Use radio work for scan requests

Avoid concurrent scan requests by using the radio work queuing
mechanism.

Signed-hostap: Jouni Malinen <j@w1.fi>

diff --git a/wpa_supplicant/events.c b/wpa_supplicant/events.c
index bc1b65e..b0ea7a2 100644 (file)
--- a/wpa_supplicant/events.c
+++ b/wpa_supplicant/events.c
@@ -1,6 +1,6 @@
 /*
  * WPA Supplicant - Driver event processing
- * Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2003-2014, Jouni Malinen <j@w1.fi>
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
@@ -1181,7 +1181,8 @@ static int _wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
                                              union wpa_event_data *data,
                                              int own_request)
 {
-       struct wpa_scan_results *scan_res;
+       struct wpa_scan_results *scan_res = NULL;
+       int ret = 0;
        int ap = 0;
 #ifndef CONFIG_NO_RANDOM_POOL
        size_t i, num;
@@ -1206,7 +1207,8 @@ static int _wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
                        wpa_s->scan_req = wpa_s->last_scan_req;
                        wpa_s->sta_scan_pending = 1;
                        wpa_supplicant_req_scan(wpa_s, 5, 0);
-                       return -1;
+                       ret = -1;
+                       goto scan_work_done;
                }
        }
        wpa_s->sta_scan_pending = 0;
@@ -1224,7 +1226,8 @@ static int _wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
                wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results - try "
                        "scanning again");
                wpa_supplicant_req_new_scan(wpa_s, 1, 0);
-               return -1;
+               ret = -1;
+               goto scan_work_done;
        }
 
 #ifndef CONFIG_NO_RANDOM_POOL
@@ -1251,9 +1254,8 @@ static int _wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
                scan_res_handler = wpa_s->scan_res_handler;
                wpa_s->scan_res_handler = NULL;
                scan_res_handler(wpa_s, scan_res);
-
-               wpa_scan_results_free(scan_res);
-               return -2;
+               ret = -2;
+               goto scan_work_done;
        }
 
        if (ap) {
@@ -1262,8 +1264,7 @@ static int _wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
                if (wpa_s->ap_iface->scan_cb)
                        wpa_s->ap_iface->scan_cb(wpa_s->ap_iface);
 #endif /* CONFIG_AP */
-               wpa_scan_results_free(scan_res);
-               return 0;
+               goto scan_work_done;
        }
 
        wpa_dbg(wpa_s, MSG_DEBUG, "New scan results available (own=%u ext=%u)",
@@ -1286,38 +1287,44 @@ static int _wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
                return 0;
        }
 
-       if (sme_proc_obss_scan(wpa_s) > 0) {
-               wpa_scan_results_free(scan_res);
-               return 0;
-       }
+       if (sme_proc_obss_scan(wpa_s) > 0)
+               goto scan_work_done;
 
-       if ((wpa_s->conf->ap_scan == 2 && !wpas_wps_searching(wpa_s))) {
-               wpa_scan_results_free(scan_res);
-               return 0;
-       }
+       if ((wpa_s->conf->ap_scan == 2 && !wpas_wps_searching(wpa_s)))
+               goto scan_work_done;
 
-       if (autoscan_notify_scan(wpa_s, scan_res)) {
-               wpa_scan_results_free(scan_res);
-               return 0;
-       }
+       if (autoscan_notify_scan(wpa_s, scan_res))
+               goto scan_work_done;
 
        if (wpa_s->disconnected) {
                wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
-               wpa_scan_results_free(scan_res);
-               return 0;
+               goto scan_work_done;
        }
 
        if (!wpas_driver_bss_selection(wpa_s) &&
-           bgscan_notify_scan(wpa_s, scan_res) == 1) {
-               wpa_scan_results_free(scan_res);
-               return 0;
-       }
+           bgscan_notify_scan(wpa_s, scan_res) == 1)
+               goto scan_work_done;
 
        wpas_wps_update_ap_info(wpa_s, scan_res);
 
        wpa_scan_results_free(scan_res);
 
+       if (wpa_s->scan_work) {
+               struct wpa_radio_work *work = wpa_s->scan_work;
+               wpa_s->scan_work = NULL;
+               radio_work_done(work);
+       }
+
        return wpas_select_network_from_last_scan(wpa_s, 1, own_request);
+
+scan_work_done:
+       wpa_scan_results_free(scan_res);
+       if (wpa_s->scan_work) {
+               struct wpa_radio_work *work = wpa_s->scan_work;
+               wpa_s->scan_work = NULL;
+               radio_work_done(work);
+       }
+       return ret;
 }
 
