mac80211: fix scan channel race

[deliverable/linux.git] / net / mac80211 / util.c

/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 *
 * 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.
 *
 * utilities for mac80211
 */

#include <net/mac80211.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/wireless.h>
#include <linux/bitmap.h>
#include <linux/crc32.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>
#include <net/rtnetlink.h>

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

/* privid for wiphys to determine whether they belong to us or not */
void *mac80211_wiphy_privid = &mac80211_wiphy_privid;

/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
const unsigned char rfc1042_header[] __aligned(2) =
	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };

/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
const unsigned char bridge_tunnel_header[] __aligned(2) =
	{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };

struct ieee80211_hw *wiphy_to_ieee80211_hw(struct wiphy *wiphy)
{
	struct ieee80211_local *local;
	BUG_ON(!wiphy);

	local = wiphy_priv(wiphy);
	return &local->hw;
}
EXPORT_SYMBOL(wiphy_to_ieee80211_hw);

u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
			enum nl80211_iftype type)
{
	__le16 fc = hdr->frame_control;

	 /* drop ACK/CTS frames and incorrect hdr len (ctrl) */
	if (len < 16)
		return NULL;

	if (ieee80211_is_data(fc)) {
		if (len < 24) /* drop incorrect hdr len (data) */
			return NULL;

		if (ieee80211_has_a4(fc))
			return NULL;
		if (ieee80211_has_tods(fc))
			return hdr->addr1;
		if (ieee80211_has_fromds(fc))
			return hdr->addr2;

		return hdr->addr3;
	}

	if (ieee80211_is_mgmt(fc)) {
		if (len < 24) /* drop incorrect hdr len (mgmt) */
			return NULL;
		return hdr->addr3;
	}

	if (ieee80211_is_ctl(fc)) {
		if(ieee80211_is_pspoll(fc))
			return hdr->addr1;

		if (ieee80211_is_back_req(fc)) {
			switch (type) {
			case NL80211_IFTYPE_STATION:
				return hdr->addr2;
			case NL80211_IFTYPE_AP:
			case NL80211_IFTYPE_AP_VLAN:
				return hdr->addr1;
			default:
				break; /* fall through to the return */
			}
		}
	}

	return NULL;
}

unsigned int ieee80211_hdrlen(__le16 fc)
{
	unsigned int hdrlen = 24;

	if (ieee80211_is_data(fc)) {
		if (ieee80211_has_a4(fc))
			hdrlen = 30;
		if (ieee80211_is_data_qos(fc))
			hdrlen += IEEE80211_QOS_CTL_LEN;
		goto out;
	}

	if (ieee80211_is_ctl(fc)) {
		/*
		 * ACK and CTS are 10 bytes, all others 16. To see how
		 * to get this condition consider
		 *   subtype mask:   0b0000000011110000 (0x00F0)
		 *   ACK subtype:    0b0000000011010000 (0x00D0)
		 *   CTS subtype:    0b0000000011000000 (0x00C0)
		 *   bits that matter:         ^^^      (0x00E0)
		 *   value of those: 0b0000000011000000 (0x00C0)
		 */
		if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
			hdrlen = 10;
		else
			hdrlen = 16;
	}
out:
	return hdrlen;
}
EXPORT_SYMBOL(ieee80211_hdrlen);

unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
{
	const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *)skb->data;
	unsigned int hdrlen;

	if (unlikely(skb->len < 10))
		return 0;
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
	if (unlikely(hdrlen > skb->len))
		return 0;
	return hdrlen;
}
EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);

int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
{
	int ae = meshhdr->flags & IEEE80211S_FLAGS_AE;
	/* 7.1.3.5a.2 */
	switch (ae) {
	case 0:
		return 6;
	case 1:
		return 12;
	case 2:
		return 18;
	case 3:
		return 24;
	default:
		return 6;
	}
}

void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx)
{
	struct sk_buff *skb = tx->skb;
	struct ieee80211_hdr *hdr;

	do {
		hdr = (struct ieee80211_hdr *) skb->data;
		hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
	} while ((skb = skb->next));
}

int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
			     int rate, int erp, int short_preamble)
{
	int dur;

