mlme.c

/*
 * BSS client mode implementation
 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.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.
 */

/* TODO:
 * order BSS list by RSSI(?) ("quality of AP")
 * scan result table filtering (by capability (privacy, IBSS/BSS, WPA/RSN IE,
 *    SSID)
 */
#include <linux/delay.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/netdevice.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 <asm/types.h>

#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "rate.h"
#include "led.h"
#include "mesh.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_MESH_HOUSEKEEPING_INTERVAL (60 * 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_PROBE_DELAY (HZ / 33)
#define IEEE80211_CHANNEL_TIME (HZ / 33)
#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 5)
#define IEEE80211_SCAN_RESULT_EXPIRE (10 * HZ)
#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
#define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)

#define IEEE80211_IBSS_MAX_STA_ENTRIES 128


#define ERP_INFO_USE_PROTECTION BIT(1)

/* mgmt header + 1 byte category code */
#define IEEE80211_MIN_ACTION_SIZE (24 + 1)

#define IEEE80211_ADDBA_PARAM_POLICY_MASK 0x0002
#define IEEE80211_ADDBA_PARAM_TID_MASK 0x003C
#define IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK 0xFFA0
#define IEEE80211_DELBA_PARAM_TID_MASK 0xF000
#define IEEE80211_DELBA_PARAM_INITIATOR_MASK 0x0800

/* next values represent the buffer size for A-MPDU frame.
 * According to IEEE802.11n spec size varies from 8K to 64K (in powers of 2) */
#define IEEE80211_MIN_AMPDU_BUF 0x8
#define IEEE80211_MAX_AMPDU_BUF 0x40

static void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
				     u8 *ssid, size_t ssid_len);
static struct ieee80211_sta_bss *
ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq,
		     u8 *ssid, u8 ssid_len);
static void ieee80211_rx_bss_put(struct ieee80211_local *local,
				 struct ieee80211_sta_bss *bss);
static int ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata,
				   struct ieee80211_if_sta *ifsta);
static int ieee80211_sta_wep_configured(struct ieee80211_sub_if_data *sdata);
static int ieee80211_sta_start_scan(struct ieee80211_sub_if_data *sdata,
				    u8 *ssid, size_t ssid_len);
static int ieee80211_sta_config_auth(struct ieee80211_sub_if_data *sdata,
				     struct ieee80211_if_sta *ifsta);
static void sta_rx_agg_session_timer_expired(unsigned long data);


static u8 * ieee80211_bss_get_ie(struct ieee80211_sta_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 ecw2cw(int ecw)
{
	return (1 << ecw) - 1;
}


static void ieee80211_sta_def_wmm_params(struct ieee80211_sub_if_data *sdata,
					 struct ieee80211_sta_bss *bss,
					 int ibss)
{
	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;


	if (local->ops->conf_tx) {
		struct ieee80211_tx_queue_params qparam;

		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++)
			local->ops->conf_tx(local_to_hw(local), i, &qparam);
	}
}

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 u32 ieee80211_handle_protect_preamb(struct ieee80211_sub_if_data *sdata,
					   bool use_protection,
					   bool use_short_preamble)
{
	struct ieee80211_bss_conf *bss_conf = &sdata->bss_conf;
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
	DECLARE_MAC_BUF(mac);
#endif
	u32 changed = 0;

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

	return changed;
}

static u32 ieee80211_handle_erp_ie(struct ieee80211_sub_if_data *sdata,
				   u8 erp_value)
{
	bool use_protection = (erp_value & WLAN_ERP_USE_PROTECTION) != 0;
	bool use_short_preamble = (erp_value & WLAN_ERP_BARKER_PREAMBLE) == 0;

	return ieee80211_handle_protect_preamb(sdata,
			use_protection, use_short_preamble);
}

static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,
					   struct ieee80211_sta_bss *bss)
{
	u32 changed = 0;

	if (bss->has_erp_value)
		changed |= ieee80211_handle_erp_ie(sdata, bss->erp_value);
	else {
		u16 capab = bss->capability;
		changed |= ieee80211_handle_protect_preamb(sdata, false,
				(capab & WLAN_CAPABILITY_SHORT_PREAMBLE) != 0);
	}

	return changed;
}

int ieee80211_ht_cap_ie_to_ht_info(struct ieee80211_ht_cap *ht_cap_ie,
				   struct ieee80211_ht_info *ht_info)
{

