diff options
Diffstat (limited to 'wpa_supplicant/bss.c')
| -rw-r--r-- | wpa_supplicant/bss.c | 606 |
1 files changed, 606 insertions, 0 deletions
diff --git a/wpa_supplicant/bss.c b/wpa_supplicant/bss.c new file mode 100644 index 0000000..e2ac230 --- /dev/null +++ b/wpa_supplicant/bss.c @@ -0,0 +1,606 @@ +/* + * BSS table + * Copyright (c) 2009-2010, Jouni Malinen <j@w1.fi> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Alternatively, this software may be distributed under the terms of BSD + * license. + * + * See README and COPYING for more details. + */ + +#include "utils/includes.h" + +#include "utils/common.h" +#include "utils/eloop.h" +#include "common/ieee802_11_defs.h" +#include "drivers/driver.h" +#include "wpa_supplicant_i.h" +#include "config.h" +#include "notify.h" +#include "scan.h" +#include "bss.h" + + +/** + * WPA_BSS_EXPIRATION_PERIOD - Period of expiration run in seconds + */ +#define WPA_BSS_EXPIRATION_PERIOD 10 + +/** + * WPA_BSS_EXPIRATION_AGE - BSS entry age after which it can be expired + * + * This value control the time in seconds after which a BSS entry gets removed + * if it has not been updated or is not in use. + */ +#define WPA_BSS_EXPIRATION_AGE 180 + +/** + * WPA_BSS_EXPIRATION_SCAN_COUNT - Expire BSS after number of scans + * + * If the BSS entry has not been seen in this many scans, it will be removed. + * Value 1 means that the entry is removed after the first scan without the + * BSSID being seen. Larger values can be used to avoid BSS entries + * disappearing if they are not visible in every scan (e.g., low signal quality + * or interference). + */ +#define WPA_BSS_EXPIRATION_SCAN_COUNT 2 + +#define WPA_BSS_FREQ_CHANGED_FLAG BIT(0) +#define WPA_BSS_SIGNAL_CHANGED_FLAG BIT(1) +#define WPA_BSS_PRIVACY_CHANGED_FLAG BIT(2) +#define WPA_BSS_MODE_CHANGED_FLAG BIT(3) +#define WPA_BSS_WPAIE_CHANGED_FLAG BIT(4) +#define WPA_BSS_RSNIE_CHANGED_FLAG BIT(5) +#define WPA_BSS_WPS_CHANGED_FLAG BIT(6) +#define WPA_BSS_RATES_CHANGED_FLAG BIT(7) +#define WPA_BSS_IES_CHANGED_FLAG BIT(8) + + +static void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss) +{ + dl_list_del(&bss->list); + dl_list_del(&bss->list_id); + wpa_s->num_bss--; + wpa_printf(MSG_DEBUG, "BSS: Remove id %u BSSID " MACSTR " SSID '%s'", + bss->id, MAC2STR(bss->bssid), + wpa_ssid_txt(bss->ssid, bss->ssid_len)); + wpas_notify_bss_removed(wpa_s, bss->bssid, bss->id); + os_free(bss); +} + + +struct wpa_bss * wpa_bss_get(struct wpa_supplicant *wpa_s, const u8 *bssid, + const u8 *ssid, size_t ssid_len) +{ + struct wpa_bss *bss; + dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) { + if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0 && + bss->ssid_len == ssid_len && + os_memcmp(bss->ssid, ssid, ssid_len) == 0) + return bss; + } + return NULL; +} + + +static void wpa_bss_copy_res(struct wpa_bss *dst, struct wpa_scan_res *src) +{ + os_time_t usec; + + dst->flags = src->flags; + os_memcpy(dst->bssid, src->bssid, ETH_ALEN); + dst->freq = src->freq; + dst->beacon_int = src->beacon_int; + dst->caps = src->caps; + dst->qual = src->qual; + dst->noise = src->noise; + dst->level = src->level; + dst->tsf = src->tsf; + + os_get_time(&dst->last_update); + dst->last_update.sec -= src->age / 1000; + usec = (src->age % 1000) * 1000; + if (dst->last_update.usec < usec) { + dst->last_update.sec--; + dst->last_update.usec += 1000000; + } + dst->last_update.usec -= usec; +} + + +static void wpa_bss_add(struct wpa_supplicant *wpa_s, + const u8 *ssid, size_t ssid_len, + struct wpa_scan_res *res) +{ + struct wpa_bss *bss; + + bss = os_zalloc(sizeof(*bss) + res->ie_len + res->beacon_ie_len); + if (bss == NULL) + return; + bss->id = wpa_s->bss_next_id++; + bss->last_update_idx = wpa_s->bss_update_idx; + wpa_bss_copy_res(bss, res); + os_memcpy(bss->ssid, ssid, ssid_len); + bss->ssid_len = ssid_len; + bss->ie_len = res->ie_len; + bss->beacon_ie_len = res->beacon_ie_len; + os_memcpy(bss + 1, res + 1, res->ie_len + res->beacon_ie_len); + + dl_list_add_tail(&wpa_s->bss, &bss->list); + dl_list_add_tail(&wpa_s->bss_id, &bss->list_id); + wpa_s->num_bss++; + wpa_printf(MSG_DEBUG, "BSS: Add new id %u BSSID " MACSTR " SSID '%s'", + bss->id, MAC2STR(bss->bssid), wpa_ssid_txt(ssid, ssid_len)); + wpas_notify_bss_added(wpa_s, bss->bssid, bss->id); + if (wpa_s->num_bss > wpa_s->conf->bss_max_count) { + /* Remove the oldest entry */ + wpa_bss_remove(wpa_s, dl_list_first(&wpa_s->bss, + struct wpa_bss, list)); + } +} + + +static int are_ies_equal(const struct wpa_bss *old, + const struct wpa_scan_res *new, u32 ie) +{ + const u8 *old_ie, *new_ie; + struct wpabuf *old_ie_buff = NULL; + struct wpabuf *new_ie_buff = NULL; + int new_ie_len, old_ie_len, ret, is_multi; + + switch (ie) { + case WPA_IE_VENDOR_TYPE: + old_ie = wpa_bss_get_vendor_ie(old, ie); + new_ie = wpa_scan_get_vendor_ie(new, ie); + is_multi = 0; + break; + case WPS_IE_VENDOR_TYPE: + old_ie_buff = wpa_bss_get_vendor_ie_multi(old, ie); + new_ie_buff = wpa_scan_get_vendor_ie_multi(new, ie); + is_multi = 1; + break; + case WLAN_EID_RSN: + case WLAN_EID_SUPP_RATES: + case WLAN_EID_EXT_SUPP_RATES: + old_ie = wpa_bss_get_ie(old, ie); + new_ie = wpa_scan_get_ie(new, ie); + is_multi = 0; + break; + default: + wpa_printf(MSG_DEBUG, "bss: %s: cannot compare IEs", __func__); + return 0; + } + + if (is_multi) { + /* in case of multiple IEs stored in buffer */ + old_ie = old_ie_buff ? wpabuf_head_u8(old_ie_buff) : NULL; + new_ie = new_ie_buff ? wpabuf_head_u8(new_ie_buff) : NULL; + old_ie_len = old_ie_buff ? wpabuf_len(old_ie_buff) : 0; + new_ie_len = new_ie_buff ? wpabuf_len(new_ie_buff) : 0; + } else { + /* in case of single IE */ + old_ie_len = old_ie ? old_ie[1] + 2 : 0; + new_ie_len = new_ie ? new_ie[1] + 2 : 0; + } + + ret = (old_ie_len == new_ie_len && + os_memcmp(old_ie, new_ie, old_ie_len) == 0); + + wpabuf_free(old_ie_buff); + wpabuf_free(new_ie_buff); + + return ret; +} + + +static u32 wpa_bss_compare_res(const struct wpa_bss *old, + const struct wpa_scan_res *new) +{ + u32 changes = 0; + int caps_diff = old->caps ^ new->caps; + + if (old->freq != new->freq) + changes |= WPA_BSS_FREQ_CHANGED_FLAG; + + if (old->level != new->level) + changes |= WPA_BSS_SIGNAL_CHANGED_FLAG; + + if (caps_diff & IEEE80211_CAP_PRIVACY) + changes |= WPA_BSS_PRIVACY_CHANGED_FLAG; + + if (caps_diff & IEEE80211_CAP_IBSS) + changes |= WPA_BSS_MODE_CHANGED_FLAG; + + if (old->ie_len == new->ie_len && + os_memcmp(old + 1, new + 1, old->ie_len) == 0) + return changes; + changes |= WPA_BSS_IES_CHANGED_FLAG; + + if (!are_ies_equal(old, new, WPA_IE_VENDOR_TYPE)) + changes |= WPA_BSS_WPAIE_CHANGED_FLAG; + + if (!are_ies_equal(old, new, WLAN_EID_RSN)) + changes |= WPA_BSS_RSNIE_CHANGED_FLAG; + + if (!are_ies_equal(old, new, WPS_IE_VENDOR_TYPE)) + changes |= WPA_BSS_WPS_CHANGED_FLAG; + + if (!are_ies_equal(old, new, WLAN_EID_SUPP_RATES) || + !are_ies_equal(old, new, WLAN_EID_EXT_SUPP_RATES)) + changes |= WPA_BSS_RATES_CHANGED_FLAG; + + return changes; +} + + +static void notify_bss_changes(struct wpa_supplicant *wpa_s, u32 changes, + const struct wpa_bss *bss) +{ + if (changes & WPA_BSS_FREQ_CHANGED_FLAG) + wpas_notify_bss_freq_changed(wpa_s, bss->id); + + if (changes & WPA_BSS_SIGNAL_CHANGED_FLAG) + wpas_notify_bss_signal_changed(wpa_s, bss->id); + + if (changes & WPA_BSS_PRIVACY_CHANGED_FLAG) + wpas_notify_bss_privacy_changed(wpa_s, bss->id); + + if (changes & WPA_BSS_MODE_CHANGED_FLAG) + wpas_notify_bss_mode_changed(wpa_s, bss->id); + + if (changes & WPA_BSS_WPAIE_CHANGED_FLAG) + wpas_notify_bss_wpaie_changed(wpa_s, bss->id); + + if (changes & WPA_BSS_RSNIE_CHANGED_FLAG) + wpas_notify_bss_rsnie_changed(wpa_s, bss->id); + + if (changes & WPA_BSS_WPS_CHANGED_FLAG) + wpas_notify_bss_wps_changed(wpa_s, bss->id); + + if (changes & WPA_BSS_IES_CHANGED_FLAG) + wpas_notify_bss_ies_changed(wpa_s, bss->id); + + if (changes & WPA_BSS_RATES_CHANGED_FLAG) + wpas_notify_bss_rates_changed(wpa_s, bss->id); +} + + +static void wpa_bss_update(struct wpa_supplicant *wpa_s, struct wpa_bss *bss, + struct wpa_scan_res *res) +{ + u32 changes; + + changes = wpa_bss_compare_res(bss, res); + bss->scan_miss_count = 0; + bss->last_update_idx = wpa_s->bss_update_idx; + wpa_bss_copy_res(bss, res); + /* Move the entry to the end of the list */ + dl_list_del(&bss->list); + if (bss->ie_len + bss->beacon_ie_len >= + res->ie_len + res->beacon_ie_len) { + os_memcpy(bss + 1, res + 1, res->ie_len + res->beacon_ie_len); + bss->ie_len = res->ie_len; + bss->beacon_ie_len = res->beacon_ie_len; + } else { + struct wpa_bss *nbss; + struct dl_list *prev = bss->list_id.prev; + dl_list_del(&bss->list_id); + nbss = os_realloc(bss, sizeof(*bss) + res->ie_len + + res->beacon_ie_len); + if (nbss) { + bss = nbss; + os_memcpy(bss + 1, res + 1, + res->ie_len + res->beacon_ie_len); + bss->ie_len = res->ie_len; + bss->beacon_ie_len = res->beacon_ie_len; + } + dl_list_add(prev, &bss->list_id); + } + dl_list_add_tail(&wpa_s->bss, &bss->list); + + notify_bss_changes(wpa_s, changes, bss); +} + + +static int wpa_bss_in_use(struct wpa_supplicant *wpa_s, struct wpa_bss *bss) +{ + return bss == wpa_s->current_bss || + os_memcmp(bss->bssid, wpa_s->bssid, ETH_ALEN) == 0 || + os_memcmp(bss->bssid, wpa_s->pending_bssid, ETH_ALEN) == 0; +} + + +void wpa_bss_update_start(struct