	/* calculate duration (in microseconds, rounded up to next higher
	 * integer if it includes a fractional microsecond) to send frame of
	 * len bytes (does not include FCS) at the given rate. Duration will
	 * also include SIFS.
	 *
	 * rate is in 100 kbps, so divident is multiplied by 10 in the
	 * DIV_ROUND_UP() operations.
	 */

	if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ || erp) {
		/*
		 * OFDM:
		 *
		 * N_DBPS = DATARATE x 4
		 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
		 *	(16 = SIGNAL time, 6 = tail bits)
		 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
		 *
		 * T_SYM = 4 usec
		 * 802.11a - 17.5.2: aSIFSTime = 16 usec
		 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
		 *	signal ext = 6 usec
		 */
		dur = 16; /* SIFS + signal ext */
		dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
		dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
		dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
					4 * rate); /* T_SYM x N_SYM */
	} else {
		/*
		 * 802.11b or 802.11g with 802.11b compatibility:
		 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
		 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
		 *
		 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
		 * aSIFSTime = 10 usec
		 * aPreambleLength = 144 usec or 72 usec with short preamble
		 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
		 */
		dur = 10; /* aSIFSTime = 10 usec */
		dur += short_preamble ? (72 + 24) : (144 + 48);

		dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
	}

	return dur;
}

/* Exported duration function for driver use */
__le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
					struct ieee80211_vif *vif,
					size_t frame_len,
					struct ieee80211_rate *rate)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_sub_if_data *sdata;
	u16 dur;
	int erp;
	bool short_preamble = false;

	erp = 0;
	if (vif) {
		sdata = vif_to_sdata(vif);
		short_preamble = sdata->vif.bss_conf.use_short_preamble;
		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
			erp = rate->flags & IEEE80211_RATE_ERP_G;
	}

	dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp,
				       short_preamble);

	return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_generic_frame_duration);

__le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
			      struct ieee80211_vif *vif, size_t frame_len,
			      const struct ieee80211_tx_info *frame_txctl)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_rate *rate;
	struct ieee80211_sub_if_data *sdata;
	bool short_preamble;
	int erp;
	u16 dur;
	struct ieee80211_supported_band *sband;

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

	short_preamble = false;

	rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];

	erp = 0;
	if (vif) {
		sdata = vif_to_sdata(vif);
		short_preamble = sdata->vif.bss_conf.use_short_preamble;
		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
			erp = rate->flags & IEEE80211_RATE_ERP_G;
	}

	/* CTS duration */
	dur = ieee80211_frame_duration(local, 10, rate->bitrate,
				       erp, short_preamble);
	/* Data frame duration */
	dur += ieee80211_frame_duration(local, frame_len, rate->bitrate,
					erp, short_preamble);
	/* ACK duration */
	dur += ieee80211_frame_duration(local, 10, rate->bitrate,
					erp, short_preamble);

	return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_rts_duration);

__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
				    struct ieee80211_vif *vif,
				    size_t frame_len,
				    const struct ieee80211_tx_info *frame_txctl)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_rate *rate;
	struct ieee80211_sub_if_data *sdata;
	bool short_preamble;
	int erp;
	u16 dur;
	struct ieee80211_supported_band *sband;

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

	short_preamble = false;

	rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
	erp = 0;
	if (vif) {
		sdata = vif_to_sdata(vif);
		short_preamble = sdata->vif.bss_conf.use_short_preamble;
		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
			erp = rate->flags & IEEE80211_RATE_ERP_G;
	}

