$search
00001 /* 00002 * BSS table 00003 * Copyright (c) 2009-2010, Jouni Malinen <j@w1.fi> 00004 * 00005 * This program is free software; you can redistribute it and/or modify 00006 * it under the terms of the GNU General Public License version 2 as 00007 * published by the Free Software Foundation. 00008 * 00009 * Alternatively, this software may be distributed under the terms of BSD 00010 * license. 00011 * 00012 * See README and COPYING for more details. 00013 */ 00014 00015 #include "utils/includes.h" 00016 00017 #include "utils/common.h" 00018 #include "utils/eloop.h" 00019 #include "common/ieee802_11_defs.h" 00020 #include "drivers/driver.h" 00021 #include "wpa_supplicant_i.h" 00022 #include "config.h" 00023 #include "notify.h" 00024 #include "scan.h" 00025 #include "bss.h" 00026 00027 00031 #define WPA_BSS_EXPIRATION_PERIOD 10 00032 00039 #define WPA_BSS_EXPIRATION_AGE 180 00040 00050 #define WPA_BSS_EXPIRATION_SCAN_COUNT 2 00051 00052 #define WPA_BSS_FREQ_CHANGED_FLAG BIT(0) 00053 #define WPA_BSS_SIGNAL_CHANGED_FLAG BIT(1) 00054 #define WPA_BSS_PRIVACY_CHANGED_FLAG BIT(2) 00055 #define WPA_BSS_MODE_CHANGED_FLAG BIT(3) 00056 #define WPA_BSS_WPAIE_CHANGED_FLAG BIT(4) 00057 #define WPA_BSS_RSNIE_CHANGED_FLAG BIT(5) 00058 #define WPA_BSS_WPS_CHANGED_FLAG BIT(6) 00059 #define WPA_BSS_RATES_CHANGED_FLAG BIT(7) 00060 #define WPA_BSS_IES_CHANGED_FLAG BIT(8) 00061 00062 00063 static void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss) 00064 { 00065 dl_list_del(&bss->list); 00066 dl_list_del(&bss->list_id); 00067 wpa_s->num_bss--; 00068 wpa_printf(MSG_DEBUG, "BSS: Remove id %u BSSID " MACSTR " SSID '%s'", 00069 bss->id, MAC2STR(bss->bssid), 00070 wpa_ssid_txt(bss->ssid, bss->ssid_len)); 00071 wpas_notify_bss_removed(wpa_s, bss->bssid, bss->id); 00072 os_free(bss); 00073 } 00074 00075 00076 struct wpa_bss * wpa_bss_get(struct wpa_supplicant *wpa_s, const u8 *bssid, 00077 const u8 *ssid, size_t ssid_len) 00078 { 00079 struct wpa_bss *bss; 00080 dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) { 00081 if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0 && 00082 bss->ssid_len == ssid_len && 00083 os_memcmp(bss->ssid, ssid, ssid_len) == 0) 00084 return bss; 00085 } 00086 return NULL; 00087 } 00088 00089 00090 static void wpa_bss_copy_res(struct wpa_bss *dst, struct wpa_scan_res *src) 00091 { 00092 os_time_t usec; 00093 00094 dst->flags = src->flags; 00095 os_memcpy(dst->bssid, src->bssid, ETH_ALEN); 00096 dst->freq = src->freq; 00097 dst->beacon_int = src->beacon_int; 00098 dst->caps = src->caps; 00099 dst->qual = src->qual; 00100 dst->noise = src->noise; 00101 dst->level = src->level; 00102 dst->tsf = src->tsf; 00103 00104 os_get_time(&dst->last_update); 00105 dst->last_update.sec -= src->age / 1000; 00106 usec = (src->age % 1000) * 1000; 00107 if (dst->last_update.usec < usec) { 00108 dst->last_update.sec--; 00109 dst->last_update.usec += 1000000; 00110 } 00111 dst->last_update.usec -= usec; 00112 } 00113 00114 00115 static void wpa_bss_add(struct wpa_supplicant *wpa_s, 00116 const u8 *ssid, size_t ssid_len, 00117 struct wpa_scan_res *res) 00118 { 00119 struct wpa_bss *bss; 00120 00121 bss = os_zalloc(sizeof(*bss) + res->ie_len + res->beacon_ie_len); 00122 if (bss == NULL) 00123 return; 00124 bss->id = wpa_s->bss_next_id++; 00125 bss->last_update_idx = wpa_s->bss_update_idx; 00126 wpa_bss_copy_res(bss, res); 00127 os_memcpy(bss->ssid, ssid, ssid_len); 00128 bss->ssid_len = ssid_len; 00129 bss->ie_len = res->ie_len; 00130 bss->beacon_ie_len = res->beacon_ie_len; 00131 os_memcpy(bss + 1, res + 1, res->ie_len + res->beacon_ie_len); 00132 00133 dl_list_add_tail(&wpa_s->bss, &bss->list); 00134 dl_list_add_tail(&wpa_s->bss_id, &bss->list_id); 00135 wpa_s->num_bss++; 00136 wpa_printf(MSG_DEBUG, "BSS: Add new id %u BSSID " MACSTR " SSID '%s'", 00137 bss->id, MAC2STR(bss->bssid), wpa_ssid_txt(ssid, ssid_len)); 00138 wpas_notify_bss_added(wpa_s, bss->bssid, bss->id); 00139 if (wpa_s->num_bss > wpa_s->conf->bss_max_count) { 00140 /* Remove the oldest entry */ 00141 wpa_bss_remove(wpa_s, dl_list_first(&wpa_s->bss, 00142 struct wpa_bss, list)); 00143 } 00144 } 00145 00146 00147 static int are_ies_equal(const struct wpa_bss *old, 00148 const struct wpa_scan_res *new, u32 ie) 00149 { 00150 const u8 *old_ie, *new_ie; 00151 struct wpabuf *old_ie_buff = NULL; 00152 struct wpabuf *new_ie_buff = NULL; 00153 int new_ie_len, old_ie_len, ret, is_multi; 00154 00155 switch (ie) { 00156 case WPA_IE_VENDOR_TYPE: 00157 old_ie = wpa_bss_get_vendor_ie(old, ie); 00158 new_ie = wpa_scan_get_vendor_ie(new, ie); 00159 is_multi = 0; 00160 break; 00161 case WPS_IE_VENDOR_TYPE: 00162 old_ie_buff = wpa_bss_get_vendor_ie_multi(old, ie); 00163 new_ie_buff = wpa_scan_get_vendor_ie_multi(new, ie); 00164 is_multi = 1; 00165 break; 00166 case WLAN_EID_RSN: 00167 case WLAN_EID_SUPP_RATES: 00168 case WLAN_EID_EXT_SUPP_RATES: 00169 old_ie = wpa_bss_get_ie(old, ie); 00170 new_ie = wpa_scan_get_ie(new, ie); 00171 is_multi = 0; 00172 break; 00173 default: 00174 wpa_printf(MSG_DEBUG, "bss: %s: cannot compare IEs", __func__); 00175 return 0; 00176 } 00177 00178 if (is_multi) { 00179 /* in case of multiple IEs stored in buffer */ 00180 old_ie = old_ie_buff ? wpabuf_head_u8(old_ie_buff) : NULL; 00181 new_ie = new_ie_buff ? wpabuf_head_u8(new_ie_buff) : NULL; 00182 old_ie_len = old_ie_buff ? wpabuf_len(old_ie_buff) : 0; 00183 new_ie_len = new_ie_buff ? wpabuf_len(new_ie_buff) : 0; 00184 } else { 00185 /* in case of single IE */ 00186 old_ie_len = old_ie ? old_ie[1] + 2 : 0; 00187 new_ie_len = new_ie ? new_ie[1] + 2 : 0; 00188 } 00189 00190 ret = (old_ie_len == new_ie_len && 00191 os_memcmp(old_ie, new_ie, old_ie_len) == 