cfg80211/nl80211: scanning (and mac80211 update to use it)

This patch adds basic scan capability to cfg80211/nl80211 and
changes mac80211 to use it. The BSS list that cfg80211 maintains
is made driver-accessible with a private area in each BSS struct,
but mac80211 doesn't yet use it. That's another large project.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-agn.c

@@ -2678,11 +2678,19 @@ static void iwl_bss_info_changed(struct ieee80211_hw *hw,
 
 }
 
-static int iwl_mac_hw_scan(struct ieee80211_hw *hw, u8 *ssid, size_t ssid_len)
+static int iwl_mac_hw_scan(struct ieee80211_hw *hw,
+			   struct cfg80211_scan_request *req)
 {
 	unsigned long flags;
 	struct iwl_priv *priv = hw->priv;
 	int ret;
+	u8 *ssid = NULL;
+	size_t ssid_len = 0;
+
+	if (req->n_ssids) {
+		ssid = req->ssids[0].ssid;
+		ssid_len = req->ssids[0].ssid_len;
+	}
 
 	IWL_DEBUG_MAC80211(priv, "enter\n");
 
@@ -2718,7 +2726,7 @@ static int iwl_mac_hw_scan(struct ieee80211_hw *hw, u8 *ssid, size_t ssid_len)
 
 	if (ssid_len) {
 		priv->one_direct_scan = 1;
-		priv->direct_ssid_len =  min_t(u8, ssid_len, IW_ESSID_MAX_SIZE);
+		priv->direct_ssid_len = ssid_len;
 		memcpy(priv->direct_ssid, ssid, priv->direct_ssid_len);
 	} else {
 		priv->one_direct_scan = 0;

drivers/net/wireless/iwlwifi/iwl-core.c

@@ -1271,6 +1271,7 @@ int iwl_setup_mac(struct iwl_priv *priv)
 		BIT(NL80211_IFTYPE_ADHOC);
 
 	hw->wiphy->custom_regulatory = true;
+	hw->wiphy->max_scan_ssids = 1;
 
 	/* Default value; 4 EDCA QOS priorities */
 	hw->queues = 4;

drivers/net/wireless/iwlwifi/iwl-scan.c

@@ -860,7 +860,7 @@ void iwl_bg_scan_completed(struct work_struct *work)
 	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 		return;
 
-	ieee80211_scan_completed(priv->hw);
+	ieee80211_scan_completed(priv->hw, false);
 
 	/* Since setting the TXPOWER may have been deferred while
 	 * performing the scan, fire one off */

drivers/net/wireless/iwlwifi/iwl3945-base.c

@@ -4442,15 +4442,23 @@ static void iwl3945_bss_info_changed(struct ieee80211_hw *hw,
 
 }
 
-static int iwl3945_mac_hw_scan(struct ieee80211_hw *hw, u8 *ssid, size_t len)
+static int iwl3945_mac_hw_scan(struct ieee80211_hw *hw,
+			       struct cfg80211_scan_request *req)
 {
 	int rc = 0;
 	unsigned long flags;
 	struct iwl_priv *priv = hw->priv;
+	size_t len = 0;
+	u8 *ssid = NULL;
 	DECLARE_SSID_BUF(ssid_buf);
 
 	IWL_DEBUG_MAC80211(priv, "enter\n");
 
+	if (req->n_ssids) {
+		ssid = req->ssids[0].ssid;
+		len = req->ssids[0].ssid_len;
+	}
+
 	mutex_lock(&priv->mutex);
 	spin_lock_irqsave(&priv->lock, flags);
 
@@ -4478,9 +4486,8 @@ static int iwl3945_mac_hw_scan(struct ieee80211_hw *hw, u8 *ssid, size_t len)
 			       print_ssid(ssid_buf, ssid, len), len);
 
 		priv->one_direct_scan = 1;
-		priv->direct_ssid_len = (u8)
-		    min((u8) len, (u8) IW_ESSID_MAX_SIZE);
-		memcpy(priv->direct_ssid, ssid, priv->direct_ssid_len);
+		priv->direct_ssid_len = len;
+		memcpy(priv->direct_ssid, ssid, len);
 	} else
 		priv->one_direct_scan = 0;
 
@@ -5412,6 +5419,8 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
 
 	hw->wiphy->custom_regulatory = true;
 
+	hw->wiphy->max_scan_ssids = 1;
+
 	/* 4 EDCA QOS priorities */
 	hw->queues = 4;
 

include/linux/nl80211.h

@@ -143,6 +143,13 @@
  *	added to all specified management frames generated by
  *	kernel/firmware/driver.
  *
+ * @NL80211_CMD_GET_SCAN: get scan results
+ * @NL80211_CMD_TRIGGER_SCAN: trigger a new scan with the given parameters
+ * @NL80211_CMD_NEW_SCAN_RESULTS: scan notification (as a reply to
+ *	NL80211_CMD_GET_SCAN and on the "scan" multicast group)
+ * @NL80211_CMD_SCAN_ABORTED: scan was aborted, for unspecified reasons,
+ *	partial scan results may be available
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -192,6 +199,11 @@ enum nl80211_commands {
 
 	NL80211_CMD_GET_REG,
 
+	NL80211_CMD_GET_SCAN,
+	NL80211_CMD_TRIGGER_SCAN,
+	NL80211_CMD_NEW_SCAN_RESULTS,
+	NL80211_CMD_SCAN_ABORTED,
+
 	/* add new commands above here */
 