	/* Data frame duration */
	dur = ieee80211_frame_duration(local, frame_len, rate->bitrate,
				       erp, short_preamble);
	if (!(frame_txctl->flags & IEEE80211_TX_CTL_NO_ACK)) {
		/* ACK duration */
		dur += ieee80211_frame_duration(local, 10, rate->bitrate,
						erp, short_preamble);
	}

	return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_ctstoself_duration);

static void __ieee80211_wake_queue(struct ieee80211_hw *hw, int queue,
				   enum queue_stop_reason reason)
{
	struct ieee80211_local *local = hw_to_local(hw);

	if (WARN_ON(queue >= hw->queues))
		return;

	__clear_bit(reason, &local->queue_stop_reasons[queue]);

	if (!skb_queue_empty(&local->pending[queue]) &&
	    local->queue_stop_reasons[queue] ==
				BIT(IEEE80211_QUEUE_STOP_REASON_PENDING))
		tasklet_schedule(&local->tx_pending_tasklet);

	if (local->queue_stop_reasons[queue] != 0)
		/* someone still has this queue stopped */
		return;

	netif_wake_subqueue(local->mdev, queue);
}

void ieee80211_wake_queue_by_reason(struct ieee80211_hw *hw, int queue,
				    enum queue_stop_reason reason)
{
	struct ieee80211_local *local = hw_to_local(hw);
	unsigned long flags;

	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
	__ieee80211_wake_queue(hw, queue, reason);
	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}

void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
{
	ieee80211_wake_queue_by_reason(hw, queue,
				       IEEE80211_QUEUE_STOP_REASON_DRIVER);
}
EXPORT_SYMBOL(ieee80211_wake_queue);

static void __ieee80211_stop_queue(struct ieee80211_hw *hw, int queue,
				   enum queue_stop_reason reason)
{
	struct ieee80211_local *local = hw_to_local(hw);

	if (WARN_ON(queue >= hw->queues))
		return;

	/*
	 * Only stop if it was previously running, this is necessary
	 * for correct pending packets handling because there we may
	 * start (but not wake) the queue and rely on that.
	 */
	if (!local->queue_stop_reasons[queue])
		netif_stop_subqueue(local->mdev, queue);

	__set_bit(reason, &local->queue_stop_reasons[queue]);
}

void ieee80211_stop_queue_by_reason(struct ieee80211_hw *hw, int queue,
				    enum queue_stop_reason reason)
{
	struct ieee80211_local *local = hw_to_local(hw);
	unsigned long flags;

	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
	__ieee80211_stop_queue(hw, queue, reason);
	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}

void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
{
	ieee80211_stop_queue_by_reason(hw, queue,
				       IEEE80211_QUEUE_STOP_REASON_DRIVER);
}
EXPORT_SYMBOL(ieee80211_stop_queue);

void ieee80211_stop_queues_by_reason(struct ieee80211_hw *hw,
				    enum queue_stop_reason reason)
{
	struct ieee80211_local *local = hw_to_local(hw);
	unsigned long flags;
	int i;

	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);

	for (i = 0; i < hw->queues; i++)
		__ieee80211_stop_queue(hw, i, reason);

	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}

void ieee80211_stop_queues(struct ieee80211_hw *hw)
{
	ieee80211_stop_queues_by_reason(hw,
					IEEE80211_QUEUE_STOP_REASON_DRIVER);
}
EXPORT_SYMBOL(ieee80211_stop_queues);

int ieee80211_queue_stopped(struct ieee80211_hw *hw, int queue)
{
	struct ieee80211_local *local = hw_to_local(hw);

	if (WARN_ON(queue >= hw->queues))
		return true;

	return __netif_subqueue_stopped(local->mdev, queue);
}
EXPORT_SYMBOL(ieee80211_queue_stopped);

void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
				     enum queue_stop_reason reason)
{
	struct ieee80211_local *local = hw_to_local(hw);
	unsigned long flags;
	int i;

	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);

	for (i = 0; i < hw->queues; i++)
		__ieee80211_wake_queue(hw, i, reason);

