mlme.c

/*
 * BSS client mode implementation
 * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
 * Copyright 2004, Instant802 Networks, Inc.
 * Copyright 2005, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.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.
 */

#include <linux/delay.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/wireless.h>
#include <linux/random.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <net/iw_handler.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>

#include "ieee80211_i.h"
#include "rate.h"
#include "led.h"

#define IEEE80211_ASSOC_SCANS_MAX_TRIES 2
#define IEEE80211_AUTH_TIMEOUT (HZ / 5)
#define IEEE80211_AUTH_MAX_TRIES 3
#define IEEE80211_ASSOC_TIMEOUT (HZ / 5)
#define IEEE80211_ASSOC_MAX_TRIES 3
#define IEEE80211_MONITORING_INTERVAL (2 * HZ)
#define IEEE80211_PROBE_INTERVAL (60 * HZ)
#define IEEE80211_RETRY_AUTH_INTERVAL (1 * HZ)
#define IEEE80211_SCAN_INTERVAL (2 * HZ)
#define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)

#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)

#define IEEE80211_IBSS_MAX_STA_ENTRIES 128


/* utils */
static int ecw2cw(int ecw)
{
	return (1 << ecw) - 1;
}

static u8 *ieee80211_bss_get_ie(struct ieee80211_bss *bss, u8 ie)
{
	u8 *end, *pos;

	pos = bss->ies;
	if (pos == NULL)
		return NULL;
	end = pos + bss->ies_len;

	while (pos + 1 < end) {
		if (pos + 2 + pos[1] > end)
			break;
		if (pos[0] == ie)
			return pos;
		pos += 2 + pos[1];
	}

	return NULL;
}

static int ieee80211_compatible_rates(struct ieee80211_bss *bss,
				      struct ieee80211_supported_band *sband,
				      u32 *rates)
{
	int i, j, count;
	*rates = 0;
	count = 0;
	for (i = 0; i < bss->supp_rates_len; i++) {
		int rate = (bss->supp_rates[i] & 0x7F) * 5;

		for (j = 0; j < sband->n_bitrates; j++)
			if (sband->bitrates[j].bitrate == rate) {
				*rates |= BIT(j);
				count++;
				break;
			}
	}

	return count;
}

/* also used by mesh code */
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;
}

/* frame sending functions */

static void add_extra_ies(struct sk_buff *skb, u8 *ies, size_t ies_len)
{
	if (ies)
		memcpy(skb_put(skb, ies_len), ies, ies_len);
}

/* also used by scanning code */
void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
			      u8 *ssid, size_t ssid_len)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_supported_band *sband;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u8 *pos, *supp_rates, *esupp_rates = NULL;
	int i;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*mgmt) + 200 +
			    sdata->u.sta.ie_probereq_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);

	supp_rates = skb_put(skb, 2);
	supp_rates[0] = WLAN_EID_SUPP_RATES;
	supp_rates[1] = 0;
	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

	for (i = 0; i < sband->n_bitrates; i++) {
		struct ieee80211_rate *rate = &sband->bitrates[i];
		if (esupp_rates) {
			pos = skb_put(skb, 1);
			esupp_rates[1]++;
		} else if (supp_rates[1] == 8) {
			esupp_rates = skb_put(skb, 3);
			esupp_rates[0] = WLAN_EID_EXT_SUPP_RATES;
			esupp_rates[1] = 1;
			pos = &esupp_rates[2];
		} else {
			pos = skb_put(skb, 1);
			supp_rates[1]++;
		}
		*pos = rate->bitrate / 5;
	}

	add_extra_ies(skb, sdata->u.sta.ie_probereq,
		      sdata->u.sta.ie_probereq_len);

	ieee80211_tx_skb(sdata, skb, 0);
}

static void ieee80211_send_auth(struct ieee80211_sub_if_data *sdata,
				struct ieee80211_if_sta *ifsta,
				int transaction, u8 *extra, size_t extra_len,
				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 +
			    sdata->u.sta.ie_auth_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, ifsta->bssid, ETH_ALEN);
	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
	memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
	mgmt->u.auth.auth_alg = cpu_to_le16(ifsta->auth_alg);
	mgmt->u.auth.auth_transaction = cpu_to_le16(transaction);
	ifsta->auth_transaction = transaction + 1;
	mgmt->u.auth.status_code = cpu_to_le16(0);
	if (extra)
		memcpy(skb_put(skb, extra_len), extra, extra_len);
	add_extra_ies(skb, sdata->u.sta.ie_auth, sdata->u.sta.ie_auth_len);

