path: root/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>
 * Copyright 2013-2015  Intel Mobile Communications GmbH
 *
 * 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.
 */

#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <net/sch_generic.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/mac80211.h>

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

#define IEEE80211_PROBE_DELAY (HZ / 33)
#define IEEE80211_CHANNEL_TIME (HZ / 33)
#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)

void ieee80211_rx_bss_put(struct ieee80211_local *local,
			  struct ieee80211_bss *bss)
{
	if (!bss)
		return;
	cfg80211_put_bss(local->hw.wiphy,
			 container_of((void *)bss, struct cfg80211_bss, priv));
}

static bool is_uapsd_supported(struct ieee802_11_elems *elems)
{
	u8 qos_info;

	if (elems->wmm_info && elems->wmm_info_len == 7
	    && elems->wmm_info[5] == 1)
		qos_info = elems->wmm_info[6];
	else if (elems->wmm_param && elems->wmm_param_len == 24
		 && elems->wmm_param[5] == 1)
		qos_info = elems->wmm_param[6];
	else
		/* no valid wmm information or parameter element found */
		return false;

	return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
}

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 = ieee80211_is_beacon(mgmt->frame_control);
	struct cfg80211_bss *cbss;
	struct ieee80211_bss *bss;
	int clen, srlen;
	struct cfg80211_inform_bss bss_meta = {};
	bool signal_valid;

	if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
		bss_meta.signal = rx_status->signal * 100;
	else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
		bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;

	bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
	if (rx_status->flag & RX_FLAG_5MHZ)
		bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
	if (rx_status->flag & RX_FLAG_10MHZ)
		bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;

	bss_meta.chan = channel;
	cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
					      mgmt, len, GFP_ATOMIC);
	if (!cbss)
		return NULL;
	/* In case the signal is invalid update the status */
	signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
		<= local->hw.wiphy->max_adj_channel_rssi_comp;
	if (!signal_valid)
		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;

	bss = (void *)cbss->priv;

	if (beacon)
		bss->device_ts_beacon = rx_status->device_timestamp;
	else
		bss->device_ts_presp = rx_status->device_timestamp;

	if (elems->parse_error) {
		if (beacon)
			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
		else
			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
	} else {
		if (beacon)
			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
		else
			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
	}

	/* save the ERP value so that it is available at association time */
	if (elems->erp_info && (!elems->parse_error