	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}

void ieee80211_wake_queues(struct ieee80211_hw *hw)
{
	ieee80211_wake_queues_by_reason(hw, IEEE80211_QUEUE_STOP_REASON_DRIVER);
}
EXPORT_SYMBOL(ieee80211_wake_queues);

void ieee80211_iterate_active_interfaces(
	struct ieee80211_hw *hw,
	void (*iterator)(void *data, u8 *mac,
			 struct ieee80211_vif *vif),
	void *data)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_sub_if_data *sdata;

	mutex_lock(&local->iflist_mtx);

	list_for_each_entry(sdata, &local->interfaces, list) {
		switch (sdata->vif.type) {
		case __NL80211_IFTYPE_AFTER_LAST:
		case NL80211_IFTYPE_UNSPECIFIED:
		case NL80211_IFTYPE_MONITOR:
		case NL80211_IFTYPE_AP_VLAN:
			continue;
		case NL80211_IFTYPE_AP:
		case NL80211_IFTYPE_STATION:
		case NL80211_IFTYPE_ADHOC:
		case NL80211_IFTYPE_WDS:
		case NL80211_IFTYPE_MESH_POINT:
			break;
		}
		if (netif_running(sdata->dev))
			iterator(data, sdata->dev->dev_addr,
				 &sdata->vif);
	}

	mutex_unlock(&local->iflist_mtx);
}
EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);

void ieee80211_iterate_active_interfaces_atomic(
	struct ieee80211_hw *hw,
	void (*iterator)(void *data, u8 *mac,
			 struct ieee80211_vif *vif),
	void *data)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_sub_if_data *sdata;

	rcu_read_lock();

	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		switch (sdata->vif.type) {
		case __NL80211_IFTYPE_AFTER_LAST:
		case NL80211_IFTYPE_UNSPECIFIED:
		case NL80211_IFTYPE_MONITOR:
		case NL80211_IFTYPE_AP_VLAN:
			continue;
		case NL80211_IFTYPE_AP:
		case NL80211_IFTYPE_STATION:
		case NL80211_IFTYPE_ADHOC:
		case NL80211_IFTYPE_WDS:
		case NL80211_IFTYPE_MESH_POINT:
			break;
		}
		if (netif_running(sdata->dev))
			iterator(data, sdata->dev->dev_addr,
				 &sdata->vif);
	}

	rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);

void ieee802_11_parse_elems(u8 *start, size_t len,
			    struct ieee802_11_elems *elems)
{
	ieee802_11_parse_elems_crc(start, len, elems, 0, 0);
}

u32 ieee802_11_parse_elems_crc(u8 *start, size_t len,
			       struct ieee802_11_elems *elems,
			       u64 filter, u32 crc)
{
	size_t left = len;
	u8 *pos = start;
	bool calc_crc = filter != 0;

	memset(elems, 0, sizeof(*elems));
	elems->ie_start = start;
	elems->total_len = len;

	while (left >= 2) {
		u8 id, elen;

		id = *pos++;
		elen = *pos++;
		left -= 2;

		if (elen > left)
			break;

		if (calc_crc && id < 64 && (filter & BIT(id)))
			crc = crc32_be(crc, pos - 2, elen + 2);

		switch (id) {
		case WLAN_EID_SSID:
			elems->ssid = pos;
			elems->ssid_len = elen;
			break;
		case WLAN_EID_SUPP_RATES:
			elems->supp_rates = pos;
			elems->supp_rates_len = elen;
			break;
		case WLAN_EID_FH_PARAMS:
			elems->fh_params = pos;
			elems->fh_params_len = elen;
			break;
		case WLAN_EID_DS_PARAMS:
			elems->ds_params = pos;
			elems->ds_params_len = elen;
			break;
		case WLAN_EID_CF_PARAMS:
			elems->cf_params = pos;
			elems->cf_params_len = elen;
			break;
		case WLAN_EID_TIM:
			if (elen >= sizeof(struct ieee80211_tim_ie)) {
				elems->tim = (void *)pos;
				elems->tim_len = elen;
			}
			break;
		case WLAN_EID_IBSS_PARAMS:
			elems->ibss_params = pos;
			elems->ibss_params_len = elen;
			break;
		case WLAN_EID_CHALLENGE:
			elems->challenge = pos;
			elems->challenge_len = elen;
			break;
		case WLAN_EID_VENDOR_SPECIFIC:
			if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 &&
			    pos[2] == 0xf2) {
				/* Microsoft OUI (00:50:F2) */

