Only expire scanned BSSes based on new scan results

Get more information about scans when updating BSS table information.
This allows the missing-from-scans expiration rule to work properly
when only partial set of channels or SSIDs are being scanned.

src/drivers/driver.h

@@ -1,6 +1,6 @@
 /*
  * WPA Supplicant - driver interface definition
- * Copyright (c) 2003-2009, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2003-2010, Jouni Malinen <j@w1.fi>
  *
  * 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
@@ -1577,7 +1577,8 @@ typedef enum wpa_event_type {
 	 * EVENT_SCAN_RESULTS call. If such event is not available from the
 	 * driver, the driver wrapper code is expected to use a registered
 	 * timeout to generate EVENT_SCAN_RESULTS call after the time that the
-	 * scan is expected to be completed.
+	 * scan is expected to be completed. Optional information about
+	 * completed scan can be provided with union wpa_event_data::scan_info.
 	 */
 	EVENT_SCAN_RESULTS,
 
@@ -1948,6 +1949,23 @@ union wpa_event_data {
 		size_t frame_len;
 		struct hostapd_frame_info *fi;
 	} rx_mgmt;
+
+	/**
+	 * struct scan_info - Optional data for EVENT_SCAN_RESULTS events
+	 * @aborted: Whether the scan was aborted
+	 * @freqs: Scanned frequencies in MHz (%NULL = all channels scanned)
+	 * @num_freqs: Number of entries in freqs array
+	 * @ssids: Scanned SSIDs (%NULL or zero-length SSID indicates wildcard
+	 *	SSID)
+	 * @num_ssids: Number of entries in ssids array
+	 */
+	struct scan_info {
+		int aborted;
+		const int *freqs;
+		size_t num_freqs;
+		struct wpa_driver_scan_ssid ssids[WPAS_MAX_SCAN_SSIDS];
+		size_t num_ssids;
+	} scan_info;
 };
 
 /**

src/drivers/driver_nl80211.c

@@ -1,6 +1,6 @@
 /*
  * Driver interaction with Linux nl80211/cfg80211
- * Copyright (c) 2002-2008, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2002-2010, Jouni Malinen <j@w1.fi>
  * Copyright (c) 2003-2004, Instant802 Networks, Inc.
  * Copyright (c) 2005-2006, Devicescape Software, Inc.
  * Copyright (c) 2007, Johannes Berg <johannes@sipsolutions.net>
@@ -707,6 +707,47 @@ static void mlme_event_join_ibss(struct wpa_driver_nl80211_data *drv,
 }
 
 
+static void send_scan_event(struct wpa_driver_nl80211_data *drv, int aborted,
+			    struct nlattr *tb[])
+{
+	union wpa_event_data event;
+	struct nlattr *nl;
+	int rem;
+	struct scan_info *info;
+#define MAX_REPORT_FREQS 50
+	int freqs[MAX_REPORT_FREQS];
+	int num_freqs = 0;
+
+	os_memset(&event, 0, sizeof(event));
+	info = &event.scan_info;
+	info->aborted = aborted;
+
+	if (tb[NL80211_ATTR_SCAN_SSIDS]) {
+		nla_for_each_nested(nl, tb[NL80211_ATTR_SCAN_SSIDS], rem) {
+			struct wpa_driver_scan_ssid *s =
+				&info->ssids[info->num_ssids];
+			s->ssid = nla_data(nl);
+			s->ssid_len = nla_len(nl);
+			info->num_ssids++;
+			if (info->num_ssids == WPAS_MAX_SCAN_SSIDS)
+				break;
+		}
+	}
+	if (tb[NL80211_ATTR_SCAN_FREQUENCIES]) {
+		nla_for_each_nested(nl, tb[NL80211_ATTR_SCAN_FREQUENCIES], rem)
+		{
+			freqs[num_freqs] = nla_get_u32(nl);
+			num_freqs++;
+			if (num_freqs == MAX_REPORT_FREQS - 1)
+				break;
+		}
+		info->freqs = freqs;
+		info->num_freqs = num_freqs;
+	}
+	wpa_supplicant_event(drv->ctx, EVENT_SCAN_RESULTS, &event);
+}
+
+
 static int process_event(struct nl_msg *msg, void *arg)
 {
 	struct wpa_driver_nl80211_data *drv = arg;
@@ -742,7 +783,7 @@ static int process_event(struct nl_msg *msg, void *arg)
 		drv->scan_complete_events = 1;
 		eloop_cancel_timeout(wpa_driver_nl80211_scan_timeout, drv,
 				     drv->ctx);
-		wpa_supplicant_event(drv->ctx, EVENT_SCAN_RESULTS, NULL);
+		send_scan_event(drv, 0, tb);
 		break;
 	case NL80211_CMD_SCAN_ABORTED:
 		wpa_printf(MSG_DEBUG, "nl80211: Scan aborted");
@@ -752,7 +793,7 @@ static int process_event(struct nl_msg *msg, void *arg)
 		 */
 		eloop_cancel_timeout(wpa_driver_nl80211_scan_timeout, drv,
 				     drv->ctx);
-		wpa_supplicant_event(drv->ctx, EVENT_SCAN_RESULTS, NULL);
+		send_scan_event(drv, 1, tb);
 		break;
 	case NL80211_CMD_AUTHENTICATE:
 	case NL80211_CMD_ASSOCIATE:

wpa_supplicant/bss.c

@@ -1,6 +1,6 @@
 /*
  * BSS table
- * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2009-2010, Jouni Malinen <j@w1.fi>
  *
  * 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
@@ -195,16 +195,58 @@ void wpa_bss_update_scan_res(struct wpa_supplicant *wpa_s,
 }
 
 
-void wpa_bss_update_end(struct wpa_supplicant *wpa_s)
+static int wpa_bss_included_in_scan(const struct wpa_bss *bss,
+				    const struct scan_info *info)
+{
+	int found;
+	size_t i;
+
+	if (info == NULL)
+		return 1;
+
+	if (info->num_freqs) {
+		found = 0;
+		for (i = 0; i < info->num_freqs; i++) {
+			if (bss->freq == info->freqs[i]) {
+				found = 1;
+				break;
+			}
+		}
+		if (!found)
+			return 0;
+	}
+
+	if (info->num_ssids) {
+		found = 0;
+		for (i = 0; i < info->num_ssids; i++) {
+			const struct wpa_driver_scan_ssid *s = &info->ssids[i];
+			if ((s->ssid == NULL || s->ssid_len == 0) ||
+			    (s->ssid_len == bss->ssid_len &&
+			     os_memcmp(s->ssid, bss->ssid, bss->ssid_len) ==
+			     0)) {
+				found = 1;
+				break;
+			}
+		}
+		if (!found)
+			return 0;
+	}
+
+	return 1;
+}
+
+
+void wpa_bss_update_end(struct wpa_supplicant *wpa_s, struct scan_info *info,
+			int new_scan)
 {
 	struct wpa_bss *bss, *n;
 
-	/* TODO: expire only entries that were on the scanned frequencies/SSIDs
-	 * list; need to get info from driver about scanned frequencies and
-	 * SSIDs to be able to figure out which entries should be expired based
-	 * on this */
+	if (!new_scan)
+		return; /* do not expire entries without new scan */
 
 	dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
+		if (!wpa_bss_included_in_scan(bss, info))
+			continue; /* expire only BSSes that were scanned */
 		if (bss->last_update_idx < wpa_s->bss_update_idx)
 			bss->scan_miss_count++;
 		if (bss->scan_miss_count >= WPA_BSS_EXPIRATION_SCAN_COUNT) {

wpa_supplicant/bss.h

@@ -1,6 +1,6 @@
 /*
  * BSS table
- * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2009-2010, Jouni Malinen <j@w1.fi>
  *
  * 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
@@ -69,7 +69,8 @@ struct wpa_bss {
 void wpa_bss_update_start(struct wpa_supplicant *wpa_s);
 void wpa_bss_update_scan_res(struct wpa_supplicant *wpa_s,
 			     struct wpa_scan_res *res);
-void wpa_bss_update_end(struct wpa_supplicant *wpa_s);
+void wpa_bss_update_end(struct wpa_supplicant *wpa_s, struct scan_info *info,
+			int new_scan);
 int wpa_bss_init(struct wpa_supplicant *wpa_s);
 void wpa_bss_deinit(struct wpa_supplicant *wpa_s);
 struct wpa_bss * wpa_bss_get(struct wpa_supplicant *wpa_s, const u8 *bssid,

wpa_supplicant/ctrl_iface.c

@@ -882,7 +882,7 @@ static int wpa_supplicant_ctrl_iface_scan_results(
 	size_t i;
 
 	if (wpa_s->scan_res == NULL &&
-	    wpa_supplicant_get_scan_results(wpa_s) < 0)
+	    wpa_supplicant_get_scan_results(wpa_s, NULL, 0) < 0)
 		return 0;
 
 	pos = buf;

wpa_supplicant/dbus/dbus_old.c

@@ -185,7 +185,7 @@ static DBusMessage * wpas_dispatch_bssid_method(DBusMessage *message,
 
 	/* Ensure we actually have scan data */
 	if (wpa_s->scan_res == NULL &&
-	    wpa_supplicant_get_scan_results(wpa_s) < 0) {
+	    wpa_supplicant_get_scan_results(wpa_s, NULL, 0) < 0) {
 		reply = wpas_dbus_new_invalid_bssid_error(message);
 		goto out;
 	}

wpa_supplicant/dbus/dbus_old_handlers.c

@@ -361,7 +361,7 @@ DBusMessage * wpas_dbus_iface_scan_results(DBusMessage *message,
 
