[deliverable/linux.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;
}

void ieee80211_scan_failed(struct ieee80211_local *local)
{
	if (WARN_ON(!local->scan_req))
		return;

	/* notify cfg80211 about the failed scan */
	if (local->scan_req != &local->int_scan_req)
		cfg80211_scan_done(local->scan_req, true);

	local->scan_req = NULL;
}

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

	if (WARN_ON(!local->hw_scanning && !local->sw_scanning))
		return;

	if (WARN_ON(!local->scan_req))
		return;

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

	local->last_scan_completed = jiffies;

	if (local->hw_scanning) {
		local->hw_scanning = false;
		/*
		 * 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;
	}

	local->sw_scanning = false;
	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_send_nullfunc(local, sdata, 0);
				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_if_config(sdata,
					    IEEE80211_IFCC_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);

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;

	/*
	 * Avoid re-scheduling when the sdata is going away.
	 */
	if (!netif_running(sdata->dev))
		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_to_hw(local), 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_start_scan(struct ieee80211_sub_if_data *scan_sdata,
			 struct cfg80211_scan_request *req)
{
	struct ieee80211_local *local = scan_sdata->local;
	struct ieee80211_sub_if_data *sdata;

	if (!req)
		return -EINVAL;

	if (local->scan_req && local->scan_req != req)
		return -EBUSY;

	local->scan_req = req;

	/* MLME-SCAN.request (page 118)  page 144 (11.1.3.1)
	 * BSSType: INFRASTRUCTURE, INDEPENDENT, ANY_BSS
	 * BSSID: MACAddress
	 * SSID
	 * ScanType: ACTIVE, PASSIVE
	 * ProbeDelay: delay (in microseconds) to be used prior to transmitting
	 *    a Probe frame during active scanning
	 * ChannelList
	 * MinChannelTime (>= ProbeDelay), in TU
	 * MaxChannelTime: (>= MinChannelTime), in TU
	 */

	 /* MLME-SCAN.confirm
	  * BSSDescriptionSet
	  * ResultCode: SUCCESS, INVALID_PARAMETERS
	 */

	if (local->sw_scanning || local->hw_scanning) {
		if (local->scan_sdata == scan_sdata)
			return 0;
		return -EBUSY;
	}

	if (local->ops->hw_scan) {
		int rc;

		local->hw_scanning = true;
		rc = local->ops->hw_scan(local_to_hw(local), req);
		if (rc) {
			local->hw_scanning = false;
			return rc;
		}
		local->scan_sdata = scan_sdata;
		return 0;
	}

	/*
	 * 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().
	 */
	local->sw_scanning = true;
	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_if_config(sdata,
					    IEEE80211_IFCC_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_send_nullfunc(local, sdata, 1);
			}
		} else
			netif_tx_stop_all_queues(sdata->dev);
	}
	mutex_unlock(&local->iflist_mtx);

	local->scan_state = SCAN_SET_CHANNEL;
	local->scan_channel_idx = 0;
	local->scan_sdata = scan_sdata;
	local->scan_req = req;

	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;
}


int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
			   struct cfg80211_scan_request *req)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_managed *ifmgd;

	if (!req)
		return -EINVAL;

	if (local->scan_req && local->scan_req != req)
		return -EBUSY;

	local->scan_req = req;

	if (sdata->vif.type != NL80211_IFTYPE_STATION)
		return ieee80211_start_scan(sdata, req);

	/*
	 * STA has a state machine that might need to defer scanning
	 * while it's trying to associate/authenticate, therefore we
	 * queue it up to the state machine in that case.
	 */

	if (local->sw_scanning || local->hw_scanning) {
		if (local->scan_sdata == sdata)
			return 0;
		return -EBUSY;
	}

	ifmgd = &sdata->u.mgd;
	set_bit(IEEE80211_STA_REQ_SCAN, &ifmgd->request);
	queue_work(local->hw.workqueue, &ifmgd->work);