				if (calc_crc)
					crc = crc32_be(crc, pos - 2, elen + 2);

				if (pos[3] == 1) {
					/* OUI Type 1 - WPA IE */
					elems->wpa = pos;
					elems->wpa_len = elen;
				} else if (elen >= 5 && pos[3] == 2) {
					/* OUI Type 2 - WMM IE */
					if (pos[4] == 0) {
						elems->wmm_info = pos;
						elems->wmm_info_len = elen;
					} else if (pos[4] == 1) {
						elems->wmm_param = pos;
						elems->wmm_param_len = elen;
					}
				}
			}
			break;
		case WLAN_EID_RSN:
			elems->rsn = pos;
			elems->rsn_len = elen;
			break;
		case WLAN_EID_ERP_INFO:
			elems->erp_info = pos;
			elems->erp_info_len = elen;
			break;
		case WLAN_EID_EXT_SUPP_RATES:
			elems->ext_supp_rates = pos;
			elems->ext_supp_rates_len = elen;
			break;
		case WLAN_EID_HT_CAPABILITY:
			if (elen >= sizeof(struct ieee80211_ht_cap))
				elems->ht_cap_elem = (void *)pos;
			break;
		case WLAN_EID_HT_INFORMATION:
			if (elen >= sizeof(struct ieee80211_ht_info))
				elems->ht_info_elem = (void *)pos;
			break;
		case WLAN_EID_MESH_ID:
			elems->mesh_id = pos;
			elems->mesh_id_len = elen;
			break;
		case WLAN_EID_MESH_CONFIG:
			elems->mesh_config = pos;
			elems->mesh_config_len = elen;
			break;
		case WLAN_EID_PEER_LINK:
			elems->peer_link = pos;
			elems->peer_link_len = elen;
			break;
		case WLAN_EID_PREQ:
			elems->preq = pos;
			elems->preq_len = elen;
			break;
		case WLAN_EID_PREP:
			elems->prep = pos;
			elems->prep_len = elen;
			break;
		case WLAN_EID_PERR:
			elems->perr = pos;
			elems->perr_len = elen;
			break;
		case WLAN_EID_CHANNEL_SWITCH:
			elems->ch_switch_elem = pos;
			elems->ch_switch_elem_len = elen;
			break;
		case WLAN_EID_QUIET:
			if (!elems->quiet_elem) {
				elems->quiet_elem = pos;
				elems->quiet_elem_len = elen;
			}
			elems->num_of_quiet_elem++;
			break;
		case WLAN_EID_COUNTRY:
			elems->country_elem = pos;
			elems->country_elem_len = elen;
			break;
		case WLAN_EID_PWR_CONSTRAINT:
			elems->pwr_constr_elem = pos;
			elems->pwr_constr_elem_len = elen;
			break;
		case WLAN_EID_TIMEOUT_INTERVAL:
			elems->timeout_int = pos;
			elems->timeout_int_len = elen;
			break;
		default:
			break;
		}

		left -= elen;
		pos += elen;
	}

	return crc;
}

void ieee80211_set_wmm_default(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_tx_queue_params qparam;
	int i;

	if (!local->ops->conf_tx)
		return;

	memset(&qparam, 0, sizeof(qparam));

	qparam.aifs = 2;

	if (local->hw.conf.channel->band == IEEE80211_BAND_2GHZ &&
	    !(sdata->flags & IEEE80211_SDATA_OPERATING_GMODE))
		qparam.cw_min = 31;
	else
		qparam.cw_min = 15;

	qparam.cw_max = 1023;
	qparam.txop = 0;

	for (i = 0; i < local_to_hw(local)->queues; i++)
		drv_conf_tx(local, i, &qparam);
}

void ieee80211_sta_def_wmm_params(struct ieee80211_sub_if_data *sdata,
				  const size_t supp_rates_len,
				  const u8 *supp_rates)
{
	struct ieee80211_local *local = sdata->local;
	int i, have_higher_than_11mbit = 0;