	if (ht_info == NULL)
		return -EINVAL;

	memset(ht_info, 0, sizeof(*ht_info));

	if (ht_cap_ie) {
		u8 ampdu_info = ht_cap_ie->ampdu_params_info;

		ht_info->ht_supported = 1;
		ht_info->cap = le16_to_cpu(ht_cap_ie->cap_info);
		ht_info->ampdu_factor =
			ampdu_info & IEEE80211_HT_CAP_AMPDU_FACTOR;
		ht_info->ampdu_density =
			(ampdu_info & IEEE80211_HT_CAP_AMPDU_DENSITY) >> 2;
		memcpy(ht_info->supp_mcs_set, ht_cap_ie->supp_mcs_set, 16);
	} else
		ht_info->ht_supported = 0;

	return 0;
}

int ieee80211_ht_addt_info_ie_to_ht_bss_info(
			struct ieee80211_ht_addt_info *ht_add_info_ie,
			struct ieee80211_ht_bss_info *bss_info)
{
	if (bss_info == NULL)
		return -EINVAL;

	memset(bss_info, 0, sizeof(*bss_info));

	if (ht_add_info_ie) {
		u16 op_mode;
		op_mode = le16_to_cpu(ht_add_info_ie->operation_mode);

		bss_info->primary_channel = ht_add_info_ie->control_chan;
		bss_info->bss_cap = ht_add_info_ie->ht_param;
		bss_info->bss_op_mode = (u8)(op_mode & 0xff);
	}

	return 0;
}

static void ieee80211_sta_send_associnfo(struct ieee80211_sub_if_data *sdata,
					 struct ieee80211_if_sta *ifsta)
{
	union iwreq_data wrqu;

	if (ifsta->assocreq_ies) {
		memset(&wrqu, 0, sizeof(wrqu));
		wrqu.data.length = ifsta->assocreq_ies_len;
		wireless_send_event(sdata->dev, IWEVASSOCREQIE, &wrqu,
				    ifsta->assocreq_ies);
	}
	if (ifsta->assocresp_ies) {
		memset(&wrqu, 0, sizeof(wrqu));
		wrqu.data.length = ifsta->assocresp_ies_len;
		wireless_send_event(sdata->dev, IWEVASSOCRESPIE, &wrqu,
				    ifsta->assocresp_ies);
	}
}


static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
				     struct ieee80211_if_sta *ifsta,
				     bool assoc)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_conf *conf = &local_to_hw(local)->conf;
	union iwreq_data wrqu;
	u32 changed = BSS_CHANGED_ASSOC;

	if (assoc) {
		struct ieee80211_sta_bss *bss;

		ifsta->flags |= IEEE80211_STA_ASSOCIATED;

		if (sdata->vif.type != IEEE80211_IF_TYPE_STA)
			return;

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

			changed |= ieee80211_handle_bss_capability(sdata, bss);

			ieee80211_rx_bss_put(local, bss);
		}

		if (conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE) {
			changed |= BSS_CHANGED_HT;
			sdata->bss_conf.assoc_ht = 1;
			sdata->bss_conf.ht_conf = &conf->ht_conf;
			sdata->bss_conf.ht_bss_conf = &conf->ht_bss_conf;
		}

		ifsta->flags |= IEEE80211_STA_PREV_BSSID_SET;
		memcpy(ifsta->prev_bssid, sdata->u.sta.bssid, ETH_ALEN);
		memcpy(wrqu.ap_addr.sa_data, sdata->u.sta.bssid, ETH_ALEN);
		ieee80211_sta_send_associnfo(sdata, ifsta);
	} else {
		netif_carrier_off(sdata->dev);
		ieee80211_sta_tear_down_BA_sessions(sdata, ifsta->bssid);
		ifsta->flags &= ~IEEE80211_STA_ASSOCIATED;
		changed |= ieee80211_reset_erp_info(sdata);

		sdata->bss_conf.assoc_ht = 0;
		sdata->bss_conf.ht_conf = NULL;
		sdata->bss_conf.ht_bss_conf = NULL;

		memset(wrqu.ap_addr.sa_data, 0, ETH_ALEN);
	}
	ifsta->last_probe = jiffies;
	ieee80211_led_assoc(local, assoc);

	sdata->bss_conf.assoc = assoc;
	ieee80211_bss_info_change_notify(sdata, changed);

