ieee80211_rx.c

linux 内核源代码

	network->listen_interval = le16_to_cpu(frame->status);
	memcpy(network->bssid, frame->header.addr3, ETH_ALEN);
	network->capability = le16_to_cpu(frame->capability);
	network->last_scanned = jiffies;
	network->rates_len = network->rates_ex_len = 0;
	network->last_associate = 0;
	network->ssid_len = 0;
	network->erp_value =
	    (network->capability & WLAN_CAPABILITY_IBSS) ? 0x3 : 0x0;

	if (stats->freq == IEEE80211_52GHZ_BAND) {
		/* for A band (No DS info) */
		network->channel = stats->received_channel;
	} else
		network->flags |= NETWORK_HAS_CCK;

	network->wpa_ie_len = 0;
	network->rsn_ie_len = 0;

	if (ieee80211_parse_info_param
	    (frame->info_element, stats->len - sizeof(*frame), network))
		return 1;

	network->mode = 0;
	if (stats->freq == IEEE80211_52GHZ_BAND)
		network->mode = IEEE_A;
	else {
		if (network->flags & NETWORK_HAS_OFDM)
			network->mode |= IEEE_G;
		if (network->flags & NETWORK_HAS_CCK)
			network->mode |= IEEE_B;
	}

	if (ieee80211_is_empty_essid(network->ssid, network->ssid_len))
		network->flags |= NETWORK_EMPTY_ESSID;

	memcpy(&network->stats, stats, sizeof(network->stats));

	if (ieee->handle_assoc_response != NULL)
		ieee->handle_assoc_response(dev, frame, network);

	return 0;
}

/***************************************************/

static int ieee80211_network_init(struct ieee80211_device *ieee, struct ieee80211_probe_response
					 *beacon,
					 struct ieee80211_network *network,
					 struct ieee80211_rx_stats *stats)
{
	DECLARE_MAC_BUF(mac);

	network->qos_data.active = 0;
	network->qos_data.supported = 0;
	network->qos_data.param_count = 0;
	network->qos_data.old_param_count = 0;

	/* Pull out fixed field data */
	memcpy(network->bssid, beacon->header.addr3, ETH_ALEN);
	network->capability = le16_to_cpu(beacon->capability);
	network->last_scanned = jiffies;
	network->time_stamp[0] = le32_to_cpu(beacon->time_stamp[0]);
	network->time_stamp[1] = le32_to_cpu(beacon->time_stamp[1]);
	network->beacon_interval = le16_to_cpu(beacon->beacon_interval);
	/* Where to pull this? beacon->listen_interval; */
	network->listen_interval = 0x0A;
	network->rates_len = network->rates_ex_len = 0;
	network->last_associate = 0;
	network->ssid_len = 0;
	network->flags = 0;
	network->atim_window = 0;
	network->erp_value = (network->capability & WLAN_CAPABILITY_IBSS) ?
	    0x3 : 0x0;

	if (stats->freq == IEEE80211_52GHZ_BAND) {
		/* for A band (No DS info) */
		network->channel = stats->received_channel;
	} else
		network->flags |= NETWORK_HAS_CCK;

	network->wpa_ie_len = 0;
	network->rsn_ie_len = 0;

	if (ieee80211_parse_info_param
	    (beacon->info_element, stats->len - sizeof(*beacon), network))
		return 1;

	network->mode = 0;
	if (stats->freq == IEEE80211_52GHZ_BAND)
		network->mode = IEEE_A;
	else {
		if (network->flags & NETWORK_HAS_OFDM)
			network->mode |= IEEE_G;
		if (network->flags & NETWORK_HAS_CCK)
			network->mode |= IEEE_B;
	}

	if (network->mode == 0) {
		IEEE80211_DEBUG_SCAN("Filtered out '%s (%s)' "
				     "network.\n",
				     escape_essid(network->ssid,
						  network->ssid_len),
				     print_mac(mac, network->bssid));
		return 1;
	}

	if (ieee80211_is_empty_essid(network->ssid, network->ssid_len))
		network->flags |= NETWORK_EMPTY_ESSID;

	memcpy(&network->stats, stats, sizeof(network->stats));

	return 0;
}

static inline int is_same_network(struct ieee80211_network *src,
				  struct ieee80211_network *dst)
{
	/* A network is only a duplicate if the channel, BSSID, and ESSID
	 * all match.  We treat all <hidden> with the same BSSID and channel
	 * as one network */
	return ((src->ssid_len == dst->ssid_len) &&
		(src->channel == dst->channel) &&
		!compare_ether_addr(src->bssid, dst->bssid) &&
		!memcmp(src->ssid, dst->ssid, src->ssid_len));
}

static void update_network(struct ieee80211_network *dst,
				  struct ieee80211_network *src)
{
	int qos_active;
	u8 old_param;
	DECLARE_MAC_BUF(mac);

	ieee80211_network_reset(dst);
	dst->ibss_dfs = src->ibss_dfs;