	return 0;
}
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
af88b907 HS	205	void ieee80211_scan_failed(struct ieee80211_local *local)
	206	{
	207	if (WARN_ON(!local->scan_req))
	208	return;
	209
	210	/* notify cfg80211 about the failed scan */
	211	if (local->scan_req != &local->int_scan_req)
	212	cfg80211_scan_done(local->scan_req, true);
	213
	214	local->scan_req = NULL;
	215	}
	216
2a519311	217	void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
0a51b27e JB	218	{
	219	struct ieee80211_local *local = hw_to_local(hw);
	220	struct ieee80211_sub_if_data *sdata;
0a51b27e	221
c2b13452	222	if (WARN_ON(!local->hw_scanning && !local->sw_scanning))
5bc75728 JB	223	return;
5bc75728 JB	224
2a519311 JB	225	if (WARN_ON(!local->scan_req))
2a519311 JB	226	return;
5bc75728	227
2a519311 JB	228	if (local->scan_req != &local->int_scan_req)
	229	cfg80211_scan_done(local->scan_req, aborted);
	230	local->scan_req = NULL;
	231
	232	local->last_scan_completed = jiffies;
0a51b27e	233
c2b13452 JB	234	if (local->hw_scanning) {
c2b13452 JB	235	local->hw_scanning = false;
e8975581 JB	236	/*
	237	* Somebody might have requested channel change during scan
	238	* that we won't have acted upon, try now. ieee80211_hw_config
	239	* will set the flag based on actual changes.
	240	*/
	241	ieee80211_hw_config(local, 0);
0a51b27e JB	242	goto done;
	243	}
	244
c2b13452	245	local->sw_scanning = false;
e8975581	246	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
0a51b27e JB	247
	248	netif_tx_lock_bh(local->mdev);
	249	netif_addr_lock(local->mdev);
	250	local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
	251	local->ops->configure_filter(local_to_hw(local),
	252	FIF_BCN_PRBRESP_PROMISC,
	253	&local->filter_flags,
	254	local->mdev->mc_count,
	255	local->mdev->mc_list);
	256
	257	netif_addr_unlock(local->mdev);
	258	netif_tx_unlock_bh(local->mdev);
	259
80e775bf MB	260	if (local->ops->sw_scan_complete)
	261	local->ops->sw_scan_complete(local_to_hw(local));
	262
078e1e60 JB	263	mutex_lock(&local->iflist_mtx);
078e1e60 JB	264	list_for_each_entry(sdata, &local->interfaces, list) {
fb9ddbf0 JB	265	if (!netif_running(sdata->dev))
	266	continue;
	267
0a51b27e	268	/* Tell AP we're back */
05c914fe	269	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
46900298	270	if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
0a51b27e JB	271	ieee80211_send_nullfunc(local, sdata, 0);
	272	netif_tx_wake_all_queues(sdata->dev);
	273	}
	274	} else
	275	netif_tx_wake_all_queues(sdata->dev);
078e1e60	276
14b80724 JB	277	/* re-enable beaconing */
	278	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	279	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	280	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
	281	ieee80211_if_config(sdata,
	282	IEEE80211_IFCC_BEACON_ENABLED);
0a51b27e	283	}
078e1e60	284	mutex_unlock(&local->iflist_mtx);
0a51b27e JB	285
	286	done:
	287	ieee80211_mlme_notify_scan_completed(local);
46900298	288	ieee80211_ibss_notify_scan_completed(local);
472dbc45	289	ieee80211_mesh_notify_scan_completed(local);
0a51b27e JB	290	}
	291	EXPORT_SYMBOL(ieee80211_scan_completed);
	292
c2b13452	293	void ieee80211_scan_work(struct work_struct *work)
0a51b27e JB	294	{
	295	struct ieee80211_local *local =
	296	container_of(work, struct ieee80211_local, scan_work.work);
	297	struct ieee80211_sub_if_data *sdata = local->scan_sdata;
0a51b27e	298	struct ieee80211_channel *chan;
2a519311	299	int skip, i;
0a51b27e JB	300	unsigned long next_delay = 0;
0a51b27e JB	301
