[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 "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);

	if (was_hw_scan) {
		/*
		 * Somebody might have requested channel change during scan
		 * that we won't have acted upon, try now. ieee80211_hw_config
		 * will set the flag based on actual changes.
		 */
		ieee80211_hw_config(local, 0);
		goto done;
	}

	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);

	netif_tx_lock_bh(local->mdev);
	netif_addr_lock(local->mdev);
	local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
	local->ops->configure_filter(local_to_hw(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);

	if (local->ops->sw_scan_complete)
		local->ops->sw_scan_complete(local_to_hw(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_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().
	 */
	if (local->ops->sw_scan_start)
		local->ops->sw_scan_start(local_to_hw(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;
	local->ops->configure_filter(local_to_hw(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.
	 */
	mutex_unlock(&local->scan_mtx);

	if (local->ops->hw_scan)
		rc = local->ops->hw_scan(local_to_hw(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;

		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"
5484e237	24	#include "mesh.h"
0a51b27e JB	25
	26	#define IEEE80211_PROBE_DELAY (HZ / 33)
	27	#define IEEE80211_CHANNEL_TIME (HZ / 33)
	28	#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 5)
	29
c2b13452	30	struct ieee80211_bss *
5484e237 JB	31	ieee80211_rx_bss_get(struct ieee80211_local local, u8 bssid, int freq,
	32	u8 *ssid, u8 ssid_len)
	33	{
00d3f14c JB	34	return (void *)cfg80211_get_bss(local->hw.wiphy,
	35	ieee80211_get_channel(local->hw.wiphy,
	36	freq),
	37	bssid, ssid, ssid_len,
	38	0, 0);
5484e237 JB	39	}
5484e237 JB	40
00d3f14c	41	static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss)
5484e237	42	{
00d3f14c	43	struct ieee80211_bss bss = (void )cbss;
5484e237	44
5484e237 JB	45	kfree(bss_mesh_id(bss));
5484e237 JB	46	kfree(bss_mesh_cfg(bss));
5484e237 JB	47	}
	48
	49	void ieee80211_rx_bss_put(struct ieee80211_local *local,
c2b13452	50	struct ieee80211_bss *bss)
5484e237	51	{
00d3f14c	52	cfg80211_put_bss((struct cfg80211_bss *)bss);
5484e237 JB	53	}
5484e237 JB	54
c2b13452	55	struct ieee80211_bss *
5484e237 JB	56	ieee80211_bss_info_update(struct ieee80211_local *local,
	57	struct ieee80211_rx_status *rx_status,
	58	struct ieee80211_mgmt *mgmt,
	59	size_t len,
	60	struct ieee802_11_elems *elems,
2a519311 JB	61	struct ieee80211_channel *channel,
2a519311 JB	62	bool beacon)
5484e237	63	{
c2b13452	64	struct ieee80211_bss *bss;
00d3f14c	65	int clen;
2a519311 JB	66	s32 signal = 0;
2a519311 JB	67
77965c97	68	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2a519311	69	signal = rx_status->signal * 100;
77965c97	70	else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
2a519311	71	signal = (rx_status->signal * 100) / local->hw.max_signal;
2a519311	72
00d3f14c	73	bss = (void *)cfg80211_inform_bss_frame(local->hw.wiphy, channel,
77965c97	74	mgmt, len, signal, GFP_ATOMIC);
5484e237	75
00d3f14c JB	76	if (!bss)
	77	return NULL;
	78
	79	bss->cbss.free_priv = ieee80211_rx_bss_free;
5484e237 JB	80
	81	/* save the ERP value so that it is available at association time */
	82	if (elems->erp_info && elems->erp_info_len >= 1) {
	83	bss->erp_value = elems->erp_info[0];
	84	bss->has_erp_value = 1;
	85	}
	86
5484e237 JB	87	if (elems->tim) {
	88	struct ieee80211_tim_ie *tim_ie =
	89	(struct ieee80211_tim_ie *)elems->tim;
	90	bss->dtim_period = tim_ie->dtim_period;
	91	}
	92
	93	/* set default value for buggy APs */
	94	if (!elems->tim \|\| bss->dtim_period == 0)
	95	bss->dtim_period = 1;
	96
	97	bss->supp_rates_len = 0;
	98	if (elems->supp_rates) {
	99	clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
	100	if (clen > elems->supp_rates_len)
	101	clen = elems->supp_rates_len;
	102	memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates,
	103	clen);
	104	bss->supp_rates_len += clen;
	105	}
	106	if (elems->ext_supp_rates) {
