[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;
	enum cfg80211_signal_type sigtype = CFG80211_SIGNAL_TYPE_NONE;
	s32 signal = 0;

	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
		sigtype = CFG80211_SIGNAL_TYPE_MBM;
		signal = rx_status->signal * 100;
	} else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) {
		sigtype = CFG80211_SIGNAL_TYPE_UNSPEC;
		signal = (rx_status->signal * 100) / local->hw.max_signal;
	}

	bss = (void *)cfg80211_inform_bss_frame(local->hw.wiphy, channel,
						mgmt, len, signal, sigtype,
						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_send_nullfunc(struct ieee80211_local *local,
				    struct ieee80211_sub_if_data *sdata,
				    int powersave)
{
	struct sk_buff *skb;
	struct ieee80211_hdr *nullfunc;
	__le16 fc;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + 24);
	if (!skb) {
		printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
		       "frame\n", sdata->dev->name);
		return;
	}
	skb_reserve(skb, local->hw.extra_tx_headroom);

	nullfunc = (struct ieee80211_hdr *) skb_put(skb, 24);
	memset(nullfunc, 0, 24);
	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC |
			 IEEE80211_FCTL_TODS);
	if (powersave)
		fc |= cpu_to_le16(IEEE80211_FCTL_PM);
	nullfunc->frame_control = fc;
	memcpy(nullfunc->addr1, sdata->u.sta.bssid, ETH_ALEN);
	memcpy(nullfunc->addr2, sdata->dev->dev_addr, ETH_ALEN);
	memcpy(nullfunc->addr3, sdata->u.sta.bssid, ETH_ALEN);

	ieee80211_tx_skb(sdata, skb, 0);
}

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);

	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.sta.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_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);
		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;
	}

	local->sw_scanning = true;

	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.sta.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_sta *ifsta;

