WORK(&local->sched_scan_stopped_work,
  		  ieee80211_sched_scan_stopped_work);
  
  	spin_lock_init(&local->ack_status_lock);
  	idr_init(&local->ack_status_frames);
  
  	sta_info_init(local);
  
  	for (i = 0; i < IEEE80211_MAX_QUEUES; i++) {
  		skb_queue_head_init(&local->pending[i]);
  		atomic_set(&local->agg_queue_stop[i], 0);
  	}
  	tasklet_init(&local->tx_pending_tasklet, ieee80211_tx_pending,
  		     (unsigned long)local);
  
  	tasklet_init(&local->tasklet,
  		     ieee80211_tasklet_handler,
  		     (unsigned long) local);
  
  	skb_queue_head_init(&local->skb_queue);
  	skb_queue_head_init(&local->skb_queue_unreliable);
  
  	ieee80211_led_names(local);
  
  	ieee80211_roc_setup(local);
  
  	return &local->hw;
  }
  EXPORT_SYMBOL(ieee80211_alloc_hw);
  
  static int ieee80211_init_cipher_suites(struct ieee80211_local *local)
  {
  	bool have_wep = !(IS_ERR(local->wep_tx_tfm) ||
  			  IS_ERR(local->wep_rx_tfm));
  	bool have_mfp = local->hw.flags & IEEE80211_HW_MFP_CAPABLE;
  	const struct ieee80211_cipher_scheme *cs = local->hw.cipher_schemes;
  	int n_suites = 0, r = 0, w = 0;
  	u32 *suites;
  	static const u32 cipher_suites[] = {
  		/* keep WEP first, it may be removed below */
  		WLAN_CIPHER_SUITE_WEP40,
  		WLAN_CIPHER_SUITE_WEP104,
  		WLAN_CIPHER_SUITE_TKIP,
  		WLAN_CIPHER_SUITE_CCMP,
  
  		/* keep last -- depends on hw flags! */
  		WLAN_CIPHER_SUITE_AES_CMAC
  	};
  
  	/* Driver specifies the ciphers, we have nothing to do... */
  	if (local->hw.wiphy->cipher_suites && have_wep)
  		return 0;
  
  	/* Set up cipher suites if driver relies on mac80211 cipher defs */
  	if (!local->hw.wiphy->cipher_suites && !cs) {
  		local->hw.wiphy->cipher_suites = cipher_suites;
  		local->hw.wiphy->n_cipher_suites = ARRAY_SIZE(cipher_suites);
  
  		if (!have_mfp)
  			local->hw.wiphy->n_cipher_suites--;
  
  		if (!have_wep) {
  			local->hw.wiphy->cipher_suites += 2;
  			local->hw.wiphy->n_cipher_suites -= 2;
  		}
  
  		return 0;
  	}
  
  	if (!local->hw.wiphy->cipher_suites) {
  		/*
  		 * Driver specifies cipher schemes only
  		 * We start counting ciphers defined by schemes, TKIP and CCMP
  		 */
  		n_suites = local->hw.n_cipher_schemes + 2;
  
  		/* check if we have WEP40 and WEP104 */
  		if (have_wep)
  			n_suites += 2;
  
  		/* check if we have AES_CMAC */
  		if (have_mfp)
  			n_suites++;
  
  		suites = kmalloc(sizeof(u32) * n_suites, GFP_KERNEL);
  		if (!suites)
  			return -ENOMEM;
  
  		suites[w++] = WLAN_CIPHER_SUITE_CCMP;
  		suites[w++] = WLAN_CIPHER_SUITE_TKIP;
  
  		if (have_wep) {
  			suites[w++] = WLAN_CIPHER_SUITE_WEP40;
  			suites[w++] = WLAN_CIPHER_SUITE_WEP104;
  		}
  
  		if (have_mfp)
  			suites[w++] = WLAN_CIPHER_SUITE_AES_CMAC;
  
  		for (r = 0; r < local->hw.n_cipher_schemes; r++)
  			suites[w++] = cs[r].cipher;
  	} else {
  		/* Driver provides cipher suites, but we need to exclude WEP */
  		suites = kmemdup(local->hw.wiphy->cipher_suites,
  				 sizeof(u32) * local->hw.wiphy->n_cipher_suites,
  				 GFP_KERNEL);
  		if (!suites)
  			return -ENOMEM;
  
  		for (r = 0; r < local->hw.wiphy->n_cipher_suites; r++) {
  			u32 suite = local->hw.wiphy->cipher_suites[r];
  