wpa_supplicant *wpa_s) +{ + wpa_s->bss_update_idx++; + wpa_printf(MSG_DEBUG, "BSS: Start scan result update %u", + wpa_s->bss_update_idx); +} + + +void wpa_bss_update_scan_res(struct wpa_supplicant *wpa_s, + struct wpa_scan_res *res) +{ + const u8 *ssid; + struct wpa_bss *bss; + + ssid = wpa_scan_get_ie(res, WLAN_EID_SSID); + if (ssid == NULL) { + wpa_printf(MSG_DEBUG, "BSS: No SSID IE included for " MACSTR, + MAC2STR(res->bssid)); + return; + } + if (ssid[1] > 32) { + wpa_printf(MSG_DEBUG, "BSS: Too long SSID IE included for " + MACSTR, MAC2STR(res->bssid)); + return; + } + + /* TODO: add option for ignoring BSSes we are not interested in + * (to save memory) */ + bss = wpa_bss_get(wpa_s, res->bssid, ssid + 2, ssid[1]); + if (bss == NULL) + wpa_bss_add(wpa_s, ssid + 2, ssid[1], res); + else + wpa_bss_update(wpa_s, bss, res); +} + + +static int wpa_bss_included_in_scan(const struct wpa_bss *bss, + const struct scan_info *info) +{ + int found; + size_t i; + + if (info == NULL) + return 1; + + if (info->num_freqs) { + found = 0; + for (i = 0; i < info->num_freqs; i++) { + if (bss->freq == info->freqs[i]) { + found = 1; + break; + } + } + if (!found) + return 0; + } + + if (info->num_ssids) { + found = 0; + for (i = 0; i < info->num_ssids; i++) { + const struct wpa_driver_scan_ssid *s = &info->ssids[i]; + if ((s->ssid == NULL || s->ssid_len == 0) || + (s->ssid_len == bss->ssid_len && + os_memcmp(s->ssid, bss->ssid, bss->ssid_len) == + 0)) { + found = 1; + break; + } + } + if (!found) + return 0; + } + + return 1; +} + + +void wpa_bss_update_end(struct wpa_supplicant *wpa_s, struct scan_info *info, + int new_scan) +{ + struct wpa_bss *bss, *n; + + if (!new_scan) + return; /* do not expire entries without new scan */ + + dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) { + if (wpa_bss_in_use(wpa_s, bss)) + continue; + if (!wpa_bss_included_in_scan(bss, info)) + continue; /* expire only BSSes that were scanned */ + if (bss->last_update_idx < wpa_s->bss_update_idx) + bss->scan_miss_count++; + if (bss->scan_miss_count >= WPA_BSS_EXPIRATION_SCAN_COUNT) { + wpa_printf(MSG_DEBUG, "BSS: Expire BSS %u due to no " + "match in scan", bss->id); + wpa_bss_remove(wpa_s, bss); + } + } +} + + +static void wpa_bss_timeout(void *eloop_ctx, void *timeout_ctx) +{ + struct wpa_supplicant *wpa_s = eloop_ctx; + struct wpa_bss *bss, *n; + struct os_time t; + + if (dl_list_empty(&wpa_s->bss)) + return; + + os_get_time(&t); + t.sec -= WPA_BSS_EXPIRATION_AGE; + + dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) { + if (wpa_bss_in_use(wpa_s, bss)) + continue; + + if (os_time_before(&bss->last_update, &t)) { + wpa_printf(MSG_DEBUG, "BSS: Expire BSS %u due to age", + bss->id); + wpa_bss_remove(wpa_s, bss); + } else + break; + } + eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0, + wpa_bss_timeout, wpa_s, NULL); +} + + +int wpa_bss_init(struct wpa_supplicant *wpa_s) +{ + dl_list_init(&wpa_s->bss); + dl_list_init(&wpa_s->bss_id); + eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0, + wpa_bss_timeout, wpa_s, NULL); + return 0; +} + + +void