	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;
	}

	ifsta = &sdata->u.sta;
	set_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request);
	queue_work(local->hw.workqueue, &ifsta->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	enum cfg80211_signal_type sigtype = CFG80211_SIGNAL_TYPE_NONE;
	67	s32 signal = 0;
	68
	69	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
	70	sigtype = CFG80211_SIGNAL_TYPE_MBM;
	71	signal = rx_status->signal * 100;
	72	} else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) {
	73	sigtype = CFG80211_SIGNAL_TYPE_UNSPEC;
	74	signal = (rx_status->signal * 100) / local->hw.max_signal;
	75	}
	76
00d3f14c JB	77	bss = (void *)cfg80211_inform_bss_frame(local->hw.wiphy, channel,
	78	mgmt, len, signal, sigtype,
	79	GFP_ATOMIC);
5484e237	80
00d3f14c JB	81	if (!bss)
	82	return NULL;
	83
	84	bss->cbss.free_priv = ieee80211_rx_bss_free;
5484e237 JB	85
	86	/* save the ERP value so that it is available at association time */
	87	if (elems->erp_info && elems->erp_info_len >= 1) {
	88	bss->erp_value = elems->erp_info[0];
	89	bss->has_erp_value = 1;
	90	}
	91
5484e237 JB	92	if (elems->tim) {
	93	struct ieee80211_tim_ie *tim_ie =
	94	(struct ieee80211_tim_ie *)elems->tim;
	95	bss->dtim_period = tim_ie->dtim_period;
	96	}
	97
	98	/* set default value for buggy APs */
	99	if (!elems->tim \|\| bss->dtim_period == 0)
	100	bss->dtim_period = 1;
	101
	102	bss->supp_rates_len = 0;
	103	if (elems->supp_rates) {
	104	clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
	105	if (clen > elems->supp_rates_len)
	106	clen = elems->supp_rates_len;
	107	memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates,
	108	clen);
	109	bss->supp_rates_len += clen;
	110	}
	111	if (elems->ext_supp_rates) {
	112	clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
	113	if (clen > elems->ext_supp_rates_len)
	114	clen = elems->ext_supp_rates_len;
	115	memcpy(&bss->supp_rates[bss->supp_rates_len],
	116	elems->ext_supp_rates, clen);
	117	bss->supp_rates_len += clen;
	118	}
	119
5484e237 JB	120	bss->wmm_used = elems->wmm_param \|\| elems->wmm_info;
	121
	122	if (!beacon)
	123	bss->last_probe_resp = jiffies;
	124
5484e237 JB	125	return bss;
5484e237 JB	126	}
0a51b27e	127
7a947080 VT	128	void ieee80211_rx_bss_remove(struct ieee80211_sub_if_data sdata, u8 bssid,
	129	int freq, u8 *ssid, u8 ssid_len)
	130	{
	131	struct ieee80211_bss *bss;
	132	struct ieee80211_local *local = sdata->local;
	133
	134	bss = ieee80211_rx_bss_get(local, bssid, freq, ssid, ssid_len);
	135	if (bss) {
00d3f14c	136	cfg80211_unlink_bss(local->hw.wiphy, (void *)bss);
7a947080 VT	137	ieee80211_rx_bss_put(local, bss);
	138	}
	139	}
	140
98c8fccf	141	ieee80211_rx_result
c2b13452 JB	142	ieee80211_scan_rx(struct ieee80211_sub_if_data sdata, struct sk_buff skb,
c2b13452 JB	143	struct ieee80211_rx_status *rx_status)
98c8fccf JB	144	{
98c8fccf JB	145	struct ieee80211_mgmt *mgmt;
c2b13452	146	struct ieee80211_bss *bss;
98c8fccf JB	147	u8 *elements;
	148	struct ieee80211_channel *channel;
	149	size_t baselen;
	150	int freq;
	151	__le16 fc;
	152	bool presp, beacon = false;
	153	struct ieee802_11_elems elems;
	154
	155	if (skb->len < 2)
	156	return RX_DROP_UNUSABLE;
	157
	158	mgmt = (struct ieee80211_mgmt *) skb->data;
	159	fc = mgmt->frame_control;
	160
	161	if (ieee80211_is_ctl(fc))
	162	return RX_CONTINUE;
	163
	164	if (skb->len < 24)
	165	return RX_DROP_MONITOR;
	166
	167	presp = ieee80211_is_probe_resp(fc);
	168	if (presp) {
	169	/* ignore ProbeResp to foreign address */
	170	if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
	171	return RX_DROP_MONITOR;
	172
	173	presp = true;
	174	elements = mgmt->u.probe_resp.variable;
	175	baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
