[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / mac80211 / scan.c

/*
 * Scanning 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: figure out how to avoid that the "current BSS" expires */

#include <linux/wireless.h>
#include <linux/if_arp.h>
#include <linux/rtnetlink.h>
#include <net/mac80211.h>
#include <net/iw_handler.h>

#include "ieee80211_i.h"
#include "driver-ops.h"
#include "mesh.h"

#define IEEE80211_PROBE_DELAY (HZ / 33)
#define IEEE80211_CHANNEL_TIME (HZ / 33)
#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 5)

struct ieee80211_bss *
ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq,
		     u8 *ssid, u8 ssid_len)
{
	return (void *)cfg80211_get_bss(local->hw.wiphy,
					ieee80211_get_channel(local->hw.wiphy,
							      freq),
					bssid, ssid, ssid_len,
					0, 0);
}

static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss)
{
	struct ieee80211_bss *bss = (void *)cbss;

	kfree(bss_mesh_id(bss));
	kfree(bss_mesh_cfg(bss));
}

void ieee80211_rx_bss_put(struct ieee80211_local *local,
			  struct ieee80211_bss *bss)
{
	cfg80211_put_bss((struct cfg80211_bss *)bss);
}

struct ieee80211_bss *
ieee80211_bss_info_update(struct ieee80211_local *local,
			  struct ieee80211_rx_status *rx_status,
			  struct ieee80211_mgmt *mgmt,
			  size_t len,
			  struct ieee802_11_elems *elems,
			  struct ieee80211_channel *channel,
			  bool beacon)
{
	struct ieee80211_bss *bss;
	int clen;
	s32 signal = 0;

	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
		signal = rx_status->signal * 100;
	else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
		signal = (rx_status->signal * 100) / local->hw.max_signal;

	bss = (void *)cfg80211_inform_bss_frame(local->hw.wiphy, channel,
						mgmt, len, signal, GFP_ATOMIC);

	if (!bss)
		return NULL;

	bss->cbss.free_priv = ieee80211_rx_bss_free;

	/* save the ERP value so that it is available at association time */
	if (elems->erp_info && elems->erp_info_len >= 1) {
		bss->erp_value = elems->erp_info[0];
		bss->has_erp_value = 1;
	}

	if (elems->tim) {
		struct ieee80211_tim_ie *tim_ie =
			(struct ieee80211_tim_ie *)elems->tim;
		bss->dtim_period = tim_ie->dtim_period;
	}

	/* set default value for buggy APs */
	if (!elems->tim || bss->dtim_period == 0)
		bss->dtim_period = 1;

	bss->supp_rates_len = 0;
	if (elems->supp_rates) {
		clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
		if (clen > elems->supp_rates_len)
			clen = elems->supp_rates_len;
		memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates,
		       clen);
		bss->supp_rates_len += clen;
	}
	if (elems->ext_supp_rates) {
		clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
		if (clen > elems->ext_supp_rates_len)
			clen = elems->ext_supp_rates_len;
		memcpy(&bss->supp_rates[bss->supp_rates_len],
		       elems->ext_supp_rates, clen);
		bss->supp_rates_len += clen;
	}

	bss->wmm_used = elems->wmm_param || elems->wmm_info;

	if (!beacon)
		bss->last_probe_resp = jiffies;

	return bss;
}

void ieee80211_rx_bss_remove(struct ieee80211_sub_if_data *sdata, u8 *bssid,
			     int freq, u8 *ssid, u8 ssid_len)
{
	struct ieee80211_bss *bss;
	struct ieee80211_local *local = sdata->local;

	bss = ieee80211_rx_bss_get(local, bssid, freq, ssid, ssid_len);
	if (bss) {
		cfg80211_unlink_bss(local->hw.wiphy, (void *)bss);
		ieee80211_rx_bss_put(local, bss);
	}
}

ieee80211_rx_result
ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
		  struct ieee80211_rx_status *rx_status)
{
	struct ieee80211_mgmt *mgmt;
	struct ieee80211_bss *bss;
	u8 *elements;
	struct ieee80211_channel *channel;
	size_t baselen;
	int freq;
	__le16 fc;
	bool presp, beacon = false;
	struct ieee802_11_elems elems;

	if (skb->len < 2)
		return RX_DROP_UNUSABLE;

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

	if (ieee80211_is_ctl(fc))
		return RX_CONTINUE;

	if (skb->len < 24)
		return RX_DROP_MONITOR;

	presp = ieee80211_is_probe_resp(fc);
	if (presp) {
		/* ignore ProbeResp to foreign address */
		if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
			return RX_DROP_MONITOR;

		presp = true;
		elements = mgmt->u.probe_resp.variable;
		baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
	} else {
		beacon = ieee80211_is_beacon(fc);
		baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
		elements = mgmt->u.beacon.variable;
	}

	if (!presp && !beacon)
		return RX_CONTINUE;

	if (baselen > skb->len)
		return RX_DROP_MONITOR;

	ieee802_11_parse_elems(elements, skb->len - baselen, &elems);

	if (elems.ds_params && elems.ds_params_len == 1)
		freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
	else
		freq = rx_status->freq;

	channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);