	ieee80211_tx_skb(sdata, skb, encrypt);
}

static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata,
				 struct ieee80211_if_sta *ifsta)
{
	struct ieee80211_local *local = sdata->local;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u8 *pos, *ies, *ht_ie, *e_ies;
	int i, len, count, rates_len, supp_rates_len;
	u16 capab;
	struct ieee80211_bss *bss;
	int wmm = 0;
	struct ieee80211_supported_band *sband;
	u32 rates = 0;
	size_t e_ies_len;

	if (ifsta->flags & IEEE80211_STA_PREV_BSSID_SET) {
		e_ies = sdata->u.sta.ie_reassocreq;
		e_ies_len = sdata->u.sta.ie_reassocreq_len;
	} else {
		e_ies = sdata->u.sta.ie_assocreq;
		e_ies_len = sdata->u.sta.ie_assocreq_len;
	}

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

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

	capab = ifsta->capab;

	if (local->hw.conf.channel->band == IEEE80211_BAND_2GHZ) {
		if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
			capab |= WLAN_CAPABILITY_SHORT_SLOT_TIME;
		if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_PREAMBLE_INCAPABLE))
			capab |= WLAN_CAPABILITY_SHORT_PREAMBLE;
	}

	bss = ieee80211_rx_bss_get(local, ifsta->bssid,
				   local->hw.conf.channel->center_freq,
				   ifsta->ssid, ifsta->ssid_len);
	if (bss) {
		if (bss->capability & WLAN_CAPABILITY_PRIVACY)
			capab |= WLAN_CAPABILITY_PRIVACY;
		if (bss->wmm_used)
			wmm = 1;

		/* get all rates supported by the device and the AP as
		 * some APs don't like getting a superset of their rates
		 * in the association request (e.g. D-Link DAP 1353 in
		 * b-only mode) */
		rates_len = ieee80211_compatible_rates(bss, sband, &rates);

		if ((bss->capability & WLAN_CAPABILITY_SPECTRUM_MGMT) &&
		    (local->hw.flags & IEEE80211_HW_SPECTRUM_MGMT))
			capab |= WLAN_CAPABILITY_SPECTRUM_MGMT;

		ieee80211_rx_bss_put(local, bss);
	} else {
		rates = ~0;
		rates_len = sband->n_bitrates;
	}

	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	memset(mgmt, 0, 24);
	memcpy(mgmt->da, ifsta->bssid, ETH_ALEN);
	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
	memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);

	if (ifsta->flags & IEEE80211_STA_PREV_BSSID_SET) {
		skb_put(skb, 10);
		mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
						  IEEE80211_STYPE_REASSOC_REQ);
		mgmt->u.reassoc_req.capab_info = cpu_to_le16(capab);
		mgmt->u.reassoc_req.listen_interval =
				cpu_to_le16(local->hw.conf.listen_interval);
		memcpy(mgmt->u.reassoc_req.current_ap, ifsta->prev_bssid,
		       ETH_ALEN);
	} else {
		skb_put(skb, 4);
		mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
						  IEEE80211_STYPE_ASSOC_REQ);
		mgmt->u.assoc_req.capab_info = cpu_to_le16(capab);
		mgmt->u.assoc_req.listen_interval =
				cpu_to_le16(local->hw.conf.listen_interval);
	}

	/* SSID */
	ies = pos = skb_put(skb, 2 + ifsta->ssid_len);
	*pos++ = WLAN_EID_SSID;
	*pos++ = ifsta->ssid_len;
	memcpy(pos, ifsta->ssid, ifsta->ssid_len);