5bc75728 JB	302	/*
	303	* Avoid re-scheduling when the sdata is going away.
	304	*/
	305	if (!netif_running(sdata->dev))
0a51b27e JB	306	return;
	307
	308	switch (local->scan_state) {
	309	case SCAN_SET_CHANNEL:
0a51b27e	310	/* if no more bands/channels left, complete scan */
2a519311 JB	311	if (local->scan_channel_idx >= local->scan_req->n_channels) {
2a519311 JB	312	ieee80211_scan_completed(local_to_hw(local), false);
0a51b27e JB	313	return;
	314	}
	315	skip = 0;
2a519311	316	chan = local->scan_req->channels[local->scan_channel_idx];
0a51b27e JB	317
0a51b27e JB	318	if (chan->flags & IEEE80211_CHAN_DISABLED \|\|
05c914fe	319	(sdata->vif.type == NL80211_IFTYPE_ADHOC &&
0a51b27e JB	320	chan->flags & IEEE80211_CHAN_NO_IBSS))
	321	skip = 1;
	322
	323	if (!skip) {
	324	local->scan_channel = chan;
e8975581 JB	325	if (ieee80211_hw_config(local,
e8975581 JB	326	IEEE80211_CONF_CHANGE_CHANNEL))
0a51b27e	327	skip = 1;
0a51b27e JB	328	}
	329
	330	/* advance state machine to next channel/band */
	331	local->scan_channel_idx++;
0a51b27e JB	332
	333	if (skip)
	334	break;
	335
	336	next_delay = IEEE80211_PROBE_DELAY +
	337	usecs_to_jiffies(local->hw.channel_change_time);
	338	local->scan_state = SCAN_SEND_PROBE;
	339	break;
	340	case SCAN_SEND_PROBE:
	341	next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
	342	local->scan_state = SCAN_SET_CHANNEL;
	343
2a519311 JB	344	if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN \|\|
2a519311 JB	345	!local->scan_req->n_ssids)
0a51b27e	346	break;
2a519311 JB	347	for (i = 0; i < local->scan_req->n_ssids; i++)
	348	ieee80211_send_probe_req(
	349	sdata, NULL,
	350	local->scan_req->ssids[i].ssid,
70692ad2 JM	351	local->scan_req->ssids[i].ssid_len,
70692ad2 JM	352	local->scan_req->ie, local->scan_req->ie_len);
0a51b27e JB	353	next_delay = IEEE80211_CHANNEL_TIME;
	354	break;
	355	}
	356
5bc75728 JB	357	queue_delayed_work(local->hw.workqueue, &local->scan_work,
5bc75728 JB	358	next_delay);
0a51b27e JB	359	}
	360
	361
c2b13452	362	int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
2a519311	363	struct cfg80211_scan_request *req)
0a51b27e JB	364	{
	365	struct ieee80211_local *local = scan_sdata->local;
	366	struct ieee80211_sub_if_data *sdata;
	367
2a519311	368	if (!req)
0a51b27e JB	369	return -EINVAL;
0a51b27e JB	370
2a519311 JB	371	if (local->scan_req && local->scan_req != req)
	372	return -EBUSY;
	373
	374	local->scan_req = req;
	375
0a51b27e JB	376	/* MLME-SCAN.request (page 118) page 144 (11.1.3.1)
	377	* BSSType: INFRASTRUCTURE, INDEPENDENT, ANY_BSS
	378	* BSSID: MACAddress
	379	* SSID
	380	* ScanType: ACTIVE, PASSIVE
	381	* ProbeDelay: delay (in microseconds) to be used prior to transmitting
	382	* a Probe frame during active scanning
	383	* ChannelList
	384	* MinChannelTime (>= ProbeDelay), in TU
	385	* MaxChannelTime: (>= MinChannelTime), in TU
	386	*/
	387
	388	/* MLME-SCAN.confirm
	389	* BSSDescriptionSet
	390	* ResultCode: SUCCESS, INVALID_PARAMETERS
	391	*/
	392
c2b13452	393	if (local->sw_scanning \|\| local->hw_scanning) {
0a51b27e JB	394	if (local->scan_sdata == scan_sdata)
	395	return 0;
	396	return -EBUSY;
	397	}
	398
	399	if (local->ops->hw_scan) {
5bc75728 JB	400	int rc;
5bc75728 JB	401
c2b13452	402	local->hw_scanning = true;
2a519311	403	rc = local->ops->hw_scan(local_to_hw(local), req);
5bc75728	404	if (rc) {
c2b13452	405	local->hw_scanning = false;
5bc75728	406	return rc;
0a51b27e	407	}
5bc75728 JB	408	local->scan_sdata = scan_sdata;
5bc75728 JB	409	return 0;
0a51b27e JB	410	}
0a51b27e JB	411