0); 00192 00193 wpabuf_free(old_ie_buff); 00194 wpabuf_free(new_ie_buff); 00195 00196 return ret; 00197 } 00198 00199 00200 static u32 wpa_bss_compare_res(const struct wpa_bss *old, 00201 const struct wpa_scan_res *new) 00202 { 00203 u32 changes = 0; 00204 int caps_diff = old->caps ^ new->caps; 00205 00206 if (old->freq != new->freq) 00207 changes |= WPA_BSS_FREQ_CHANGED_FLAG; 00208 00209 if (old->level != new->level) 00210 changes |= WPA_BSS_SIGNAL_CHANGED_FLAG; 00211 00212 if (caps_diff & IEEE80211_CAP_PRIVACY) 00213 changes |= WPA_BSS_PRIVACY_CHANGED_FLAG; 00214 00215 if (caps_diff & IEEE80211_CAP_IBSS) 00216 changes |= WPA_BSS_MODE_CHANGED_FLAG; 00217 00218 if (old->ie_len == new->ie_len && 00219 os_memcmp(old + 1, new + 1, old->ie_len) == 0) 00220 return changes; 00221 changes |= WPA_BSS_IES_CHANGED_FLAG; 00222 00223 if (!are_ies_equal(old, new, WPA_IE_VENDOR_TYPE)) 00224 changes |= WPA_BSS_WPAIE_CHANGED_FLAG; 00225 00226 if (!are_ies_equal(old, new, WLAN_EID_RSN)) 00227 changes |= WPA_BSS_RSNIE_CHANGED_FLAG; 00228 00229 if (!are_ies_equal(old, new, WPS_IE_VENDOR_TYPE)) 00230 changes |= WPA_BSS_WPS_CHANGED_FLAG; 00231 00232 if (!are_ies_equal(old, new, WLAN_EID_SUPP_RATES) || 00233 !are_ies_equal(old, new, WLAN_EID_EXT_SUPP_RATES)) 00234 changes |= WPA_BSS_RATES_CHANGED_FLAG; 00235 00236 return changes; 00237 } 00238 00239 00240 static void notify_bss_changes(struct wpa_supplicant *wpa_s, u32 changes, 00241 const struct wpa_bss *bss) 00242 { 00243 if (changes & WPA_BSS_FREQ_CHANGED_FLAG) 00244 wpas_notify_bss_freq_changed(wpa_s, bss->id); 00245 00246 if (changes & WPA_BSS_SIGNAL_CHANGED_FLAG) 00247 wpas_notify_bss_signal_changed(wpa_s, bss->id); 00248 00249 if (changes & WPA_BSS_PRIVACY_CHANGED_FLAG) 00250 wpas_notify_bss_privacy_changed(wpa_s, bss->id); 00251 00252 if (changes & WPA_BSS_MODE_CHANGED_FLAG) 00253 wpas_notify_bss_mode_changed(wpa_s, bss->id); 00254 00255 if (changes & WPA_BSS_WPAIE_CHANGED_FLAG) 00256 wpas_notify_bss_wpaie_changed(wpa_s, bss->id); 00257 00258 if (changes & WPA_BSS_RSNIE_CHANGED_FLAG) 00259 wpas_notify_bss_rsnie_changed(wpa_s, bss->id); 00260 00261 if (changes & WPA_BSS_WPS_CHANGED_FLAG) 00262 wpas_notify_bss_wps_changed(wpa_s, bss->id); 00263 00264 if (changes & WPA_BSS_IES_CHANGED_FLAG) 00265 wpas_notify_bss_ies_changed(wpa_s, bss->id); 00266 00267 if (changes & WPA_BSS_RATES_CHANGED_FLAG) 00268 wpas_notify_bss_rates_changed(wpa_s, bss->id); 00269 } 00270 00271 00272 static void wpa_bss_update(struct wpa_supplicant *wpa_s, struct wpa_bss *bss, 00273 struct wpa_scan_res *res) 00274 { 00275 u32 changes; 00276 00277 changes = wpa_bss_compare_res(bss, res); 00278 bss->scan_miss_count = 0; 00279 bss->last_update_idx = wpa_s->bss_update_idx; 00280 wpa_bss_copy_res(bss, res); 00281 /* Move the entry to the end of the list */ 00282 