  			if (suite == WLAN_CIPHER_SUITE_WEP40 ||
  			    suite == WLAN_CIPHER_SUITE_WEP104)
  				continue;
  			suites[w++] = suite;
  		}
  	}
  
  	local->hw.wiphy->cipher_suites = suites;
  	local->hw.wiphy->n_cipher_suites = w;
  	local->wiphy_ciphers_allocated = true;
  
  	return 0;
  }
  
  int ieee80211_register_hw(struct ieee80211_hw *hw)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  	int result, i;
  	enum ieee80211_band band;
  	int channels, max_bitrates;
  	bool supp_ht, supp_vht;
  	netdev_features_t feature_whitelist;
  	struct cfg80211_chan_def dflt_chandef = {};
  
  	if (hw->flags & IEEE80211_HW_QUEUE_CONTROL &&
  	    (local->hw.offchannel_tx_hw_queue == IEEE80211_INVAL_HW_QUEUE ||
  	     local->hw.offchannel_tx_hw_queue >= local->hw.queues))
  		return -EINVAL;
  
  #ifdef CONFIG_PM
  	if (hw->wiphy->wowlan && (!local->ops->suspend || !local->ops->resume))
  		return -EINVAL;
  #endif
  
  	if (!local->use_chanctx) {
  		for (i = 0; i < local->hw.wiphy->n_iface_combinations; i++) {
  			const struct ieee80211_iface_combination *comb;
  
  			comb = &local->hw.wiphy->iface_combinations[i];
  
  			if (comb->num_different_channels > 1)
  				return -EINVAL;
  		}
  	} else {
  		/*
  		 * WDS is currently prohibited when channel contexts are used
  		 * because there's no clear definition of which channel WDS
  		 * type interfaces use
  		 */
  		if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_WDS))
  			return -EINVAL;
  
  		/* DFS currently not supported with channel context drivers */
  		for (i = 0; i < local->hw.wiphy->n_iface_combinations; i++) {
  			const struct ieee80211_iface_combination *comb;
  
  			comb = &local->hw.wiphy->iface_combinations[i];
  
  			if (comb->radar_detect_widths)
  				return -EINVAL;
  		}
  	}
  
  	/* Only HW csum features are currently compatible with mac80211 */
  	feature_whitelist = NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
  			    NETIF_F_HW_CSUM;
  	if (WARN_ON(hw->netdev_features & ~feature_whitelist))
  		return -EINVAL;
  
  	if (hw->max_report_rates == 0)
  		hw->max_report_rates = hw->max_rates;
  
  	local->rx_chains = 1;
  
  	/*
  	 * generic code guarantees at least one band,
  	 * set this very early because much code assumes
  	 * that hw.conf.channel is assigned
  	 */
  	channels = 0;
  	max_bitrates = 0;
  	supp_ht = false;
  	supp_vht = false;
  	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
  		struct ieee80211_supported_band *sband;
  
  		sband = local->hw.wiphy->bands[band];
  		if (!sband)
  			continue;
  
  		if (!dflt_chandef.chan) {
  			cfg80211_chandef_create(&dflt_chandef,
  						&sband->channels[0],
  						NL80211_CHAN_NO_HT);
  			/* init channel we're on */
  			if (!local->use_chanctx && !local->_oper_chandef.chan) {
  				local->hw.conf.chandef = dflt_chandef;
  				local->_oper_chandef = dflt_chandef;
  			}
  			local->monitor_chandef = dflt_chandef;
  		}
  
  		channels += sband->n_channels;
  
  		if (max_bitrates < sband->n_bitrates)
  			max_bitrates = sband->n_bitrates;
  		supp_ht = supp_ht || sband->ht_cap.ht_supported;
  		supp_vht = supp_vht || sband->vht_cap.vht_supported;
  
  		if (sband->ht_cap.ht_supported)
  			local->rx_chains =
  				max(ieee80211_mcs_to_chains(&sband->ht_cap.mcs),
  				    local->rx_chains);
  
  		/* TODO: consider VHT for RX chains, hopefully it's the same */
  	}
  
  	/* if low-level driver supports AP, we also support VLAN */
  	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP)) {
  		hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_AP_VLAN);
  		hw->wiphy->software_iftypes |= BIT(NL80211_IFTYPE_AP_VLAN);
  	}
  
