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>
 *
 * 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 <linux/pm_qos.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 / 8)

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

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

void ieee80211_rx_bss_put(struct ieee80211_local *local,
			  struct ieee80211_bss *bss)
{
	if (!bss)
		return;
	cfg80211_put_bss(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)
{
	struct cfg80211_bss *cbss;
	struct ieee80211_bss *bss;
	int clen, srlen;
	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;

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

	if (!cbss)
		return NULL;

	cbss->free_priv = ieee80211_rx_bss_free;
	bss = (void *)cbss->priv;

	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->erp_info_len >= 1 &&
			(!elems->parse_error ||
			 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
		bss->erp_value = elems->erp_info[0];
		bss->has_erp_value = true;
		if (!elems->parse_error)
			bss->valid_data |= IEEE80211_BSS_VALID_ERP;
	}

	if (elems->tim && (!elems->parse_error ||
			   !(bss->valid_data & IEEE80211_BSS_VALID_DTIM))) {
		struct ieee80211_tim_ie *tim_ie =
			(struct ieee80211_tim_ie *)elems->tim;
		bss->dtim_period = tim_ie->dtim_period;
		if (!elems->parse_error)
				bss->valid_data |= IEEE80211_BSS_VALID_DTIM;
	}

	/* If the beacon had no TIM IE, or it was invalid, use 1 */
	if (beacon && !bss->dtim_period)
		bss->dtim_period = 1;

	/* replace old supported rates if we get new values */
	if (!elems->parse_error ||
	    !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
		srlen = 0;
		if