	/* We only update the statistics if they were created by receiving
	 * the network information on the actual channel the network is on.
	 *
	 * This keeps beacons received on neighbor channels from bringing
	 * down the signal level of an AP. */
	if (dst->channel == src->stats.received_channel)
		memcpy(&dst->stats, &src->stats,
		       sizeof(struct ieee80211_rx_stats));
	else
		IEEE80211_DEBUG_SCAN("Network %s info received "
			"off channel (%d vs. %d)\n", print_mac(mac, src->bssid),
			dst->channel, src->stats.received_channel);

	dst->capability = src->capability;
	memcpy(dst->rates, src->rates, src->rates_len);
	dst->rates_len = src->rates_len;
	memcpy(dst->rates_ex, src->rates_ex, src->rates_ex_len);
	dst->rates_ex_len = src->rates_ex_len;

	dst->mode = src->mode;
	dst->flags = src->flags;
	dst->time_stamp[0] = src->time_stamp[0];
	dst->time_stamp[1] = src->time_stamp[1];

	dst->beacon_interval = src->beacon_interval;
	dst->listen_interval = src->listen_interval;
	dst->atim_window = src->atim_window;
	dst->erp_value = src->erp_value;
	dst->tim = src->tim;

	memcpy(dst->wpa_ie, src->wpa_ie, src->wpa_ie_len);
	dst->wpa_ie_len = src->wpa_ie_len;
	memcpy(dst->rsn_ie, src->rsn_ie, src->rsn_ie_len);
	dst->rsn_ie_len = src->rsn_ie_len;

	dst->last_scanned = jiffies;
	qos_active = src->qos_data.active;
	old_param = dst->qos_data.old_param_count;
	if (dst->flags & NETWORK_HAS_QOS_MASK)
		memcpy(&dst->qos_data, &src->qos_data,
		       sizeof(struct ieee80211_qos_data));
	else {
		dst->qos_data.supported = src->qos_data.supported;
		dst->qos_data.param_count = src->qos_data.param_count;
	}

	if (dst->qos_data.supported == 1) {
		if (dst->ssid_len)
			IEEE80211_DEBUG_QOS
			    ("QoS the network %s is QoS supported\n",
			     dst->ssid);
		else
			IEEE80211_DEBUG_QOS
			    ("QoS the network is QoS supported\n");
	}
	dst->qos_data.active = qos_active;
	dst->qos_data.old_param_count = old_param;

	/* dst->last_associate is not overwritten */
}

static inline int is_beacon(__le16 fc)
{
	return (WLAN_FC_GET_STYPE(le16_to_cpu(fc)) == IEEE80211_STYPE_BEACON);
}

static void ieee80211_process_probe_response(struct ieee80211_device
						    *ieee, struct
						    ieee80211_probe_response
						    *beacon, struct ieee80211_rx_stats
						    *stats)
{
	struct net_device *dev = ieee->dev;
	struct ieee80211_network network = {
		.ibss_dfs = NULL,
	};
	struct ieee80211_network *target;
	struct ieee80211_network *oldest = NULL;
#ifdef CONFIG_IEEE80211_DEBUG
	struct ieee80211_info_element *info_element = beacon->info_element;
#endif
	unsigned long flags;
	DECLARE_MAC_BUF(mac);

	IEEE80211_DEBUG_SCAN("'%s' (%s"
			     "): %c%c%c%c %c%c%c%c-%c%c%c%c %c%c%c%c\n",
			     escape_essid(info_element->data,
					  info_element->len),
			     print_mac(mac, beacon->header.addr3),
			     (beacon->capability & (1 << 0xf)) ? '1' : '0',
			     (beacon->capability & (1 << 0xe)) ? '1' : '0',
			     (beacon->capability & (1 << 0xd)) ? '1' : '0',
			     (beacon->capability & (1 << 0xc)) ? '1' : '0',
			     (beacon->capability & (1 << 0xb)) ? '1' : '0',
			     (beacon->capability & (1 << 0xa)) ? '1' : '0',
			     (beacon->capability & (1 << 0x9)) ? '1' : '0',
			     (beacon->capability & (1 << 0x8)) ? '1' : '0',
			     (beacon->capability & (1 << 0x7)) ? '1' : '0',
			     (beacon->capability & (1 << 0x6)) ? '1' : '0',
			     (beacon->capability & (1 << 0x5)) ? '1' : '0',
			     (beacon->capability & (1 << 0x4)) ? '1' : '0',
			     (beacon->capability & (1 << 0x3)) ? '1' : '0',
			     (beacon->capability & (1 << 0x2)) ? '1' : '0',
			     (beacon->capability & (1 << 0x1)) ? '1' : '0',
			     (beacon->capability & (1 << 0x0)) ? '1' : '0');

