2 * WPA Supplicant - background scan and roaming module: simple
3 * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
19 #include "drivers/driver.h"
20 #include "config_ssid.h"
21 #include "wpa_supplicant_i.h"
25 struct bgscan_simple_data {
26 struct wpa_supplicant *wpa_s;
27 const struct wpa_ssid *ssid;
32 static void bgscan_simple_timeout(void *eloop_ctx, void *timeout_ctx)
34 struct bgscan_simple_data *data = eloop_ctx;
35 struct wpa_supplicant *wpa_s = data->wpa_s;
36 struct wpa_driver_scan_params params;
38 os_memset(¶ms, 0, sizeof(params));
40 params.ssids[0].ssid = data->ssid->ssid;
41 params.ssids[0].ssid_len = data->ssid->ssid_len;
42 params.freqs = data->ssid->scan_freq;
45 * A more advanced bgscan module would learn about most like channels
46 * over time and request scans only for some channels (probing others
47 * every now and then) to reduce effect on the data connection.
50 wpa_printf(MSG_DEBUG, "bgscan simple: Request a background scan");
51 if (wpa_supplicant_trigger_scan(wpa_s, ¶ms)) {
52 wpa_printf(MSG_DEBUG, "bgscan simple: Failed to trigger scan");
53 eloop_register_timeout(data->scan_interval, 0,
54 bgscan_simple_timeout, data, NULL);
59 static void * bgscan_simple_init(struct wpa_supplicant *wpa_s,
61 const struct wpa_ssid *ssid)
63 struct bgscan_simple_data *data;
65 data = os_zalloc(sizeof(*data));
71 data->scan_interval = atoi(params);
72 if (data->scan_interval <= 0)
73 data->scan_interval = 30;
74 eloop_register_timeout(data->scan_interval, 0, bgscan_simple_timeout,
80 static void bgscan_simple_deinit(void *priv)
82 struct bgscan_simple_data *data = priv;
83 eloop_cancel_timeout(bgscan_simple_timeout, data, NULL);
88 static int bgscan_simple_notify_scan(void *priv)
90 struct bgscan_simple_data *data = priv;
92 wpa_printf(MSG_DEBUG, "bgscan simple: scan result notification");
94 eloop_cancel_timeout(bgscan_simple_timeout, data, NULL);
95 eloop_register_timeout(data->scan_interval, 0, bgscan_simple_timeout,
99 * A more advanced bgscan could process scan results internally, select
100 * the BSS and request roam if needed. This sample uses the existing
101 * BSS/ESS selection routine. Change this to return 1 if selection is
102 * done inside the bgscan module.
109 static void bgscan_simple_notify_beacon_loss(void *priv)
111 wpa_printf(MSG_DEBUG, "bgscan simple: beacon loss");
112 /* TODO: speed up background scanning */
116 static void bgscan_simple_notify_signal_change(void *priv)
118 wpa_printf(MSG_DEBUG, "bgscan simple: signal level changed");
119 /* TODO: if signal strength dropped enough, speed up background
124 const struct bgscan_ops bgscan_simple_ops = {
126 .init = bgscan_simple_init,
127 .deinit = bgscan_simple_deinit,
128 .notify_scan = bgscan_simple_notify_scan,
129 .notify_beacon_loss = bgscan_simple_notify_beacon_loss,
130 .notify_signal_change = bgscan_simple_notify_signal_change,