	107	clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
	108	if (clen > elems->ext_supp_rates_len)
	109	clen = elems->ext_supp_rates_len;
	110	memcpy(&bss->supp_rates[bss->supp_rates_len],
	111	elems->ext_supp_rates, clen);
	112	bss->supp_rates_len += clen;
	113	}
	114
5484e237 JB	115	bss->wmm_used = elems->wmm_param \|\| elems->wmm_info;
	116
	117	if (!beacon)
	118	bss->last_probe_resp = jiffies;
	119
5484e237 JB	120	return bss;
5484e237 JB	121	}
0a51b27e	122
7a947080 VT	123	void ieee80211_rx_bss_remove(struct ieee80211_sub_if_data sdata, u8 bssid,
	124	int freq, u8 *ssid, u8 ssid_len)
	125	{
	126	struct ieee80211_bss *bss;
	127	struct ieee80211_local *local = sdata->local;
	128
	129	bss = ieee80211_rx_bss_get(local, bssid, freq, ssid, ssid_len);
	130	if (bss) {
00d3f14c	131	cfg80211_unlink_bss(local->hw.wiphy, (void *)bss);
7a947080 VT	132	ieee80211_rx_bss_put(local, bss);
	133	}
	134	}
	135
98c8fccf	136	ieee80211_rx_result
c2b13452 JB	137	ieee80211_scan_rx(struct ieee80211_sub_if_data sdata, struct sk_buff skb,
c2b13452 JB	138	struct ieee80211_rx_status *rx_status)
98c8fccf JB	139	{
98c8fccf JB	140	struct ieee80211_mgmt *mgmt;
c2b13452	141	struct ieee80211_bss *bss;
98c8fccf JB	142	u8 *elements;
	143	struct ieee80211_channel *channel;
	144	size_t baselen;
	145	int freq;
	146	__le16 fc;
	147	bool presp, beacon = false;
	148	struct ieee802_11_elems elems;
	149
	150	if (skb->len < 2)
	151	return RX_DROP_UNUSABLE;
	152
	153	mgmt = (struct ieee80211_mgmt *) skb->data;
	154	fc = mgmt->frame_control;
	155
	156	if (ieee80211_is_ctl(fc))
	157	return RX_CONTINUE;
	158
	159	if (skb->len < 24)
	160	return RX_DROP_MONITOR;
	161
	162	presp = ieee80211_is_probe_resp(fc);
	163	if (presp) {
	164	/* ignore ProbeResp to foreign address */
	165	if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
	166	return RX_DROP_MONITOR;
	167
	168	presp = true;
	169	elements = mgmt->u.probe_resp.variable;
	170	baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
	171	} else {
	172	beacon = ieee80211_is_beacon(fc);
	173	baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
	174	elements = mgmt->u.beacon.variable;
	175	}
	176
	177	if (!presp && !beacon)
	178	return RX_CONTINUE;
	179
	180	if (baselen > skb->len)
	181	return RX_DROP_MONITOR;
	182
	183	ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
	184
	185	if (elems.ds_params && elems.ds_params_len == 1)
	186	freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
	187	else
	188	freq = rx_status->freq;
	189
	190	channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
	191
	192	if (!channel \|\| channel->flags & IEEE80211_CHAN_DISABLED)
	193	return RX_DROP_MONITOR;
	194
	195	bss = ieee80211_bss_info_update(sdata->local, rx_status,
	196	mgmt, skb->len, &elems,
2a519311	197	channel, beacon);
d048e503 JM	198	if (bss)
d048e503 JM	199	ieee80211_rx_bss_put(sdata->local, bss);
98c8fccf JB	200
	201	dev_kfree_skb(skb);
	202	return RX_QUEUED;
	203	}
	204
9050bdd8 KV	205	/*
	206	* inform AP that we will go to sleep so that it will buffer the frames
	207	* while we scan
	208	*/
	209	static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
	210	{
	211	struct ieee80211_local *local = sdata->local;
	212	bool ps = false;
	213
	214	/* FIXME: what to do when local->pspolling is true? */
	215
	216	del_timer_sync(&local->dynamic_ps_timer);
	217	cancel_work_sync(&local->dynamic_ps_enable_work);
	218
	219	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
	220	ps = true;
	221	local->hw.conf.flags &= ~IEEE80211_CONF_PS;
	222	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	223	}
	224
	225	if (!ps \|\| !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
	226	/*
	227	* If power save was enabled, no need to send a nullfunc
	228	* frame because AP knows that we are sleeping. But if the
	229	* hardware is creating the nullfunc frame for power save
	230	* status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
	231	* enabled) and power save was enabled, the firmware just
	232	* sent a null frame with power save disabled. So we need
	233	* to send a new nullfunc frame to inform the AP that we
	234	* are again sleeping.