  	/* mac80211 always supports monitor */
  	hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_MONITOR);
  	hw->wiphy->software_iftypes |= BIT(NL80211_IFTYPE_MONITOR);
  
  	/* mac80211 doesn't support more than one IBSS interface right now */
  	for (i = 0; i < hw->wiphy->n_iface_combinations; i++) {
  		const struct ieee80211_iface_combination *c;
  		int j;
  
  		c = &hw->wiphy->iface_combinations[i];
  
  		for (j = 0; j < c->n_limits; j++)
  			if ((c->limits[j].types & BIT(NL80211_IFTYPE_ADHOC)) &&
  			    c->limits[j].max > 1)
  				return -EINVAL;
  	}
  
  	local->int_scan_req = kzalloc(sizeof(*local->int_scan_req) +
  				      sizeof(void *) * channels, GFP_KERNEL);
  	if (!local->int_scan_req)
  		return -ENOMEM;
  
  	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
  		if (!local->hw.wiphy->bands[band])
  			continue;
  		local->int_scan_req->rates[band] = (u32) -1;
  	}
  
  #ifndef CONFIG_MAC80211_MESH
  	/* mesh depends on Kconfig, but drivers should set it if they want */
  	local->hw.wiphy->interface_modes &= ~BIT(NL80211_IFTYPE_MESH_POINT);
  #endif
  
  	/* if the underlying driver supports mesh, mac80211 will (at least)
  	 * provide routing of mesh authentication frames to userspace */
  	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_MESH_POINT))
  		local->hw.wiphy->flags |= WIPHY_FLAG_MESH_AUTH;
  
  	/* mac80211 supports control port protocol changing */
  	local->hw.wiphy->flags |= WIPHY_FLAG_CONTROL_PORT_PROTOCOL;
  
  	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
  		local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_MBM;
  	} else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) {
  		local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_UNSPEC;
  		if (hw->max_signal <= 0) {
  			result = -EINVAL;
  			goto fail_wiphy_register;
  		}
  	}
  
  	WARN((local->hw.flags & IEEE80211_HW_SUPPORTS_UAPSD)
  	     && (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK),
  	     "U-APSD not supported with HW_PS_NULLFUNC_STACK\n");
  
  	/*
  	 * Calculate scan IE length -- we need this to alloc
  	 * memory and to subtract from the driver limit. It
  	 * includes the DS Params, (extended) supported rates, and HT
  	 * information -- SSID is the driver's responsibility.
  	 */
  	local->scan_ies_len = 4 + max_bitrates /* (ext) supp rates */ +
  		3 /* DS Params */;
  	if (supp_ht)
  		local->scan_ies_len += 2 + sizeof(struct ieee80211_ht_cap);
  
  	if (supp_vht)
  		local->scan_ies_len +=
  			2 + sizeof(struct ieee80211_vht_cap);
  
  	if (!local->ops->hw_scan) {
  		/* For hw_scan, driver needs to set these up. */
  		local->hw.wiphy->max_scan_ssids = 4;
  		local->hw.wiphy->max_scan_ie_len = IEEE80211_MAX_DATA_LEN;
  	}
  
  	/*
  	 * If the driver supports any scan IEs, then assume the
  	 * limit includes the IEs mac80211 will add, otherwise
  	 * leave it at zero and let the driver sort it out; we
  	 * still pass our IEs to the driver but userspace will
  	 * not be allowed to in that case.
  	 */
  	if (local->hw.wiphy->max_scan_ie_len)
  		local->hw.wiphy->max_scan_ie_len -= local->scan_ies_len;
  
  	WARN_ON(!ieee80211_cs_list_valid(local->hw.cipher_schemes,
  					 local->hw.n_cipher_schemes));
  
  	result = ieee80211_init_cipher_suites(local);
  	if (result < 0)
  		goto fail_wiphy_register;
  
  	if (!local->ops->remain_on_channel)
  		local->hw.wiphy->max_remain_on_channel_duration = 5000;
  
  	/* mac80211 based drivers don't support internal TDLS setup */
  	if (local->hw.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS)
  		local->hw.wiphy->flags |= WIPHY_FLAG_TDLS_EXTERNAL_SETUP;
  
  	local->hw.wiphy->max_num_csa_counters = IEEE80211_MAX_CSA_COUNTERS_NUM;
  
  	result = wiphy_register(local->hw.wiphy);
  	if (result < 0)
  		goto fail_wiphy_register;
  