 	/* used to define NL80211_CMD_MAX below */
@@ -305,6 +317,18 @@ enum nl80211_commands {
  * @NL80211_ATTR_IE: Information element(s) data (used, e.g., with
  *	%NL80211_CMD_SET_MGMT_EXTRA_IE).
  *
+ * @NL80211_ATTR_MAX_NUM_SCAN_SSIDS: number of SSIDs you can scan with
+ *	a single scan request, a wiphy attribute.
+ *
+ * @NL80211_ATTR_SCAN_FREQUENCIES: nested attribute with frequencies (in MHz)
+ * @NL80211_ATTR_SCAN_SSIDS: nested attribute with SSIDs, leave out for passive
+ *	scanning and include a zero-length SSID (wildcard) for wildcard scan
+ * @NL80211_ATTR_SCAN_GENERATION: the scan generation increases whenever the
+ *	scan result list changes (BSS expired or added) so that applications
+ *	can verify that they got a single, consistent snapshot (when all dump
+ *	messages carried the same generation number)
+ * @NL80211_ATTR_BSS: scan result BSS
+ *
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
  */
@@ -372,6 +396,13 @@ enum nl80211_attrs {
 	NL80211_ATTR_MGMT_SUBTYPE,
 	NL80211_ATTR_IE,
 
+	NL80211_ATTR_MAX_NUM_SCAN_SSIDS,
+
+	NL80211_ATTR_SCAN_FREQUENCIES,
+	NL80211_ATTR_SCAN_SSIDS,
+	NL80211_ATTR_SCAN_GENERATION,
+	NL80211_ATTR_BSS,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
@@ -841,4 +872,38 @@ enum nl80211_channel_type {
 	NL80211_CHAN_HT40MINUS,
 	NL80211_CHAN_HT40PLUS
 };
+
+/**
+ * enum nl80211_bss - netlink attributes for a BSS
+ *
+ * @__NL80211_BSS_INVALID: invalid
+ * @NL80211_BSS_FREQUENCY: frequency in MHz (u32)
+ * @NL80211_BSS_TSF: TSF of the received probe response/beacon (u64)
+ * @NL80211_BSS_BEACON_INTERVAL: beacon interval of the (I)BSS (u16)
+ * @NL80211_BSS_CAPABILITY: capability field (CPU order, u16)
+ * @NL80211_BSS_INFORMATION_ELEMENTS: binary attribute containing the
+ *	raw information elements from the probe response/beacon (bin)
+ * @NL80211_BSS_SIGNAL_MBM: signal strength of probe response/beacon
+ *	in mBm (100 * dBm) (s32)
+ * @NL80211_BSS_SIGNAL_UNSPEC: signal strength of the probe response/beacon
+ *	in unspecified units, scaled to 0..100 (u8)
+ * @__NL80211_BSS_AFTER_LAST: internal
+ * @NL80211_BSS_MAX: highest BSS attribute
+ */
+enum nl80211_bss {
+	__NL80211_BSS_INVALID,
+	NL80211_BSS_BSSID,
+	NL80211_BSS_FREQUENCY,
+	NL80211_BSS_TSF,
+	NL80211_BSS_BEACON_INTERVAL,
+	NL80211_BSS_CAPABILITY,
+	NL80211_BSS_INFORMATION_ELEMENTS,
+	NL80211_BSS_SIGNAL_MBM,
+	NL80211_BSS_SIGNAL_UNSPEC,
+
+	/* keep last */
+	__NL80211_BSS_AFTER_LAST,
+	NL80211_BSS_MAX = __NL80211_BSS_AFTER_LAST - 1
+};
+
 #endif /* __LINUX_NL80211_H */

include/net/cfg80211.h

@@ -4,6 +4,10 @@
 #include <linux/netlink.h>
 #include <linux/skbuff.h>
 #include <linux/nl80211.h>
+#include <linux/if_ether.h>
+#include <linux/ieee80211.h>
+#include <linux/wireless.h>
+#include <net/iw_handler.h>
 #include <net/genetlink.h>
 /* remove once we remove the wext stuff */
 #include <net/iw_handler.h>
@@ -504,6 +508,83 @@ struct wiphy;
 /* from net/ieee80211.h */
 struct ieee80211_channel;
 
+/**
+ * struct cfg80211_ssid - SSID description
+ * @ssid: the SSID
+ * @ssid_len: length of the ssid
+ */
+struct cfg80211_ssid {
+	u8 ssid[IEEE80211_MAX_SSID_LEN];
+	u8 ssid_len;
+};
+
+/**
+ * struct cfg80211_scan_request - scan request description
+ *
+ * @ssids: SSIDs to scan for (active scan only)
+ * @n_ssids: number of SSIDs
+ * @channels: channels to scan on.
+ * @n_channels: number of channels for each band
+ * @wiphy: the wiphy this was for
+ * @ifidx: the interface index
+ */
+struct cfg80211_scan_request {
+	struct cfg80211_ssid *ssids;
+	int n_ssids;
+	struct ieee80211_channel **channels;
+	u32 n_channels;
+
+	/* internal */
+	struct wiphy *wiphy;
+	int ifidx;
+};
+
+/**
+ * enum cfg80211_signal_type - signal type
+ *
+ * @CFG80211_SIGNAL_TYPE_NONE: no signal strength information available
+ * @CFG80211_SIGNAL_TYPE_MBM: signal strength in mBm (100*dBm)
+ * @CFG80211_SIGNAL_TYPE_UNSPEC: signal strength, increasing from 0 through 100
+ */
+enum cfg80211_signal_type {
+	CFG80211_SIGNAL_TYPE_NONE,
+	CFG80211_SIGNAL_TYPE_MBM,
+	CFG80211_SIGNAL_TYPE_UNSPEC,
+};
+
+/**
+ * struct cfg80211_bss - BSS description
+ *
+ * This structure describes a BSS (which may also be a mesh network)
+ * for use in scan results and similar.
+ *
+ * @bssid: BSSID of the BSS
+ * @tsf: timestamp of last received update
+ * @beacon_interval: the beacon interval as from the frame
+ * @capability: the capability field in host byte order
+ * @information_elements: the information elements (Note that there
+ *	is no guarantee that these are well-formed!)
+ * @len_information_elements: total length of the information elements
+ * @signal: signal strength value
+ * @signal_type: signal type
+ * @priv: private area for driver use, has at least wiphy->bss_priv_size bytes
+ */
+struct cfg80211_bss {
+	struct ieee80211_channel *channel;
+
+	u8 bssid[ETH_ALEN];
+	u64 tsf;
+	u16 beacon_interval;
+	u16 capability;
+	u8 *information_elements;
+	size_t len_information_elements;
+
+	s32 signal;
+	enum cfg80211_signal_type signal_type;
+
+	u8 priv[0] __attribute__((__aligned__(sizeof(void *))));
+};
+
 /**
  * struct cfg80211_ops - backend description for wireless configuration
  *
@@ -571,6 +652,11 @@ struct ieee80211_channel;
  * @set_channel: Set channel
  *
  * @set_mgmt_extra_ie: Set extra IE data for management frames
+ *
+ * @scan: Request to do a scan. If returning zero, the scan request is given
+ *	the driver, and will be valid until passed to cfg80211_scan_done().
+ *	For scan results, call cfg80211_inform_bss(); you can call this outside
+ *	the scan/scan_done bracket too.
  */
 struct cfg80211_ops {
 	int	(*suspend)(struct wiphy *wiphy);
@@ -648,6 +734,9 @@ struct cfg80211_ops {
 	int	(*set_mgmt_extra_ie)(struct wiphy *wiphy,
 				     struct net_device *dev,
 				     struct mgmt_extra_ie_params *params);
+
+	int	(*scan)(struct wiphy *wiphy, struct net_device *dev,
+			struct cfg80211_scan_request *request);
 };
 