	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
		return RX_DROP_MONITOR;

	bss = ieee80211_bss_info_update(sdata->local, rx_status,
					mgmt, skb->len, &elems,
					channel, beacon);
	if (bss)
		ieee80211_rx_bss_put(sdata->local, bss);

	dev_kfree_skb(skb);
	return RX_QUEUED;
}

/*
 * inform AP that we will go to sleep so that it will buffer the frames
 * while we scan
 */
static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	bool ps = false;

	/* FIXME: what to do when local->pspolling is true? */

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

	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
		ps = true;
		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	}

	if (!ps || !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
		/*
		 * If power save was enabled, no need to send a nullfunc
		 * frame because AP knows that we are sleeping. But if the
		 * hardware is creating the nullfunc frame for power save
		 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
		 * enabled) and power save was enabled, the firmware just
		 * sent a null frame with power save disabled. So we need
		 * to send a new nullfunc frame to inform the AP that we
		 * are again sleeping.
		 */
		ieee80211_send_nullfunc(local, sdata, 1);
}

/* inform AP that we are awake again, unless power save is enabled */
static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;

	if (!local->ps_sdata)
		ieee80211_send_nullfunc(local, sdata, 0);
	else {
		/*
		 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
		 * will send a nullfunc frame with the powersave bit set
		 * even though the AP already knows that we are sleeping.
		 * This could be avoided by sending a null frame with power
		 * save bit disabled before enabling the power save, but
		 * this doesn't gain anything.
		 *
		 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
		 * to send a nullfunc frame because AP already knows that
		 * we are sleeping, let's just enable power save mode in
		 * hardware.
		 */
		local->hw.conf.flags |= IEEE80211_CONF_PS;
		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	}
}

static void ieee80211_restore_scan_ies(struct ieee80211_local *local)
{
	kfree(local->scan_req->ie);
	local->scan_req->ie = local->orig_ies;
	local->scan_req->ie_len = local->orig_ies_len;
}

void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_sub_if_data *sdata;
	bool was_hw_scan;

	mutex_lock(&local->scan_mtx);

	if (WARN_ON(!local->hw_scanning && !local->sw_scanning)) {
		mutex_unlock(&local->scan_mtx);
		return;
	}

	if (WARN_ON(!local->scan_req)) {
		mutex_unlock(&local->scan_mtx);
		return;
	}

	if (local->hw_scanning)
		ieee80211_restore_scan_ies(local);

	if (local->scan_req != &local->int_scan_req)
		cfg80211_scan_done(local->scan_req, aborted);
	local->scan_req = NULL;

	was_hw_scan = local->hw_scanning;
	local->hw_scanning = false;
	local->sw_scanning = false;

	/* we only have to protect scan_req and hw/sw scan */
	mutex_unlock(&local->scan_mtx);

	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
	if (was_hw_scan)
		goto done;

	netif_tx_lock_bh(local->mdev);
	netif_addr_lock(local->mdev);
	local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
	drv_configure_filter(local, FIF_BCN_PRBRESP_PROMISC,
			     &local->filter_flags,
			     local->mdev->mc_count,
			     local->mdev->mc_list);

	netif_addr_unlock(local->mdev);
	netif_tx_unlock_bh(local->mdev);

	drv_sw_scan_complete(local);

	mutex_lock(&local->iflist_mtx);
	list_for_each_entry(sdata, &local->interfaces, list) {
		if (!netif_running(sdata->dev))
			continue;

		/* Tell AP we're back */
		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
			if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
				ieee80211_scan_ps_disable(sdata);
				netif_tx_wake_all_queues(sdata->dev);
			}
		} else
			netif_tx_wake_all_queues(sdata->dev);

		/* re-enable beaconing */
		if (sdata->vif.type == NL80211_IFTYPE_AP ||
		    sdata->vif.type == NL80211_IFTYPE_ADHOC ||
		    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
			ieee80211_bss_info_change_notify(
				sdata, BSS_CHANGED_BEACON_ENABLED);
	}
	mutex_unlock(&local->iflist_mtx);

 done:
	ieee80211_recalc_idle(local);
	ieee80211_mlme_notify_scan_completed(local);
	ieee80211_ibss_notify_scan_completed(local);
	ieee80211_mesh_notify_scan_completed(local);
}
EXPORT_SYMBOL(ieee80211_scan_completed);

static int ieee80211_start_sw_scan(struct ieee80211_local *local)
{
	struct ieee80211_sub_if_data *sdata;

	/*
	 * Hardware/driver doesn't support hw_scan, so use software
	 * scanning instead. First send a nullfunc frame with power save
	 * bit on so that AP will buffer the frames for us while we are not
	 * listening, then send probe requests to each channel and wait for
	 * the responses. After all channels are scanned, tune back to the
	 * original channel and send a nullfunc frame with power save bit
	 * off to trigger the AP to send us all the buffered frames.
	 *
	 * Note that while local->sw_scanning is true everything else but
	 * nullfunc frames and probe requests will be dropped in
	 * ieee80211_tx_h_check_assoc().
	 */
	drv_sw_scan_start(local);

	mutex_lock(&local->iflist_mtx);
	list_for_each_entry(sdata, &local->interfaces, list) {
		if (!netif_running(sdata->dev))
			continue;

		/* disable beaconing */
		if (sdata->vif.type == NL80211_IFTYPE_AP ||
		    sdata->vif.type == NL80211_IFTYPE_ADHOC ||
		    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
			ieee80211_bss_info_change_notify(
				sdata, BSS_CHANGED_BEACON_ENABLED);