 

diff --git a/wpa_supplicant/scan.c b/wpa_supplicant/scan.c
index 428a668..763fc13 100644 (file)
--- a/wpa_supplicant/scan.c
+++ b/wpa_supplicant/scan.c
@@ -142,34 +142,67 @@ static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 }
 
 
-/**
- * wpa_supplicant_trigger_scan - Request driver to start a scan
- * @wpa_s: Pointer to wpa_supplicant data
- * @params: Scan parameters
- * Returns: 0 on success, -1 on failure
- */
-int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
-                               struct wpa_driver_scan_params *params)
+static void wpas_trigger_scan_cb(struct wpa_radio_work *work, int deinit)
 {
+       struct wpa_supplicant *wpa_s = work->wpa_s;
+       struct wpa_driver_scan_params *params = work->ctx;
        int ret;
 
+       if (deinit) {
+               wpa_scan_free_params(params);
+               return;
+       }
+
        wpa_supplicant_notify_scanning(wpa_s, 1);
 
        if (wpa_s->clear_driver_scan_cache)
                params->only_new_results = 1;
        ret = wpa_drv_scan(wpa_s, params);
+       wpa_scan_free_params(params);
+       work->ctx = NULL;
        if (ret) {
                wpa_supplicant_notify_scanning(wpa_s, 0);
                wpas_notify_scan_done(wpa_s, 0);
-       } else {
-               os_get_reltime(&wpa_s->scan_trigger_time);
-               wpa_s->scan_runs++;
-               wpa_s->normal_scans++;
-               wpa_s->own_scan_requested = 1;
-               wpa_s->clear_driver_scan_cache = 0;
+               radio_work_done(work);
+               return;
        }
 
-       return ret;
+       os_get_reltime(&wpa_s->scan_trigger_time);
+       wpa_s->scan_runs++;
+       wpa_s->normal_scans++;
+       wpa_s->own_scan_requested = 1;
+       wpa_s->clear_driver_scan_cache = 0;
+       wpa_s->scan_work = work;
+}
+
+
+/**
+ * wpa_supplicant_trigger_scan - Request driver to start a scan
+ * @wpa_s: Pointer to wpa_supplicant data
+ * @params: Scan parameters
+ * Returns: 0 on success, -1 on failure
+ */
+int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
+                               struct wpa_driver_scan_params *params)
+{
+       struct wpa_driver_scan_params *ctx;
+
+       if (wpa_s->scan_work) {
+               wpa_dbg(wpa_s, MSG_INFO, "Reject scan trigger since one is already pending");
+               return -1;
+       }
+
+       ctx = wpa_scan_clone_params(params);
+       if (ctx == NULL)
+               return -1;
+
+       if (radio_add_work(wpa_s, 0, "scan", 0, wpas_trigger_scan_cb, ctx) < 0)
+       {
+               wpa_scan_free_params(ctx);
+               return -1;
+       }
+
+       return 0;
 }
 
 
@@ -1699,6 +1732,11 @@ void scan_only_handler(struct wpa_supplicant *wpa_s,
        }
        wpas_notify_scan_results(wpa_s);
        wpas_notify_scan_done(wpa_s, 1);
+       if (wpa_s->scan_work) {
+               struct wpa_radio_work *work = wpa_s->scan_work;
+               wpa_s->scan_work = NULL;
+               radio_work_done(work);
+       }
 }
 
 

diff --git a/wpa_supplicant/wpa_supplicant.c b/wpa_supplicant/wpa_supplicant.c
index fa819ec..f04d60d 100644 (file)
--- a/wpa_supplicant/wpa_supplicant.c
+++ b/wpa_supplicant/wpa_supplicant.c
@@ -2903,6 +2903,13 @@ static struct wpa_radio * radio_add_interface(struct wpa_supplicant *wpa_s,
 
 static void radio_work_free(struct wpa_radio_work *work)
 {
+       if (work->wpa_s->scan_work == work) {
+               /* This should not really happen. */
+               wpa_dbg(work->wpa_s, MSG_INFO, "Freeing radio work '%s'@%p (started=%d) that is marked as scan_work",
+                       work->type, work, work->started);
+               work->wpa_s->scan_work = NULL;
+       }
+
        dl_list_del(&work->list);
        os_free(work);
 }

diff --git a/wpa_supplicant/wpa_supplicant_i.h b/wpa_supplicant/wpa_supplicant_i.h
index 46db3dc..c2d0a36 100644 (file)
--- a/wpa_supplicant/wpa_supplicant_i.h
+++ b/wpa_supplicant/wpa_supplicant_i.h
@@ -442,6 +442,7 @@ struct wpa_supplicant {
        struct ctrl_iface_priv *ctrl_iface;
 
        enum wpa_states wpa_state;
+       struct wpa_radio_work *scan_work;
        int scanning;
        int sched_scanning;
        int new_connection;