 /* temporary wext handlers */
@@ -658,5 +747,47 @@ int cfg80211_wext_siwmode(struct net_device *dev, struct iw_request_info *info,
 			  u32 *mode, char *extra);
 int cfg80211_wext_giwmode(struct net_device *dev, struct iw_request_info *info,
 			  u32 *mode, char *extra);
+int cfg80211_wext_siwscan(struct net_device *dev,
+			  struct iw_request_info *info,
+			  union iwreq_data *wrqu, char *extra);
+int cfg80211_wext_giwscan(struct net_device *dev,
+			  struct iw_request_info *info,
+			  struct iw_point *data, char *extra);
+
+/**
+ * cfg80211_scan_done - notify that scan finished
+ *
+ * @request: the corresponding scan request
+ * @aborted: set to true if the scan was aborted for any reason,
+ *	userspace will be notified of that
+ */
+void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted);
+
+/**
+ * cfg80211_inform_bss - inform cfg80211 of a new BSS
+ *
+ * @wiphy: the wiphy reporting the BSS
+ * @bss: the found BSS
+ * @gfp: context flags
+ *
+ * This informs cfg80211 that BSS information was found and
+ * the BSS should be updated/added.
+ */
+struct cfg80211_bss*
+cfg80211_inform_bss_frame(struct wiphy *wiphy,
+			  struct ieee80211_channel *channel,
+			  struct ieee80211_mgmt *mgmt, size_t len,
+			  s32 signal, enum cfg80211_signal_type sigtype,
+			  gfp_t gfp);
+
+struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
+				      struct ieee80211_channel *channel,
+				      const u8 *bssid,
+				      const u8 *ssid, size_t ssid_len);
+struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
+				       struct ieee80211_channel *channel,
+				       const u8 *meshid, size_t meshidlen,
+				       const u8 *meshcfg);
+void cfg80211_put_bss(struct cfg80211_bss *bss);
 
 #endif /* __NET_CFG80211_H */

include/net/mac80211.h

@@ -1406,7 +1406,8 @@ struct ieee80211_ops {
 	void (*update_tkip_key)(struct ieee80211_hw *hw,
 			struct ieee80211_key_conf *conf, const u8 *address,
 			u32 iv32, u16 *phase1key);
-	int (*hw_scan)(struct ieee80211_hw *hw, u8 *ssid, size_t len);
+	int (*hw_scan)(struct ieee80211_hw *hw,
+		       struct cfg80211_scan_request *req);
 	int (*get_stats)(struct ieee80211_hw *hw,
 			 struct ieee80211_low_level_stats *stats);
 	void (*get_tkip_seq)(struct ieee80211_hw *hw, u8 hw_key_idx,
@@ -1844,8 +1845,9 @@ void ieee80211_wake_queues(struct ieee80211_hw *hw);
  * mac80211 that the scan finished.
  *
  * @hw: the hardware that finished the scan
+ * @aborted: set to true if scan was aborted
  */
-void ieee80211_scan_completed(struct ieee80211_hw *hw);
+void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted);
 
 /**
  * ieee80211_iterate_active_interfaces - iterate active interfaces

include/net/wireless.h

@@ -213,6 +213,9 @@ struct wiphy {
 	bool custom_regulatory;
 	bool strict_regulatory;
 
+	int bss_priv_size;
+	u8 max_scan_ssids;
+
 	/* If multiple wiphys are registered and you're handed e.g.
 	 * a regular netdev with assigned ieee80211_ptr, you won't
 	 * know whether it points to a wiphy your driver has registered

net/mac80211/cfg.c

@@ -1277,6 +1277,25 @@ static int ieee80211_resume(struct wiphy *wiphy)
 #define ieee80211_resume NULL
 #endif
 
+static int ieee80211_scan(struct wiphy *wiphy,
+			  struct net_device *dev,
+			  struct cfg80211_scan_request *req)
+{
+	struct ieee80211_sub_if_data *sdata;
+
+	if (!netif_running(dev))
+		return -ENETDOWN;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	if (sdata->vif.type != NL80211_IFTYPE_STATION &&
+	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
+	    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
+		return -EOPNOTSUPP;
+
+	return ieee80211_request_scan(sdata, req);
+}
+
 struct cfg80211_ops mac80211_config_ops = {
 	.add_virtual_intf = ieee80211_add_iface,
 	.del_virtual_intf = ieee80211_del_iface,
@@ -1309,4 +1328,5 @@ struct cfg80211_ops mac80211_config_ops = {
 	.set_mgmt_extra_ie = ieee80211_set_mgmt_extra_ie,
 	.suspend = ieee80211_suspend,
 	.resume = ieee80211_resume,
+	.scan = ieee80211_scan,
 };

net/mac80211/ieee80211_i.h

@@ -294,8 +294,6 @@ struct ieee80211_if_sta {
 	u8 ssid[IEEE80211_MAX_SSID_LEN];
 	enum ieee80211_sta_mlme_state state;
 	size_t ssid_len;
-	u8 scan_ssid[IEEE80211_MAX_SSID_LEN];
-	size_t scan_ssid_len;
 	u16 aid;
 	u16 ap_capab, capab;
 	u8 *extra_ie; /* to be added to the end of AssocReq */
@@ -658,17 +656,18 @@ struct ieee80211_local {
 