	/* cf. IEEE 802.11 9.2.12 */
	for (i = 0; i < supp_rates_len; i++)
		if ((supp_rates[i] & 0x7f) * 5 > 110)
			have_higher_than_11mbit = 1;

	if (local->hw.conf.channel->band == IEEE80211_BAND_2GHZ &&
	    have_higher_than_11mbit)
		sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
	else
		sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;

	ieee80211_set_wmm_default(sdata);
}

void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
		      int encrypt)
{
	skb->dev = sdata->local->mdev;
	skb_set_mac_header(skb, 0);
	skb_set_network_header(skb, 0);
	skb_set_transport_header(skb, 0);

	skb->iif = sdata->dev->ifindex;
	skb->do_not_encrypt = !encrypt;

	dev_queue_xmit(skb);
}

int ieee80211_set_freq(struct ieee80211_sub_if_data *sdata, int freqMHz)
{
	int ret = -EINVAL;
	struct ieee80211_channel *chan;
	struct ieee80211_local *local = sdata->local;

	chan = ieee80211_get_channel(local->hw.wiphy, freqMHz);

	if (chan && !(chan->flags & IEEE80211_CHAN_DISABLED)) {
		if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
		    chan->flags & IEEE80211_CHAN_NO_IBSS)
			return ret;
		local->oper_channel = chan;
		local->oper_channel_type = NL80211_CHAN_NO_HT;

		if (local->sw_scanning || local->hw_scanning)
			ret = 0;
		else
			ret = ieee80211_hw_config(
				local, IEEE80211_CONF_CHANGE_CHANNEL);
	}

	return ret;
}

u32 ieee80211_mandatory_rates(struct ieee80211_local *local,
			      enum ieee80211_band band)
{
	struct ieee80211_supported_band *sband;
	struct ieee80211_rate *bitrates;
	u32 mandatory_rates;
	enum ieee80211_rate_flags mandatory_flag;
	int i;

	sband = local->hw.wiphy->bands[band];
	if (!sband) {
		WARN_ON(1);
		sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
	}

	if (band == IEEE80211_BAND_2GHZ)
		mandatory_flag = IEEE80211_RATE_MANDATORY_B;
	else
		mandatory_flag = IEEE80211_RATE_MANDATORY_A;

	bitrates = sband->bitrates;
	mandatory_rates = 0;
	for (i = 0; i < sband->n_bitrates; i++)
		if (bitrates[i].flags & mandatory_flag)
			mandatory_rates |= BIT(i);
	return mandatory_rates;
}

void ieee80211_send_auth(struct ieee80211_sub_if_data *sdata,
			 u16 transaction, u16 auth_alg,
			 u8 *extra, size_t extra_len,
			 const u8 *bssid, int encrypt)
{
	struct ieee80211_local *local = sdata->local;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom +
			    sizeof(*mgmt) + 6 + extra_len);
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for auth "
		       "frame\n", sdata->dev->name);
		return;
	}
	skb_reserve(skb, local->hw.extra_tx_headroom);