  	/*
  	 * We use the number of queues for feature tests (QoS, HT) internally
  	 * so restrict them appropriately.
  	 */
  	if (hw->queues > IEEE80211_MAX_QUEUES)
  		hw->queues = IEEE80211_MAX_QUEUES;
  
  	local->workqueue =
  		alloc_ordered_workqueue("%s", 0, wiphy_name(local->hw.wiphy));
  	if (!local->workqueue) {
  		result = -ENOMEM;
  		goto fail_workqueue;
  	}
  
  	/*
  	 * The hardware needs headroom for sending the frame,
  	 * and we need some headroom for passing the frame to monitor
  	 * interfaces, but never both at the same time.
  	 */
  	local->tx_headroom = max_t(unsigned int , local->hw.extra_tx_headroom,
  				   IEEE80211_TX_STATUS_HEADROOM);
  
  	debugfs_hw_add(local);
  
  	/*
  	 * if the driver doesn't specify a max listen interval we
  	 * use 5 which should be a safe default
  	 */
  	if (local->hw.max_listen_interval == 0)
  		local->hw.max_listen_interval = 5;
  
  	local->hw.conf.listen_interval = local->hw.max_listen_interval;
  
  	local->dynamic_ps_forced_timeout = -1;
  
  	result = ieee80211_wep_init(local);
  	if (result < 0)
  		wiphy_debug(local->hw.wiphy, "Failed to initialize wep: %d\n",
  			    result);
  
  	local->hw.conf.flags = IEEE80211_CONF_IDLE;
  
  	ieee80211_led_init(local);
  
  	rtnl_lock();
  
  	result = ieee80211_init_rate_ctrl_alg(local,
  					      hw->rate_control_algorithm);
  	if (result < 0) {
  		wiphy_debug(local->hw.wiphy,
  			    "Failed to initialize rate control algorithm\n");
  		goto fail_rate;
  	}
  
  	/* add one default STA interface if supported */
  	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION)) {
  		result = ieee80211_if_add(local, "wlan%d", NULL,
  					  NL80211_IFTYPE_STATION, NULL);
  		if (result)
  			wiphy_warn(local->hw.wiphy,
  				   "Failed to add default virtual iface\n");
  	}
  
  	rtnl_unlock();
  
  	local->network_latency_notifier.notifier_call =
  		ieee80211_max_network_latency;
  	result = pm_qos_add_notifier(PM_QOS_NETWORK_LATENCY,
  				     &local->network_latency_notifier);
  	if (result) {
  		rtnl_lock();
  		goto fail_pm_qos;
  	}
  
  #ifdef CONFIG_INET
  	local->ifa_notifier.notifier_call = ieee80211_ifa_changed;
  	result = register_inetaddr_notifier(&local->ifa_notifier);
  	if (result)
  		goto fail_ifa;
  #endif
  
  #if IS_ENABLED(CONFIG_IPV6)
  	local->ifa6_notifier.notifier_call = ieee80211_ifa6_changed;
  	result = register_inet6addr_notifier(&local->ifa6_notifier);
  	if (result)
  		goto fail_ifa6;
  #endif
  
  	return 0;
  
  #if IS_ENABLED(CONFIG_IPV6)
   fail_ifa6:
  #ifdef CONFIG_INET
  	unregister_inetaddr_notifier(&local->ifa_notifier);
  #endif
  #endif
  #if defined(CONFIG_INET) || defined(CONFIG_IPV6)
   fail_ifa:
  	pm_qos_remove_notifier(PM_QOS_NETWORK_LATENCY,
  			       &local->network_latency_notifier);
  	rtnl_lock();
  #endif
   fail_pm_qos:
  	ieee80211_led_exit(local);
  	ieee80211_remove_interfaces(local);
   fail_rate:
  	rtnl_unlock();
  	ieee80211_wep_free(local);
  	sta_info_stop(local);
  	destroy_workqueue(local->workqueue);
   fail_workqueue:
  	wiphy_unregister(local->hw.wiphy);
   fail_wiphy_register:
  	if (local->wiphy_ciphers_allocated)
  		kfree(local->hw.wiphy->cipher_suites);
  	kfree(local->int_scan_req);
  	return result;
  }
  EXPORT_SYMBOL(ieee80211_register_hw);
  
  void ieee80211_napi_add(struct ieee80211_hw *hw, struct napi_struct *napi,
  			struct net_device *napi_dev,
  			int (*poll)(struct napi_struct *, int),
  			int weight)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  
  	netif_napi_add(napi_dev, napi, poll, weight);
  	local->napi = napi;
  }
  EXPORT_SYMBOL_GPL(ieee80211_napi_add);
  