dl_list_del(&bss->list); 00283 if (bss->ie_len + bss->beacon_ie_len >= 00284 res->ie_len + res->beacon_ie_len) { 00285 os_memcpy(bss + 1, res + 1, res->ie_len + res->beacon_ie_len); 00286 bss->ie_len = res->ie_len; 00287 bss->beacon_ie_len = res->beacon_ie_len; 00288 } else { 00289 struct wpa_bss *nbss; 00290 struct dl_list *prev = bss->list_id.prev; 00291 dl_list_del(&bss->list_id); 00292 nbss = os_realloc(bss, sizeof(*bss) + res->ie_len + 00293 res->beacon_ie_len); 00294 if (nbss) { 00295 bss = nbss; 00296 os_memcpy(bss + 1, res + 1, 00297 res->ie_len + res->beacon_ie_len); 00298 bss->ie_len = res->ie_len; 00299 bss->beacon_ie_len = res->beacon_ie_len; 00300 } 00301 dl_list_add(prev, &bss->list_id); 00302 } 00303 dl_list_add_tail(&wpa_s->bss, &bss->list); 00304 00305 notify_bss_changes(wpa_s, changes, bss); 00306 } 00307 00308 00309 static int wpa_bss_in_use(struct wpa_supplicant *wpa_s, struct wpa_bss *bss) 00310 { 00311 return bss == wpa_s->current_bss || 00312 os_memcmp(bss->bssid, wpa_s->bssid, ETH_ALEN) == 0 || 00313 os_memcmp(bss->bssid, wpa_s->pending_bssid, ETH_ALEN) == 0; 00314 } 00315 00316 00317 void wpa_bss_update_start(struct wpa_supplicant *wpa_s) 00318 { 00319 wpa_s->bss_update_idx++; 00320 wpa_printf(MSG_DEBUG, "BSS: Start scan result update %u", 00321 wpa_s->bss_update_idx); 00322 } 00323 00324 00325 void wpa_bss_update_scan_res(struct wpa_supplicant *wpa_s, 00326 struct wpa_scan_res *res) 00327 { 00328 const u8 *ssid; 00329 struct wpa_bss *bss; 00330 00331 ssid = wpa_scan_get_ie(res, WLAN_EID_SSID); 00332 if (ssid == NULL) { 00333 wpa_printf(MSG_DEBUG, "BSS: No SSID IE included for " MACSTR, 00334 MAC2STR(res->bssid)); 00335 return; 00336 } 00337 if (ssid[1] > 32) { 00338 wpa_printf(MSG_DEBUG, "BSS: Too long SSID IE included for " 00339 MACSTR, MAC2STR(res->bssid)); 00340 return; 00341 } 00342 00343 /* TODO: add option for ignoring BSSes we are not interested in 00344 * (to save memory) */ 00345 bss = wpa_bss_get(wpa_s, res->bssid, ssid + 2, ssid[1]); 00346 if (bss == NULL) 00347 wpa_bss_add(wpa_s, ssid + 2, ssid[1], res); 00348 else 00349 wpa_bss_update(wpa_s, bss, res); 00350 } 00351 00352 00353 static int wpa_bss_included_in_scan(const struct wpa_bss *bss, 00354 const struct scan_info *info) 00355 { 00356 int found; 00357 size_t i; 00358 00359 if (info == NULL) 00360 return 1; 00361 00362 if (info->num_freqs) { 00363 found = 0; 00364 for (i = 0; i < info->num_freqs; i++) { 00365 if (bss->freq == info->freqs[i]) { 00366 found = 1; 00367 break; 00368 } 00369 } 00370 if (!found) 00371 return 0; 00372 } 00373 00374 if (info->num_ssids) { 00375 found = 0; 00376 for (i = 0; i < info->num_ssids; i++) { 00377 const struct wpa_driver_scan_ssid *s = &info->ssids[i]; 00378 if ((s->ssid == NULL || s->ssid_len == 0) || 00379 (s->ssid_len == bss->ssid_len && 00380 os_memcmp(s->ssid, bss->ssid, bss->ssid_len) == 