	176	} else {
	177	beacon = ieee80211_is_beacon(fc);
	178	baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
	179	elements = mgmt->u.beacon.variable;
	180	}
	181
	182	if (!presp && !beacon)
	183	return RX_CONTINUE;
	184
	185	if (baselen > skb->len)
	186	return RX_DROP_MONITOR;
	187
	188	ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
	189
	190	if (elems.ds_params && elems.ds_params_len == 1)
	191	freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
	192	else
	193	freq = rx_status->freq;
	194
	195	channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
	196
	197	if (!channel \|\| channel->flags & IEEE80211_CHAN_DISABLED)
	198	return RX_DROP_MONITOR;
	199
	200	bss = ieee80211_bss_info_update(sdata->local, rx_status,
	201	mgmt, skb->len, &elems,
2a519311	202	channel, beacon);
d048e503 JM	203	if (bss)
d048e503 JM	204	ieee80211_rx_bss_put(sdata->local, bss);
98c8fccf JB	205
	206	dev_kfree_skb(skb);
	207	return RX_QUEUED;
	208	}
	209
a97b77b9	210	void ieee80211_send_nullfunc(struct ieee80211_local *local,
0a51b27e JB	211	struct ieee80211_sub_if_data *sdata,
	212	int powersave)
	213	{
	214	struct sk_buff *skb;
	215	struct ieee80211_hdr *nullfunc;
	216	__le16 fc;
	217
	218	skb = dev_alloc_skb(local->hw.extra_tx_headroom + 24);
	219	if (!skb) {
	220	printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
	221	"frame\n", sdata->dev->name);
	222	return;
	223	}
	224	skb_reserve(skb, local->hw.extra_tx_headroom);
	225
	226	nullfunc = (struct ieee80211_hdr *) skb_put(skb, 24);
	227	memset(nullfunc, 0, 24);
	228	fc = cpu_to_le16(IEEE80211_FTYPE_DATA \| IEEE80211_STYPE_NULLFUNC \|
	229	IEEE80211_FCTL_TODS);
	230	if (powersave)
	231	fc \|= cpu_to_le16(IEEE80211_FCTL_PM);
	232	nullfunc->frame_control = fc;
	233	memcpy(nullfunc->addr1, sdata->u.sta.bssid, ETH_ALEN);
	234	memcpy(nullfunc->addr2, sdata->dev->dev_addr, ETH_ALEN);
	235	memcpy(nullfunc->addr3, sdata->u.sta.bssid, ETH_ALEN);
	236
e50db65c	237	ieee80211_tx_skb(sdata, skb, 0);
0a51b27e JB	238	}
0a51b27e JB	239
2a519311	240	void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
0a51b27e JB	241	{
	242	struct ieee80211_local *local = hw_to_local(hw);
	243	struct ieee80211_sub_if_data *sdata;
0a51b27e	244
c2b13452	245	if (WARN_ON(!local->hw_scanning && !local->sw_scanning))
5bc75728 JB	246	return;
5bc75728 JB	247
2a519311 JB	248	if (WARN_ON(!local->scan_req))
2a519311 JB	249	return;
5bc75728	250
2a519311 JB	251	if (local->scan_req != &local->int_scan_req)
	252	cfg80211_scan_done(local->scan_req, aborted);
	253	local->scan_req = NULL;
	254
	255	local->last_scan_completed = jiffies;
0a51b27e	256
c2b13452 JB	257	if (local->hw_scanning) {
c2b13452 JB	258	local->hw_scanning = false;
e8975581 JB	259	/*
	260	* Somebody might have requested channel change during scan
	261	* that we won't have acted upon, try now. ieee80211_hw_config
	262	* will set the flag based on actual changes.
	263	*/
	264	ieee80211_hw_config(local, 0);
0a51b27e JB	265	goto done;
	266	}
	267
c2b13452	268	local->sw_scanning = false;
e8975581	269	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
0a51b27e JB	270
	271	netif_tx_lock_bh(local->mdev);
	272	netif_addr_lock(local->mdev);
	273	local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
	274	local->ops->configure_filter(local_to_hw(local),
	275	FIF_BCN_PRBRESP_PROMISC,
	276	&local->filter_flags,
	277	local->mdev->mc_count,
	278	local->mdev->mc_list);
	279
	280	netif_addr_unlock(local->mdev);
	281	netif_tx_unlock_bh(local->mdev);
	282
078e1e60 JB	283	mutex_lock(&local->iflist_mtx);
078e1e60 JB	284	list_for_each_entry(sdata, &local->interfaces, list) {
fb9ddbf0 JB	285	if (!netif_running(sdata->dev))
	286	continue;
	287
0a51b27e	288	/* Tell AP we're back */