	/* add all rates which were marked to be used above */
	supp_rates_len = rates_len;
	if (supp_rates_len > 8)
		supp_rates_len = 8;

	len = sband->n_bitrates;
	pos = skb_put(skb, supp_rates_len + 2);
	*pos++ = WLAN_EID_SUPP_RATES;
	*pos++ = supp_rates_len;

	count = 0;
	for (i = 0; i < sband->n_bitrates; i++) {
		if (BIT(i) & rates) {
			int rate = sband->bitrates[i].bitrate;
			*pos++ = (u8) (rate / 5);
			if (++count == 8)
				break;
		}
	}

	if (rates_len > count) {
		pos = skb_put(skb, rates_len - count + 2);
		*pos++ = WLAN_EID_EXT_SUPP_RATES;
		*pos++ = rates_len - count;

		for (i++; i < sband->n_bitrates; i++) {
			if (BIT(i) & rates) {
				int rate = sband->bitrates[i].bitrate;
				*pos++ = (u8) (rate / 5);
			}
		}
	}

	if (capab & WLAN_CAPABILITY_SPECTRUM_MGMT) {
		/* 1. power capabilities */
		pos = skb_put(skb, 4);
		*pos++ = WLAN_EID_PWR_CAPABILITY;
		*pos++ = 2;
		*pos++ = 0; /* min tx power */
		*pos++ = local->hw.conf.channel->max_power; /* max tx power */

		/* 2. supported channels */
		/* TODO: get this in reg domain format */
		pos = skb_put(skb, 2 * sband->n_channels + 2);
		*pos++ = WLAN_EID_SUPPORTED_CHANNELS;
		*pos++ = 2 * sband->n_channels;
		for (i = 0; i < sband->n_channels; i++) {
			*pos++ = ieee80211_frequency_to_channel(
					sband->channels[i].center_freq);
			*pos++ = 1; /* one channel in the subband*/
		}
	}

	if (ifsta->extra_ie) {
		pos = skb_put(skb, ifsta->extra_ie_len);
		memcpy(pos, ifsta->extra_ie, ifsta->extra_ie_len);
	}

	if (wmm && (ifsta->flags & IEEE80211_STA_WMM_ENABLED)) {
		pos = skb_put(skb, 9);
		*pos++ = WLAN_EID_VENDOR_SPECIFIC;
		*pos++ = 7; /* len */
		*pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
		*pos++ = 0x50;
		*pos++ = 0xf2;
		*pos++ = 2; /* WME */
		*pos++ = 0; /* WME info */
		*pos++ = 1; /* WME ver */
		*pos++ = 0;
	}

	/* wmm support is a must to HT */
	/*
	 * IEEE802.11n does not allow TKIP/WEP as pairwise
	 * ciphers in HT mode. We still associate in non-ht
	 * mode (11a/b/g) if any one of these ciphers is
	 * configured as pairwise.
	 */
	if (wmm && (ifsta->flags & IEEE80211_STA_WMM_ENABLED) &&
	    sband->ht_cap.ht_supported &&
	    (ht_ie = ieee80211_bss_get_ie(bss, WLAN_EID_HT_INFORMATION)) &&
	    ht_ie[1] >= sizeof(struct ieee80211_ht_info) &&
	    (!(ifsta->flags & IEEE80211_STA_TKIP_WEP_USED))) {
		struct ieee80211_ht_info *ht_info =
			(struct ieee80211_ht_info *)(ht_ie + 2);
		u16 cap = sband->ht_cap.cap;
		__le16 tmp;
		u32 flags = local->hw.conf.channel->flags;

		switch (ht_info->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
		case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
			if (flags & IEEE80211_CHAN_NO_FAT_ABOVE) {
				cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
				cap &= ~IEEE80211_HT_CAP_SGI_40;
			}
			break;
		case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
			if (flags & IEEE80211_CHAN_NO_FAT_BELOW) {
				cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
				cap &= ~IEEE80211_HT_CAP_SGI_40;
			}
			break;
		}

		tmp = cpu_to_le16(cap);
		pos = skb_put(skb, sizeof(struct ieee80211_ht_cap)+2);
		*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));
	}

	add_extra_ies(skb, e_ies, e_ies_len);

	kfree(ifsta->assocreq_ies);
	ifsta->assocreq_ies_len = (skb->data + skb->len) - ies;
	ifsta->assocreq_ies = kmalloc(ifsta->assocreq_ies_len, GFP_KERNEL);
	if (ifsta->assocreq_ies)
		memcpy(ifsta->assocreq_ies, ies, ifsta->assocreq_ies_len);

	ieee80211_tx_skb(sdata, skb, 0);
}


static void ieee80211_send_deauth_disassoc(struct ieee80211_sub_if_data *sdata,
					   u16 stype, u16 reason)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u8 *ies;
	size_t ies_len;

	if (stype == IEEE80211_STYPE_DEAUTH) {
		ies = sdata->u.sta.ie_deauth;
		ies_len = sdata->u.sta.ie_deauth_len;
	} else {
		ies = sdata->u.sta.ie_disassoc;
		ies_len = sdata->u.sta.ie_disassoc_len;
	}

