ieee80211_sta.c

linux 内核源代码

		if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PROBE_RESP) {
			ieee80211_rx_mgmt_probe_resp(dev, mgmt,
						     skb->len, rx_status);
		} else if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON) {
			ieee80211_rx_mgmt_beacon(dev, mgmt, skb->len,
						 rx_status);
		}
	}

	dev_kfree_skb(skb);
}


static int ieee80211_sta_active_ibss(struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	int active = 0;
	struct sta_info *sta;

	read_lock_bh(&local->sta_lock);
	list_for_each_entry(sta, &local->sta_list, list) {
		if (sta->dev == dev &&
		    time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
			       jiffies)) {
			active++;
			break;
		}
	}
	read_unlock_bh(&local->sta_lock);

	return active;
}


static void ieee80211_sta_expire(struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct sta_info *sta, *tmp;
	LIST_HEAD(tmp_list);
	DECLARE_MAC_BUF(mac);

	write_lock_bh(&local->sta_lock);
	list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
		if (time_after(jiffies, sta->last_rx +
			       IEEE80211_IBSS_INACTIVITY_LIMIT)) {
			printk(KERN_DEBUG "%s: expiring inactive STA %s\n",
			       dev->name, print_mac(mac, sta->addr));
			__sta_info_get(sta);
			sta_info_remove(sta);
			list_add(&sta->list, &tmp_list);
		}
	write_unlock_bh(&local->sta_lock);

	list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
		sta_info_free(sta);
		sta_info_put(sta);
	}
}


static void ieee80211_sta_merge_ibss(struct net_device *dev,
				     struct ieee80211_if_sta *ifsta)
{
	mod_timer(&ifsta->timer, jiffies + IEEE80211_IBSS_MERGE_INTERVAL);

	ieee80211_sta_expire(dev);
	if (ieee80211_sta_active_ibss(dev))
		return;

	printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
	       "IBSS networks with same SSID (merge)\n", dev->name);
	ieee80211_sta_req_scan(dev, ifsta->ssid, ifsta->ssid_len);
}


void ieee80211_sta_timer(unsigned long data)
{
	struct ieee80211_sub_if_data *sdata =
		(struct ieee80211_sub_if_data *) data;
	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
	struct ieee80211_local *local = wdev_priv(&sdata->wdev);

	set_bit(IEEE80211_STA_REQ_RUN, &ifsta->request);
	queue_work(local->hw.workqueue, &ifsta->work);
}


void ieee80211_sta_work(struct work_struct *work)
{
	struct ieee80211_sub_if_data *sdata =
		container_of(work, struct ieee80211_sub_if_data, u.sta.work);
	struct net_device *dev = sdata->dev;
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_if_sta *ifsta;
	struct sk_buff *skb;

	if (!netif_running(dev))
		return;

	if (local->sta_scanning)
		return;

	if (sdata->type != IEEE80211_IF_TYPE_STA &&
	    sdata->type != IEEE80211_IF_TYPE_IBSS) {
		printk(KERN_DEBUG "%s: ieee80211_sta_work: non-STA interface "
		       "(type=%d)\n", dev->name, sdata->type);
		return;
	}
	ifsta = &sdata->u.sta;

	while ((skb = skb_dequeue(&ifsta->skb_queue)))
		ieee80211_sta_rx_queued_mgmt(dev, skb);

	if (ifsta->state != IEEE80211_AUTHENTICATE &&
	    ifsta->state != IEEE80211_ASSOCIATE &&
	    test_and_clear_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request)) {
		if (ifsta->scan_ssid_len)
			ieee80211_sta_start_scan(dev, ifsta->scan_ssid, ifsta->scan_ssid_len);
		else
			ieee80211_sta_start_scan(dev, NULL, 0);
		return;
	}

	if (test_and_clear_bit(IEEE80211_STA_REQ_AUTH, &ifsta->request)) {
		if (ieee80211_sta_config_auth(dev, ifsta))
			return;
		clear_bit(IEEE80211_STA_REQ_RUN, &ifsta->request);
	} else if (!test_and_clear_bit(IEEE80211_STA_REQ_RUN, &ifsta->request))
		return;