		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
			if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
				netif_tx_stop_all_queues(sdata->dev);
				ieee80211_scan_ps_enable(sdata);
			}
		} else
			netif_tx_stop_all_queues(sdata->dev);
	}
	mutex_unlock(&local->iflist_mtx);

	local->scan_state = SCAN_SET_CHANNEL;
	local->scan_channel_idx = 0;

	netif_addr_lock_bh(local->mdev);
	local->filter_flags |= FIF_BCN_PRBRESP_PROMISC;
	drv_configure_filter(local, FIF_BCN_PRBRESP_PROMISC,
			     &local->filter_flags,
			     local->mdev->mc_count,
			     local->mdev->mc_list);
	netif_addr_unlock_bh(local->mdev);

	/* TODO: start scan as soon as all nullfunc frames are ACKed */
	queue_delayed_work(local->hw.workqueue, &local->scan_work,
			   IEEE80211_CHANNEL_TIME);

	return 0;
}


static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
				  struct cfg80211_scan_request *req)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
	int rc;

	if (local->scan_req)
		return -EBUSY;

	if (local->ops->hw_scan) {
		u8 *ies;
		int ielen;

		ies = kmalloc(2 + IEEE80211_MAX_SSID_LEN +
			      local->scan_ies_len + req->ie_len, GFP_KERNEL);
		if (!ies)
			return -ENOMEM;

		ielen = ieee80211_build_preq_ies(local, ies,
						 req->ie, req->ie_len);
		local->orig_ies = req->ie;
		local->orig_ies_len = req->ie_len;
		req->ie = ies;
		req->ie_len = ielen;
	}

	local->scan_req = req;
	local->scan_sdata = sdata;

	if (req != &local->int_scan_req &&
	    sdata->vif.type == NL80211_IFTYPE_STATION &&
	    (ifmgd->state == IEEE80211_STA_MLME_DIRECT_PROBE ||
	     ifmgd->state == IEEE80211_STA_MLME_AUTHENTICATE ||
	     ifmgd->state == IEEE80211_STA_MLME_ASSOCIATE)) {
		/* actually wait for the assoc to finish/time out */
		set_bit(IEEE80211_STA_REQ_SCAN, &ifmgd->request);
		return 0;
	}

	if (local->ops->hw_scan)
		local->hw_scanning = true;
	else
		local->sw_scanning = true;
	/*
	 * Kicking off the scan need not be protected,
	 * only the scan variable stuff, since now
	 * local->scan_req is assigned and other callers
	 * will abort their scan attempts.
	 *
	 * This avoids getting a scan_mtx -> iflist_mtx
	 * dependency, so that the scan completed calls
	 * have more locking freedom.
	 */

	ieee80211_recalc_idle(local);
	mutex_unlock(&local->scan_mtx);

	if (local->ops->hw_scan)
		rc = drv_hw_scan(local, local->scan_req);
	else
		rc = ieee80211_start_sw_scan(local);

	mutex_lock(&local->scan_mtx);

	if (rc) {
		if (local->ops->hw_scan) {
			local->hw_scanning = false;
			ieee80211_restore_scan_ies(local);
		} else
			local->sw_scanning = false;

		ieee80211_recalc_idle(local);

		local->scan_req = NULL;
		local->scan_sdata = NULL;
	}

	return rc;
}

void ieee80211_scan_work(struct work_struct *work)
{
	struct ieee80211_local *local =
		container_of(work, struct ieee80211_local, scan_work.work);
	struct ieee80211_sub_if_data *sdata = local->scan_sdata;
	struct ieee80211_channel *chan;
	int skip, i;
	unsigned long next_delay = 0;

	mutex_lock(&local->scan_mtx);
	if (!sdata || !local->scan_req) {
		mutex_unlock(&local->scan_mtx);
		return;
	}

	if (local->scan_req && !(local->sw_scanning || local->hw_scanning)) {
		struct cfg80211_scan_request *req = local->scan_req;
		int rc;

		local->scan_req = NULL;

		rc = __ieee80211_start_scan(sdata, req);
		mutex_unlock(&local->scan_mtx);

		if (rc)
			ieee80211_scan_completed(&local->hw, true);
		return;
	}

	mutex_unlock(&local->scan_mtx);

	/*
	 * Avoid re-scheduling when the sdata is going away.
	 */
	if (!netif_running(sdata->dev)) {
		ieee80211_scan_completed(&local->hw, true);
		return;
	}

	switch (local->scan_state) {
	case SCAN_SET_CHANNEL:
		/* if no more bands/channels left, complete scan */
		if (local->scan_channel_idx >= local->scan_req->n_channels) {
			ieee80211_scan_completed(&local->hw, false);
			return;
		}
		skip = 0;
		chan = local->scan_req->channels[local->scan_channel_idx];

		if (chan->flags & IEEE80211_CHAN_DISABLED ||
		    (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
		     chan->flags & IEEE80211_CHAN_NO_IBSS))
			skip = 1;

		if (!skip) {
			local->scan_channel = chan;
			if (ieee80211_hw_config(local,
						IEEE80211_CONF_CHANGE_CHANNEL))
				skip = 1;
		}