 	/* Ensure we've actually got scan results to return */
 	if (wpa_s->scan_res == NULL &&
-	    wpa_supplicant_get_scan_results(wpa_s) < 0) {
+	    wpa_supplicant_get_scan_results(wpa_s, NULL, 0) < 0) {
 		return dbus_message_new_error(message, WPAS_ERROR_SCAN_ERROR,
 					      "An error ocurred getting scan "
 					       "results.");

wpa_supplicant/events.c

@@ -1,6 +1,6 @@
 /*
  * WPA Supplicant - Driver event processing
- * Copyright (c) 2003-2009, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2003-2010, Jouni Malinen <j@w1.fi>
  *
  * 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
@@ -763,14 +763,16 @@ static void wpa_supplicant_rsn_preauth_scan_results(
 }
 
 
-static void wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s)
+static void wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
+					      union wpa_event_data *data)
 {
 	struct wpa_scan_res *selected;
 	struct wpa_ssid *ssid = NULL;
 
 	wpa_supplicant_notify_scanning(wpa_s, 0);
 
-	if (wpa_supplicant_get_scan_results(wpa_s) < 0) {
+	if (wpa_supplicant_get_scan_results(wpa_s, data ? &data->scan_info :
+					    NULL, 1) < 0) {
 		if (wpa_s->conf->ap_scan == 2)
 			return;
 		wpa_printf(MSG_DEBUG, "Failed to get scan results - try "
@@ -1402,7 +1404,7 @@ void wpa_supplicant_event(void *ctx, wpa_event_type event,
 		break;
 #ifndef CONFIG_NO_SCAN_PROCESSING
 	case EVENT_SCAN_RESULTS:
-		wpa_supplicant_event_scan_results(wpa_s);
+		wpa_supplicant_event_scan_results(wpa_s, data);
 		break;
 #endif /* CONFIG_NO_SCAN_PROCESSING */
 	case EVENT_ASSOCINFO:

wpa_supplicant/wpa_supplicant.c

@@ -1570,12 +1570,15 @@ int wpa_supplicant_set_debug_params(struct wpa_global *global, int debug_level,
 /**
  * wpa_supplicant_get_scan_results - Get scan results
  * @wpa_s: Pointer to wpa_supplicant data
+ * @info: Information about what was scanned or %NULL if not available
+ * @new_scan: Whether a new scan was performed
  * Returns: 0 on success, -1 on failure
  *
  * This function request the current scan results from the driver and updates
  * the local BSS list wpa_s->bss.
  */
-int wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s)
+int wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
+				    struct scan_info *info, int new_scan)
 {
 	size_t i;
 
@@ -1594,7 +1597,7 @@ int wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s)
 	wpa_bss_update_start(wpa_s);
 	for (i = 0; i < wpa_s->scan_res->num; i++)
 		wpa_bss_update_scan_res(wpa_s, wpa_s->scan_res->res[i]);
-	wpa_bss_update_end(wpa_s);
+	wpa_bss_update_end(wpa_s, info, new_scan);
 
 	return 0;
 }

wpa_supplicant/wpa_supplicant_i.h

@@ -33,6 +33,7 @@ struct wpa_scan_res;
 struct wpa_sm;
 struct wpa_supplicant;
 struct ibss_rsn;
+struct scan_info;
 
 /*
  * Forward declarations of private structures used within the ctrl_iface
@@ -445,7 +446,8 @@ void wpa_supplicant_associate(struct wpa_supplicant *wpa_s,
 void wpa_supplicant_set_non_wpa_policy(struct wpa_supplicant *wpa_s,
 				       struct wpa_ssid *ssid);
 void wpa_supplicant_initiate_eapol(struct wpa_supplicant *wpa_s);
-int wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s);
+int wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
+				    struct scan_info *info, int new_scan);
 void wpa_clear_keys(struct wpa_supplicant *wpa_s, const u8 *addr);
 void wpa_supplicant_req_auth_timeout(struct wpa_supplicant *wpa_s,
 				     int sec, int usec);

wpa_supplicant/wpas_glue.c

@@ -348,7 +348,7 @@ static int wpa_supplicant_get_beacon_ie(void *ctx)
 
 	/* No WPA/RSN IE found in the cached scan results. Try to get updated
 	 * scan results from the driver. */
-	if (wpa_supplicant_get_scan_results(wpa_s) < 0) {
+	if (wpa_supplicant_get_scan_results(wpa_s, NULL, 0) < 0) {
 		return -1;
 	}