path: root/net/mac80211/work.c

/*
 * mac80211 work implementation
 *
 * Copyright 2003-2008, Jouni Malinen <j@w1.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 2009, Johannes Berg <johannes@sipsolutions.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/delay.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/crc32.h>
#include <linux/slab.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>

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

#define IEEE80211_AUTH_TIMEOUT (HZ / 5)
#define IEEE80211_AUTH_MAX_TRIES 3
#define IEEE80211_ASSOC_TIMEOUT (HZ / 5)
#define IEEE80211_ASSOC_MAX_TRIES 3

enum work_action {
	WORK_ACT_MISMATCH,
	WORK_ACT_NONE,
	WORK_ACT_TIMEOUT,
	WORK_ACT_DONE,
};


/* utils */
static inline void ASSERT_WORK_MTX(struct ieee80211_local *local)
{
	lockdep_assert_held(&local->mtx);
}

/*
 * We can have multiple work items (and connection probing)
 * scheduling this timer, but we need to take care to only
 * reschedule it when it should fire _earlier_ than it was
 * asked for before, or if it's not pending right now. This
 * function ensures that. Note that it then is required to
 * run this function for all timeouts after the first one
 * has happened -- the work that runs from this timer will
 * do that.
 */
static void run_again(struct ieee80211_local *local,
		      unsigned long timeout)
{
	ASSERT_WORK_MTX(local);

	if (!timer_pending(&local->work_timer) ||
	    time_before(timeout, local->work_timer.expires))
		mod_timer(&local->work_timer, timeout);
}

void free_work(struct ieee80211_work *wk)
{
	kfree_rcu(wk, rcu_head);
}

static int ieee80211_compatible_rates(const u8 *supp_rates, int supp_rates_len,
				      struct ieee80211_supported_band *sband,
				      u32 *rates)
{
	int i, j, count;
	*rates = 0;
	count = 0;
	for (i = 0; i < supp_rates_len; i++) {
		int rate = (supp_rates[i] & 0x7F) * 5;

		for (j = 0; j < sband->n_bitrates; j++)
			if (sband->bitrates[j].bitrate == rate) {
				*rates |= BIT(j);
				count++;
				break;
			}
	}

	return count;
}

/* frame sending functions */

static void ieee80211_add_ht_ie(struct ieee80211_sub_if_data *sdata,
				struct sk_buff *skb, const u8 *ht_info_ie,
				struct ieee80211_supported_band *sband,
				struct ieee80211_channel *channel,
				enum ieee80211_smps_mode smps)
{
	struct ieee80211_ht_info *ht_info;
	u8 *pos;
	u32 flags = channel->flags;
	u16 cap;
	struct ieee80211_sta_ht_cap ht_cap;

	BUILD_BUG_ON(sizeof(ht_cap) != sizeof(sband->ht_cap));

	if (!sband->ht_cap.ht_supported)
		return;

	if (!ht_info_ie)
		return;

	if (ht_info_ie[1] < sizeof(struct ieee80211_ht_info))
		return;

	memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
	ieee80211_apply_htcap_overrides(sdata, &ht_cap);

	ht_info = (struct ieee80211_ht_info *)(ht_info_ie + 2);