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*mgmt) +
			    ies_len);
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for "
		       "deauth/disassoc frame\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);
	memcpy(mgmt->da, ifsta->bssid, ETH_ALEN);
	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
	memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | stype);
	skb_put(skb, 2);
	/* u.deauth.reason_code == u.disassoc.reason_code */
	mgmt->u.deauth.reason_code = cpu_to_le16(reason);

	add_extra_ies(skb, ies, ies_len);

	ieee80211_tx_skb(sdata, skb, ifsta->flags & IEEE80211_STA_MFP_ENABLED);
}

/* MLME */
static void ieee80211_sta_def_wmm_params(struct ieee80211_sub_if_data *sdata,
					 struct ieee80211_bss *bss)
{
	struct ieee80211_local *local = sdata->local;
	int i, have_higher_than_11mbit = 0;

	/* cf. IEEE 802.11 9.2.12 */
	for (i = 0; i < bss->supp_rates_len; i++)
		if ((bss->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);
}

static void ieee80211_sta_wmm_params(struct ieee80211_local *local,
				     struct ieee80211_if_sta *ifsta,
				     u8 *wmm_param, size_t wmm_param_len)
{
	struct ieee80211_tx_queue_params params;
	size_t left;
	int count;
	u8 *pos;

	if (!(ifsta->flags & IEEE80211_STA_WMM_ENABLED))
		return;

	if (!wmm_param)
		return;

	if (wmm_param_len < 8 || wmm_param[5] /* version */ != 1)
		return;
	count = wmm_param[6] & 0x0f;
	if (count == ifsta->wmm_last_param_set)
		return;
	ifsta->wmm_last_param_set = count;

	pos = wmm_param + 8;
	left = wmm_param_len - 8;

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

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

	local->wmm_acm = 0;
	for (; left >= 4; left -= 4, pos += 4) {
		int aci = (pos[0] >> 5) & 0x03;
		int acm = (pos[0] >> 4) & 0x01;
		int queue;

		switch (aci) {
		case 1:
			queue = 3;
			if (acm)
				local->wmm_acm |= BIT(0) | BIT(3);
			break;
		case 2:
			queue = 1;
			if (acm)
				local->wmm_acm |= BIT(4) | BIT(5);
			break;
		case 3:
			queue = 0;
			if (acm)
				local->wmm_acm |= BIT(6) | BIT(7);
			break;
		case 0:
		default:
			queue = 2;
			if (acm)
				local->wmm_acm |= BIT(1) | BIT(2);
			break;
		}

		params.aifs = pos[0] & 0x0f;
		params.cw_max = ecw2cw((pos[1] & 0xf0) >> 4);
		params.cw_min = ecw2cw(pos[1] & 0x0f);
		params.txop = get_unaligned_le16(pos + 2);
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		printk(KERN_DEBUG "%s: WMM queue=%d aci=%d acm=%d aifs=%d "
		       "cWmin=%d cWmax=%d txop=%d\n",
		       local->mdev->name, queue, aci, acm, params.aifs, params.cw_min,
		       params.cw_max, params.txop);
#endif
		/* TODO: handle ACM (block TX, fallback to next lowest allowed
		 * AC for now) */
		if (local->ops->conf_tx(local_to_hw(local), queue, &params)) {
			printk(KERN_DEBUG "%s: failed to set TX queue "
			       "parameters for queue %d\n", local->mdev->name, queue);
		}
	}
}

static bool check_tim(struct ieee802_11_elems *elems, u16 aid, bool *is_mc)
{
	u8 mask;
	u8 index, indexn1, indexn2;
	struct ieee80211_tim_ie *tim = (struct ieee80211_tim_ie *) elems->tim;

	aid &= 0x3fff;
	index = aid / 8;
	mask  = 1 << (aid & 7);

	if (tim->bitmap_ctrl & 0x01)
		*is_mc = true;

