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.
15 #include "utils/includes.h"
17 #include "utils/common.h"
18 #include "utils/eloop.h"
19 #include "common/ieee802_11_defs.h"
20 #include "drivers/driver.h"
21 #include "wpa_supplicant_i.h"
26 #ifndef WPA_BSS_MAX_COUNT
27 #define WPA_BSS_MAX_COUNT 200
28 #endif /* WPA_BSS_MAX_COUNT */
31 * WPA_BSS_EXPIRATION_PERIOD - Period of expiration run in seconds
33 #define WPA_BSS_EXPIRATION_PERIOD 10
36 * WPA_BSS_EXPIRATION_AGE - BSS entry age after which it can be expired
38 * This value control the time in seconds after which a BSS entry gets removed
39 * if it has not been updated or is not in use.
41 #define WPA_BSS_EXPIRATION_AGE 180
44 * WPA_BSS_EXPIRATION_SCAN_COUNT - Expire BSS after number of scans
46 * If the BSS entry has not been seen in this many scans, it will be removed.
47 * Value 1 means that the entry is removed after the first scan without the
48 * BSSID being seen. Larger values can be used to avoid BSS entries
49 * disappearing if they are not visible in every scan (e.g., low signal quality
52 #define WPA_BSS_EXPIRATION_SCAN_COUNT 2
55 static void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
57 dl_list_del(&bss->list);
58 dl_list_del(&bss->list_id);
60 wpa_printf(MSG_DEBUG, "BSS: Remove id %u BSSID " MACSTR " SSID '%s'",
61 bss->id, MAC2STR(bss->bssid),
62 wpa_ssid_txt(bss->ssid, bss->ssid_len));
63 wpas_notify_bss_removed(wpa_s, bss->bssid);
68 static struct wpa_bss * wpa_bss_get(struct wpa_supplicant *wpa_s,
69 const u8 *bssid, const u8 *ssid,
73 dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
74 if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0 &&
75 bss->ssid_len == ssid_len &&
76 os_memcmp(bss->ssid, ssid, ssid_len) == 0)
83 static void wpa_bss_copy_res(struct wpa_bss *dst, struct wpa_scan_res *src)
87 dst->flags = src->flags;
88 os_memcpy(dst->bssid, src->bssid, ETH_ALEN);
89 dst->freq = src->freq;
90 dst->beacon_int = src->beacon_int;
91 dst->caps = src->caps;
92 dst->qual = src->qual;
93 dst->noise = src->noise;
94 dst->level = src->level;
97 os_get_time(&dst->last_update);
98 dst->last_update.sec -= src->age / 1000;
99 usec = (src->age % 1000) * 1000;
100 if (dst->last_update.usec < usec) {
101 dst->last_update.sec--;
102 dst->last_update.usec += 1000000;
104 dst->last_update.usec -= usec;
108 static void wpa_bss_add(struct wpa_supplicant *wpa_s,
109 const u8 *ssid, size_t ssid_len,
110 struct wpa_scan_res *res)
114 bss = os_zalloc(sizeof(*bss) + res->ie_len);
117 bss->id = wpa_s->bss_next_id++;
118 bss->last_update_idx = wpa_s->bss_update_idx;
119 wpa_bss_copy_res(bss, res);
120 os_memcpy(bss->ssid, ssid, ssid_len);
121 bss->ssid_len = ssid_len;
122 bss->ie_len = res->ie_len;
123 os_memcpy(bss + 1, res + 1, res->ie_len);
125 dl_list_add_tail(&wpa_s->bss, &bss->list);
126 dl_list_add_tail(&wpa_s->bss_id, &bss->list_id);
128 wpa_printf(MSG_DEBUG, "BSS: Add new id %u BSSID " MACSTR " SSID '%s'",
129 bss->id, MAC2STR(bss->bssid), wpa_ssid_txt(ssid, ssid_len));
130 wpas_notify_bss_added(wpa_s, res->bssid);
131 if (wpa_s->num_bss > WPA_BSS_MAX_COUNT) {
132 /* Remove the oldest entry */
133 wpa_bss_remove(wpa_s, dl_list_first(&wpa_s->bss,
134 struct wpa_bss, list));
139 static void wpa_bss_update(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
140 struct wpa_scan_res *res)
142 bss->scan_miss_count = 0;
143 bss->last_update_idx = wpa_s->bss_update_idx;
144 wpa_bss_copy_res(bss, res);
145 /* Move the entry to the end of the list */
146 dl_list_del(&bss->list);
147 if (bss->ie_len >= res->ie_len) {
148 os_memcpy(bss + 1, res + 1, res->ie_len);
149 bss->ie_len = res->ie_len;
151 struct wpa_bss *nbss;
152 nbss = os_realloc(bss, sizeof(*bss) + res->ie_len);
155 os_memcpy(bss + 1, res + 1, res->ie_len);
156 bss->ie_len = res->ie_len;
159 dl_list_add_tail(&wpa_s->bss, &bss->list);
163 void wpa_bss_update_start(struct wpa_supplicant *wpa_s)
165 wpa_s->bss_update_idx++;
166 wpa_printf(MSG_DEBUG, "BSS: Start scan result update %u",
167 wpa_s->bss_update_idx);
171 void wpa_bss_update_scan_res(struct wpa_supplicant *wpa_s,
172 struct wpa_scan_res *res)
177 ssid = wpa_scan_get_ie(res, WLAN_EID_SSID);
179 wpa_printf(MSG_DEBUG, "BSS: No SSID IE included for " MACSTR,
180 MAC2STR(res->bssid));
184 wpa_printf(MSG_DEBUG, "BSS: Too long SSID IE included for "
185 MACSTR, MAC2STR(res->bssid));
189 /* TODO: add option for ignoring BSSes we are not interested in
190 * (to save memory) */
191 bss = wpa_bss_get(wpa_s, res->bssid, ssid + 2, ssid[1]);
193 wpa_bss_add(wpa_s, ssid + 2, ssid[1], res);
195 wpa_bss_update(wpa_s, bss, res);
199 void wpa_bss_update_end(struct wpa_supplicant *wpa_s)
201 struct wpa_bss *bss, *n;
203 /* TODO: expire only entries that were on the scanned frequencies/SSIDs
204 * list; need to get info from driver about scanned frequencies and
205 * SSIDs to be able to figure out which entries should be expired based
208 dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
209 if (bss->last_update_idx < wpa_s->bss_update_idx)
210 bss->scan_miss_count++;
211 if (bss->scan_miss_count >= WPA_BSS_EXPIRATION_SCAN_COUNT) {
212 wpa_printf(MSG_DEBUG, "BSS: Expire BSS %u due to no "
213 "match in scan", bss->id);
214 wpa_bss_remove(wpa_s, bss);
220 static void wpa_bss_timeout(void *eloop_ctx, void *timeout_ctx)
222 struct wpa_supplicant *wpa_s = eloop_ctx;
223 struct wpa_bss *bss, *n;
226 if (dl_list_empty(&wpa_s->bss))
230 t.sec -= WPA_BSS_EXPIRATION_AGE;
232 dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
233 if (os_memcmp(bss->bssid, wpa_s->bssid, ETH_ALEN) == 0 ||
234 os_memcmp(bss->bssid, wpa_s->pending_bssid, ETH_ALEN) == 0)
235 continue; /* do not expire BSSes that are in use */
237 if (os_time_before(&bss->last_update, &t)) {
238 wpa_printf(MSG_DEBUG, "BSS: Expire BSS %u due to age",
240 wpa_bss_remove(wpa_s, bss);
244 eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0,
245 wpa_bss_timeout, wpa_s, NULL);
249 int wpa_bss_init(struct wpa_supplicant *wpa_s)
251 dl_list_init(&wpa_s->bss);
252 dl_list_init(&wpa_s->bss_id);
253 eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0,
254 wpa_bss_timeout, wpa_s, NULL);
259 void wpa_bss_deinit(struct wpa_supplicant *wpa_s)
261 struct wpa_bss *bss, *n;
262 eloop_cancel_timeout(wpa_bss_timeout, wpa_s, NULL);
263 dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list)
264 wpa_bss_remove(wpa_s, bss);
268 struct wpa_bss * wpa_bss_get_bssid(struct wpa_supplicant *wpa_s,
272 dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
273 if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0)
280 struct wpa_bss * wpa_bss_get_id(struct wpa_supplicant *wpa_s, unsigned int id)
283 dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
291 const u8 * wpa_bss_get_ie(const struct wpa_bss *bss, u8 ie)
295 pos = (const u8 *) (bss + 1);
296 end = pos + bss->ie_len;
298 while (pos + 1 < end) {
299 if (pos + 2 + pos[1] > end)
310 const u8 * wpa_bss_get_vendor_ie(const struct wpa_bss *bss, u32 vendor_type)
314 pos = (const u8 *) (bss + 1);
315 end = pos + bss->ie_len;
317 while (pos + 1 < end) {
318 if (pos + 2 + pos[1] > end)
320 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
321 vendor_type == WPA_GET_BE32(&pos[2]))
330 struct wpabuf * wpa_bss_get_vendor_ie_multi(const struct wpa_bss *bss,
336 buf = wpabuf_alloc(bss->ie_len);
340 pos = (const u8 *) (bss + 1);
341 end = pos + bss->ie_len;
343 while (pos + 1 < end) {
344 if (pos + 2 + pos[1] > end)
346 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
347 vendor_type == WPA_GET_BE32(&pos[2]))
348 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
352 if (wpabuf_len(buf) == 0) {