ieee80211_sta.c

linux 内核源代码

	list_for_each_entry_safe(bss, tmp, &local->sta_bss_list, list)
		ieee80211_rx_bss_put(dev, bss);
}


static void ieee80211_rx_bss_info(struct net_device *dev,
				  struct ieee80211_mgmt *mgmt,
				  size_t len,
				  struct ieee80211_rx_status *rx_status,
				  int beacon)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee802_11_elems elems;
	size_t baselen;
	int channel, clen;
	struct ieee80211_sta_bss *bss;
	struct sta_info *sta;
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	u64 timestamp;
	DECLARE_MAC_BUF(mac);
	DECLARE_MAC_BUF(mac2);

	if (!beacon && memcmp(mgmt->da, dev->dev_addr, ETH_ALEN))
		return; /* ignore ProbeResp to foreign address */

#if 0
	printk(KERN_DEBUG "%s: RX %s from %s to %s\n",
	       dev->name, beacon ? "Beacon" : "Probe Response",
	       print_mac(mac, mgmt->sa), print_mac(mac2, mgmt->da));
#endif

	baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
	if (baselen > len)
		return;

	timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);

	if (sdata->type == IEEE80211_IF_TYPE_IBSS && beacon &&
	    memcmp(mgmt->bssid, sdata->u.sta.bssid, ETH_ALEN) == 0) {
#ifdef CONFIG_MAC80211_IBSS_DEBUG
		static unsigned long last_tsf_debug = 0;
		u64 tsf;
		if (local->ops->get_tsf)
			tsf = local->ops->get_tsf(local_to_hw(local));
		else
			tsf = -1LLU;
		if (time_after(jiffies, last_tsf_debug + 5 * HZ)) {
			printk(KERN_DEBUG "RX beacon SA=%s BSSID="
			       "%s TSF=0x%llx BCN=0x%llx diff=%lld "
			       "@%lu\n",
			       print_mac(mac, mgmt->sa), print_mac(mac2, mgmt->bssid),
			       (unsigned long long)tsf,
			       (unsigned long long)timestamp,
			       (unsigned long long)(tsf - timestamp),
			       jiffies);
			last_tsf_debug = jiffies;
		}
#endif /* CONFIG_MAC80211_IBSS_DEBUG */
	}

	ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);

	if (sdata->type == IEEE80211_IF_TYPE_IBSS && elems.supp_rates &&
	    memcmp(mgmt->bssid, sdata->u.sta.bssid, ETH_ALEN) == 0 &&
	    (sta = sta_info_get(local, mgmt->sa))) {
		struct ieee80211_hw_mode *mode;
		struct ieee80211_rate *rates;
		size_t num_rates;
		u32 supp_rates, prev_rates;
		int i, j;

		mode = local->sta_scanning ?
		       local->scan_hw_mode : local->oper_hw_mode;
		rates = mode->rates;
		num_rates = mode->num_rates;

		supp_rates = 0;
		for (i = 0; i < elems.supp_rates_len +
			     elems.ext_supp_rates_len; i++) {
			u8 rate = 0;
			int own_rate;
			if (i < elems.supp_rates_len)
				rate = elems.supp_rates[i];
			else if (elems.ext_supp_rates)
				rate = elems.ext_supp_rates
					[i - elems.supp_rates_len];
			own_rate = 5 * (rate & 0x7f);
			for (j = 0; j < num_rates; j++)
				if (rates[j].rate == own_rate)
					supp_rates |= BIT(j);
		}

		prev_rates = sta->supp_rates;
		sta->supp_rates &= supp_rates;
		if (sta->supp_rates == 0) {
			/* No matching rates - this should not really happen.
			 * Make sure that at least one rate is marked
			 * supported to avoid issues with TX rate ctrl. */
			sta->supp_rates = sdata->u.sta.supp_rates_bits;
		}
		if (sta->supp_rates != prev_rates) {
			printk(KERN_DEBUG "%s: updated supp_rates set for "
			       "%s based on beacon info (0x%x & 0x%x -> "
			       "0x%x)\n",
			       dev->name, print_mac(mac, sta->addr), prev_rates,
			       supp_rates, sta->supp_rates);
		}
		sta_info_put(sta);
	}

	if (!elems.ssid)
		return;

	if (elems.ds_params && elems.ds_params_len == 1)
		channel = elems.ds_params[0];
	else
		channel = rx_status->channel;

	bss = ieee80211_rx_bss_get(dev, mgmt->bssid, channel,
				   elems.ssid, elems.ssid_len);
	if (!bss) {
		bss = ieee80211_rx_bss_add(dev, mgmt->bssid, channel,
					   elems.ssid, elems.ssid_len);
		if (!bss)
			return;
	} else {
#if 0
		/* TODO: order by RSSI? */
		spin_lock_bh(&local->sta_bss_lock);
		list_move_tail(&bss->list, &local->sta_bss_list);
		spin_unlock_bh(&local->sta_bss_lock);
#endif
	}

	if (bss->probe_resp && beacon) {
		/* Do not allow beacon to override data from Probe Response. */
		ieee80211_rx_bss_put(dev, bss);
		return;
	}