05c914fe	289	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
0a51b27e JB	290	if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
	291	ieee80211_send_nullfunc(local, sdata, 0);
	292	netif_tx_wake_all_queues(sdata->dev);
	293	}
	294	} else
	295	netif_tx_wake_all_queues(sdata->dev);
078e1e60	296
14b80724 JB	297	/* re-enable beaconing */
	298	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	299	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	300	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
	301	ieee80211_if_config(sdata,
	302	IEEE80211_IFCC_BEACON_ENABLED);
0a51b27e	303	}
078e1e60	304	mutex_unlock(&local->iflist_mtx);
0a51b27e JB	305
	306	done:
	307	ieee80211_mlme_notify_scan_completed(local);
472dbc45	308	ieee80211_mesh_notify_scan_completed(local);
0a51b27e JB	309	}
	310	EXPORT_SYMBOL(ieee80211_scan_completed);
	311
c2b13452	312	void ieee80211_scan_work(struct work_struct *work)
0a51b27e JB	313	{
	314	struct ieee80211_local *local =
	315	container_of(work, struct ieee80211_local, scan_work.work);
	316	struct ieee80211_sub_if_data *sdata = local->scan_sdata;
0a51b27e	317	struct ieee80211_channel *chan;
2a519311	318	int skip, i;
0a51b27e JB	319	unsigned long next_delay = 0;
0a51b27e JB	320
5bc75728 JB	321	/*
	322	* Avoid re-scheduling when the sdata is going away.
	323	*/
	324	if (!netif_running(sdata->dev))
0a51b27e JB	325	return;
	326
	327	switch (local->scan_state) {
	328	case SCAN_SET_CHANNEL:
0a51b27e	329	/* if no more bands/channels left, complete scan */
2a519311 JB	330	if (local->scan_channel_idx >= local->scan_req->n_channels) {
2a519311 JB	331	ieee80211_scan_completed(local_to_hw(local), false);
0a51b27e JB	332	return;
	333	}
	334	skip = 0;
2a519311	335	chan = local->scan_req->channels[local->scan_channel_idx];
0a51b27e JB	336
0a51b27e JB	337	if (chan->flags & IEEE80211_CHAN_DISABLED \|\|
05c914fe	338	(sdata->vif.type == NL80211_IFTYPE_ADHOC &&
0a51b27e JB	339	chan->flags & IEEE80211_CHAN_NO_IBSS))
	340	skip = 1;
	341
	342	if (!skip) {
	343	local->scan_channel = chan;
e8975581 JB	344	if (ieee80211_hw_config(local,
e8975581 JB	345	IEEE80211_CONF_CHANGE_CHANNEL))
0a51b27e	346	skip = 1;
0a51b27e JB	347	}
	348
	349	/* advance state machine to next channel/band */
	350	local->scan_channel_idx++;
0a51b27e JB	351
	352	if (skip)
	353	break;
	354
	355	next_delay = IEEE80211_PROBE_DELAY +
	356	usecs_to_jiffies(local->hw.channel_change_time);
	357	local->scan_state = SCAN_SEND_PROBE;
	358	break;
	359	case SCAN_SEND_PROBE:
	360	next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
	361	local->scan_state = SCAN_SET_CHANNEL;
	362
2a519311 JB	363	if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN \|\|
2a519311 JB	364	!local->scan_req->n_ssids)
0a51b27e	365	break;
2a519311 JB	366	for (i = 0; i < local->scan_req->n_ssids; i++)
	367	ieee80211_send_probe_req(
	368	sdata, NULL,
	369	local->scan_req->ssids[i].ssid,
	370	local->scan_req->ssids[i].ssid_len);
0a51b27e JB	371	next_delay = IEEE80211_CHANNEL_TIME;
	372	break;
	373	}
	374
5bc75728 JB	375	queue_delayed_work(local->hw.workqueue, &local->scan_work,
5bc75728 JB	376	next_delay);
0a51b27e JB	377	}
	378
	379
c2b13452	380	int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
2a519311	381	struct cfg80211_scan_request *req)
0a51b27e JB	382	{
	383	struct ieee80211_local *local = scan_sdata->local;
	384	struct ieee80211_sub_if_data *sdata;
	385
2a519311	386	if (!req)
0a51b27e JB	387	return -EINVAL;
0a51b27e JB	388
2a519311 JB	389	if (local->scan_req && local->scan_req != req)
	390	return -EBUSY;
	391
	392	local->scan_req = req;
	393
0a51b27e JB	394	/* MLME-SCAN.request (page 118) page 144 (11.1.3.1)
	395	* BSSType: INFRASTRUCTURE, INDEPENDENT, ANY_BSS