 	/* Scanning and BSS list */
 	bool sw_scanning, hw_scanning;
+	struct cfg80211_ssid scan_ssid;
+	struct cfg80211_scan_request int_scan_req;
+	struct cfg80211_scan_request *scan_req;
+	struct ieee80211_channel *scan_channel;
 	int scan_channel_idx;
-	enum ieee80211_band scan_band;
 
 	enum { SCAN_SET_CHANNEL, SCAN_SEND_PROBE } scan_state;
 	unsigned long last_scan_completed;
 	struct delayed_work scan_work;
 	struct ieee80211_sub_if_data *scan_sdata;
-	struct ieee80211_channel *oper_channel, *scan_channel, *csa_channel;
 	enum nl80211_channel_type oper_channel_type;
-	u8 scan_ssid[IEEE80211_MAX_SSID_LEN];
-	size_t scan_ssid_len;
+	struct ieee80211_channel *oper_channel, *csa_channel;
 	struct list_head bss_list;
 	struct ieee80211_bss *bss_hash[STA_HASH_SIZE];
 	spinlock_t bss_lock;
@@ -929,7 +928,7 @@ void ieee80211_send_pspoll(struct ieee80211_local *local,
 
 /* scan/BSS handling */
 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
-			   u8 *ssid, size_t ssid_len);
+			   struct cfg80211_scan_request *req);
 int ieee80211_scan_results(struct ieee80211_local *local,
 			   struct iw_request_info *info,
 			   char *buf, size_t len);
@@ -944,14 +943,15 @@ int ieee80211_sta_set_extra_ie(struct ieee80211_sub_if_data *sdata,
 
 void ieee80211_mlme_notify_scan_completed(struct ieee80211_local *local);
 int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
-			 u8 *ssid, size_t ssid_len);
+			 struct cfg80211_scan_request *req);
 struct ieee80211_bss *
 ieee80211_bss_info_update(struct ieee80211_local *local,
 			  struct ieee80211_rx_status *rx_status,
 			  struct ieee80211_mgmt *mgmt,
 			  size_t len,
 			  struct ieee802_11_elems *elems,
-			  int freq, bool beacon);
+			  struct ieee80211_channel *channel,
+			  bool beacon);
 struct ieee80211_bss *
 ieee80211_rx_bss_add(struct ieee80211_local *local, u8 *bssid, int freq,
 		     u8 *ssid, u8 ssid_len);

net/mac80211/iface.c

@@ -522,7 +522,7 @@ static int ieee80211_stop(struct net_device *dev)
 			 * scan event to userspace -- the scan is incomplete.
 			 */
 			if (local->sw_scanning)
-				ieee80211_scan_completed(&local->hw);
+				ieee80211_scan_completed(&local->hw, true);
 		}
 
 		conf.vif = &sdata->vif;

net/mac80211/main.c

@@ -733,6 +733,7 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 		return NULL;
 
 	wiphy->privid = mac80211_wiphy_privid;
+	wiphy->max_scan_ssids = 4;
 
 	local = wiphy_priv(wiphy);
 	local->hw.wiphy = wiphy;
@@ -817,25 +818,33 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	enum ieee80211_band band;
 	struct net_device *mdev;
 	struct ieee80211_master_priv *mpriv;
+	int channels, i, j;
 
 	/*
 	 * generic code guarantees at least one band,
 	 * set this very early because much code assumes
 	 * that hw.conf.channel is assigned
 	 */
+	channels = 0;
 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 		struct ieee80211_supported_band *sband;
 
 		sband = local->hw.wiphy->bands[band];
-		if (sband) {
+		if (sband && !local->oper_channel) {
 			/* init channel we're on */
 			local->hw.conf.channel =
 			local->oper_channel =
 			local->scan_channel = &sband->channels[0];
-			break;
 		}
+		if (sband)
+			channels += sband->n_channels;
 	}
 
+	local->int_scan_req.n_channels = channels;
+	local->int_scan_req.channels = kzalloc(sizeof(void *) * channels, GFP_KERNEL);
+	if (!local->int_scan_req.channels)
+		return -ENOMEM;
+
 	/* if low-level driver supports AP, we also support VLAN */
 	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP))
 		local->hw.wiphy->interface_modes |= BIT(NL80211_IFTYPE_AP_VLAN);
@@ -845,7 +854,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 
 	result = wiphy_register(local->hw.wiphy);
 	if (result < 0)
-		return result;
+		goto fail_wiphy_register;
 
 	/*
 	 * We use the number of queues for feature tests (QoS, HT) internally
@@ -948,6 +957,20 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 
 	ieee80211_led_init(local);
 
+	/* alloc internal scan request */
+	i = 0;
+	local->int_scan_req.ssids = &local->scan_ssid;
+	local->int_scan_req.n_ssids = 1;
+	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+		if (!hw->wiphy->bands[band])
+			continue;
+		for (j = 0; j < hw->wiphy->bands[band]->n_channels; j++) {
+			local->int_scan_req.channels[i] =
+				&hw->wiphy->bands[band]->channels[j];
+			i++;
+		}
+	}
+
 	return 0;
 
 fail_wep:
@@ -966,6 +989,8 @@ fail_workqueue:
 		free_netdev(local->mdev);
 fail_mdev_alloc:
 	wiphy_unregister(local->hw.wiphy);
+fail_wiphy_register:
+	kfree(local->int_scan_req.channels);
 	return result;
 }
 EXPORT_SYMBOL(ieee80211_register_hw);
@@ -1011,6 +1036,7 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw)
 	ieee80211_wep_free(local);
 	ieee80211_led_exit(local);
 	free_netdev(local->mdev);
+	kfree(local->int_scan_req.channels);
 }
 EXPORT_SYMBOL(ieee80211_unregister_hw);
 

net/mac80211/mlme.c

@@ -1743,7 +1743,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 	}
 
 	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
-					freq, beacon);
+					channel, beacon);
 	if (!bss)
 		return;
 