	/* save the ERP value so that it is available at association time */
	if (elems.erp_info && elems.erp_info_len >= 1) {
		bss->erp_value = elems.erp_info[0];
		bss->has_erp_value = 1;
	}

	bss->beacon_int = le16_to_cpu(mgmt->u.beacon.beacon_int);
	bss->capability = le16_to_cpu(mgmt->u.beacon.capab_info);

	bss->supp_rates_len = 0;
	if (elems.supp_rates) {
		clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
		if (clen > elems.supp_rates_len)
			clen = elems.supp_rates_len;
		memcpy(&bss->supp_rates[bss->supp_rates_len], elems.supp_rates,
		       clen);
		bss->supp_rates_len += clen;
	}
	if (elems.ext_supp_rates) {
		clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
		if (clen > elems.ext_supp_rates_len)
			clen = elems.ext_supp_rates_len;
		memcpy(&bss->supp_rates[bss->supp_rates_len],
		       elems.ext_supp_rates, clen);
		bss->supp_rates_len += clen;
	}

	if (elems.wpa &&
	    (!bss->wpa_ie || bss->wpa_ie_len != elems.wpa_len ||
	     memcmp(bss->wpa_ie, elems.wpa, elems.wpa_len))) {
		kfree(bss->wpa_ie);
		bss->wpa_ie = kmalloc(elems.wpa_len + 2, GFP_ATOMIC);
		if (bss->wpa_ie) {
			memcpy(bss->wpa_ie, elems.wpa - 2, elems.wpa_len + 2);
			bss->wpa_ie_len = elems.wpa_len + 2;
		} else
			bss->wpa_ie_len = 0;
	} else if (!elems.wpa && bss->wpa_ie) {
		kfree(bss->wpa_ie);
		bss->wpa_ie = NULL;
		bss->wpa_ie_len = 0;
	}

	if (elems.rsn &&
	    (!bss->rsn_ie || bss->rsn_ie_len != elems.rsn_len ||
	     memcmp(bss->rsn_ie, elems.rsn, elems.rsn_len))) {
		kfree(bss->rsn_ie);
		bss->rsn_ie = kmalloc(elems.rsn_len + 2, GFP_ATOMIC);
		if (bss->rsn_ie) {
			memcpy(bss->rsn_ie, elems.rsn - 2, elems.rsn_len + 2);
			bss->rsn_ie_len = elems.rsn_len + 2;
		} else
			bss->rsn_ie_len = 0;
	} else if (!elems.rsn && bss->rsn_ie) {
		kfree(bss->rsn_ie);
		bss->rsn_ie = NULL;
		bss->rsn_ie_len = 0;
	}

	if (elems.wmm_param &&
	    (!bss->wmm_ie || bss->wmm_ie_len != elems.wmm_param_len ||
	     memcmp(bss->wmm_ie, elems.wmm_param, elems.wmm_param_len))) {
		kfree(bss->wmm_ie);
		bss->wmm_ie = kmalloc(elems.wmm_param_len + 2, GFP_ATOMIC);
		if (bss->wmm_ie) {
			memcpy(bss->wmm_ie, elems.wmm_param - 2,
			       elems.wmm_param_len + 2);
			bss->wmm_ie_len = elems.wmm_param_len + 2;
		} else
			bss->wmm_ie_len = 0;
	} else if (!elems.wmm_param && bss->wmm_ie) {
		kfree(bss->wmm_ie);
		bss->wmm_ie = NULL;
		bss->wmm_ie_len = 0;
	}