	indexn1 = tim->bitmap_ctrl & 0xfe;
	indexn2 = elems->tim_len + indexn1 - 4;

	if (index < indexn1 || index > indexn2)
		return false;

	index -= indexn1;

	return !!(tim->virtual_map[index] & mask);
}

static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,
					   u16 capab, bool erp_valid, u8 erp)
{
	struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
#endif
	u32 changed = 0;
	bool use_protection;
	bool use_short_preamble;
	bool use_short_slot;

	if (erp_valid) {
		use_protection = (erp & WLAN_ERP_USE_PROTECTION) != 0;
		use_short_preamble = (erp & WLAN_ERP_BARKER_PREAMBLE) == 0;
	} else {
		use_protection = false;
		use_short_preamble = !!(capab & WLAN_CAPABILITY_SHORT_PREAMBLE);
	}

	use_short_slot = !!(capab & WLAN_CAPABILITY_SHORT_SLOT_TIME);

	if (use_protection != bss_conf->use_cts_prot) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		if (net_ratelimit()) {
			printk(KERN_DEBUG "%s: CTS protection %s (BSSID=%pM)\n",
			       sdata->dev->name,
			       use_protection ? "enabled" : "disabled",
			       ifsta->bssid);
		}
#endif
		bss_conf->use_cts_prot = use_protection;
		changed |= BSS_CHANGED_ERP_CTS_PROT;
	}

	if (use_short_preamble != bss_conf->use_short_preamble) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		if (net_ratelimit()) {
			printk(KERN_DEBUG "%s: switched to %s barker preamble"
			       " (BSSID=%pM)\n",
			       sdata->dev->name,
			       use_short_preamble ? "short" : "long",
			       ifsta->bssid);
		}
#endif
		bss_conf->use_short_preamble = use_short_preamble;
		changed |= BSS_CHANGED_ERP_PREAMBLE;
	}

	if (use_short_slot != bss_conf->use_short_slot) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		if (net_ratelimit()) {
			printk(KERN_DEBUG "%s: switched to %s slot time"
			       " (BSSID=%pM)\n",
			       sdata->dev->name,
			       use_short_slot ? "short" : "long",
			       ifsta->bssid);
		}
#endif
		bss_conf->use_short_slot = use_short_slot;
		changed |= BSS_CHANGED_ERP_SLOT;
	}

	return changed;
}

static void ieee80211_sta_send_apinfo(struct ieee80211_sub_if_data *sdata,
					struct ieee80211_if_sta *ifsta)
{
	union iwreq_data wrqu;
	memset(&wrqu, 0, sizeof(wrqu));
	if (ifsta->flags & IEEE80211_STA_ASSOCIATED)
		memcpy(wrqu.ap_addr.sa_data, sdata->u.sta.bssid, ETH_ALEN);
	wrqu.ap_addr.sa_family = ARPHRD_ETHER;
	wireless_send_event(sdata->dev, SIOCGIWAP, &wrqu, NULL);
}

static void ieee80211_sta_send_associnfo(struct ieee80211_sub_if_data *sdata,
					 struct ieee80211_if_sta *ifsta)
{
	char *buf;
	size_t len;
	int i;
	union iwreq_data wrqu;

	if (!ifsta->assocreq_ies && !ifsta->assocresp_ies)
		return;

	buf = kmalloc(50 + 2 * (ifsta->assocreq_ies_len +
				ifsta->assocresp_ies_len), GFP_KERNEL);
	if (!buf)
		return;

	len = sprintf(buf, "ASSOCINFO(");
	if (ifsta->assocreq_ies) {
		len += sprintf(buf + len, "ReqIEs=");
		for (i = 0; i < ifsta->assocreq_ies_len; i++) {
			len += sprintf(buf + len, "%02x",
				       ifsta->assocreq_ies[i]);
		}
	}
	if (ifsta->assocresp_ies) {
		if (ifsta->assocreq_ies)
			len += sprintf(buf + len, " ");
		len += sprintf(buf + len, "RespIEs=");
		for (i = 0; i < ifsta->assocresp_ies_len; i++) {
			len += sprintf(buf + len, "%02x",
				       ifsta->assocresp_ies[i]);
		}
	}
	len += sprintf(buf + len, ")");