wpa_bss_deinit(struct wpa_supplicant *wpa_s) +{ + struct wpa_bss *bss, *n; + eloop_cancel_timeout(wpa_bss_timeout, wpa_s, NULL); + if (wpa_s->bss.next == NULL) + return; /* BSS table not yet initialized */ + dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) + wpa_bss_remove(wpa_s, bss); +} + + +struct wpa_bss * wpa_bss_get_bssid(struct wpa_supplicant *wpa_s, + const u8 *bssid) +{ + struct wpa_bss *bss; + dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) { + if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0) + return bss; + } + return NULL; +} + + +struct wpa_bss * wpa_bss_get_id(struct wpa_supplicant *wpa_s, unsigned int id) +{ + struct wpa_bss *bss; + dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) { + if (bss->id == id) + return bss; + } + return NULL; +} + + +const u8 * wpa_bss_get_ie(const struct wpa_bss *bss, u8 ie) +{ + const u8 *end, *pos; + + pos = (const u8 *) (bss + 1); + end = pos + bss->ie_len; + + while (pos + 1 < end) { + if (pos + 2 + pos[1] > end) + break; + if (pos[0] == ie) + return pos; + pos += 2 + pos[1]; + } + + return NULL; +} + + +const u8 * wpa_bss_get_vendor_ie(const struct wpa_bss *bss, u32 vendor_type) +{ + const u8 *end, *pos; + + pos = (const u8 *) (bss + 1); + end = pos + bss->ie_len; + + while (pos + 1 < end) { + if (pos + 2 + pos[1] > end) + break; + if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 && + vendor_type == WPA_GET_BE32(&pos[2])) + return pos; + pos += 2 + pos[1]; + } + + return NULL; +} + + +struct wpabuf * wpa_bss_get_vendor_ie_multi(const struct wpa_bss *bss, + u32 vendor_type) +{ + struct wpabuf *buf; + const u8 *end, *pos; + + buf = wpabuf_alloc(bss->ie_len); + if (buf == NULL) + return NULL; + + pos = (const u8 *) (bss + 1); + end = pos + bss->ie_len; + + while (pos + 1 < end) { + if (pos + 2 + pos[1] > end) + break; + if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 && + vendor_type == WPA_GET_BE32(&pos[2])) + wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4); + pos += 2 + pos[1]; + } + + if (wpabuf_len(buf) == 0) { + wpabuf_free(buf); + buf = NULL; + } + + return buf; +} + + +int wpa_bss_get_max_rate(const struct wpa_bss *bss) +{ + int rate = 0; + const u8 *ie; + int i; + + ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES); + for (i = 0; ie && i < ie[1]; i++) { + if ((ie[i + 2] & 0x7f) > rate) + rate = ie[i + 2] & 0x7f; + } + + ie = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES); + for (i = 0; ie && i < ie[1]; i++) { + if ((ie[i + 2] & 0x7f) > rate) + rate = ie[i + 2] & 0x7f; + } + + return rate; +} + + +int wpa_bss_get_bit_rates(const struct wpa_bss *bss, u8 **rates) +{ + const u8 *ie, *ie2; + int i, j; + unsigned int len; + u8 *r; + + ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES); + ie2 = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES); + + len = (ie ? ie[1] : 0) + (ie2 ? ie2[1] : 0); + + r = os_malloc(len); + if (!r) + return -1; + + for (i = 0; ie && i < ie[1]; i++) + r[i] = ie[i + 2] & 0x7f; + + for (j = 0; ie2 && j < ie2[1]; j++) + r[i + j] = ie2[j + 2] & 0x7f; + + *rates = r; + return len; +} |