	if (ieee80211_network_init(ieee, beacon, &network, stats)) {
		IEEE80211_DEBUG_SCAN("Dropped '%s' (%s) via %s.\n",
				     escape_essid(info_element->data,
						  info_element->len),
				     print_mac(mac, beacon->header.addr3),
				     is_beacon(beacon->header.frame_ctl) ?
				     "BEACON" : "PROBE RESPONSE");
		return;
	}

	/* The network parsed correctly -- so now we scan our known networks
	 * to see if we can find it in our list.
	 *
	 * NOTE:  This search is definitely not optimized.  Once its doing
	 *        the "right thing" we'll optimize it for efficiency if
	 *        necessary */

	/* Search for this entry in the list and update it if it is
	 * already there. */

	spin_lock_irqsave(&ieee->lock, flags);

	list_for_each_entry(target, &ieee->network_list, list) {
		if (is_same_network(target, &network))
			break;

		if ((oldest == NULL) ||
		    (target->last_scanned < oldest->last_scanned))
			oldest = target;
	}

	/* If we didn't find a match, then get a new network slot to initialize
	 * with this beacon's information */
	if (&target->list == &ieee->network_list) {
		if (list_empty(&ieee->network_free_list)) {
			/* If there are no more slots, expire the oldest */
			list_del(&oldest->list);
			target = oldest;
			IEEE80211_DEBUG_SCAN("Expired '%s' (%s) from "
					     "network list.\n",
					     escape_essid(target->ssid,
							  target->ssid_len),
					     print_mac(mac, target->bssid));
			ieee80211_network_reset(target);
		} else {
			/* Otherwise just pull from the free list */
			target = list_entry(ieee->network_free_list.next,
					    struct ieee80211_network, list);
			list_del(ieee->network_free_list.next);
		}

#ifdef CONFIG_IEEE80211_DEBUG
		IEEE80211_DEBUG_SCAN("Adding '%s' (%s) via %s.\n",
				     escape_essid(network.ssid,
						  network.ssid_len),
				     print_mac(mac, network.bssid),
				     is_beacon(beacon->header.frame_ctl) ?
				     "BEACON" : "PROBE RESPONSE");
#endif
		memcpy(target, &network, sizeof(*target));
		network.ibss_dfs = NULL;
		list_add_tail(&target->list, &ieee->network_list);
	} else {
		IEEE80211_DEBUG_SCAN("Updating '%s' (%s) via %s.\n",
				     escape_essid(target->ssid,
						  target->ssid_len),
				     print_mac(mac, target->bssid),
				     is_beacon(beacon->header.frame_ctl) ?
				     "BEACON" : "PROBE RESPONSE");
		update_network(target, &network);
		network.ibss_dfs = NULL;
	}

	spin_unlock_irqrestore(&ieee->lock, flags);

	if (is_beacon(beacon->header.frame_ctl)) {
		if (ieee->handle_beacon != NULL)
			ieee->handle_beacon(dev, beacon, target);
	} else {
		if (ieee->handle_probe_response != NULL)
			ieee->handle_probe_response(dev, beacon, target);
	}
}

void ieee80211_rx_mgt(struct ieee80211_device *ieee,
		      struct ieee80211_hdr_4addr *header,
		      struct ieee80211_rx_stats *stats)
{
	switch (WLAN_FC_GET_STYPE(le16_to_cpu(header->frame_ctl))) {
	case IEEE80211_STYPE_ASSOC_RESP:
		IEEE80211_DEBUG_MGMT("received ASSOCIATION RESPONSE (%d)\n",
				     WLAN_FC_GET_STYPE(le16_to_cpu
						       (header->frame_ctl)));
		ieee80211_handle_assoc_resp(ieee,
					    (struct ieee80211_assoc_response *)
					    header, stats);
		break;