	if (assoc)
		netif_carrier_on(sdata->dev);

	wrqu.ap_addr.sa_family = ARPHRD_ETHER;
	wireless_send_event(sdata->dev, SIOCGIWAP, &wrqu, NULL);
}

static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
				   struct ieee80211_if_sta *ifsta, int deauth)
{
	if (deauth) {
		ifsta->direct_probe_tries = 0;
		ifsta->auth_tries = 0;
	}
	ifsta->assoc_scan_tries = 0;
	ifsta->assoc_tries = 0;
	ieee80211_set_associated(sdata, ifsta, 0);
}

void ieee80211_sta_tx(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);
}


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);
	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);

	ieee80211_sta_tx(sdata, skb, encrypt);
}

static void ieee80211_direct_probe(struct ieee80211_sub_if_data *sdata,
				   struct ieee80211_if_sta *ifsta)
{
	DECLARE_MAC_BUF(mac);

	ifsta->direct_probe_tries++;
	if (ifsta->direct_probe_tries > IEEE80211_AUTH_MAX_TRIES) {
		printk(KERN_DEBUG "%s: direct probe to AP %s timed out\n",
		       sdata->dev->name, print_mac(mac, ifsta->bssid));
		ifsta->state = IEEE80211_STA_MLME_DISABLED;
		return;
	}

	printk(KERN_DEBUG "%s: direct probe to AP %s try %d\n",
			sdata->dev->name, print_mac(mac, 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)
{
	DECLARE_MAC_BUF(mac);

	ifsta->auth_tries++;
	if (ifsta->auth_tries > IEEE80211_AUTH_MAX_TRIES) {
		printk(KERN_DEBUG "%s: authentication with AP %s"
		       " timed out\n",
		       sdata->dev->name, print_mac(mac, ifsta->bssid));
		ifsta->state = IEEE80211_STA_MLME_DISABLED;
		return;
	}

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

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

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

static int ieee80211_compatible_rates(struct ieee80211_sta_bss *bss,
				      struct ieee80211_supported_band *sband,
				      u64 *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;
}

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_add_ie;
	int i, len, count, rates_len, supp_rates_len;
	u16 capab;
	struct ieee80211_sta_bss *bss;
	int wmm = 0;
	struct ieee80211_supported_band *sband;
	u64 rates = 0;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom +
			    sizeof(*mgmt) + 200 + ifsta->extra_ie_len +
			    ifsta->ssid_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.reassoc_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 */
	if (wmm && (ifsta->flags & IEEE80211_STA_WMM_ENABLED) &&
	    sband->ht_info.ht_supported &&
	    (ht_add_ie = ieee80211_bss_get_ie(bss, WLAN_EID_HT_EXTRA_INFO))) {
		struct ieee80211_ht_addt_info *ht_add_info =
			(struct ieee80211_ht_addt_info *)ht_add_ie;
		u16 cap = sband->ht_info.cap;
		__le16 tmp;
		u32 flags = local->hw.conf.channel->flags;

		switch (ht_add_info->ht_param & IEEE80211_HT_IE_CHA_SEC_OFFSET) {
		case IEEE80211_HT_IE_CHA_SEC_ABOVE:
			if (flags & IEEE80211_CHAN_NO_FAT_ABOVE) {
				cap &= ~IEEE80211_HT_CAP_SUP_WIDTH;
				cap &= ~IEEE80211_HT_CAP_SGI_40;
			}
			break;
		case IEEE80211_HT_IE_CHA_SEC_BELOW:
			if (flags & IEEE80211_CHAN_NO_FAT_BELOW) {
				cap &= ~IEEE80211_HT_CAP_SUP_WIDTH;
				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_info.ampdu_factor |
			 (sband->ht_info.ampdu_density << 2);
		memcpy(pos, sband->ht_info.supp_mcs_set, 16);
	}