	if (len > IW_CUSTOM_MAX) {
		len = sprintf(buf, "ASSOCRESPIE=");
		for (i = 0; i < ifsta->assocresp_ies_len; i++) {
			len += sprintf(buf + len, "%02x",
				       ifsta->assocresp_ies[i]);
		}
	}

	if (len <= IW_CUSTOM_MAX) {
		memset(&wrqu, 0, sizeof(wrqu));
		wrqu.data.length = len;
		wireless_send_event(sdata->dev, IWEVCUSTOM, &wrqu, buf);
	}

	kfree(buf);
}


static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
				     struct ieee80211_if_sta *ifsta,
				     u32 bss_info_changed)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_conf *conf = &local_to_hw(local)->conf;

	struct ieee80211_bss *bss;

	bss_info_changed |= BSS_CHANGED_ASSOC;
	ifsta->flags |= IEEE80211_STA_ASSOCIATED;

	if (sdata->vif.type != NL80211_IFTYPE_STATION)
		return;

	bss = ieee80211_rx_bss_get(local, ifsta->bssid,
				   conf->channel->center_freq,
				   ifsta->ssid, ifsta->ssid_len);
	if (bss) {
		/* set timing information */
		sdata->vif.bss_conf.beacon_int = bss->beacon_int;
		sdata->vif.bss_conf.timestamp = bss->timestamp;
		sdata->vif.bss_conf.dtim_period = bss->dtim_period;

		bss_info_changed |= ieee80211_handle_bss_capability(sdata,
			bss->capability, bss->has_erp_value, bss->erp_value);

		ieee80211_rx_bss_put(local, bss);
	}

	ifsta->flags |= IEEE80211_STA_PREV_BSSID_SET;
	memcpy(ifsta->prev_bssid, sdata->u.sta.bssid, ETH_ALEN);
	ieee80211_sta_send_associnfo(sdata, ifsta);

	ifsta->last_probe = jiffies;
	ieee80211_led_assoc(local, 1);

	sdata->vif.bss_conf.assoc = 1;
	/*
	 * For now just always ask the driver to update the basic rateset
	 * when we have associated, we aren't checking whether it actually
	 * changed or not.
	 */
	bss_info_changed |= BSS_CHANGED_BASIC_RATES;
	ieee80211_bss_info_change_notify(sdata, bss_info_changed);

	if (local->powersave) {
		if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS) &&
		    local->hw.conf.dynamic_ps_timeout > 0) {
			mod_timer(&local->dynamic_ps_timer, jiffies +
				  msecs_to_jiffies(
					local->hw.conf.dynamic_ps_timeout));
		} else {
			if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
				ieee80211_send_nullfunc(local, sdata, 1);
			conf->flags |= IEEE80211_CONF_PS;
			ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
		}
	}

	netif_tx_start_all_queues(sdata->dev);
	netif_carrier_on(sdata->dev);

	ieee80211_sta_send_apinfo(sdata, ifsta);
}

static void ieee80211_direct_probe(struct ieee80211_sub_if_data *sdata,
				   struct ieee80211_if_sta *ifsta)
{
	ifsta->direct_probe_tries++;
	if (ifsta->direct_probe_tries > IEEE80211_AUTH_MAX_TRIES) {
		printk(KERN_DEBUG "%s: direct probe to AP %pM timed out\n",
		       sdata->dev->name, ifsta->bssid);
		ifsta->state = IEEE80211_STA_MLME_DISABLED;
		ieee80211_sta_send_apinfo(sdata, ifsta);
		return;
	}

	printk(KERN_DEBUG "%s: direct probe to AP %pM try %d\n",
			sdata->dev->name, ifsta->bssid,
			ifsta->direct_probe_tries);

	ifsta->state = IEEE80211_STA_MLME_DIRECT_PROBE;

	set_bit(IEEE80211_STA_REQ_DIRECT_PROBE, &ifsta->request);