		/* advance state machine to next channel/band */
		local->scan_channel_idx++;

		if (skip)
			break;

		next_delay = IEEE80211_PROBE_DELAY +
			     usecs_to_jiffies(local->hw.channel_change_time);
		local->scan_state = SCAN_SEND_PROBE;
		break;
	case SCAN_SEND_PROBE:
		next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
		local->scan_state = SCAN_SET_CHANNEL;

		if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN ||
		    !local->scan_req->n_ssids)
			break;
		for (i = 0; i < local->scan_req->n_ssids; i++)
			ieee80211_send_probe_req(
				sdata, NULL,
				local->scan_req->ssids[i].ssid,
				local->scan_req->ssids[i].ssid_len,
				local->scan_req->ie, local->scan_req->ie_len);
		next_delay = IEEE80211_CHANNEL_TIME;
		break;
	}

	queue_delayed_work(local->hw.workqueue, &local->scan_work,
			   next_delay);
}

int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
			   struct cfg80211_scan_request *req)
{
	int res;

	mutex_lock(&sdata->local->scan_mtx);
	res = __ieee80211_start_scan(sdata, req);
	mutex_unlock(&sdata->local->scan_mtx);

	return res;
}

int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
				    const u8 *ssid, u8 ssid_len)
{
	struct ieee80211_local *local = sdata->local;
	int ret = -EBUSY;

	mutex_lock(&local->scan_mtx);

	/* busy scanning */
	if (local->scan_req)
		goto unlock;

	memcpy(local->int_scan_req.ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
	local->int_scan_req.ssids[0].ssid_len = ssid_len;