@@ -2162,7 +2162,15 @@ static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata,
 
 	printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 	       "IBSS networks with same SSID (merge)\n", sdata->dev->name);
-	ieee80211_request_scan(sdata, ifsta->ssid, ifsta->ssid_len);
+
+	/* XXX maybe racy? */
+	if (sdata->local->scan_req)
+		return;
+
+	memcpy(sdata->local->int_scan_req.ssids[0].ssid,
+	       ifsta->ssid, IEEE80211_MAX_SSID_LEN);
+	sdata->local->int_scan_req.ssids[0].ssid_len = ifsta->ssid_len;
+	ieee80211_request_scan(sdata, &sdata->local->int_scan_req);
 }
 
 
@@ -2378,8 +2386,15 @@ dont_join:
 			      IEEE80211_SCAN_INTERVAL)) {
 		printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 		       "join\n", sdata->dev->name);
-		return ieee80211_request_scan(sdata, ifsta->ssid,
-					      ifsta->ssid_len);
+
+		/* XXX maybe racy? */
+		if (local->scan_req)
+			return -EBUSY;
+
+		memcpy(local->int_scan_req.ssids[0].ssid,
+		       ifsta->ssid, IEEE80211_MAX_SSID_LEN);
+		local->int_scan_req.ssids[0].ssid_len = ifsta->ssid_len;
+		return ieee80211_request_scan(sdata, &local->int_scan_req);
 	} else if (ifsta->state != IEEE80211_STA_MLME_IBSS_JOINED) {
 		int interval = IEEE80211_SCAN_INTERVAL;
 
@@ -2478,11 +2493,16 @@ static int ieee80211_sta_config_auth(struct ieee80211_sub_if_data *sdata,
 	} else {
 		if (ifsta->assoc_scan_tries < IEEE80211_ASSOC_SCANS_MAX_TRIES) {
 			ifsta->assoc_scan_tries++;
+			/* XXX maybe racy? */
+			if (local->scan_req)
+				return -1;
+			memcpy(local->int_scan_req.ssids[0].ssid,
+			       ifsta->ssid, IEEE80211_MAX_SSID_LEN);
 			if (ifsta->flags & IEEE80211_STA_AUTO_SSID_SEL)
-				ieee80211_start_scan(sdata, NULL, 0);
+				local->int_scan_req.ssids[0].ssid_len = 0;
 			else
-				ieee80211_start_scan(sdata, ifsta->ssid,
-							 ifsta->ssid_len);
+				local->int_scan_req.ssids[0].ssid_len = ifsta->ssid_len;
+			ieee80211_start_scan(sdata, &local->int_scan_req);
 			ifsta->state = IEEE80211_STA_MLME_AUTHENTICATE;
 			set_bit(IEEE80211_STA_REQ_AUTH, &ifsta->request);
 		} else {
@@ -2520,8 +2540,7 @@ static void ieee80211_sta_work(struct work_struct *work)
 	    ifsta->state != IEEE80211_STA_MLME_AUTHENTICATE &&
 	    ifsta->state != IEEE80211_STA_MLME_ASSOCIATE &&
 	    test_and_clear_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request)) {
-		ieee80211_start_scan(sdata, ifsta->scan_ssid,
-				     ifsta->scan_ssid_len);
+		ieee80211_start_scan(sdata, local->scan_req);
 		return;
 	}
 

net/mac80211/wext.c

@@ -173,8 +173,9 @@ static int ieee80211_ioctl_giwrange(struct net_device *dev,
 	range->num_encoding_sizes = 2;
 	range->max_encoding_tokens = NUM_DEFAULT_KEYS;
 
+	/* cfg80211 requires this, and enforces 0..100 */
 	if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
-		range->max_qual.level = local->hw.max_signal;
+		range->max_qual.level = 100;
 	else if  (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
 		range->max_qual.level = -110;
 	else
@@ -415,58 +416,6 @@ static int ieee80211_ioctl_giwap(struct net_device *dev,
 }
 
 
-static int ieee80211_ioctl_siwscan(struct net_device *dev,
-				   struct iw_request_info *info,
-				   union iwreq_data *wrqu, char *extra)
-{
-	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-	struct iw_scan_req *req = NULL;
-	u8 *ssid = NULL;
-	size_t ssid_len = 0;
-
-	if (!netif_running(dev))
-		return -ENETDOWN;
-
-	if (sdata->vif.type != NL80211_IFTYPE_STATION &&
-	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
-	    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
-		return -EOPNOTSUPP;
-
-	/* if SSID was specified explicitly then use that */
-	if (wrqu->data.length == sizeof(struct iw_scan_req) &&
-	    wrqu->data.flags & IW_SCAN_THIS_ESSID) {
-		req = (struct iw_scan_req *)extra;
-		ssid = req->essid;
-		ssid_len = req->essid_len;
-	}
-
-	return ieee80211_request_scan(sdata, ssid, ssid_len);
-}
-
-
-static int ieee80211_ioctl_giwscan(struct net_device *dev,
-				   struct iw_request_info *info,
-				   struct iw_point *data, char *extra)
-{
-	int res;
-	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-	struct ieee80211_sub_if_data *sdata;
-
-	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-
-	if (local->sw_scanning || local->hw_scanning)
-		return -EAGAIN;
-
-	res = ieee80211_scan_results(local, info, extra, data->length);
-	if (res >= 0) {
-		data->length = res;
-		return 0;
-	}
-	data->length = 0;
-	return res;
-}
-
-
 static int ieee80211_ioctl_siwrate(struct net_device *dev,
 				  struct iw_request_info *info,
 				  struct iw_param *rate, char *extra)
@@ -1165,8 +1114,8 @@ static const iw_handler ieee80211_handler[] =
 	(iw_handler) ieee80211_ioctl_giwap,		/* SIOCGIWAP */
 	(iw_handler) ieee80211_ioctl_siwmlme,		/* SIOCSIWMLME */
 	(iw_handler) NULL,				/* SIOCGIWAPLIST */
-	(iw_handler) ieee80211_ioctl_siwscan,		/* SIOCSIWSCAN */
-	(iw_handler) ieee80211_ioctl_giwscan,		/* SIOCGIWSCAN */
+	(iw_handler) cfg80211_wext_siwscan,		/* SIOCSIWSCAN */
+	(iw_handler) cfg80211_wext_giwscan,		/* SIOCGIWSCAN */
 	(iw_handler) ieee80211_ioctl_siwessid,		/* SIOCSIWESSID */
 	(iw_handler) ieee80211_ioctl_giwessid,		/* SIOCGIWESSID */
 	(iw_handler) NULL,				/* SIOCSIWNICKN */