	235	*/
	236	ieee80211_send_nullfunc(local, sdata, 1);
	237	}
	238
	239	/* inform AP that we are awake again, unless power save is enabled */
	240	static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata)
	241	{
	242	struct ieee80211_local *local = sdata->local;
	243
965bedad	244	if (!local->ps_sdata)
9050bdd8 KV	245	ieee80211_send_nullfunc(local, sdata, 0);
	246	else {
	247	/*
	248	* In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
	249	* will send a nullfunc frame with the powersave bit set
	250	* even though the AP already knows that we are sleeping.
	251	* This could be avoided by sending a null frame with power
	252	* save bit disabled before enabling the power save, but
	253	* this doesn't gain anything.
	254	*
	255	* When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
	256	* to send a nullfunc frame because AP already knows that
	257	* we are sleeping, let's just enable power save mode in
	258	* hardware.
	259	*/
	260	local->hw.conf.flags \|= IEEE80211_CONF_PS;
	261	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	262	}
	263	}
	264
f3b85252 JB	265	static void ieee80211_restore_scan_ies(struct ieee80211_local *local)
	266	{
	267	kfree(local->scan_req->ie);
	268	local->scan_req->ie = local->orig_ies;
	269	local->scan_req->ie_len = local->orig_ies_len;
	270	}
	271
2a519311	272	void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
0a51b27e JB	273	{
	274	struct ieee80211_local *local = hw_to_local(hw);
	275	struct ieee80211_sub_if_data *sdata;
f3b85252	276	bool was_hw_scan;
0a51b27e	277
f3b85252	278	mutex_lock(&local->scan_mtx);
5bc75728	279
f3b85252 JB	280	if (WARN_ON(!local->hw_scanning && !local->sw_scanning)) {
f3b85252 JB	281	mutex_unlock(&local->scan_mtx);
2a519311	282	return;
f3b85252	283	}
5bc75728	284
f3b85252 JB	285	if (WARN_ON(!local->scan_req)) {
	286	mutex_unlock(&local->scan_mtx);
	287	return;
de95a54b JB	288	}
de95a54b JB	289
f3b85252 JB	290	if (local->hw_scanning)
	291	ieee80211_restore_scan_ies(local);
	292
2a519311 JB	293	if (local->scan_req != &local->int_scan_req)
	294	cfg80211_scan_done(local->scan_req, aborted);
	295	local->scan_req = NULL;
	296
f3b85252 JB	297	was_hw_scan = local->hw_scanning;
	298	local->hw_scanning = false;
	299	local->sw_scanning = false;
	300
	301	/* we only have to protect scan_req and hw/sw scan */
	302	mutex_unlock(&local->scan_mtx);
	303
	304	if (was_hw_scan) {
e8975581 JB	305	/*
	306	* Somebody might have requested channel change during scan
	307	* that we won't have acted upon, try now. ieee80211_hw_config
	308	* will set the flag based on actual changes.