	ret = __ieee80211_start_scan(sdata, &sdata->local->int_scan_req);
 unlock:
	mutex_unlock(&local->scan_mtx);
	return ret;
}
Commit	Line	Data
0a51b27e	1	/*
5484e237 JB	2	* Scanning implementation
5484e237 JB	3	*
0a51b27e JB	4	* Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
	5	* Copyright 2004, Instant802 Networks, Inc.
	6	* Copyright 2005, Devicescape Software, Inc.
	7	* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
	8	* Copyright 2007, Michael Wu <flamingice@sourmilk.net>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*/
	14
00d3f14c	15	/* TODO: figure out how to avoid that the "current BSS" expires */
5484e237	16
0a51b27e JB	17	#include <linux/wireless.h>
0a51b27e JB	18	#include <linux/if_arp.h>
078e1e60	19	#include <linux/rtnetlink.h>
0a51b27e JB	20	#include <net/mac80211.h>
	21	#include <net/iw_handler.h>
	22
	23	#include "ieee80211_i.h"
24487981	24	#include "driver-ops.h"
5484e237	25	#include "mesh.h"
0a51b27e JB	26
	27	#define IEEE80211_PROBE_DELAY (HZ / 33)
	28	#define IEEE80211_CHANNEL_TIME (HZ / 33)
	29	#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 5)
	30
c2b13452	31	struct ieee80211_bss *
5484e237 JB	32	ieee80211_rx_bss_get(struct ieee80211_local local, u8 bssid, int freq,
	33	u8 *ssid, u8 ssid_len)
	34	{
00d3f14c JB	35	return (void *)cfg80211_get_bss(local->hw.wiphy,
	36	ieee80211_get_channel(local->hw.wiphy,
	37	freq),
	38	bssid, ssid, ssid_len,
	39	0, 0);
5484e237 JB	40	}
5484e237 JB	41
00d3f14c	42	static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss)
5484e237	43	{
00d3f14c	44	struct ieee80211_bss bss = (void )cbss;
5484e237	45
5484e237 JB	46	kfree(bss_mesh_id(bss));
5484e237 JB	47	kfree(bss_mesh_cfg(bss));
5484e237 JB	48	}
	49
	50	void ieee80211_rx_bss_put(struct ieee80211_local *local,
c2b13452	51	struct ieee80211_bss *bss)
5484e237	52	{
00d3f14c	53	cfg80211_put_bss((struct cfg80211_bss *)bss);
5484e237 JB	54	}
5484e237 JB	55
c2b13452	56	struct ieee80211_bss *
5484e237 JB	57	ieee80211_bss_info_update(struct ieee80211_local *local,
	58	struct ieee80211_rx_status *rx_status,
	59	struct ieee80211_mgmt *mgmt,
	60	size_t len,
	61	struct ieee802_11_elems *elems,
2a519311 JB	62	struct ieee80211_channel *channel,
2a519311 JB	63	bool beacon)
5484e237	64	{
c2b13452	65	struct ieee80211_bss *bss;
00d3f14c	66	int clen;
2a519311 JB	67	s32 signal = 0;
2a519311 JB	68
77965c97	69	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2a519311	70	signal = rx_status->signal * 100;
77965c97	71	else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
2a519311	72	signal = (rx_status->signal * 100) / local->hw.max_signal;
2a519311	73
00d3f14c	74	bss = (void *)cfg80211_inform_bss_frame(local->hw.wiphy, channel,
77965c97	75	mgmt, len, signal, GFP_ATOMIC);
5484e237	76
00d3f14c JB	77	if (!bss)
	78	return NULL;
	79
	80	bss->cbss.free_priv = ieee80211_rx_bss_free;
5484e237 JB	81
	82	/* save the ERP value so that it is available at association time */
	83	if (elems->erp_info && elems->erp_info_len >= 1) {
	84	bss->erp_value = elems->erp_info[0];
	85	bss->has_erp_value = 1;
	86	}
	87
5484e237 JB	88	if (elems->tim) {
	89	struct ieee80211_tim_ie *tim_ie =
	90	(struct ieee80211_tim_ie *)elems->tim;
	91	bss->dtim_period = tim_ie->dtim_period;
	92	}
	93
	94	/* set default value for buggy APs */
	95	if (!elems->tim \|\| bss->dtim_period == 0)
	96	bss->dtim_period = 1;
	97
	98	bss->supp_rates_len = 0;
	99	if (elems->supp_rates) {
	100	clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
	101	if (clen > elems->supp_rates_len)
	102	clen = elems->supp_rates_len;
	103	memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates,
	104	clen);
	105	bss->supp_rates_len += clen;
	106	}
	107	if (elems->ext_supp_rates) {
	108	clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
	109	if (clen > elems->ext_supp_rates_len)
	110	clen = elems->ext_supp_rates_len;
	111	memcpy(&bss->supp_rates[bss->supp_rates_len],
	112	elems->ext_supp_rates, clen);
	113	bss->supp_rates_len += clen;
	114	}
	115
5484e237 JB	116	bss->wmm_used = elems->wmm_param \|\| elems->wmm_info;
	117
	118	if (!beacon)
	119	bss->last_probe_resp = jiffies;
	120
5484e237 JB	121	return bss;
5484e237 JB	122	}
0a51b27e	123
7a947080 VT	124	void ieee80211_rx_bss_remove(struct ieee80211_sub_if_data sdata, u8 bssid,
	125	int freq, u8 *ssid, u8 ssid_len)
	126	{
	127	struct ieee80211_bss *bss;
	128	struct ieee80211_local *local = sdata->local;
	129
	130	bss = ieee80211_rx_bss_get(local, bssid, freq, ssid, ssid_len);
	131	if (bss) {
00d3f14c	132	cfg80211_unlink_bss(local->hw.wiphy, (void *)bss);
7a947080 VT	133	ieee80211_rx_bss_put(local, bss);
	134	}
	135	}
	136
98c8fccf	137	ieee80211_rx_result
c2b13452 JB	138	ieee80211_scan_rx(struct ieee80211_sub_if_data sdata, struct sk_buff skb,
c2b13452 JB	139	struct ieee80211_rx_status *rx_status)
98c8fccf JB	140	{
98c8fccf JB	141	struct ieee80211_mgmt *mgmt;
c2b13452	142	struct ieee80211_bss *bss;
98c8fccf JB	143	u8 *elements;
	144	struct ieee80211_channel *channel;
	145	size_t baselen;
	146	int freq;
	147	__le16 fc;
	148	bool presp, beacon = false;
	149	struct ieee802_11_elems elems;
	150
	151	if (skb->len < 2)
	152	return RX_DROP_UNUSABLE;
	153