net/wireless/Makefile

@@ -5,7 +5,7 @@ obj-$(CONFIG_LIB80211_CRYPT_WEP) += lib80211_crypt_wep.o
 obj-$(CONFIG_LIB80211_CRYPT_CCMP) += lib80211_crypt_ccmp.o
 obj-$(CONFIG_LIB80211_CRYPT_TKIP) += lib80211_crypt_tkip.o
 
-cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o
+cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o
 cfg80211-$(CONFIG_WIRELESS_EXT) += wext-compat.o
 cfg80211-$(CONFIG_NL80211) += nl80211.o
 

net/wireless/core.c

@@ -240,6 +240,8 @@ struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
 	mutex_init(&drv->mtx);
 	mutex_init(&drv->devlist_mtx);
 	INIT_LIST_HEAD(&drv->netdev_list);
+	spin_lock_init(&drv->bss_lock);
+	INIT_LIST_HEAD(&drv->bss_list);
 
 	device_initialize(&drv->wiphy.dev);
 	drv->wiphy.dev.class = &ieee80211_class;
@@ -259,6 +261,9 @@ int wiphy_register(struct wiphy *wiphy)
 	int i;
 	u16 ifmodes = wiphy->interface_modes;
 
+	if (WARN_ON(wiphy->max_scan_ssids < 1))
+		return -EINVAL;
+
 	/* sanity check ifmodes */
 	WARN_ON(!ifmodes);
 	ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1;
@@ -367,8 +372,11 @@ EXPORT_SYMBOL(wiphy_unregister);
 
 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
 {
+	struct cfg80211_internal_bss *scan, *tmp;
 	mutex_destroy(&drv->mtx);
 	mutex_destroy(&drv->devlist_mtx);
+	list_for_each_entry_safe(scan, tmp, &drv->bss_list, list)
+		kfree(scan);
 	kfree(drv);
 }
 

net/wireless/core.h

@@ -8,6 +8,8 @@
 #include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/netdevice.h>
+#include <linux/kref.h>
+#include <linux/rbtree.h>
 #include <net/genetlink.h>
 #include <net/wireless.h>
 #include <net/cfg80211.h>
@@ -41,6 +43,13 @@ struct cfg80211_registered_device {
 	struct mutex devlist_mtx;
 	struct list_head netdev_list;
 
+	/* BSSes/scanning */
+	spinlock_t bss_lock;
+	struct list_head bss_list;
+	struct rb_root bss_tree;
+	u32 bss_generation;
+	struct cfg80211_scan_request *scan_req; /* protected by RTNL */
+
 	/* must be last because of the way we do wiphy_priv(),
 	 * and it should at least be aligned to NETDEV_ALIGN */
 	struct wiphy wiphy __attribute__((__aligned__(NETDEV_ALIGN)));
@@ -56,6 +65,15 @@ struct cfg80211_registered_device *wiphy_to_dev(struct wiphy *wiphy)
 extern struct mutex cfg80211_drv_mutex;
 extern struct list_head cfg80211_drv_list;
 
+struct cfg80211_internal_bss {
+	struct list_head list;
+	struct rb_node rbn;
+	unsigned long ts;
+	struct kref ref;
+	/* must be last because of priv member */
+	struct cfg80211_bss pub;
+};
+
 /*
  * This function returns a pointer to the driver
  * that the genl_info item that is passed refers to.
@@ -94,4 +112,6 @@ extern int cfg80211_dev_rename(struct cfg80211_registered_device *drv,
 void ieee80211_set_bitrate_flags(struct wiphy *wiphy);
 void wiphy_update_regulatory(struct wiphy *wiphy, enum reg_set_by setby);
 
+void cfg80211_bss_expire(struct cfg80211_registered_device *dev);
+
 #endif /* __NET_WIRELESS_CORE_H */

net/wireless/nl80211.c

@@ -14,6 +14,7 @@
 #include <linux/nl80211.h>
 #include <linux/rtnetlink.h>
 #include <linux/netlink.h>
+#include <linux/etherdevice.h>
 #include <net/genetlink.h>
 #include <net/cfg80211.h>
 #include "core.h"
@@ -109,6 +110,8 @@ static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
 	[NL80211_ATTR_MGMT_SUBTYPE] = { .type = NLA_U8 },
 	[NL80211_ATTR_IE] = { .type = NLA_BINARY,
 			      .len = IEEE80211_MAX_DATA_LEN },
+	[NL80211_ATTR_SCAN_FREQUENCIES] = { .type = NLA_NESTED },
+	[NL80211_ATTR_SCAN_SSIDS] = { .type = NLA_NESTED },
 };
 
 /* message building helper */
@@ -141,6 +144,8 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
 