a9a6ffff KV	412	/*
	413	* Hardware/driver doesn't support hw_scan, so use software
	414	* scanning instead. First send a nullfunc frame with power save
	415	* bit on so that AP will buffer the frames for us while we are not
	416	* listening, then send probe requests to each channel and wait for
	417	* the responses. After all channels are scanned, tune back to the
	418	* original channel and send a nullfunc frame with power save bit
	419	* off to trigger the AP to send us all the buffered frames.
	420	*
	421	* Note that while local->sw_scanning is true everything else but
	422	* nullfunc frames and probe requests will be dropped in
	423	* ieee80211_tx_h_check_assoc().
	424	*/
c2b13452	425	local->sw_scanning = true;
80e775bf MB	426	if (local->ops->sw_scan_start)
80e775bf MB	427	local->ops->sw_scan_start(local_to_hw(local));
0a51b27e	428
078e1e60 JB	429	mutex_lock(&local->iflist_mtx);
078e1e60 JB	430	list_for_each_entry(sdata, &local->interfaces, list) {
fb9ddbf0 JB	431	if (!netif_running(sdata->dev))
	432	continue;
	433
14b80724 JB	434	/* disable beaconing */
	435	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	436	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	437	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
	438	ieee80211_if_config(sdata,
	439	IEEE80211_IFCC_BEACON_ENABLED);
078e1e60	440
05c914fe	441	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
46900298	442	if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
0a51b27e JB	443	netif_tx_stop_all_queues(sdata->dev);
	444	ieee80211_send_nullfunc(local, sdata, 1);
	445	}
	446	} else
	447	netif_tx_stop_all_queues(sdata->dev);
	448	}
078e1e60	449	mutex_unlock(&local->iflist_mtx);
0a51b27e	450
0a51b27e JB	451	local->scan_state = SCAN_SET_CHANNEL;
0a51b27e JB	452	local->scan_channel_idx = 0;
0a51b27e	453	local->scan_sdata = scan_sdata;
2a519311	454	local->scan_req = req;
0a51b27e JB	455
	456	netif_addr_lock_bh(local->mdev);
	457	local->filter_flags \|= FIF_BCN_PRBRESP_PROMISC;
	458	local->ops->configure_filter(local_to_hw(local),
	459	FIF_BCN_PRBRESP_PROMISC,
	460	&local->filter_flags,
	461	local->mdev->mc_count,
	462	local->mdev->mc_list);
	463	netif_addr_unlock_bh(local->mdev);
	464
	465	/* TODO: start scan as soon as all nullfunc frames are ACKed */
	466	queue_delayed_work(local->hw.workqueue, &local->scan_work,
	467	IEEE80211_CHANNEL_TIME);
	468
	469	return 0;
	470	}
	471
	472
c2b13452	473	int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
2a519311	474	struct cfg80211_scan_request *req)
0a51b27e	475	{
0a51b27e	476	struct ieee80211_local *local = sdata->local;
46900298	477	struct ieee80211_if_managed *ifmgd;
0a51b27e	478
2a519311 JB	479	if (!req)
	480	return -EINVAL;
	481
	482	if (local->scan_req && local->scan_req != req)
	483	return -EBUSY;
	484
	485	local->scan_req = req;
	486
05c914fe	487	if (sdata->vif.type != NL80211_IFTYPE_STATION)
2a519311	488	return ieee80211_start_scan(sdata, req);
0a51b27e	489
9116dd01 JB	490	/*
	491	* STA has a state machine that might need to defer scanning
	492	* while it's trying to associate/authenticate, therefore we
	493	* queue it up to the state machine in that case.
	494	*/
	495
c2b13452	496	if (local->sw_scanning \|\| local->hw_scanning) {
0a51b27e JB	497	if (local->scan_sdata == sdata)
	498	return 0;
	499	return -EBUSY;
	500	}
	501
46900298 JB	502	ifmgd = &sdata->u.mgd;
	503	set_bit(IEEE80211_STA_REQ_SCAN, &ifmgd->request);
	504	queue_work(local->hw.workqueue, &ifmgd->work);
9116dd01	505
0a51b27e JB	506	return 0;
0a51b27e JB	507	}