	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24 + 6);
	memset(mgmt, 0, 24 + 6);
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_AUTH);
	if (encrypt)
		mgmt->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
	memcpy(mgmt->da, bssid, ETH_ALEN);
	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
	memcpy(mgmt->bssid, bssid, ETH_ALEN);
	mgmt->u.auth.auth_alg = cpu_to_le16(auth_alg);
	mgmt->u.auth.auth_transaction = cpu_to_le16(transaction);
	mgmt->u.auth.status_code = cpu_to_le16(0);
	if (extra)
		memcpy(skb_put(skb, extra_len), extra, extra_len);

	ieee80211_tx_skb(sdata, skb, encrypt);
}

int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
			     const u8 *ie, size_t ie_len)
{
	struct ieee80211_supported_band *sband;
	u8 *pos, *supp_rates_len, *esupp_rates_len = NULL;
	int i;

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

	pos = buffer;

	*pos++ = WLAN_EID_SUPP_RATES;
	supp_rates_len = pos;
	*pos++ = 0;

	for (i = 0; i < sband->n_bitrates; i++) {
		struct ieee80211_rate *rate = &sband->bitrates[i];

		if (esupp_rates_len) {
			*esupp_rates_len += 1;
		} else if (*supp_rates_len == 8) {
			*pos++ = WLAN_EID_EXT_SUPP_RATES;
			esupp_rates_len = pos;
			*pos++ = 1;
		} else
			*supp_rates_len += 1;

		*pos++ = rate->bitrate / 5;
	}

	if (sband->ht_cap.ht_supported) {
		__le16 tmp = cpu_to_le16(sband->ht_cap.cap);

		*pos++ = WLAN_EID_HT_CAPABILITY;
		*pos++ = sizeof(struct ieee80211_ht_cap);
		memset(pos, 0, sizeof(struct ieee80211_ht_cap));
		memcpy(pos, &tmp, sizeof(u16));
		pos += sizeof(u16);
		/* TODO: needs a define here for << 2 */
		*pos++ = sband->ht_cap.ampdu_factor |
			 (sband->ht_cap.ampdu_density << 2);
		memcpy(pos, &sband->ht_cap.mcs, sizeof(sband->ht_cap.mcs));
		pos += sizeof(sband->ht_cap.mcs);
		pos += 2 + 4 + 1; /* ext info, BF cap, antsel */
	}

	/*
	 * If adding more here, adjust code in main.c
	 * that calculates local->scan_ies_len.
	 */

	if (ie) {
		memcpy(pos, ie, ie_len);
		pos += ie_len;
	}

	return pos - buffer;
}

void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
			      const u8 *ssid, size_t ssid_len,
			      const u8 *ie, size_t ie_len)
{
	struct ieee80211_local *local = sdata->local;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u8 *pos;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*mgmt) + 200 +
			    ie_len);
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
		       "request\n", sdata->dev->name);
		return;
	}
	skb_reserve(skb, local->hw.extra_tx_headroom);

	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	memset(mgmt, 0, 24);
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_PROBE_REQ);
	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
	if (dst) {
		memcpy(mgmt->da, dst, ETH_ALEN);
		memcpy(mgmt->bssid, dst, ETH_ALEN);
	} else {
		memset(mgmt->da, 0xff, ETH_ALEN);
		memset(mgmt->bssid, 0xff, ETH_ALEN);
	}
	pos = skb_put(skb, 2 + ssid_len);
	*pos++ = WLAN_EID_SSID;
	*pos++ = ssid_len;
	memcpy(pos, ssid, ssid_len);
	pos += ssid_len;

	skb_put(skb, ieee80211_build_preq_ies(local, pos, ie, ie_len));

	ieee80211_tx_skb(sdata, skb, 0);
}

u32 ieee80211_sta_get_rates(struct ieee80211_local *local,
			    struct ieee802_11_elems *elems,
			    enum ieee80211_band band)
{
	struct ieee80211_supported_band *sband;
	struct ieee80211_rate *bitrates;
	size_t num_rates;
	u32 supp_rates;
	int i, j;
	sband = local->hw.wiphy->bands[band];

	if (!sband) {
		WARN_ON(1);
		sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
	}