 	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, dev->idx);
 	NLA_PUT_STRING(msg, NL80211_ATTR_WIPHY_NAME, wiphy_name(&dev->wiphy));
+	NLA_PUT_U8(msg, NL80211_ATTR_MAX_NUM_SCAN_SSIDS,
+		   dev->wiphy.max_scan_ssids);
 
 	nl_modes = nla_nest_start(msg, NL80211_ATTR_SUPPORTED_IFTYPES);
 	if (!nl_modes)
@@ -2270,6 +2275,246 @@ static int nl80211_set_mgmt_extra_ie(struct sk_buff *skb,
 	return err;
 }
 
+static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_registered_device *drv;
+	struct net_device *dev;
+	struct cfg80211_scan_request *request;
+	struct cfg80211_ssid *ssid;
+	struct ieee80211_channel *channel;
+	struct nlattr *attr;
+	struct wiphy *wiphy;
+	int err, tmp, n_ssids = 0, n_channels = 0, i;
+	enum ieee80211_band band;
+
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
+	if (err)
+		return err;
+
+	wiphy = &drv->wiphy;
+
+	if (!drv->ops->scan) {
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
+	rtnl_lock();
+
+	if (drv->scan_req) {
+		err = -EBUSY;
+		goto out_unlock;
+	}
+
+	if (info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]) {
+		nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_FREQUENCIES], tmp)
+			n_channels++;
+		if (!n_channels) {
+			err = -EINVAL;
+			goto out_unlock;
+		}
+	} else {
+		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
+			if (wiphy->bands[band])
+				n_channels += wiphy->bands[band]->n_channels;
+	}
+
+	if (info->attrs[NL80211_ATTR_SCAN_SSIDS])
+		nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_SSIDS], tmp)
+			n_ssids++;
+
+	if (n_ssids > wiphy->max_scan_ssids) {
+		err = -EINVAL;
+		goto out_unlock;
+	}
+
+	request = kzalloc(sizeof(*request)
+			+ sizeof(*ssid) * n_ssids
+			+ sizeof(channel) * n_channels, GFP_KERNEL);
+	if (!request) {
+		err = -ENOMEM;
+		goto out_unlock;
+	}
+
+	request->channels = (void *)((char *)request + sizeof(*request));
+	request->n_channels = n_channels;
+	if (n_ssids)
+		request->ssids = (void *)(request->channels + n_channels);
+	request->n_ssids = n_ssids;
+
+	if (info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]) {
+		/* user specified, bail out if channel not found */
+		request->n_channels = n_channels;
+		i = 0;
+		nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_FREQUENCIES], tmp) {
+			request->channels[i] = ieee80211_get_channel(wiphy, nla_get_u32(attr));
+			if (!request->channels[i]) {
+				err = -EINVAL;
+				goto out_free;
+			}
+			i++;
+		}
+	} else {
+		/* all channels */
+		i = 0;
+		for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+			int j;
+			if (!wiphy->bands[band])
+				continue;
+			for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
+				request->channels[i] = &wiphy->bands[band]->channels[j];
+				i++;
+			}
+		}
+	}
+
+	i = 0;
+	if (info->attrs[NL80211_ATTR_SCAN_SSIDS]) {
+		nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_SSIDS], tmp) {
+			if (request->ssids[i].ssid_len > IEEE80211_MAX_SSID_LEN) {
+				err = -EINVAL;
+				goto out_free;
+			}
+			memcpy(request->ssids[i].ssid, nla_data(attr), nla_len(attr));
+			request->ssids[i].ssid_len = nla_len(attr);
+			i++;
+		}
+	}
+
+	request->ifidx = dev->ifindex;
+	request->wiphy = &drv->wiphy;
+
+	drv->scan_req = request;
+	err = drv->ops->scan(&drv->wiphy, dev, request);
+
+ out_free:
+	if (err) {
+		drv->scan_req = NULL;
+		kfree(request);
+	}
+ out_unlock:
+	rtnl_unlock();
+ out:
+	cfg80211_put_dev(drv);
+	dev_put(dev);
+	return err;
+}
+
+static int nl80211_send_bss(struct sk_buff *msg, u32 pid, u32 seq, int flags,
+			    struct cfg80211_registered_device *rdev,
+			    struct net_device *dev,
+			    struct cfg80211_bss *res)
+{
+	void *hdr;
+	struct nlattr *bss;
+
+	hdr = nl80211hdr_put(msg, pid, seq, flags,
+			     NL80211_CMD_NEW_SCAN_RESULTS);
+	if (!hdr)
+		return -1;
+
+	NLA_PUT_U32(msg, NL80211_ATTR_SCAN_GENERATION,
+		    rdev->bss_generation);
+	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, dev->ifindex);
+
+	bss = nla_nest_start(msg, NL80211_ATTR_BSS);
+	if (!bss)
+		goto nla_put_failure;
+	if (!is_zero_ether_addr(res->bssid))
+		NLA_PUT(msg, NL80211_BSS_BSSID, ETH_ALEN, res->bssid);
+	if (res->information_elements && res->len_information_elements)
+		NLA_PUT(msg, NL80211_BSS_INFORMATION_ELEMENTS,
+			res->len_information_elements,
+			res->information_elements);
+	if (res->tsf)
+		NLA_PUT_U64(msg, NL80211_BSS_TSF, res->tsf);
+	if (res->beacon_interval)
+		NLA_PUT_U16(msg, NL80211_BSS_BEACON_INTERVAL, res->beacon_interval);
+	NLA_PUT_U16(msg, NL80211_BSS_CAPABILITY, res->capability);
+	NLA_PUT_U32(msg, NL80211_BSS_FREQUENCY, res->channel->center_freq);
+
+	switch (res->signal_type) {
+	case CFG80211_SIGNAL_TYPE_MBM:
+		NLA_PUT_U32(msg, NL80211_BSS_SIGNAL_MBM, res->signal);
+		break;
+	case CFG80211_SIGNAL_TYPE_UNSPEC:
+		NLA_PUT_U8(msg, NL80211_BSS_SIGNAL_UNSPEC, res->signal);
+		break;
+	default:
+		break;
+	}
+
+	nla_nest_end(msg, bss);
+
+	return genlmsg_end(msg, hdr);
+
+ nla_put_failure:
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
+static int nl80211_dump_scan(struct sk_buff *skb,
+			     struct netlink_callback *cb)
+{
+	struct cfg80211_registered_device *dev;
+	struct net_device *netdev;
+	struct cfg80211_internal_bss *scan;
+	int ifidx = cb->args[0];
+	int start = cb->args[1], idx = 0;
+	int err;
+
+	if (!ifidx) {
+		err = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
+				  nl80211_fam.attrbuf, nl80211_fam.maxattr,
+				  nl80211_policy);
+		if (err)
+			return err;
+
+		if (!nl80211_fam.attrbuf[NL80211_ATTR_IFINDEX])
+			return -EINVAL;
+
+		ifidx = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_IFINDEX]);
+		if (!ifidx)
+			return -EINVAL;
+		cb->args[0] = ifidx;
+	}
+
+	netdev = dev_get_by_index(&init_net, ifidx);
+	if (!netdev)
+		return -ENODEV;
+
+	dev = cfg80211_get_dev_from_ifindex(ifidx);
+	if (IS_ERR(dev)) {
+		err = PTR_ERR(dev);
+		goto out_put_netdev;
+	}
+
+	spin_lock_bh(&dev->bss_lock);
+	cfg80211_bss_expire(dev);
+
+	list_for_each_entry(scan, &dev->bss_list, list) {
+		if (++idx <= start)
+			continue;
+		if (nl80211_send_bss(skb,
+				NETLINK_CB(cb->skb).pid,
+				cb->nlh->nlmsg_seq, NLM_F_MULTI,
+				dev, netdev, &scan->pub) < 0) {
+			idx--;
+			goto out;
+		}
+	}
+
+ out:
+	spin_unlock_bh(&dev->bss_lock);
+
+	cb->args[1] = idx;
+	err = skb->len;
+	cfg80211_put_dev(dev);
+ out_put_netdev:
+	dev_put(netdev);
+
+	return err;
+}
+
 static struct genl_ops nl80211_ops[] = {
 	{
 		.cmd = NL80211_CMD_GET_WIPHY,
@@ -2443,12 +2688,26 @@ static struct genl_ops nl80211_ops[] = {
 		.policy = nl80211_policy,
 		.flags = GENL_ADMIN_PERM,
 	},
+	{
+		.cmd = NL80211_CMD_TRIGGER_SCAN,
+		.doit = nl80211_trigger_scan,
+		.policy = nl80211_policy,
+		.flags = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd = NL80211_CMD_GET_SCAN,
+		.policy = nl80211_policy,
+		.dumpit = nl80211_dump_scan,
+	},
 };
 
