autoreconf

[libeap.git] / wpa_supplicant / bgscan_simple.c

diff --git a/wpa_supplicant/bgscan_simple.c b/wpa_supplicant/bgscan_simple.c
index bf780d5..409d9ce 100644 (file)
--- a/wpa_supplicant/bgscan_simple.c
+++ b/wpa_supplicant/bgscan_simple.c
@@ -1,6 +1,6 @@
 /*
  * WPA Supplicant - background scan and roaming module: simple
- * 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
@@ -19,6 +19,7 @@
 #include "drivers/driver.h"
 #include "config_ssid.h"
 #include "wpa_supplicant_i.h"
+#include "driver_i.h"
 #include "scan.h"
 #include "bgscan.h"
 
@@ -26,6 +27,10 @@ struct bgscan_simple_data {
        struct wpa_supplicant *wpa_s;
        const struct wpa_ssid *ssid;
        int scan_interval;
+       int signal_threshold;
+       int short_interval; /* use if signal < threshold */
+       int long_interval; /* use if signal > threshold */
+       struct os_time last_bgscan;
 };
 
 
@@ -52,7 +57,36 @@ static void bgscan_simple_timeout(void *eloop_ctx, void *timeout_ctx)
                wpa_printf(MSG_DEBUG, "bgscan simple: Failed to trigger scan");
                eloop_register_timeout(data->scan_interval, 0,
                                       bgscan_simple_timeout, data, NULL);
+       } else
+               os_get_time(&data->last_bgscan);
+}
+
+
+static int bgscan_simple_get_params(struct bgscan_simple_data *data,
+                                   const char *params)
+{
+       const char *pos;
+
+       if (params == NULL)
+               return 0;
+
+       data->short_interval = atoi(params);
+
+       pos = os_strchr(params, ':');
+       if (pos == NULL)
+               return 0;
+       pos++;
+       data->signal_threshold = atoi(pos);
+       pos = os_strchr(pos, ':');
+       if (pos == NULL) {
+               wpa_printf(MSG_ERROR, "bgscan simple: Missing scan interval "
+                          "for high signal");
+               return -1;
        }
+       pos++;
+       data->long_interval = atoi(pos);
+
+       return 0;
 }
 
 
@@ -67,12 +101,38 @@ static void * bgscan_simple_init(struct wpa_supplicant *wpa_s,
                return NULL;
        data->wpa_s = wpa_s;
        data->ssid = ssid;
-       if (params)
-               data->scan_interval = atoi(params);
-       if (data->scan_interval <= 0)
-               data->scan_interval = 30;
+       if (bgscan_simple_get_params(data, params) < 0) {
+               os_free(data);
+               return NULL;
+       }
+       if (data->short_interval <= 0)
+               data->short_interval = 30;
+       if (data->long_interval <= 0)
+               data->long_interval = 30;
+
+       wpa_printf(MSG_DEBUG, "bgscan simple: Signal strength threshold %d  "
+                  "Short bgscan interval %d  Long bgscan interval %d",
+                  data->signal_threshold, data->short_interval,
+                  data->long_interval);
+
+       if (data->signal_threshold &&
+           wpa_drv_signal_monitor(wpa_s, data->signal_threshold, 4) < 0) {
+               wpa_printf(MSG_ERROR, "bgscan simple: Failed to enable "
+                          "signal strength monitoring");
+       }
+
+       data->scan_interval = data->short_interval;
        eloop_register_timeout(data->scan_interval, 0, bgscan_simple_timeout,
                               data, NULL);
+
+       /*
+        * This function is called immediately after an association, so it is
+        * reasonable to assume that a scan was completed recently. This makes
+        * us skip an immediate new scan in cases where the current signal
+        * level is below the bgscan threshold.
+        */
+       os_get_time(&data->last_bgscan);
+
        return data;
 }
 
@@ -81,11 +141,14 @@ static void bgscan_simple_deinit(void *priv)
 {
        struct bgscan_simple_data *data = priv;
        eloop_cancel_timeout(bgscan_simple_timeout, data, NULL);
+       if (data->signal_threshold)
+               wpa_drv_signal_monitor(data->wpa_s, 0, 0);
        os_free(data);
 }
 
 
-static int bgscan_simple_notify_scan(void *priv)
+static int bgscan_simple_notify_scan(void *priv,
+                                    struct wpa_scan_results *scan_res)
 {
        struct bgscan_simple_data *data = priv;
 
@@ -113,11 +176,53 @@ static void bgscan_simple_notify_beacon_loss(void *priv)
 }
 
 
-static void bgscan_simple_notify_signal_change(void *priv)
+static void bgscan_simple_notify_signal_change(void *priv, int above,
+                                              int current_signal,
+                                              int current_noise,
+                                              int current_txrate)
 {
-       wpa_printf(MSG_DEBUG, "bgscan simple: signal level changed");
-       /* TODO: if signal strength dropped enough, speed up background
-        * scanning */
+       struct bgscan_simple_data *data = priv;
+       int scan = 0;
+       struct os_time now;
+
+       if (data->short_interval == data->long_interval ||
+           data->signal_threshold == 0)
+               return;
+
+       wpa_printf(MSG_DEBUG, "bgscan simple: signal level changed "
+                  "(above=%d current_signal=%d current_noise=%d "
+                  "current_txrate=%d))", above, current_signal,
+                  current_noise, current_txrate);
+       if (data->scan_interval == data->long_interval && !above) {
+               wpa_printf(MSG_DEBUG, "bgscan simple: Start using short "
+                          "bgscan interval");
+               data->scan_interval = data->short_interval;
+               os_get_time(&now);
+               if (now.sec > data->last_bgscan.sec + 1)
+                       scan = 1;
+       } else if (data->scan_interval == data->short_interval && above) {
+               wpa_printf(MSG_DEBUG, "bgscan simple: Start using long bgscan "
+                          "interval");
+               data->scan_interval = data->long_interval;
+               eloop_cancel_timeout(bgscan_simple_timeout, data, NULL);
+               eloop_register_timeout(data->scan_interval, 0,
+                                      bgscan_simple_timeout, data, NULL);
+       } else if (!above) {
+               /*
+                * Signal dropped further 4 dB. Request a new scan if we have
+                * not yet scanned in a while.
+                */
+               os_get_time(&now);
+               if (now.sec > data->last_bgscan.sec + 10)
+                       scan = 1;
+       }
+
+       if (scan) {
+               wpa_printf(MSG_DEBUG, "bgscan simple: Trigger immediate scan");
+               eloop_cancel_timeout(bgscan_simple_timeout, data, NULL);
+               eloop_register_timeout(0, 0, bgscan_simple_timeout, data,
+                                      NULL);
+       }
 }