	bitrates = sband->bitrates;
	num_rates = sband->n_bitrates;
	supp_rates = 0;
	for (i = 0; i < elems->supp_rates_len +
		     elems->ext_supp_rates_len; i++) {
		u8 rate = 0;
		int own_rate;
		if (i < elems->supp_rates_len)
			rate = elems->supp_rates[i];
		else if (elems->ext_supp_rates)
			rate = elems->ext_supp_rates
				[i - elems->supp_rates_len];
		own_rate = 5 * (rate & 0x7f);
		for (j = 0; j < num_rates; j++)
			if (bitrates[j].bitrate == own_rate)
				supp_rates |= BIT(j);
	}
	return supp_rates;
}

int ieee80211_reconfig(struct ieee80211_local *local)
{
	struct ieee80211_hw *hw = &local->hw;
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_init_conf conf;
	struct sta_info *sta;
	unsigned long flags;
	int res;

	/* restart hardware */
	if (local->open_count) {
		res = drv_start(local);

		ieee80211_led_radio(local, hw->conf.radio_enabled);
	}

	/* add interfaces */
	list_for_each_entry(sdata, &local->interfaces, list) {
		if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
		    sdata->vif.type != NL80211_IFTYPE_MONITOR &&
		    netif_running(sdata->dev)) {
			conf.vif = &sdata->vif;
			conf.type = sdata->vif.type;
			conf.mac_addr = sdata->dev->dev_addr;
			res = drv_add_interface(local, &conf);
		}
	}

	/* add STAs back */
	if (local->ops->sta_notify) {
		spin_lock_irqsave(&local->sta_lock, flags);
		list_for_each_entry(sta, &local->sta_list, list) {
			if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
				sdata = container_of(sdata->bss,
					     struct ieee80211_sub_if_data,
					     u.ap);

			drv_sta_notify(local, &sdata->vif, STA_NOTIFY_ADD,
				       &sta->sta);
		}
		spin_unlock_irqrestore(&local->sta_lock, flags);
	}

	/* Clear Suspend state so that ADDBA requests can be processed */

	rcu_read_lock();

	if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
		list_for_each_entry_rcu(sta, &local->sta_list, list) {
			clear_sta_flags(sta, WLAN_STA_SUSPEND);
		}
	}

	rcu_read_unlock();

	/* setup RTS threshold */
	drv_set_rts_threshold(local, hw->wiphy->rts_threshold);

	/* reconfigure hardware */
	ieee80211_hw_config(local, ~0);

	netif_addr_lock_bh(local->mdev);
	ieee80211_configure_filter(local);
	netif_addr_unlock_bh(local->mdev);

	/* Finally also reconfigure all the BSS information */
	list_for_each_entry(sdata, &local->interfaces, list) {
		u32 changed = ~0;
		if (!netif_running(sdata->dev))
			continue;
		switch (sdata->vif.type) {
		case NL80211_IFTYPE_STATION:
			/* disable beacon change bits */
			changed &= ~(BSS_CHANGED_BEACON |
				     BSS_CHANGED_BEACON_ENABLED);
			/* fall through */
		case NL80211_IFTYPE_ADHOC:
		case NL80211_IFTYPE_AP:
		case NL80211_IFTYPE_MESH_POINT:
			ieee80211_bss_info_change_notify(sdata, changed);
			break;
		case NL80211_IFTYPE_WDS:
			break;
		case NL80211_IFTYPE_AP_VLAN:
		case NL80211_IFTYPE_MONITOR:
			/* ignore virtual */
			break;
		case NL80211_IFTYPE_UNSPECIFIED:
		case __NL80211_IFTYPE_AFTER_LAST:
			WARN_ON(1);
			break;
		}
	}

	/* add back keys */
	list_for_each_entry(sdata, &local->interfaces, list)
		if (netif_running(sdata->dev))
			ieee80211_enable_keys(sdata);

	ieee80211_wake_queues_by_reason(hw,
			IEEE80211_QUEUE_STOP_REASON_SUSPEND);

	return 0;
}