	case IEEE80211_STYPE_REASSOC_RESP:
		IEEE80211_DEBUG_MGMT("received REASSOCIATION RESPONSE (%d)\n",
				     WLAN_FC_GET_STYPE(le16_to_cpu
						       (header->frame_ctl)));
		break;

	case IEEE80211_STYPE_PROBE_REQ:
		IEEE80211_DEBUG_MGMT("received auth (%d)\n",
				     WLAN_FC_GET_STYPE(le16_to_cpu
						       (header->frame_ctl)));

		if (ieee->handle_probe_request != NULL)
			ieee->handle_probe_request(ieee->dev,
						   (struct
						    ieee80211_probe_request *)
						   header, stats);
		break;

	case IEEE80211_STYPE_PROBE_RESP:
		IEEE80211_DEBUG_MGMT("received PROBE RESPONSE (%d)\n",
				     WLAN_FC_GET_STYPE(le16_to_cpu
						       (header->frame_ctl)));
		IEEE80211_DEBUG_SCAN("Probe response\n");
		ieee80211_process_probe_response(ieee,
						 (struct
						  ieee80211_probe_response *)
						 header, stats);
		break;

	case IEEE80211_STYPE_BEACON:
		IEEE80211_DEBUG_MGMT("received BEACON (%d)\n",
				     WLAN_FC_GET_STYPE(le16_to_cpu
						       (header->frame_ctl)));
		IEEE80211_DEBUG_SCAN("Beacon\n");
		ieee80211_process_probe_response(ieee,
						 (struct
						  ieee80211_probe_response *)
						 header, stats);
		break;
	case IEEE80211_STYPE_AUTH:

		IEEE80211_DEBUG_MGMT("received auth (%d)\n",
				     WLAN_FC_GET_STYPE(le16_to_cpu
						       (header->frame_ctl)));

		if (ieee->handle_auth != NULL)
			ieee->handle_auth(ieee->dev,
					  (struct ieee80211_auth *)header);
		break;

	case IEEE80211_STYPE_DISASSOC:
		if (ieee->handle_disassoc != NULL)
			ieee->handle_disassoc(ieee->dev,
					      (struct ieee80211_disassoc *)
					      header);
		break;

	case IEEE80211_STYPE_ACTION:
		IEEE80211_DEBUG_MGMT("ACTION\n");
		if (ieee->handle_action)
			ieee->handle_action(ieee->dev,
					    (struct ieee80211_action *)
					    header, stats);
		break;

	case IEEE80211_STYPE_REASSOC_REQ:
		IEEE80211_DEBUG_MGMT("received reassoc (%d)\n",
				     WLAN_FC_GET_STYPE(le16_to_cpu
						       (header->frame_ctl)));

		IEEE80211_DEBUG_MGMT("%s: IEEE80211_REASSOC_REQ received\n",
				     ieee->dev->name);
		if (ieee->handle_reassoc_request != NULL)
			ieee->handle_reassoc_request(ieee->dev,
						    (struct ieee80211_reassoc_request *)
						     header);
		break;

	case IEEE80211_STYPE_ASSOC_REQ:
		IEEE80211_DEBUG_MGMT("received assoc (%d)\n",
				     WLAN_FC_GET_STYPE(le16_to_cpu
						       (header->frame_ctl)));

		IEEE80211_DEBUG_MGMT("%s: IEEE80211_ASSOC_REQ received\n",
				     ieee->dev->name);
		if (ieee->handle_assoc_request != NULL)
			ieee->handle_assoc_request(ieee->dev);
		break;

	case IEEE80211_STYPE_DEAUTH:
		IEEE80211_DEBUG_MGMT("DEAUTH\n");
		if (ieee->handle_deauth != NULL)
			ieee->handle_deauth(ieee->dev,
					    (struct ieee80211_deauth *)
					    header);
		break;
	default:
		IEEE80211_DEBUG_MGMT("received UNKNOWN (%d)\n",
				     WLAN_FC_GET_STYPE(le16_to_cpu
						       (header->frame_ctl)));
		IEEE80211_DEBUG_MGMT("%s: Unknown management packet: %d\n",
				     ieee->dev->name,
				     WLAN_FC_GET_STYPE(le16_to_cpu
						       (header->frame_ctl)));
		break;
	}
}

EXPORT_SYMBOL_GPL(ieee80211_rx_any);
EXPORT_SYMBOL(ieee80211_rx_mgt);
EXPORT_SYMBOL(ieee80211_rx);