	154	mgmt = (struct ieee80211_mgmt *) skb->data;
	155	fc = mgmt->frame_control;
	156
	157	if (ieee80211_is_ctl(fc))
	158	return RX_CONTINUE;
	159
	160	if (skb->len < 24)
	161	return RX_DROP_MONITOR;
	162
	163	presp = ieee80211_is_probe_resp(fc);
	164	if (presp) {
	165	/* ignore ProbeResp to foreign address */
	166	if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
	167	return RX_DROP_MONITOR;
	168
	169	presp = true;
	170	elements = mgmt->u.probe_resp.variable;
	171	baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
	172	} else {
	173	beacon = ieee80211_is_beacon(fc);
	174	baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
	175	elements = mgmt->u.beacon.variable;
	176	}
	177
	178	if (!presp && !beacon)
	179	return RX_CONTINUE;
	180
	181	if (baselen > skb->len)
	182	return RX_DROP_MONITOR;
	183
	184	ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
	185
	186	if (elems.ds_params && elems.ds_params_len == 1)
	187	freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
	188	else
	189	freq = rx_status->freq;
	190
	191	channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
	192
	193	if (!channel \|\| channel->flags & IEEE80211_CHAN_DISABLED)
	194	return RX_DROP_MONITOR;
	195
	196	bss = ieee80211_bss_info_update(sdata->local, rx_status,
	197	mgmt, skb->len, &elems,
2a519311	198	channel, beacon);
d048e503 JM	199	if (bss)
d048e503 JM	200	ieee80211_rx_bss_put(sdata->local, bss);
98c8fccf JB	201
	202	dev_kfree_skb(skb);
	203	return RX_QUEUED;
	204	}
	205
9050bdd8 KV	206	/*
	207	* inform AP that we will go to sleep so that it will buffer the frames
	208	* while we scan
	209	*/
	210	static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
	211	{
	212	struct ieee80211_local *local = sdata->local;
	213	bool ps = false;
	214
	215	/* FIXME: what to do when local->pspolling is true? */
	216
	217	del_timer_sync(&local->dynamic_ps_timer);
	218	cancel_work_sync(&local->dynamic_ps_enable_work);
	219
	220	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
	221	ps = true;
	222	local->hw.conf.flags &= ~IEEE80211_CONF_PS;
	223	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	224	}
	225
	226	if (!ps \|\| !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
	227	/*
	228	* If power save was enabled, no need to send a nullfunc
	229	* frame because AP knows that we are sleeping. But if the
	230	* hardware is creating the nullfunc frame for power save
	231	* status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
	232	* enabled) and power save was enabled, the firmware just
	233	* sent a null frame with power save disabled. So we need
	234	* to send a new nullfunc frame to inform the AP that we
	235	* are again sleeping.
	236	*/
	237	ieee80211_send_nullfunc(local, sdata, 1);
	238	}
	239
	240	/* inform AP that we are awake again, unless power save is enabled */
	241	static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata)
	242	{
	243	struct ieee80211_local *local = sdata->local;
	244
965bedad	245	if (!local->ps_sdata)
9050bdd8 KV	246	ieee80211_send_nullfunc(local, sdata, 0);
	247	else {
	248	/*
	249	* In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
	250	* will send a nullfunc frame with the powersave bit set
	251	* even though the AP already knows that we are sleeping.
	252	* This could be avoided by sending a null frame with power
	253	* save bit disabled before enabling the power save, but
	254	* this doesn't gain anything.
	255	*
	256	* When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
	257	* to send a nullfunc frame because AP already knows that
	258	* we are sleeping, let's just enable power save mode in
	259	* hardware.
	260	*/
	261	local->hw.conf.flags \|= IEEE80211_CONF_PS;
	262	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	263	}
	264	}
	265
f3b85252 JB	266	static void ieee80211_restore_scan_ies(struct ieee80211_local *local)
	267	{
	268	kfree(local->scan_req->ie);
	269	local->scan_req->ie = local->orig_ies;
	270	local->scan_req->ie_len = local->orig_ies_len;
	271	}
	272
2a519311	273	void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
0a51b27e JB	274	{
	275	struct ieee80211_local *local = hw_to_local(hw);
	276	struct ieee80211_sub_if_data *sdata;
f3b85252	277	bool was_hw_scan;
0a51b27e	278
f3b85252	279	mutex_lock(&local->scan_mtx);
5bc75728	280
f3b85252 JB	281	if (WARN_ON(!local->hw_scanning && !local->sw_scanning)) {
f3b85252 JB	282	mutex_unlock(&local->scan_mtx);
2a519311	283	return;
f3b85252	284	}
5bc75728	285
f3b85252 JB	286	if (WARN_ON(!local->scan_req)) {
	287	mutex_unlock(&local->scan_mtx);
	288	return;
de95a54b JB	289	}
de95a54b JB	290
f3b85252 JB	291	if (local->hw_scanning)
	292	ieee80211_restore_scan_ies(local);
	293
2a519311 JB	294	if (local->scan_req != &local->int_scan_req)
	295	cfg80211_scan_done(local->scan_req, aborted);
	296	local->scan_req = NULL;
	297
f3b85252 JB	298	was_hw_scan = local->hw_scanning;
	299	local->hw_scanning = false;
	300	local->sw_scanning = false;
	301
	302	/* we only have to protect scan_req and hw/sw scan */
	303	mutex_unlock(&local->scan_mtx);
	304
e8975581	305	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
5cff20e6 JB	306	if (was_hw_scan)
5cff20e6 JB	307	goto done;
0a51b27e JB	308