	bss->hw_mode = rx_status->phymode;
	bss->freq = rx_status->freq;
	if (channel != rx_status->channel &&
	    (bss->hw_mode == MODE_IEEE80211G ||
	     bss->hw_mode == MODE_IEEE80211B) &&
	    channel >= 1 && channel <= 14) {
		static const int freq_list[] = {
			2412, 2417, 2422, 2427, 2432, 2437, 2442,
			2447, 2452, 2457, 2462, 2467, 2472, 2484
		};
		/* IEEE 802.11g/b mode can receive packets from neighboring
		 * channels, so map the channel into frequency. */
		bss->freq = freq_list[channel - 1];
	}
	bss->timestamp = timestamp;
	bss->last_update = jiffies;
	bss->rssi = rx_status->ssi;
	bss->signal = rx_status->signal;
	bss->noise = rx_status->noise;
	if (!beacon)
		bss->probe_resp++;
	ieee80211_rx_bss_put(dev, bss);
}


static void ieee80211_rx_mgmt_probe_resp(struct net_device *dev,
					 struct ieee80211_mgmt *mgmt,
					 size_t len,
					 struct ieee80211_rx_status *rx_status)
{
	ieee80211_rx_bss_info(dev, mgmt, len, rx_status, 0);
}


static void ieee80211_rx_mgmt_beacon(struct net_device *dev,
				     struct ieee80211_mgmt *mgmt,
				     size_t len,
				     struct ieee80211_rx_status *rx_status)
{
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_sta *ifsta;
	size_t baselen;
	struct ieee802_11_elems elems;

	ieee80211_rx_bss_info(dev, mgmt, len, rx_status, 1);

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	if (sdata->type != IEEE80211_IF_TYPE_STA)
		return;
	ifsta = &sdata->u.sta;

	if (!(ifsta->flags & IEEE80211_STA_ASSOCIATED) ||
	    memcmp(ifsta->bssid, mgmt->bssid, ETH_ALEN) != 0)
		return;

	/* Process beacon from the current BSS */
	baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
	if (baselen > len)
		return;

	ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);

	if (elems.erp_info && elems.erp_info_len >= 1)
		ieee80211_handle_erp_ie(dev, elems.erp_info[0]);

	if (elems.wmm_param && (ifsta->flags & IEEE80211_STA_WMM_ENABLED)) {
		ieee80211_sta_wmm_params(dev, ifsta, elems.wmm_param,
					 elems.wmm_param_len);
	}
}


static void ieee80211_rx_mgmt_probe_req(struct net_device *dev,
					struct ieee80211_if_sta *ifsta,
					struct ieee80211_mgmt *mgmt,
					size_t len,
					struct ieee80211_rx_status *rx_status)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	int tx_last_beacon;
	struct sk_buff *skb;
	struct ieee80211_mgmt *resp;
	u8 *pos, *end;
	DECLARE_MAC_BUF(mac);
#ifdef CONFIG_MAC80211_IBSS_DEBUG
	DECLARE_MAC_BUF(mac2);
	DECLARE_MAC_BUF(mac3);
#endif

	if (sdata->type != IEEE80211_IF_TYPE_IBSS ||
	    ifsta->state != IEEE80211_IBSS_JOINED ||
	    len < 24 + 2 || !ifsta->probe_resp)
		return;

	if (local->ops->tx_last_beacon)
		tx_last_beacon = local->ops->tx_last_beacon(local_to_hw(local));
	else
		tx_last_beacon = 1;

#ifdef CONFIG_MAC80211_IBSS_DEBUG
	printk(KERN_DEBUG "%s: RX ProbeReq SA=%s DA=%s BSSID="
	       "%s (tx_last_beacon=%d)\n",
	       dev->name, print_mac(mac, mgmt->sa), print_mac(mac2, mgmt->da),
	       print_mac(mac3, mgmt->bssid), tx_last_beacon);
#endif /* CONFIG_MAC80211_IBSS_DEBUG */

	if (!tx_last_beacon)
		return;

	if (memcmp(mgmt->bssid, ifsta->bssid, ETH_ALEN) != 0 &&
	    memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
		return;

	end = ((u8 *) mgmt) + len;
	pos = mgmt->u.probe_req.variable;
	if (pos[0] != WLAN_EID_SSID ||
	    pos + 2 + pos[1] > end) {
		if (net_ratelimit()) {
			printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
			       "from %s\n",
			       dev->name, print_mac(mac, mgmt->sa));
		}
		return;
	}
	if (pos[1] != 0 &&
	    (pos[1] != ifsta->ssid_len ||
	     memcmp(pos + 2, ifsta->ssid, ifsta->ssid_len) != 0)) {
		/* Ignore ProbeReq for foreign SSID */
		return;
	}