	switch (ifsta->state) {
	case IEEE80211_DISABLED:
		break;
	case IEEE80211_AUTHENTICATE:
		ieee80211_authenticate(dev, ifsta);
		break;
	case IEEE80211_ASSOCIATE:
		ieee80211_associate(dev, ifsta);
		break;
	case IEEE80211_ASSOCIATED:
		ieee80211_associated(dev, ifsta);
		break;
	case IEEE80211_IBSS_SEARCH:
		ieee80211_sta_find_ibss(dev, ifsta);
		break;
	case IEEE80211_IBSS_JOINED:
		ieee80211_sta_merge_ibss(dev, ifsta);
		break;
	default:
		printk(KERN_DEBUG "ieee80211_sta_work: Unknown state %d\n",
		       ifsta->state);
		break;
	}

	if (ieee80211_privacy_mismatch(dev, ifsta)) {
		printk(KERN_DEBUG "%s: privacy configuration mismatch and "
		       "mixed-cell disabled - disassociate\n", dev->name);

		ieee80211_send_disassoc(dev, ifsta, WLAN_REASON_UNSPECIFIED);
		ieee80211_set_disassoc(dev, ifsta, 0);
	}
}


static void ieee80211_sta_reset_auth(struct net_device *dev,
				     struct ieee80211_if_sta *ifsta)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);

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

	ifsta->wmm_last_param_set = -1; /* allow any WMM update */


	if (ifsta->auth_algs & IEEE80211_AUTH_ALG_OPEN)
		ifsta->auth_alg = WLAN_AUTH_OPEN;
	else if (ifsta->auth_algs & IEEE80211_AUTH_ALG_SHARED_KEY)
		ifsta->auth_alg = WLAN_AUTH_SHARED_KEY;
	else if (ifsta->auth_algs & IEEE80211_AUTH_ALG_LEAP)
		ifsta->auth_alg = WLAN_AUTH_LEAP;
	else
		ifsta->auth_alg = WLAN_AUTH_OPEN;
	printk(KERN_DEBUG "%s: Initial auth_alg=%d\n", dev->name,
	       ifsta->auth_alg);
	ifsta->auth_transaction = -1;
	ifsta->flags &= ~IEEE80211_STA_ASSOCIATED;
	ifsta->auth_tries = ifsta->assoc_tries = 0;
	netif_carrier_off(dev);
}


void ieee80211_sta_req_auth(struct net_device *dev,
			    struct ieee80211_if_sta *ifsta)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	if (sdata->type != IEEE80211_IF_TYPE_STA)
		return;

	if ((ifsta->flags & (IEEE80211_STA_BSSID_SET |
				IEEE80211_STA_AUTO_BSSID_SEL)) &&
	    (ifsta->flags & (IEEE80211_STA_SSID_SET |
				IEEE80211_STA_AUTO_SSID_SEL))) {
		set_bit(IEEE80211_STA_REQ_AUTH, &ifsta->request);
		queue_work(local->hw.workqueue, &ifsta->work);
	}
}

static int ieee80211_sta_match_ssid(struct ieee80211_if_sta *ifsta,
				    const char *ssid, int ssid_len)
{
	int tmp, hidden_ssid;

	if (ssid_len == ifsta->ssid_len &&
	    !memcmp(ifsta->ssid, ssid, ssid_len))
		return 1;

	if (ifsta->flags & IEEE80211_STA_AUTO_BSSID_SEL)
		return 0;

	hidden_ssid = 1;
	tmp = ssid_len;
	while (tmp--) {
		if (ssid[tmp] != '\0') {
			hidden_ssid = 0;
			break;
		}
	}

	if (hidden_ssid && ifsta->ssid_len == ssid_len)
		return 1;

	if (ssid_len == 1 && ssid[0] == ' ')
		return 1;