 /* multicast groups */
 static struct genl_multicast_group nl80211_config_mcgrp = {
 	.name = "config",
 };
+static struct genl_multicast_group nl80211_scan_mcgrp = {
+	.name = "scan",
+};
 
 /* notification functions */
 
@@ -2468,6 +2727,66 @@ void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev)
 	genlmsg_multicast(msg, 0, nl80211_config_mcgrp.id, GFP_KERNEL);
 }
 
+static int nl80211_send_scan_donemsg(struct sk_buff *msg,
+				    struct cfg80211_registered_device *rdev,
+				    struct net_device *netdev,
+				    u32 pid, u32 seq, int flags,
+				    u32 cmd)
+{
+	void *hdr;
+
+	hdr = nl80211hdr_put(msg, pid, seq, flags, cmd);
+	if (!hdr)
+		return -1;
+
+	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, rdev->idx);
+	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, netdev->ifindex);
+
+	/* XXX: we should probably bounce back the request? */
+
+	return genlmsg_end(msg, hdr);
+
+ nla_put_failure:
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
+void nl80211_send_scan_done(struct cfg80211_registered_device *rdev,
+			    struct net_device *netdev)
+{
+	struct sk_buff *msg;
+
+	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!msg)
+		return;
+
+	if (nl80211_send_scan_donemsg(msg, rdev, netdev, 0, 0, 0,
+				      NL80211_CMD_NEW_SCAN_RESULTS) < 0) {
+		nlmsg_free(msg);
+		return;
+	}
+
+	genlmsg_multicast(msg, 0, nl80211_scan_mcgrp.id, GFP_KERNEL);
+}
+
+void nl80211_send_scan_aborted(struct cfg80211_registered_device *rdev,
+			       struct net_device *netdev)
+{
+	struct sk_buff *msg;
+
+	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!msg)
+		return;
+
+	if (nl80211_send_scan_donemsg(msg, rdev, netdev, 0, 0, 0,
+				      NL80211_CMD_SCAN_ABORTED) < 0) {
+		nlmsg_free(msg);
+		return;
+	}
+
+	genlmsg_multicast(msg, 0, nl80211_scan_mcgrp.id, GFP_KERNEL);
+}
+
 /* initialisation/exit functions */
 
 int nl80211_init(void)
@@ -2488,6 +2807,10 @@ int nl80211_init(void)
 	if (err)
 		goto err_out;
 
+	err = genl_register_mc_group(&nl80211_fam, &nl80211_scan_mcgrp);
+	if (err)
+		goto err_out;
+
 	return 0;
  err_out:
 	genl_unregister_family(&nl80211_fam);

net/wireless/nl80211.h

@@ -7,6 +7,10 @@
 extern int nl80211_init(void);
 extern void nl80211_exit(void);
 extern void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev);
+extern void nl80211_send_scan_done(struct cfg80211_registered_device *rdev,
+				   struct net_device *netdev);
+extern void nl80211_send_scan_aborted(struct cfg80211_registered_device *rdev,
+				      struct net_device *netdev);
 #else
 static inline int nl80211_init(void)
 {
@@ -19,6 +23,10 @@ static inline void nl80211_notify_dev_rename(
 	struct cfg80211_registered_device *rdev)
 {
 }
+static inline void
+nl80211_send_scan_done(struct cfg80211_registered_device *rdev,
+		       struct net_device *netdev)
+{}
 #endif /* CONFIG_NL80211 */
 
 #endif /* __NET_WIRELESS_NL80211_H */