	396	* BSSID: MACAddress
	397	* SSID
	398	* ScanType: ACTIVE, PASSIVE
	399	* ProbeDelay: delay (in microseconds) to be used prior to transmitting
	400	* a Probe frame during active scanning
	401	* ChannelList
	402	* MinChannelTime (>= ProbeDelay), in TU
	403	* MaxChannelTime: (>= MinChannelTime), in TU
	404	*/
	405
	406	/* MLME-SCAN.confirm
	407	* BSSDescriptionSet
	408	* ResultCode: SUCCESS, INVALID_PARAMETERS
	409	*/
	410
c2b13452	411	if (local->sw_scanning \|\| local->hw_scanning) {
0a51b27e JB	412	if (local->scan_sdata == scan_sdata)
	413	return 0;
	414	return -EBUSY;
	415	}
	416
	417	if (local->ops->hw_scan) {
5bc75728 JB	418	int rc;
5bc75728 JB	419
c2b13452	420	local->hw_scanning = true;
2a519311	421	rc = local->ops->hw_scan(local_to_hw(local), req);
5bc75728	422	if (rc) {
c2b13452	423	local->hw_scanning = false;
5bc75728	424	return rc;
0a51b27e	425	}
5bc75728 JB	426	local->scan_sdata = scan_sdata;
5bc75728 JB	427	return 0;
0a51b27e JB	428	}
0a51b27e JB	429
c2b13452	430	local->sw_scanning = true;
0a51b27e	431
078e1e60 JB	432	mutex_lock(&local->iflist_mtx);
078e1e60 JB	433	list_for_each_entry(sdata, &local->interfaces, list) {
fb9ddbf0 JB	434	if (!netif_running(sdata->dev))
	435	continue;
	436
14b80724 JB	437	/* disable beaconing */
	438	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	439	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	440	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
	441	ieee80211_if_config(sdata,
	442	IEEE80211_IFCC_BEACON_ENABLED);
078e1e60	443
05c914fe	444	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
0a51b27e JB	445	if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
	446	netif_tx_stop_all_queues(sdata->dev);
	447	ieee80211_send_nullfunc(local, sdata, 1);
	448	}
	449	} else
	450	netif_tx_stop_all_queues(sdata->dev);
	451	}
078e1e60	452	mutex_unlock(&local->iflist_mtx);
0a51b27e	453
0a51b27e JB	454	local->scan_state = SCAN_SET_CHANNEL;
0a51b27e JB	455	local->scan_channel_idx = 0;
0a51b27e	456	local->scan_sdata = scan_sdata;
2a519311	457	local->scan_req = req;
0a51b27e JB	458
	459	netif_addr_lock_bh(local->mdev);
	460	local->filter_flags \|= FIF_BCN_PRBRESP_PROMISC;
	461	local->ops->configure_filter(local_to_hw(local),
	462	FIF_BCN_PRBRESP_PROMISC,
	463	&local->filter_flags,
	464	local->mdev->mc_count,
	465	local->mdev->mc_list);
	466	netif_addr_unlock_bh(local->mdev);
	467
	468	/* TODO: start scan as soon as all nullfunc frames are ACKed */
	469	queue_delayed_work(local->hw.workqueue, &local->scan_work,
	470	IEEE80211_CHANNEL_TIME);
	471
	472	return 0;
	473	}
	474
	475
c2b13452	476	int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
2a519311	477	struct cfg80211_scan_request *req)
0a51b27e	478	{
0a51b27e	479	struct ieee80211_local *local = sdata->local;
9116dd01	480	struct ieee80211_if_sta *ifsta;
0a51b27e	481
2a519311 JB	482	if (!req)
	483	return -EINVAL;
	484
	485	if (local->scan_req && local->scan_req != req)
	486	return -EBUSY;
	487
	488	local->scan_req = req;
	489
05c914fe	490	if (sdata->vif.type != NL80211_IFTYPE_STATION)
2a519311	491	return ieee80211_start_scan(sdata, req);
0a51b27e	492
9116dd01 JB	493	/*
	494	* STA has a state machine that might need to defer scanning
	495	* while it's trying to associate/authenticate, therefore we
	496	* queue it up to the state machine in that case.
	497	*/
	498
c2b13452	499	if (local->sw_scanning \|\| local->hw_scanning) {
0a51b27e JB	500	if (local->scan_sdata == sdata)
	501	return 0;
	502	return -EBUSY;
	503	}
	504
9116dd01	505	ifsta = &sdata->u.sta;
0a51b27e JB	506	set_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request);
0a51b27e JB	507	queue_work(local->hw.workqueue, &ifsta->work);
9116dd01	508
0a51b27e JB	509	return 0;
0a51b27e JB	510	}