	return 0;
}

static int ieee80211_sta_config_auth(struct net_device *dev,
				     struct ieee80211_if_sta *ifsta)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_sta_bss *bss, *selected = NULL;
	int top_rssi = 0, freq;

	if (!(ifsta->flags & (IEEE80211_STA_AUTO_SSID_SEL |
	    IEEE80211_STA_AUTO_BSSID_SEL | IEEE80211_STA_AUTO_CHANNEL_SEL))) {
		ifsta->state = IEEE80211_AUTHENTICATE;
		ieee80211_sta_reset_auth(dev, ifsta);
		return 0;
	}

	spin_lock_bh(&local->sta_bss_lock);
	freq = local->oper_channel->freq;
	list_for_each_entry(bss, &local->sta_bss_list, list) {
		if (!(bss->capability & WLAN_CAPABILITY_ESS))
			continue;

		if (!!(bss->capability & WLAN_CAPABILITY_PRIVACY) ^
		    !!sdata->default_key)
			continue;

		if (!(ifsta->flags & IEEE80211_STA_AUTO_CHANNEL_SEL) &&
		    bss->freq != freq)
			continue;

		if (!(ifsta->flags & IEEE80211_STA_AUTO_BSSID_SEL) &&
		    memcmp(bss->bssid, ifsta->bssid, ETH_ALEN))
			continue;

		if (!(ifsta->flags & IEEE80211_STA_AUTO_SSID_SEL) &&
		    !ieee80211_sta_match_ssid(ifsta, bss->ssid, bss->ssid_len))
			continue;

		if (!selected || top_rssi < bss->rssi) {
			selected = bss;
			top_rssi = bss->rssi;
		}
	}
	if (selected)
		atomic_inc(&selected->users);
	spin_unlock_bh(&local->sta_bss_lock);

	if (selected) {
		ieee80211_set_channel(local, -1, selected->freq);
		if (!(ifsta->flags & IEEE80211_STA_SSID_SET))
			ieee80211_sta_set_ssid(dev, selected->ssid,
					       selected->ssid_len);
		ieee80211_sta_set_bssid(dev, selected->bssid);
		ieee80211_rx_bss_put(dev, selected);
		ifsta->state = IEEE80211_AUTHENTICATE;
		ieee80211_sta_reset_auth(dev, ifsta);
		return 0;
	} else {
		if (ifsta->state != IEEE80211_AUTHENTICATE) {
			if (ifsta->flags & IEEE80211_STA_AUTO_SSID_SEL)
				ieee80211_sta_start_scan(dev, NULL, 0);
			else
				ieee80211_sta_start_scan(dev, ifsta->ssid,
							 ifsta->ssid_len);
			ifsta->state = IEEE80211_AUTHENTICATE;
			set_bit(IEEE80211_STA_REQ_AUTH, &ifsta->request);
		} else
			ifsta->state = IEEE80211_DISABLED;
	}
	return -1;
}

static int ieee80211_sta_join_ibss(struct net_device *dev,
				   struct ieee80211_if_sta *ifsta,
				   struct ieee80211_sta_bss *bss)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	int res, rates, i, j;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	struct ieee80211_tx_control control;
	struct ieee80211_rate *rate;
	struct ieee80211_hw_mode *mode;
	struct rate_control_extra extra;
	u8 *pos;
	struct ieee80211_sub_if_data *sdata;

	/* Remove possible STA entries from other IBSS networks. */
	sta_info_flush(local, NULL);

	if (local->ops->reset_tsf) {
		/* Reset own TSF to allow time synchronization work. */
		local->ops->reset_tsf(local_to_hw(local));
	}
	memcpy(ifsta->bssid, bss->bssid, ETH_ALEN);
	res = ieee80211_if_config(dev);
	if (res)
		return res;