	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_sta_tx(sdata, skb, 0);
}


static void ieee80211_send_deauth(struct ieee80211_sub_if_data *sdata,
				  struct ieee80211_if_sta *ifsta, u16 reason)
{
	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));
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for deauth "
		       "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 |
					  IEEE80211_STYPE_DEAUTH);
	skb_put(skb, 2);
	mgmt->u.deauth.reason_code = cpu_to_le16(reason);

	ieee80211_sta_tx(sdata, skb, 0);
}


static void ieee80211_send_disassoc(struct ieee80211_sub_if_data *sdata,
				    struct ieee80211_if_sta *ifsta, u16 reason)
{
	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));
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for 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 |
					  IEEE80211_STYPE_DISASSOC);
	skb_put(skb, 2);
	mgmt->u.disassoc.reason_code = cpu_to_le16(reason);

	ieee80211_sta_tx(sdata, skb, 0);
}


static int ieee80211_privacy_mismatch(struct ieee80211_sub_if_data *sdata,
				      struct ieee80211_if_sta *ifsta)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_sta_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);

	ieee80211_rx_bss_put(local, bss);

	if ((bss_privacy == wep_privacy) || (bss_privacy == privacy_invoked))
		return 0;

	return 1;
}


static void ieee80211_associate(struct ieee80211_sub_if_data *sdata,
				struct ieee80211_if_sta *ifsta)
{
	DECLARE_MAC_BUF(mac);

	ifsta->assoc_tries++;
	if (ifsta->assoc_tries > IEEE80211_ASSOC_MAX_TRIES) {
		printk(KERN_DEBUG "%s: association with AP %s"
		       " timed out\n",
		       sdata->dev->name, print_mac(mac, ifsta->bssid));
		ifsta->state = IEEE80211_STA_MLME_DISABLED;
		return;
	}

	ifsta->state = IEEE80211_STA_MLME_ASSOCIATE;
	printk(KERN_DEBUG "%s: associate with AP %s\n",
	       sdata->dev->name, print_mac(mac, ifsta->bssid));
	if (ieee80211_privacy_mismatch(sdata, ifsta)) {
		printk(KERN_DEBUG "%s: mismatch in privacy configuration and "
		       "mixed-cell disabled - abort association\n", sdata->dev->name);
		ifsta->state = IEEE80211_STA_MLME_DISABLED;
		return;
	}

	ieee80211_send_assoc(sdata, ifsta);

	mod_timer(&ifsta->timer, jiffies + IEEE80211_ASSOC_TIMEOUT);
}


static void ieee80211_associated(struct ieee80211_sub_if_data *sdata,
				 struct ieee80211_if_sta *ifsta)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	int disassoc;
	DECLARE_MAC_BUF(mac);

	/* TODO: start monitoring current AP signal quality and number of
	 * missed beacons. Scan other channels every now and then and search
	 * for better APs. */
	/* TODO: remove expired BSSes */

	ifsta->state = IEEE80211_STA_MLME_ASSOCIATED;

	rcu_read_lock();

	sta = sta_info_get(local, ifsta->bssid);
	if (!sta) {
		printk(KERN_DEBUG "%s: No STA entry for own AP %s\n",
		       sdata->dev->name, print_mac(mac, ifsta->bssid));
		disassoc = 1;
	} else {
		disassoc = 0;
		if (time_after(jiffies,
			       sta->last_rx + IEEE80211_MONITORING_INTERVAL)) {
			if (ifsta->flags & IEEE80211_STA_PROBEREQ_POLL) {
				printk(KERN_DEBUG "%s: No ProbeResp from "
				       "current AP %s - assume out of "
				       "range\n",
				       sdata->dev->name, print_mac(mac, ifsta->bssid));
				disassoc = 1;
				sta_info_unlink(&sta);
			} else
				ieee80211_send_probe_req(sdata, ifsta->bssid,
							 local->scan_ssid,
							 local->scan_ssid_len);
			ifsta->flags ^= IEEE80211_STA_PROBEREQ_POLL;
		} else {
			ifsta->flags &= ~IEEE80211_STA_PROBEREQ_POLL;
			if (time_after(jiffies, ifsta->last_probe +
				       IEEE80211_PROBE_INTERVAL)) {
				ifsta->last_probe = jiffies;
				ieee80211_send_probe_req(sdata, ifsta->bssid,
							 ifsta->ssid,
							 ifsta->ssid_len);
			}
		}
	}

	rcu_read_unlock();

	if (disassoc && sta)
		sta_info_destroy(sta);

	if (disassoc) {
		ifsta->state = IEEE80211_STA_MLME_DISABLED;
		ieee80211_set_associated(sdata, ifsta, 0);
	} else {
		mod_timer(&ifsta->timer, jiffies +
				      IEEE80211_MONITORING_INTERVAL);
	}
}


static 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);
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
		       "request\n", sdata->dev->name);