	309	*/
	310	ieee80211_hw_config(local, 0);
0a51b27e JB	311	goto done;
	312	}
	313
e8975581	314	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
0a51b27e JB	315
	316	netif_tx_lock_bh(local->mdev);
	317	netif_addr_lock(local->mdev);
	318	local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
	319	local->ops->configure_filter(local_to_hw(local),
	320	FIF_BCN_PRBRESP_PROMISC,
	321	&local->filter_flags,
	322	local->mdev->mc_count,
	323	local->mdev->mc_list);
	324
	325	netif_addr_unlock(local->mdev);
	326	netif_tx_unlock_bh(local->mdev);
	327
80e775bf MB	328	if (local->ops->sw_scan_complete)
	329	local->ops->sw_scan_complete(local_to_hw(local));
	330
078e1e60 JB	331	mutex_lock(&local->iflist_mtx);
078e1e60 JB	332	list_for_each_entry(sdata, &local->interfaces, list) {
fb9ddbf0 JB	333	if (!netif_running(sdata->dev))
	334	continue;
	335
0a51b27e	336	/* Tell AP we're back */
05c914fe	337	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
46900298	338	if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
9050bdd8	339	ieee80211_scan_ps_disable(sdata);
0a51b27e JB	340	netif_tx_wake_all_queues(sdata->dev);
	341	}
	342	} else
	343	netif_tx_wake_all_queues(sdata->dev);
078e1e60	344
14b80724 JB	345	/* re-enable beaconing */
	346	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	347	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	348	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
2d0ddec5 JB	349	ieee80211_bss_info_change_notify(
2d0ddec5 JB	350	sdata, BSS_CHANGED_BEACON_ENABLED);
0a51b27e	351	}
078e1e60	352	mutex_unlock(&local->iflist_mtx);
0a51b27e JB	353
	354	done:
	355	ieee80211_mlme_notify_scan_completed(local);
46900298	356	ieee80211_ibss_notify_scan_completed(local);
472dbc45	357	ieee80211_mesh_notify_scan_completed(local);
0a51b27e JB	358	}
	359	EXPORT_SYMBOL(ieee80211_scan_completed);
	360
f3b85252 JB	361	static int ieee80211_start_sw_scan(struct ieee80211_local *local)
	362	{
	363	struct ieee80211_sub_if_data *sdata;
	364
	365	/*
	366	* Hardware/driver doesn't support hw_scan, so use software
	367	* scanning instead. First send a nullfunc frame with power save
	368	* bit on so that AP will buffer the frames for us while we are not
	369	* listening, then send probe requests to each channel and wait for
	370	* the responses. After all channels are scanned, tune back to the
	371	* original channel and send a nullfunc frame with power save bit
	372	* off to trigger the AP to send us all the buffered frames.
	373	*
	374	* Note that while local->sw_scanning is true everything else but
	375	* nullfunc frames and probe requests will be dropped in
	376	* ieee80211_tx_h_check_assoc().
	377	*/
	378	if (local->ops->sw_scan_start)
	379	local->ops->sw_scan_start(local_to_hw(local));
	380
	381	mutex_lock(&local->iflist_mtx);
	382	list_for_each_entry(sdata, &local->interfaces, list) {
	383	if (!netif_running(sdata->dev))
	384	continue;
	385
	386	/* disable beaconing */
	387	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	388	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	389	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
2d0ddec5 JB	390	ieee80211_bss_info_change_notify(
2d0ddec5 JB	391	sdata, BSS_CHANGED_BEACON_ENABLED);
f3b85252 JB	392
	393	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
	394	if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
	395	netif_tx_stop_all_queues(sdata->dev);
	396	ieee80211_scan_ps_enable(sdata);
	397	}
	398	} else
	399	netif_tx_stop_all_queues(sdata->dev);
	400	}
	401	mutex_unlock(&local->iflist_mtx);
	402
	403	local->scan_state = SCAN_SET_CHANNEL;
	404	local->scan_channel_idx = 0;