	/* Reply with ProbeResp */
	skb = skb_copy(ifsta->probe_resp, GFP_KERNEL);
	if (!skb)
		return;

	resp = (struct ieee80211_mgmt *) skb->data;
	memcpy(resp->da, mgmt->sa, ETH_ALEN);
#ifdef CONFIG_MAC80211_IBSS_DEBUG
	printk(KERN_DEBUG "%s: Sending ProbeResp to %s\n",
	       dev->name, print_mac(mac, resp->da));
#endif /* CONFIG_MAC80211_IBSS_DEBUG */
	ieee80211_sta_tx(dev, skb, 0);
}


void ieee80211_sta_rx_mgmt(struct net_device *dev, struct sk_buff *skb,
			   struct ieee80211_rx_status *rx_status)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_sta *ifsta;
	struct ieee80211_mgmt *mgmt;
	u16 fc;

	if (skb->len < 24)
		goto fail;

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	ifsta = &sdata->u.sta;

	mgmt = (struct ieee80211_mgmt *) skb->data;
	fc = le16_to_cpu(mgmt->frame_control);

	switch (fc & IEEE80211_FCTL_STYPE) {
	case IEEE80211_STYPE_PROBE_REQ:
	case IEEE80211_STYPE_PROBE_RESP:
	case IEEE80211_STYPE_BEACON:
		memcpy(skb->cb, rx_status, sizeof(*rx_status));
	case IEEE80211_STYPE_AUTH:
	case IEEE80211_STYPE_ASSOC_RESP:
	case IEEE80211_STYPE_REASSOC_RESP:
	case IEEE80211_STYPE_DEAUTH:
	case IEEE80211_STYPE_DISASSOC:
		skb_queue_tail(&ifsta->skb_queue, skb);
		queue_work(local->hw.workqueue, &ifsta->work);
		return;
	default:
		printk(KERN_DEBUG "%s: received unknown management frame - "
		       "stype=%d\n", dev->name,
		       (fc & IEEE80211_FCTL_STYPE) >> 4);
		break;
	}

 fail:
	kfree_skb(skb);
}


static void ieee80211_sta_rx_queued_mgmt(struct net_device *dev,
					 struct sk_buff *skb)
{
	struct ieee80211_rx_status *rx_status;
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_sta *ifsta;
	struct ieee80211_mgmt *mgmt;
	u16 fc;

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	ifsta = &sdata->u.sta;

	rx_status = (struct ieee80211_rx_status *) skb->cb;
	mgmt = (struct ieee80211_mgmt *) skb->data;
	fc = le16_to_cpu(mgmt->frame_control);

	switch (fc & IEEE80211_FCTL_STYPE) {
	case IEEE80211_STYPE_PROBE_REQ:
		ieee80211_rx_mgmt_probe_req(dev, ifsta, mgmt, skb->len,
					    rx_status);
		break;
	case IEEE80211_STYPE_PROBE_RESP:
		ieee80211_rx_mgmt_probe_resp(dev, mgmt, skb->len, rx_status);
		break;
	case IEEE80211_STYPE_BEACON:
		ieee80211_rx_mgmt_beacon(dev, mgmt, skb->len, rx_status);
		break;
	case IEEE80211_STYPE_AUTH:
		ieee80211_rx_mgmt_auth(dev, ifsta, mgmt, skb->len);
		break;
	case IEEE80211_STYPE_ASSOC_RESP:
		ieee80211_rx_mgmt_assoc_resp(dev, ifsta, mgmt, skb->len, 0);
		break;
	case IEEE80211_STYPE_REASSOC_RESP:
		ieee80211_rx_mgmt_assoc_resp(dev, ifsta, mgmt, skb->len, 1);
		break;
	case IEEE80211_STYPE_DEAUTH:
		ieee80211_rx_mgmt_deauth(dev, ifsta, mgmt, skb->len);
		break;
	case IEEE80211_STYPE_DISASSOC:
		ieee80211_rx_mgmt_disassoc(dev, ifsta, mgmt, skb->len);
		break;
	}

	kfree_skb(skb);
}


void ieee80211_sta_rx_scan(struct net_device *dev, struct sk_buff *skb,
			   struct ieee80211_rx_status *rx_status)
{
	struct ieee80211_mgmt *mgmt;
	u16 fc;

	if (skb->len < 24) {
		dev_kfree_skb(skb);
		return;
	}

	mgmt = (struct ieee80211_mgmt *) skb->data;
	fc = le16_to_cpu(mgmt->frame_control);

	if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT) {