path: root/net/mac80211/ibss.c

/*
 * IBSS mode 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/slab.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <net/mac80211.h>

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

#define IEEE80211_SCAN_INTERVAL (2 * HZ)
#define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)

#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)

#define IEEE80211_IBSS_MAX_STA_ENTRIES 128


static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				      const u8 *bssid, const int beacon_int,
				      struct ieee80211_channel *chan,
				      const u32 basic_rates,
				      const u16 capability, u64 tsf)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	int rates, i;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u8 *pos;
	struct ieee80211_supported_band *sband;
	struct cfg80211_bss *bss;
	u32 bss_change;
	u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
	enum nl80211_channel_type channel_type;

	lockdep_assert_held(&ifibss->mtx);

	/* Reset own TSF to allow time synchronization work. */
	drv_reset_tsf(local, sdata);

	skb = ifibss->skb;
	RCU_INIT_POINTER(ifibss->presp, NULL);
	synchronize_rcu();
	skb->data = skb->head;
	skb->len = 0;
	skb_reset_tail_pointer(skb);
	skb_reserve(skb, sdata->local->hw.extra_tx_headroom);

	if (!ether_addr_equal(ifibss->bssid, bssid))
		sta_info_flush(sdata->local, sdata);

	/* if merging, indicate to driver that we leave the old IBSS */
	if (sdata->vif.bss_conf.ibss_joined) {
		sdata->vif.bss_conf.ibss_joined = false;
		netif_carrier_off(sdata->dev);
		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
	}

	memcpy(ifibss->bssid, bssid, ETH_ALEN);

	sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;

	local->oper_channel = chan;
	channel_type = ifibss->channel_type;
	if (channel_type > NL80211_CHAN_HT20 &&
	    !cfg80211_can_beacon_sec_chan(local->hw.wiphy, chan, channel_type))
		channel_type = NL80211_CHAN_HT20;
	if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
		/* can only fail due to HT40+/- mismatch */
		channel_type = NL80211_CHAN_HT20;
		WARN_ON(!ieee80211_set_channel_type(local, sdata,
						    NL80211_CHAN_HT20));
	}
	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);

	sband = local->hw.wiphy->bands[chan->band];

	/* build supported rates array */
	pos = supp_rates