	405
	406	netif_addr_lock_bh(local->mdev);
	407	local->filter_flags \|= FIF_BCN_PRBRESP_PROMISC;
	408	local->ops->configure_filter(local_to_hw(local),
	409	FIF_BCN_PRBRESP_PROMISC,
	410	&local->filter_flags,
	411	local->mdev->mc_count,
	412	local->mdev->mc_list);
	413	netif_addr_unlock_bh(local->mdev);
	414
	415	/* TODO: start scan as soon as all nullfunc frames are ACKed */
	416	queue_delayed_work(local->hw.workqueue, &local->scan_work,
	417	IEEE80211_CHANNEL_TIME);
	418
	419	return 0;
	420	}
	421
	422
	423	static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
	424	struct cfg80211_scan_request *req)
	425	{
	426	struct ieee80211_local *local = sdata->local;
	427	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
	428	int rc;
	429
	430	if (local->scan_req)
	431	return -EBUSY;
	432
	433	if (local->ops->hw_scan) {
	434	u8 *ies;
	435	int ielen;
	436
	437	ies = kmalloc(2 + IEEE80211_MAX_SSID_LEN +
	438	local->scan_ies_len + req->ie_len, GFP_KERNEL);
	439	if (!ies)
	440	return -ENOMEM;
	441
	442	ielen = ieee80211_build_preq_ies(local, ies,
	443	req->ie, req->ie_len);
	444	local->orig_ies = req->ie;
	445	local->orig_ies_len = req->ie_len;
	446	req->ie = ies;
	447	req->ie_len = ielen;
	448	}
	449
	450	local->scan_req = req;
	451	local->scan_sdata = sdata;
	452
	453	if (req != &local->int_scan_req &&
	454	sdata->vif.type == NL80211_IFTYPE_STATION &&
	455	(ifmgd->state == IEEE80211_STA_MLME_DIRECT_PROBE \|\|
456	ifmgd->state == IEEE80211_STA_MLME_AUTHENTICATE \|\|
457	ifmgd->state == IEEE80211_STA_MLME_ASSOCIATE)) {
458	/* actually wait for the assoc to finish/time out */
459	set_bit(IEEE80211_STA_REQ_SCAN, &ifmgd->request);
460	return 0;
461	}
462
463	if (local->ops->hw_scan)
464	local->hw_scanning = true;
465	else
466	local->sw_scanning = true;
467	/*
468	* Kicking off the scan need not be protected,
469	* only the scan variable stuff, since now
470	* local->scan_req is assigned and other callers
471	* will abort their scan attempts.
472	*
473	* This avoids getting a scan_mtx -> iflist_mtx
474	* dependency, so that the scan completed calls
475	* have more locking freedom.
476	*/
477	mutex_unlock(&local->scan_mtx);
478
479	if (local->ops->hw_scan)
480	rc = local->ops->hw_scan(local_to_hw(local),
481	local->scan_req);
482	else
483	rc = ieee80211_start_sw_scan(local);
484
485	mutex_lock(&local->scan_mtx);
486
487	if (rc) {
488	if (local->ops->hw_scan) {
489	local->hw_scanning = false;
490	ieee80211_restore_scan_ies(local);
491	} else
492	local->sw_scanning = false;
493
494	local->scan_req = NULL;
495	local->scan_sdata = NULL;
496	}
497
498	return rc;
499	}
500
c2b13452	501	void ieee80211_scan_work(struct work_struct *work)
0a51b27e JB	502	{
	503	struct ieee80211_local *local =
	504	container_of(work, struct ieee80211_local, scan_work.work);
	505	struct ieee80211_sub_if_data *sdata = local->scan_sdata;
0a51b27e	506	struct ieee80211_channel *chan;
2a519311	507	int skip, i;
0a51b27e JB	508	unsigned long next_delay = 0;
0a51b27e JB	509
f3b85252 JB	510	mutex_lock(&local->scan_mtx);
	511	if (!sdata \|\| !local->scan_req) {
	512	mutex_unlock(&local->scan_mtx);
	513	return;
	514	}
	515
	516	if (local->scan_req && !(local->sw_scanning \|\| local->hw_scanning)) {
	517	struct cfg80211_scan_request *req = local->scan_req;
	518	int rc;
	519
	520	local->scan_req = NULL;
	521
	522	rc = __ieee80211_start_scan(sdata, req);
	523	mutex_unlock(&local->scan_mtx);
	524
	525	if (rc)
	526	ieee80211_scan_completed(&local->hw, true);
	527	return;
	528	}
	529
	530	mutex_unlock(&local->scan_mtx);
	531
5bc75728 JB	532	/*
	533	* Avoid re-scheduling when the sdata is going away.