00381 0)) { 00382 found = 1; 00383 break; 00384 } 00385 } 00386 if (!found) 00387 return 0; 00388 } 00389 00390 return 1; 00391 } 00392 00393 00394 void wpa_bss_update_end(struct wpa_supplicant *wpa_s, struct scan_info *info, 00395 int new_scan) 00396 { 00397 struct wpa_bss *bss, *n; 00398 00399 if (!new_scan) 00400 return; /* do not expire entries without new scan */ 00401 00402 dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) { 00403 if (wpa_bss_in_use(wpa_s, bss)) 00404 continue; 00405 if (!wpa_bss_included_in_scan(bss, info)) 00406 continue; /* expire only BSSes that were scanned */ 00407 if (bss->last_update_idx < wpa_s->bss_update_idx) 00408 bss->scan_miss_count++; 00409 if (bss->scan_miss_count >= WPA_BSS_EXPIRATION_SCAN_COUNT) { 00410 wpa_printf(MSG_DEBUG, "BSS: Expire BSS %u due to no " 00411 "match in scan", bss->id); 00412 wpa_bss_remove(wpa_s, bss); 00413 } 00414 } 00415 } 00416 00417 00418 static void wpa_bss_timeout(void *eloop_ctx, void *timeout_ctx) 00419 { 00420 struct wpa_supplicant *wpa_s = eloop_ctx; 00421 struct wpa_bss *bss, *n; 00422 struct os_time t; 00423 00424 if (dl_list_empty(&wpa_s->bss)) 00425 return; 00426 00427 os_get_time(&t); 00428 t.sec -= WPA_BSS_EXPIRATION_AGE; 00429 00430 dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) { 00431 if (wpa_bss_in_use(wpa_s, bss)) 00432 continue; 00433 00434 if (os_time_before(&bss->last_update, &t)) { 00435 wpa_printf(MSG_DEBUG, "BSS: Expire BSS %u due to age", 00436 bss->id); 00437 wpa_bss_remove(wpa_s, bss); 00438 } else 00439 break; 00440 } 00441 eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0, 00442 wpa_bss_timeout, wpa_s, NULL); 00443 } 00444 00445 00446 int wpa_bss_init(struct wpa_supplicant *wpa_s) 00447 { 00448 dl_list_init(&wpa_s->bss); 00449 dl_list_init(&wpa_s->bss_id); 00450 eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0, 00451 wpa_bss_timeout, wpa_s, NULL); 00452 return 0; 00453 } 00454 00455 00456 void wpa_bss_deinit(struct wpa_supplicant *wpa_s) 00457 { 00458 struct wpa_bss *bss, *n; 00459 eloop_cancel_timeout(wpa_bss_timeout, wpa_s, NULL); 00460 if (wpa_s->bss.next == NULL) 00461 return; /* BSS table not yet initialized */ 00462 dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) 00463 wpa_bss_remove(wpa_s, bss); 00464 } 00465 00466 00467 struct wpa_bss * wpa_bss_get_bssid(struct wpa_supplicant *wpa_s, 00468 const u8 *bssid) 00469 { 00470 struct wpa_bss *bss; 00471 dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) { 00472 if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0) 00473 return bss; 00474 } 00475 return NULL; 00476 } 00477 00478 00479 struct wpa_bss * wpa_bss_get_id(struct wpa_supplicant *wpa_s, unsigned int id) 00480 { 00481 struct wpa_bss *bss; 00482 dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) { 00483 if (bss->id == id) 00484 return bss; 00485 } 00486 return NULL; 00487 } 00488 00489 00490 const u8 * wpa_bss_get_ie(const struct wpa_bss *bss, u8 ie) 00491 { 00492 const u8 *end, *pos; 00493 00494 pos = (const u8 *) (bss + 1); 00495 end = pos + bss->ie_len; 00496 00497 while (pos + 1 < end) { 00498 if (pos + 2 + pos[1] > end) 00499 break; 00500 if (pos[0] == ie) 00501 return pos; 00502 pos += 2 + pos[1]; 00503 } 00504 00505 return NULL; 00506 } 00507 00508 00509 const u8 * wpa_bss_get_vendor_ie(const struct wpa_bss *bss, u32 vendor_type) 00510 { 00511 const u8 *end, *pos; 00512 00513 pos = (const u8 *) (bss + 1); 00514 end = pos + bss->ie_len; 00515 00516 while (pos + 1 < end) { 00517 if (pos + 2 + pos[1] > end) 00518 break; 00519 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 && 00520 vendor_type == WPA_GET_BE32(&pos[2])) 00521 return pos; 00522 pos += 2 + pos[1]; 00523 } 00524 00525 return NULL; 00526 } 00527 00528 00529 struct wpabuf * wpa_bss_get_vendor_ie_multi(const struct wpa_bss *bss, 00530 u32 vendor_type) 00531 { 00532 struct wpabuf *buf; 00533 const u8 *end, *pos; 00534 00535 buf = wpabuf_alloc(bss->ie_len); 00536 if (buf == NULL) 00537 return NULL; 00538 00539 pos = (const u8 *) (bss + 1); 00540 end = pos + bss->ie_len; 00541 00542 while (pos + 1 < end) { 00543 if (pos + 2 + pos[1] > end) 00544 break; 00545 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 && 00546 vendor_type == WPA_GET_BE32(&pos[2])) 00547 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4); 00548 pos += 2 + pos[1]; 00549 } 00550 00551 if (wpabuf_len(buf) == 0) { 00552 wpabuf_free(buf); 00553 buf = NULL; 00554 } 00555 00556 return buf; 00557 } 00558 00559 00560 int wpa_bss_get_max_rate(const struct wpa_bss *bss) 00561 { 00562 int rate = 0; 00563 const u8 *ie; 00564 int i; 00565 00566 ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES); 00567 for (i = 0; ie && i < ie[1]; i++) { 00568 if ((ie[i + 2] & 0x7f) > rate) 00569 rate = ie[i + 2] & 0x7f; 00570 } 00571 00572 ie = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES); 00573 for (i = 0; ie && i < ie[1]; i++) { 00574 if ((ie[i + 2] & 0x7f) > rate) 00575 rate = ie[i + 2] & 0x7f; 00576 } 00577 00578 return rate; 00579 } 00580 00581 00582 int wpa_bss_get_bit_rates(const struct wpa_bss *bss, u8 **rates) 00583 { 00584 const u8 *ie, *ie2; 00585 int i, j; 00586 unsigned int len; 00587 u8 *r; 00588 00589 ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES); 00590 ie2 = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES); 00591 00592 len = (ie ? ie[1] : 0) + (ie2 ? ie2[1] : 0); 00593 00594 r = os_malloc(len); 00595 if (!r) 00596 return -1; 00597 00598 for (i = 0; ie && i < ie[1]; i++) 00599 r[i] = ie[i + 2] & 0x7f; 00600 00601 for (j = 0; ie2 && j < ie2[1]; j++) 00602 r[i + j] = ie2[j + 2] & 0x7f; 00603 00604 *rates = r; 00605 return len; 00606 }