	309	netif_tx_lock_bh(local->mdev);
	310	netif_addr_lock(local->mdev);
	311	local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
24487981 JB	312	drv_configure_filter(local, FIF_BCN_PRBRESP_PROMISC,
	313	&local->filter_flags,
	314	local->mdev->mc_count,
	315	local->mdev->mc_list);
0a51b27e JB	316
	317	netif_addr_unlock(local->mdev);
	318	netif_tx_unlock_bh(local->mdev);
	319
24487981	320	drv_sw_scan_complete(local);
80e775bf	321
078e1e60 JB	322	mutex_lock(&local->iflist_mtx);
078e1e60 JB	323	list_for_each_entry(sdata, &local->interfaces, list) {
fb9ddbf0 JB	324	if (!netif_running(sdata->dev))
	325	continue;
	326
0a51b27e	327	/* Tell AP we're back */
05c914fe	328	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
46900298	329	if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
9050bdd8	330	ieee80211_scan_ps_disable(sdata);
0a51b27e JB	331	netif_tx_wake_all_queues(sdata->dev);
	332	}
	333	} else
	334	netif_tx_wake_all_queues(sdata->dev);
078e1e60	335
14b80724 JB	336	/* re-enable beaconing */
	337	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	338	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	339	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
2d0ddec5 JB	340	ieee80211_bss_info_change_notify(
2d0ddec5 JB	341	sdata, BSS_CHANGED_BEACON_ENABLED);
0a51b27e	342	}
078e1e60	343	mutex_unlock(&local->iflist_mtx);
0a51b27e JB	344
0a51b27e JB	345	done:
5cff20e6	346	ieee80211_recalc_idle(local);
0a51b27e	347	ieee80211_mlme_notify_scan_completed(local);
46900298	348	ieee80211_ibss_notify_scan_completed(local);
472dbc45	349	ieee80211_mesh_notify_scan_completed(local);
0a51b27e JB	350	}
	351	EXPORT_SYMBOL(ieee80211_scan_completed);
	352
f3b85252 JB	353	static int ieee80211_start_sw_scan(struct ieee80211_local *local)
	354	{
	355	struct ieee80211_sub_if_data *sdata;
	356
	357	/*
	358	* Hardware/driver doesn't support hw_scan, so use software
	359	* scanning instead. First send a nullfunc frame with power save
	360	* bit on so that AP will buffer the frames for us while we are not
	361	* listening, then send probe requests to each channel and wait for
	362	* the responses. After all channels are scanned, tune back to the
	363	* original channel and send a nullfunc frame with power save bit
	364	* off to trigger the AP to send us all the buffered frames.
	365	*
	366	* Note that while local->sw_scanning is true everything else but
	367	* nullfunc frames and probe requests will be dropped in
	368	* ieee80211_tx_h_check_assoc().
	369	*/
24487981	370	drv_sw_scan_start(local);
f3b85252 JB	371
	372	mutex_lock(&local->iflist_mtx);
	373	list_for_each_entry(sdata, &local->interfaces, list) {
	374	if (!netif_running(sdata->dev))
	375	continue;
	376
	377	/* disable beaconing */
	378	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	379	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	380	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
2d0ddec5 JB	381	ieee80211_bss_info_change_notify(
2d0ddec5 JB	382	sdata, BSS_CHANGED_BEACON_ENABLED);
f3b85252 JB	383
	384	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
	385	if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
	386	netif_tx_stop_all_queues(sdata->dev);
	387	ieee80211_scan_ps_enable(sdata);
	388	}
	389	} else
	390	netif_tx_stop_all_queues(sdata->dev);
	391	}
	392	mutex_unlock(&local->iflist_mtx);
	393
	394	local->scan_state = SCAN_SET_CHANNEL;
	395	local->scan_channel_idx = 0;
	396
	397	netif_addr_lock_bh(local->mdev);
	398	local->filter_flags \|= FIF_BCN_PRBRESP_PROMISC;
24487981 JB	399	drv_configure_filter(local, FIF_BCN_PRBRESP_PROMISC,
	400	&local->filter_flags,
	401	local->mdev->mc_count,
	402	local->mdev->mc_list);
f3b85252 JB	403	netif_addr_unlock_bh(local->mdev);
	404
	405	/* TODO: start scan as soon as all nullfunc frames are ACKed */
	406	queue_delayed_work(local->hw.workqueue, &local->scan_work,
	407	IEEE80211_CHANNEL_TIME);
	408
	409	return 0;
	410	}
	411
	412
	413	static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
	414	struct cfg80211_scan_request *req)
	415	{
	416	struct ieee80211_local *local = sdata->local;
	417	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
	418	int rc;
	419
	420	if (local->scan_req)
	421	return -EBUSY;
	422
	423	if (local->ops->hw_scan) {
	424	u8 *ies;
	425	int ielen;
	426
	427	ies = kmalloc(2 + IEEE80211_MAX_SSID_LEN +
	428	local->scan_ies_len + req->ie_len, GFP_KERNEL);
	429	if (!ies)
	430	return -ENOMEM;
	431
	432	ielen = ieee80211_build_preq_ies(local, ies,
	433	req->ie, req->ie_len);
	434	local->orig_ies = req->ie;
	435	local->orig_ies_len = req->ie_len;
	436	req->ie = ies;
	437	req->ie_len = ielen;
	438	}
	439
	440	local->scan_req = req;
	441	local->scan_sdata = sdata;
	442
	443	if (req != &local->int_scan_req &&
	444	sdata->vif.type == NL80211_IFTYPE_STATION &&
	445	(ifmgd->state == IEEE80211_STA_MLME_DIRECT_PROBE \|\|
	446	ifmgd->state == IEEE80211_STA_MLME_AUTHENTICATE \|\|
	447	ifmgd->state == IEEE80211_STA_MLME_ASSOCIATE)) {
	448	/* actually wait for the assoc to finish/time out */
	449	set_bit(IEEE80211_STA_REQ_SCAN, &ifmgd->request);
	450	return 0;
	451	}
	452
	453	if (local->ops->hw_scan)
	454	local->hw_scanning = true;