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

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	sdata->drop_unencrypted = bss->capability &
		WLAN_CAPABILITY_PRIVACY ? 1 : 0;

	res = ieee80211_set_channel(local, -1, bss->freq);

	if (!(local->oper_channel->flag & IEEE80211_CHAN_W_IBSS)) {
		printk(KERN_DEBUG "%s: IBSS not allowed on channel %d "
		       "(%d MHz)\n", dev->name, local->hw.conf.channel,
		       local->hw.conf.freq);
		return -1;
	}

	/* Set beacon template based on scan results */
	skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
	do {
		if (!skb)
			break;

		skb_reserve(skb, local->hw.extra_tx_headroom);

		mgmt = (struct ieee80211_mgmt *)
			skb_put(skb, 24 + sizeof(mgmt->u.beacon));
		memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
		mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
						   IEEE80211_STYPE_BEACON);
		memset(mgmt->da, 0xff, ETH_ALEN);
		memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
		memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
		mgmt->u.beacon.beacon_int =
			cpu_to_le16(local->hw.conf.beacon_int);
		mgmt->u.beacon.capab_info = cpu_to_le16(bss->capability);

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

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

		pos = skb_put(skb, 2 + 1);
		*pos++ = WLAN_EID_DS_PARAMS;
		*pos++ = 1;
		*pos++ = bss->channel;

		pos = skb_put(skb, 2 + 2);
		*pos++ = WLAN_EID_IBSS_PARAMS;
		*pos++ = 2;
		/* FIX: set ATIM window based on scan results */
		*pos++ = 0;
		*pos++ = 0;

		if (bss->supp_rates_len > 8) {
			rates = bss->supp_rates_len - 8;
			pos = skb_put(skb, 2 + rates);
			*pos++ = WLAN_EID_EXT_SUPP_RATES;
			*pos++ = rates;
			memcpy(pos, &bss->supp_rates[8], rates);
		}

		memset(&control, 0, sizeof(control));
		memset(&extra, 0, sizeof(extra));
		extra.mode = local->oper_hw_mode;
		rate = rate_control_get_rate(local, dev, skb, &extra);
		if (!rate) {
			printk(KERN_DEBUG "%s: Failed to determine TX rate "
			       "for IBSS beacon\n", dev->name);
			break;
		}
		control.tx_rate =
			((sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE) &&
			(rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
			rate->val2 : rate->val;
		control.antenna_sel_tx = local->hw.conf.antenna_sel_tx;
		control.power_level = local->hw.conf.power_level;
		control.flags |= IEEE80211_TXCTL_NO_ACK;
		control.retry_limit = 1;

		ifsta->probe_resp = skb_copy(skb, GFP_ATOMIC);
		if (ifsta->probe_resp) {
			mgmt = (struct ieee80211_mgmt *)
				ifsta->probe_resp->data;
			mgmt->frame_control =
				IEEE80211_FC(IEEE80211_FTYPE_MGMT,
					     IEEE80211_STYPE_PROBE_RESP);
		} else {
			printk(KERN_DEBUG "%s: Could not allocate ProbeResp "
			       "template for IBSS\n", dev->name);
		}

		if (local->ops->beacon_update &&
		    local->ops->beacon_update(local_to_hw(local),
					     skb, &control) == 0) {
			printk(KERN_DEBUG "%s: Configured IBSS beacon "
			       "template based on scan results\n", dev->name);
			skb = NULL;
		}

		rates = 0;
		mode = local->oper_hw_mode;
		for (i = 0; i < bss->supp_rates_len; i++) {
			int bitrate = (bss->supp_rates[i] & 0x7f) * 5;
			for (j = 0; j < mode->num_rates; j++)
				if (mode->rates[j].rate == bitrate)
					rates |= BIT(j);
		}
		ifsta->supp_rates_bits = rates;
	} while (0);

	if (skb) {
		printk(KERN_DEBUG "%s: Failed to configure IBSS beacon "
		       "template\n", dev->name);
		dev_kfree_skb(skb);
	}

	ifsta->state = IEEE80211_IBSS_JOINED;
	mod_timer(&ifsta->timer, jiffies + IEEE80211_IBSS_MERGE_INTERVAL);

	ieee80211_rx_bss_put