  void ieee80211_unregister_hw(struct ieee80211_hw *hw)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  
  	tasklet_kill(&local->tx_pending_tasklet);
  	tasklet_kill(&local->tasklet);
  
  	pm_qos_remove_notifier(PM_QOS_NETWORK_LATENCY,
  			       &local->network_latency_notifier);
  #ifdef CONFIG_INET
  	unregister_inetaddr_notifier(&local->ifa_notifier);
  #endif
  #if IS_ENABLED(CONFIG_IPV6)
  	unregister_inet6addr_notifier(&local->ifa6_notifier);
  #endif
  
  	rtnl_lock();
  
  	/*
  	 * At this point, interface list manipulations are fine
  	 * because the driver cannot be handing us frames any
  	 * more and the tasklet is killed.
  	 */
  	ieee80211_remove_interfaces(local);
  
  	rtnl_unlock();
  
  	cancel_work_sync(&local->restart_work);
  	cancel_work_sync(&local->reconfig_filter);
  	flush_work(&local->sched_scan_stopped_work);
  
  	ieee80211_clear_tx_pending(local);
  	rate_control_deinitialize(local);
  
  	if (skb_queue_len(&local->skb_queue) ||
  	    skb_queue_len(&local->skb_queue_unreliable))
  		wiphy_warn(local->hw.wiphy, "skb_queue not empty\n");
  	skb_queue_purge(&local->skb_queue);
  	skb_queue_purge(&local->skb_queue_unreliable);
  
  	destroy_workqueue(local->workqueue);
  	wiphy_unregister(local->hw.wiphy);
  	sta_info_stop(local);
  	ieee80211_wep_free(local);
  	ieee80211_led_exit(local);
  	kfree(local->int_scan_req);
  }
  EXPORT_SYMBOL(ieee80211_unregister_hw);
  
  static int ieee80211_free_ack_frame(int id, void *p, void *data)
  {
  	WARN_ONCE(1, "Have pending ack frames!\n");
  	kfree_skb(p);
  	return 0;
  }
  
  void ieee80211_free_hw(struct ieee80211_hw *hw)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  
  	mutex_destroy(&local->iflist_mtx);
  	mutex_destroy(&local->mtx);
  
  	if (local->wiphy_ciphers_allocated)
  		kfree(local->hw.wiphy->cipher_suites);
  
  	idr_for_each(&local->ack_status_frames,
  		     ieee80211_free_ack_frame, NULL);
  	idr_destroy(&local->ack_status_frames);
  
  	kfree(rcu_access_pointer(local->tx_latency));
  
  	wiphy_free(local->hw.wiphy);
  }
  EXPORT_SYMBOL(ieee80211_free_hw);
  
  static int __init ieee80211_init(void)
  {
  	struct sk_buff *skb;
  	int ret;
  
  	BUILD_BUG_ON(sizeof(struct ieee80211_tx_info) > sizeof(skb->cb));
  	BUILD_BUG_ON(offsetof(struct ieee80211_tx_info, driver_data) +
  		     IEEE80211_TX_INFO_DRIVER_DATA_SIZE > sizeof(skb->cb));
  
  	ret = rc80211_minstrel_init();
  	if (ret)
  		return ret;
  
  	ret = rc80211_minstrel_ht_init();
  	if (ret)
  		goto err_minstrel;
  
  	ret = rc80211_pid_init();
  	if (ret)
  		goto err_pid;
  
  	ret = ieee80211_iface_init();
  	if (ret)
  		goto err_netdev;
  
  	return 0;
   err_netdev:
  	rc80211_pid_exit();
   err_pid:
  	rc80211_minstrel_ht_exit();
   err_minstrel:
  	rc80211_minstrel_exit();
  
  	return ret;
  }
  
  static void __exit ieee80211_exit(void)
  {
  	rc80211_pid_exit();
  	rc80211_minstrel_ht_exit();
  	rc80211_minstrel_exit();
  
  	ieee80211s_stop();
  
  	ieee80211_iface_exit();
  
  	rcu_barrier();
  }
  
  
  subsys_initcall(ieee80211_init);
  module_exit(ieee80211_exit);
  
  MODULE_DESCRIPTION("IEEE 802.11 subsystem");
  MODULE_LICENSE("GPL");
  