	/* Direct probe is sent to broadcast address as some APs
	 * will not answer to direct packet in unassociated state.
	 */
	ieee80211_send_probe_req(sdata, NULL,
				 ifsta->ssid, ifsta->ssid_len);

	mod_timer(&ifsta->timer, jiffies + IEEE80211_AUTH_TIMEOUT);
}


static void ieee80211_authenticate(struct ieee80211_sub_if_data *sdata,
				   struct ieee80211_if_sta *ifsta)
{
	ifsta->auth_tries++;
	if (ifsta->auth_tries > IEEE80211_AUTH_MAX_TRIES) {
		printk(KERN_DEBUG "%s: authentication with AP %pM"
		       " timed out\n",
		       sdata->dev->name, ifsta->bssid);
		ifsta->state = IEEE80211_STA_MLME_DISABLED;
		ieee80211_sta_send_apinfo(sdata, ifsta);
		return;
	}

	ifsta->state = IEEE80211_STA_MLME_AUTHENTICATE;
	printk(KERN_DEBUG "%s: authenticate with AP %pM\n",
	       sdata->dev->name, ifsta->bssid);

	ieee80211_send_auth(sdata, ifsta, 1, NULL, 0, 0);

	mod_timer(&ifsta->timer, jiffies + IEEE80211_AUTH_TIMEOUT);
}

/*
 * The disassoc 'reason' argument can be either our own reason
 * if self disconnected or a reason code from the AP.
 */
static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
				   struct ieee80211_if_sta *ifsta, bool deauth,
				   bool self_disconnected, u16 reason)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	u32 changed = 0, config_changed = 0;

	rcu_read_lock();

	sta = sta_info_get(local, ifsta->bssid);
	if (!sta) {
		rcu_read_unlock();
		return;
	}

	if (deauth) {
		ifsta->direct_probe_tries = 0;
		ifsta->auth_tries = 0;
	}
	ifsta->assoc_scan_tries = 0;
	ifsta->assoc_tries = 0;

	netif_tx_stop_all_queues(sdata->dev);
	netif_carrier_off(sdata->dev);

	ieee80211_sta_tear_down_BA_sessions(sdata, sta->sta.addr);

	if (self_disconnected) {
		if (deauth)
			ieee80211_send_deauth_disassoc(sdata,
				IEEE80211_STYPE_DEAUTH, reason);
		else
			ieee80211_send_deauth_disassoc(sdata,
				IEEE80211_STYPE_DISASSOC, reason);
	}

	ifsta->flags &= ~IEEE80211_STA_ASSOCIATED;
	changed |= ieee80211_reset_erp_info(sdata);

	ieee80211_led_assoc(local, 0);
	changed |= BSS_CHANGED_ASSOC;
	sdata->vif.bss_conf.assoc = false;

	ieee80211_sta_send_apinfo(sdata, ifsta);

	if (self_disconnected || reason == WLAN_REASON_DISASSOC_STA_HAS_LEFT)
		ifsta->state = IEEE80211_STA_MLME_DISABLED;

	rcu_read_unlock();

	/* channel(_type) changes are handled by ieee80211_hw_config */
	local->oper_channel_type = NL80211_CHAN_NO_HT;

	local->power_constr_level = 0;

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

	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
		config_changed |= IEEE80211_CONF_CHANGE_PS;
	}

	ieee80211_hw_config(local, config_changed);
	ieee80211_bss_info_change_notify(sdata, changed);

	rcu_read_lock();

	sta = sta_info_get(local, ifsta->bssid);
	if (!sta) {
		rcu_read_unlock();
		return;
	}

	sta_info_unlink(&sta);

	rcu_read_unlock();

	sta_info_destroy(sta);
}

static int ieee80211_sta_wep_configured(struct ieee80211_sub_if_data *sdata)
{
	if (!sdata || !sdata->default_key ||
	    sdata->default_key->conf.alg != ALG_WEP)
		return 0;
	return 1;
}

static int ieee80211_privacy_mismatch(struct ieee80211_sub_if_data *sdata,
				      struct ieee80211_if_sta *ifsta)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_bss *bss;
	int bss_privacy;
	int wep_privacy;
	int privacy_invoked;

	if (!ifsta || (ifsta->flags & IEEE80211_STA_MIXED_CELL))
		return 0;

	bss = ieee80211_rx_bss_get(local, ifsta->bssid,
				   local->hw.conf.channel->center_freq,
				   ifsta->ssid, ifsta->ssid_len);
	if (!bss)
		return 0;

	bss_privacy = !!(bss->capability & WLAN_CAPABILITY_PRIVACY);
	wep_privacy = !!ieee80211_sta_wep_configured(sdata);
	privacy_invoked = !!(ifsta->flags & IEEE80211_STA_PRIVACY_INVOKED);