1 /*
2  * WPA Supplicant - auto scan exponential module
3  * Copyright (c) 2012, Intel Corporation. All rights reserved.
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #include "includes.h"
10 
11 #include "common.h"
12 #include "wpa_supplicant_i.h"
13 #include "autoscan.h"
14 
15 struct autoscan_exponential_data {
16 	struct wpa_supplicant *wpa_s;
17 	int base;
18 	int limit;
19 	int interval;
20 };
21 
22 
23 static int
24 autoscan_exponential_get_params(struct autoscan_exponential_data *data,
25 				const char *params)
26 {
27 	const char *pos;
28 
29 	if (params == NULL)
30 		return -1;
31 
32 	data->base = atoi(params);
33 
34 	pos = os_strchr(params, ':');
35 	if (pos == NULL)
36 		return -1;
37 
38 	pos++;
39 	data->limit = atoi(pos);
40 
41 	return 0;
42 }
43 
44 
45 static void * autoscan_exponential_init(struct wpa_supplicant *wpa_s,
46 					const char *params)
47 {
48 	struct autoscan_exponential_data *data;
49 
50 	data = os_zalloc(sizeof(struct autoscan_exponential_data));
51 	if (data == NULL)
52 		return NULL;
53 
54 	if (autoscan_exponential_get_params(data, params) < 0) {
55 		os_free(data);
56 		return NULL;
57 	}
58 
59 	wpa_printf(MSG_DEBUG, "autoscan exponential: base exponential is %d "
60 		   "and limit is %d", data->base, data->limit);
61 
62 	data->wpa_s = wpa_s;
63 
64 	return data;
65 }
66 
67 
68 static void autoscan_exponential_deinit(void *priv)
69 {
70 	struct autoscan_exponential_data *data = priv;
71 
72 	os_free(data);
73 }
74 
75 
76 static int autoscan_exponential_notify_scan(void *priv,
77 					    struct wpa_scan_results *scan_res)
78 {
79 	struct autoscan_exponential_data *data = priv;
80 
81 	wpa_printf(MSG_DEBUG, "autoscan exponential: scan result "
82 		   "notification");
83 
84 	if (data->interval >= data->limit)
85 		return data->limit;
86 
87 	if (data->interval <= 0)
88 		data->interval = data->base;
89 	else {
90 		data->interval = data->interval * data->base;
91 		if (data->interval > data->limit)
92 			return data->limit;
93 	}
94 
95 	return data->interval;
96 }
97 
98 
99 const struct autoscan_ops autoscan_exponential_ops = {
100 	.name = "exponential",
101 	.init = autoscan_exponential_init,
102 	.deinit = autoscan_exponential_deinit,
103 	.notify_scan = autoscan_exponential_notify_scan,
104 };
105