	534	*/
f3b85252 JB	535	if (!netif_running(sdata->dev)) {
f3b85252 JB	536	ieee80211_scan_completed(&local->hw, true);
0a51b27e	537	return;
f3b85252	538	}
0a51b27e JB	539
	540	switch (local->scan_state) {
	541	case SCAN_SET_CHANNEL:
0a51b27e	542	/* if no more bands/channels left, complete scan */
2a519311	543	if (local->scan_channel_idx >= local->scan_req->n_channels) {
f3b85252	544	ieee80211_scan_completed(&local->hw, false);
0a51b27e JB	545	return;
	546	}
	547	skip = 0;
2a519311	548	chan = local->scan_req->channels[local->scan_channel_idx];
0a51b27e JB	549
0a51b27e JB	550	if (chan->flags & IEEE80211_CHAN_DISABLED \|\|
05c914fe	551	(sdata->vif.type == NL80211_IFTYPE_ADHOC &&
0a51b27e JB	552	chan->flags & IEEE80211_CHAN_NO_IBSS))
	553	skip = 1;
	554
	555	if (!skip) {
	556	local->scan_channel = chan;
e8975581 JB	557	if (ieee80211_hw_config(local,
e8975581 JB	558	IEEE80211_CONF_CHANGE_CHANNEL))
0a51b27e	559	skip = 1;
0a51b27e JB	560	}
	561
	562	/* advance state machine to next channel/band */
	563	local->scan_channel_idx++;
0a51b27e JB	564
	565	if (skip)
	566	break;
	567
	568	next_delay = IEEE80211_PROBE_DELAY +
	569	usecs_to_jiffies(local->hw.channel_change_time);
	570	local->scan_state = SCAN_SEND_PROBE;
	571	break;
	572	case SCAN_SEND_PROBE:
	573	next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
	574	local->scan_state = SCAN_SET_CHANNEL;
	575
2a519311 JB	576	if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN \|\|
2a519311 JB	577	!local->scan_req->n_ssids)
0a51b27e	578	break;
2a519311 JB	579	for (i = 0; i < local->scan_req->n_ssids; i++)
	580	ieee80211_send_probe_req(
	581	sdata, NULL,
	582	local->scan_req->ssids[i].ssid,
70692ad2 JM	583	local->scan_req->ssids[i].ssid_len,
70692ad2 JM	584	local->scan_req->ie, local->scan_req->ie_len);
0a51b27e JB	585	next_delay = IEEE80211_CHANNEL_TIME;
	586	break;
	587	}
	588
5bc75728 JB	589	queue_delayed_work(local->hw.workqueue, &local->scan_work,
5bc75728 JB	590	next_delay);
0a51b27e JB	591	}
0a51b27e JB	592
f3b85252 JB	593	int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
f3b85252 JB	594	struct cfg80211_scan_request *req)
0a51b27e	595	{
f3b85252	596	int res;
de95a54b	597
f3b85252 JB	598	mutex_lock(&sdata->local->scan_mtx);
	599	res = __ieee80211_start_scan(sdata, req);
	600	mutex_unlock(&sdata->local->scan_mtx);
0a51b27e	601
f3b85252	602	return res;
0a51b27e JB	603	}
0a51b27e JB	604
f3b85252 JB	605	int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
f3b85252 JB	606	const u8 *ssid, u8 ssid_len)
0a51b27e	607	{
0a51b27e	608	struct ieee80211_local *local = sdata->local;
f3b85252	609	int ret = -EBUSY;
2a519311	610
f3b85252	611	mutex_lock(&local->scan_mtx);
0a51b27e	612
f3b85252 JB	613	/* busy scanning */
	614	if (local->scan_req)
	615	goto unlock;
9116dd01	616
f3b85252 JB	617	memcpy(local->int_scan_req.ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
f3b85252 JB	618	local->int_scan_req.ssids[0].ssid_len = ssid_len;
9116dd01	619
f3b85252 JB	620	ret = __ieee80211_start_scan(sdata, &sdata->local->int_scan_req);
	621	unlock:
	622	mutex_unlock(&local->scan_mtx);
	623	return ret;
0a51b27e	624	}