	455	else
	456	local->sw_scanning = true;
	457	/*
	458	* Kicking off the scan need not be protected,
	459	* only the scan variable stuff, since now
	460	* local->scan_req is assigned and other callers
	461	* will abort their scan attempts.
	462	*
	463	* This avoids getting a scan_mtx -> iflist_mtx
	464	* dependency, so that the scan completed calls
	465	* have more locking freedom.
	466	*/
5cff20e6 JB	467
5cff20e6 JB	468	ieee80211_recalc_idle(local);
f3b85252 JB	469	mutex_unlock(&local->scan_mtx);
	470
	471	if (local->ops->hw_scan)
24487981	472	rc = drv_hw_scan(local, local->scan_req);
f3b85252 JB	473	else
	474	rc = ieee80211_start_sw_scan(local);
	475
	476	mutex_lock(&local->scan_mtx);
	477
	478	if (rc) {
	479	if (local->ops->hw_scan) {
	480	local->hw_scanning = false;
	481	ieee80211_restore_scan_ies(local);
	482	} else
	483	local->sw_scanning = false;
	484
5cff20e6 JB	485	ieee80211_recalc_idle(local);
5cff20e6 JB	486
f3b85252 JB	487	local->scan_req = NULL;
	488	local->scan_sdata = NULL;
	489	}
	490
	491	return rc;
	492	}
	493
c2b13452	494	void ieee80211_scan_work(struct work_struct *work)
0a51b27e JB	495	{
	496	struct ieee80211_local *local =
	497	container_of(work, struct ieee80211_local, scan_work.work);
	498	struct ieee80211_sub_if_data *sdata = local->scan_sdata;
0a51b27e	499	struct ieee80211_channel *chan;
2a519311	500	int skip, i;
0a51b27e JB	501	unsigned long next_delay = 0;
0a51b27e JB	502
f3b85252 JB	503	mutex_lock(&local->scan_mtx);
	504	if (!sdata \|\| !local->scan_req) {
	505	mutex_unlock(&local->scan_mtx);
	506	return;
	507	}
	508
	509	if (local->scan_req && !(local->sw_scanning \|\| local->hw_scanning)) {
	510	struct cfg80211_scan_request *req = local->scan_req;
	511	int rc;
	512
	513	local->scan_req = NULL;
	514
	515	rc = __ieee80211_start_scan(sdata, req);
	516	mutex_unlock(&local->scan_mtx);
	517
	518	if (rc)
	519	ieee80211_scan_completed(&local->hw, true);
	520	return;
	521	}
	522
	523	mutex_unlock(&local->scan_mtx);
	524
5bc75728 JB	525	/*
	526	* Avoid re-scheduling when the sdata is going away.
	527	*/
f3b85252 JB	528	if (!netif_running(sdata->dev)) {
f3b85252 JB	529	ieee80211_scan_completed(&local->hw, true);
0a51b27e	530	return;
f3b85252	531	}
0a51b27e JB	532
	533	switch (local->scan_state) {
	534	case SCAN_SET_CHANNEL:
0a51b27e	535	/* if no more bands/channels left, complete scan */
2a519311	536	if (local->scan_channel_idx >= local->scan_req->n_channels) {
f3b85252	537	ieee80211_scan_completed(&local->hw, false);
0a51b27e JB	538	return;
	539	}
	540	skip = 0;
2a519311	541	chan = local->scan_req->channels[local->scan_channel_idx];
0a51b27e JB	542
0a51b27e JB	543	if (chan->flags & IEEE80211_CHAN_DISABLED \|\|
05c914fe	544	(sdata->vif.type == NL80211_IFTYPE_ADHOC &&
0a51b27e JB	545	chan->flags & IEEE80211_CHAN_NO_IBSS))
	546	skip = 1;
	547
	548	if (!skip) {
	549	local->scan_channel = chan;
e8975581 JB	550	if (ieee80211_hw_config(local,
e8975581 JB	551	IEEE80211_CONF_CHANGE_CHANNEL))
0a51b27e	552	skip = 1;
0a51b27e JB	553	}
	554
	555	/* advance state machine to next channel/band */
	556	local->scan_channel_idx++;
0a51b27e JB	557
	558	if (skip)
	559	break;
	560
	561	next_delay = IEEE80211_PROBE_DELAY +
	562	usecs_to_jiffies(local->hw.channel_change_time);
	563	local->scan_state = SCAN_SEND_PROBE;
	564	break;
	565	case SCAN_SEND_PROBE:
	566	next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
	567	local->scan_state = SCAN_SET_CHANNEL;
	568
2a519311 JB	569	if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN \|\|
2a519311 JB	570	!local->scan_req->n_ssids)
0a51b27e	571	break;
2a519311 JB	572	for (i = 0; i < local->scan_req->n_ssids; i++)
	573	ieee80211_send_probe_req(
	574	sdata, NULL,
	575	local->scan_req->ssids[i].ssid,
70692ad2 JM	576	local->scan_req->ssids[i].ssid_len,
70692ad2 JM	577	local->scan_req->ie, local->scan_req->ie_len);
0a51b27e JB	578	next_delay = IEEE80211_CHANNEL_TIME;
	579	break;
	580	}
	581
5bc75728 JB	582	queue_delayed_work(local->hw.workqueue, &local->scan_work,
5bc75728 JB	583	next_delay);
0a51b27e JB	584	}
0a51b27e JB	585
f3b85252 JB	586	int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
f3b85252 JB	587	struct cfg80211_scan_request *req)
0a51b27e	588	{
f3b85252	589	int res;
de95a54b	590
f3b85252 JB	591	mutex_lock(&sdata->local->scan_mtx);
	592	res = __ieee80211_start_scan(sdata, req);
	593	mutex_unlock(&sdata->local->scan_mtx);
0a51b27e	594
f3b85252	595	return res;
0a51b27e JB	596	}
0a51b27e JB	597
f3b85252 JB	598	int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
f3b85252 JB	599	const u8 *ssid, u8 ssid_len)
0a51b27e	600	{
0a51b27e	601	struct ieee80211_local *local = sdata->local;
f3b85252	602	int ret = -EBUSY;
2a519311	603
f3b85252	604	mutex_lock(&local->scan_mtx);
0a51b27e	605
f3b85252 JB	606	/* busy scanning */
	607	if (local->scan_req)
	608	goto unlock;
9116dd01	609
f3b85252 JB	610	memcpy(local->int_scan_req.ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
f3b85252 JB	611	local->int_scan_req.ssids[0].ssid_len = ssid_len;
9116dd01	612
f3b85252 JB	613	ret = __ieee80211_start_scan(sdata, &sdata->local->int_scan_req);
	614	unlock:
	615	mutex_unlock(&local->scan_mtx);
	616	return ret;
0a51b27e	617	}