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/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 <asm/unaligned.h>

#include "ieee80211_i.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_MERGE_DELAY 0x400000
#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)

#define IEEE80211_IBSS_MAX_STA_ENTRIES 128


static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
					struct ieee80211_mgmt *mgmt,
					size_t len)
{
	u16 auth_alg, auth_transaction, status_code;

	if (len < 24 + 6)
		return;

	auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
	auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
	status_code = le16_to_cpu(mgmt->u.auth.status_code);

	/*
	 * IEEE 802.11 standard does not require authentication in IBSS
	 * networks and most implementations do not seem to use it.
	 * However, try to reply to authentication attempts if someone
	 * has actually implemented this.
	 */
	if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
		ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
				    sdata->u.ibss.bssid, 0);
}

static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				      const u8 *bssid, const int beacon_int,
				      struct ieee80211_channel *chan,
				      const size_t supp_rates_len,
				      const u8 *supp_rates,
				      const u16 capability, u64 tsf)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	int rates, i, j;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u8 *pos;
	struct ieee80211_supported_band *sband;

	if (local->ops->reset_tsf) {
		/* Reset own TSF to allow time synchronization work. */
		local->ops->reset_tsf(local_to_hw(local));
	}

	skb = ifibss->skb;
	rcu_assign_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 (memcmp(ifibss->bssid, bssid, ETH_ALEN))
		sta_info_flush(sdata->local, sdata);

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

	local->hw.conf.beacon_int = beacon_int >= 10 ? beacon_int : 10;

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

	ieee80211_if_config(sdata, IEEE80211_IFCC_BSSID);

	local->oper_channel = chan;
	local->oper_channel_type = NL80211_CHAN_NO_HT;
	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
	sband = local->hw.wiphy->bands[chan->band];

	/* Build IBSS probe response */
	mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
	memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_PROBE_RESP);
	memset(mgmt->da, 0xff, ETH_ALEN);
	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
	memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
	mgmt->u.beacon.beacon_int = cpu_to_le16(local->hw.conf.beacon_int);
	mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
	mgmt->u.beacon.capab_info = cpu_to_le16(capability);

	pos = skb_put(skb, 2 + ifibss->ssid_len);
	*pos++ = WLAN_EID_SSID;
	*pos++ = ifibss->ssid_len;
	memcpy(pos, ifibss->ssid, ifibss->ssid_len);

	rates = supp_rates_len;
	if (rates > 8)
		rates = 8;
	pos = skb_put(skb, 2 + rates);
	*pos++ = WLAN_EID_SUPP_RATES;
	*pos++ = rates;
	memcpy(pos, supp_rates, rates);

	if (sband->band == IEEE80211_BAND_2GHZ) {
		pos = skb_put(skb, 2 + 1);
		*pos++ = WLAN_EID_DS_PARAMS;
		*pos++ = 1;
		*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
	}

	pos = skb_put(skb, 2 + 2);
	*pos++ = WLAN_EID_IBSS_PARAMS;
	*pos++ = 2;
	/* FIX: