3 * Copyright (c) 2009-2010, 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"
27 #ifndef WPA_BSS_MAX_COUNT
28 #define WPA_BSS_MAX_COUNT 200
29 #endif /* WPA_BSS_MAX_COUNT */
32 * WPA_BSS_EXPIRATION_PERIOD - Period of expiration run in seconds
34 #define WPA_BSS_EXPIRATION_PERIOD 10
37 * WPA_BSS_EXPIRATION_AGE - BSS entry age after which it can be expired
39 * This value control the time in seconds after which a BSS entry gets removed
40 * if it has not been updated or is not in use.
42 #define WPA_BSS_EXPIRATION_AGE 180
45 * WPA_BSS_EXPIRATION_SCAN_COUNT - Expire BSS after number of scans
47 * If the BSS entry has not been seen in this many scans, it will be removed.
48 * Value 1 means that the entry is removed after the first scan without the
49 * BSSID being seen. Larger values can be used to avoid BSS entries
50 * disappearing if they are not visible in every scan (e.g., low signal quality
53 #define WPA_BSS_EXPIRATION_SCAN_COUNT 2
56 static void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
58 dl_list_del(&bss->list);
59 dl_list_del(&bss->list_id);
61 wpa_printf(MSG_DEBUG, "BSS: Remove id %u BSSID " MACSTR " SSID '%s'",
62 bss->id, MAC2STR(bss->bssid),
63 wpa_ssid_txt(bss->ssid, bss->ssid_len));
64 wpas_notify_bss_removed(wpa_s, bss->bssid, bss->id);
69 struct wpa_bss * wpa_bss_get(struct wpa_supplicant *wpa_s, const u8 *bssid,
70 const u8 *ssid, size_t ssid_len)
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, bss->bssid, bss->id);
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 struct dl_list *prev = bss->list_id.prev;
153 dl_list_del(&bss->list_id);
154 nbss = os_realloc(bss, sizeof(*bss) + res->ie_len);
157 os_memcpy(bss + 1, res + 1, res->ie_len);
158 bss->ie_len = res->ie_len;
160 dl_list_add(prev, &bss->list_id);
162 dl_list_add_tail(&wpa_s->bss, &bss->list);
166 static int wpa_bss_in_use(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
168 return bss == wpa_s->current_bss ||
169 os_memcmp(bss->bssid, wpa_s->bssid, ETH_ALEN) == 0 ||
170 os_memcmp(bss->bssid, wpa_s->pending_bssid, ETH_ALEN) == 0;
174 void wpa_bss_update_start(struct wpa_supplicant *wpa_s)
176 wpa_s->bss_update_idx++;
177 wpa_printf(MSG_DEBUG, "BSS: Start scan result update %u",
178 wpa_s->bss_update_idx);
182 void wpa_bss_update_scan_res(struct wpa_supplicant *wpa_s,
183 struct wpa_scan_res *res)
188 ssid = wpa_scan_get_ie(res, WLAN_EID_SSID);
190 wpa_printf(MSG_DEBUG, "BSS: No SSID IE included for " MACSTR,
191 MAC2STR(res->bssid));
195 wpa_printf(MSG_DEBUG, "BSS: Too long SSID IE included for "
196 MACSTR, MAC2STR(res->bssid));
200 /* TODO: add option for ignoring BSSes we are not interested in
201 * (to save memory) */
202 bss = wpa_bss_get(wpa_s, res->bssid, ssid + 2, ssid[1]);
204 wpa_bss_add(wpa_s, ssid + 2, ssid[1], res);
206 wpa_bss_update(wpa_s, bss, res);
210 static int wpa_bss_included_in_scan(const struct wpa_bss *bss,
211 const struct scan_info *info)
219 if (info->num_freqs) {
221 for (i = 0; i < info->num_freqs; i++) {
222 if (bss->freq == info->freqs[i]) {
231 if (info->num_ssids) {
233 for (i = 0; i < info->num_ssids; i++) {
234 const struct wpa_driver_scan_ssid *s = &info->ssids[i];
235 if ((s->ssid == NULL || s->ssid_len == 0) ||
236 (s->ssid_len == bss->ssid_len &&
237 os_memcmp(s->ssid, bss->ssid, bss->ssid_len) ==
251 void wpa_bss_update_end(struct wpa_supplicant *wpa_s, struct scan_info *info,
254 struct wpa_bss *bss, *n;
257 return; /* do not expire entries without new scan */
259 dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
260 if (wpa_bss_in_use(wpa_s, bss))
262 if (!wpa_bss_included_in_scan(bss, info))
263 continue; /* expire only BSSes that were scanned */
264 if (bss->last_update_idx < wpa_s->bss_update_idx)
265 bss->scan_miss_count++;
266 if (bss->scan_miss_count >= WPA_BSS_EXPIRATION_SCAN_COUNT) {
267 wpa_printf(MSG_DEBUG, "BSS: Expire BSS %u due to no "
268 "match in scan", bss->id);
269 wpa_bss_remove(wpa_s, bss);
275 static void wpa_bss_timeout(void *eloop_ctx, void *timeout_ctx)
277 struct wpa_supplicant *wpa_s = eloop_ctx;
278 struct wpa_bss *bss, *n;
281 if (dl_list_empty(&wpa_s->bss))
285 t.sec -= WPA_BSS_EXPIRATION_AGE;
287 dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
288 if (wpa_bss_in_use(wpa_s, bss))
291 if (os_time_before(&bss->last_update, &t)) {
292 wpa_printf(MSG_DEBUG, "BSS: Expire BSS %u due to age",
294 wpa_bss_remove(wpa_s, bss);
298 eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0,
299 wpa_bss_timeout, wpa_s, NULL);
303 int wpa_bss_init(struct wpa_supplicant *wpa_s)
305 dl_list_init(&wpa_s->bss);
306 dl_list_init(&wpa_s->bss_id);
307 eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0,
308 wpa_bss_timeout, wpa_s, NULL);
313 void wpa_bss_deinit(struct wpa_supplicant *wpa_s)
315 struct wpa_bss *bss, *n;
316 eloop_cancel_timeout(wpa_bss_timeout, wpa_s, NULL);
317 if (wpa_s->bss.next == NULL)
318 return; /* BSS table not yet initialized */
319 dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list)
320 wpa_bss_remove(wpa_s, bss);
324 struct wpa_bss * wpa_bss_get_bssid(struct wpa_supplicant *wpa_s,
328 dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
329 if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0)
336 struct wpa_bss * wpa_bss_get_id(struct wpa_supplicant *wpa_s, unsigned int id)
339 dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
347 const u8 * wpa_bss_get_ie(const struct wpa_bss *bss, u8 ie)
351 pos = (const u8 *) (bss + 1);
352 end = pos + bss->ie_len;
354 while (pos + 1 < end) {
355 if (pos + 2 + pos[1] > end)
366 const u8 * wpa_bss_get_vendor_ie(const struct wpa_bss *bss, u32 vendor_type)
370 pos = (const u8 *) (bss + 1);
371 end = pos + bss->ie_len;
373 while (pos + 1 < end) {
374 if (pos + 2 + pos[1] > end)
376 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
377 vendor_type == WPA_GET_BE32(&pos[2]))
386 struct wpabuf * wpa_bss_get_vendor_ie_multi(const struct wpa_bss *bss,
392 buf = wpabuf_alloc(bss->ie_len);
396 pos = (const u8 *) (bss + 1);
397 end = pos + bss->ie_len;
399 while (pos + 1 < end) {
400 if (pos + 2 + pos[1] > end)
402 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
403 vendor_type == WPA_GET_BE32(&pos[2]))
404 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
408 if (wpabuf_len(buf) == 0) {
417 int wpa_bss_get_max_rate(const struct wpa_bss *bss)
423 ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES);
424 for (i = 0; ie && i < ie[1]; i++) {
425 if ((ie[i + 2] & 0x7f) > rate)
426 rate = ie[i + 2] & 0x7f;
429 ie = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES);
430 for (i = 0; ie && i < ie[1]; i++) {
431 if ((ie[i + 2] & 0x7f) > rate)
432 rate = ie[i + 2] & 0x7f;