}
-int wnm_scan_process(struct wpa_supplicant *wpa_s, int reply_on_fail)
+int wnm_scan_process(struct wpa_supplicant *wpa_s, bool pre_scan_check)
{
struct wpa_bss *bss;
struct wpa_ssid *ssid = wpa_s->current_ssid;
wpa_dbg(wpa_s, MSG_DEBUG,
"WNM: Process scan results for BSS Transition Management");
- if (os_reltime_before(&wpa_s->wnm_cand_valid_until,
+ if (!pre_scan_check &&
+ os_reltime_before(&wpa_s->wnm_cand_valid_until,
&wpa_s->scan_trigger_time)) {
wpa_printf(MSG_DEBUG, "WNM: Previously stored BSS transition candidate list is not valid anymore - drop it");
wnm_deallocate_memory(wpa_s);
/* Compare the Neighbor Report and scan results */
bss = compare_scan_neighbor_results(wpa_s, 0, &reason);
+
+ /*
+ * If this is a pre-scan check, returning 0 will trigger a scan and
+ * another call. In that case, reject "bad" candidates in the hope of
+ * finding a better candidate after scanning.
+ *
+ * Use a simple heuristic to check whether the selection is reasonable
+ * or a scan is a good idea. For that, we need to have found a
+ * candidate BSS (which might be the current one), it is up-to-date,
+ * and we don't want to immediately roam back again.
+ */
+ if (pre_scan_check) {
+ struct os_reltime age;
+
+ if (!bss)
+ return 0;
+
+ os_reltime_age(&bss->last_update, &age);
+ if (age.sec >= 10)
+ return 0;
+
+#ifndef CONFIG_NO_ROAMING
+ if (bss != wpa_s->current_bss &&
+ wpa_supplicant_need_to_roam_within_ess(wpa_s,
+ wpa_s->current_bss,
+ bss))
+ return 0;
+#endif /* CONFIG_NO_ROAMING */
+ }
+
if (!bss) {
wpa_printf(MSG_DEBUG, "WNM: No BSS transition candidate match found");
status = WNM_BSS_TM_REJECT_NO_SUITABLE_CANDIDATES;
return 1;
send_bss_resp_fail:
- if (!reply_on_fail)
- return 0;
-
/* Send reject response for all the failures */
if (wpa_s->wnm_reply) {
}
-static int wnm_fetch_scan_results(struct wpa_supplicant *wpa_s)
-{
- struct wpa_scan_results *scan_res;
- struct wpa_bss *bss;
- struct wpa_ssid *ssid = wpa_s->current_ssid;
- u8 i, found = 0;
- size_t j;
-
- wpa_dbg(wpa_s, MSG_DEBUG,
- "WNM: Fetch current scan results from the driver for checking transition candidates");
- scan_res = wpa_drv_get_scan_results2(wpa_s);
- if (!scan_res) {
- wpa_dbg(wpa_s, MSG_DEBUG, "WNM: Failed to get scan results");
- return 0;
- }
-
- if (scan_res->fetch_time.sec == 0)
- os_get_reltime(&scan_res->fetch_time);
-
- filter_scan_res(wpa_s, scan_res);
-
- for (i = 0; i < wpa_s->wnm_num_neighbor_report; i++) {
- struct neighbor_report *nei;
-
- nei = &wpa_s->wnm_neighbor_report_elements[i];
- if (nei->preference_present && nei->preference == 0)
- continue;
-
- for (j = 0; j < scan_res->num; j++) {
- struct wpa_scan_res *res;
- const u8 *ssid_ie;
-
- res = scan_res->res[j];
- if (!ether_addr_equal(nei->bssid, res->bssid) ||
- res->age > WNM_SCAN_RESULT_AGE * 1000)
- continue;
- bss = wpa_s->current_bss;
- ssid_ie = wpa_scan_get_ie(res, WLAN_EID_SSID);
- if (bss && ssid_ie && ssid_ie[1] &&
- (bss->ssid_len != ssid_ie[1] ||
- os_memcmp(bss->ssid, ssid_ie + 2,
- bss->ssid_len) != 0))
- continue; /* Skip entries for other ESSs */
-
- /* Potential candidate found */
- found = 1;
- scan_snr(res);
- scan_est_throughput(wpa_s, res);
- wpa_bss_update_scan_res(wpa_s, res,
- &scan_res->fetch_time);
- }
- }
-
- wpa_scan_results_free(scan_res);
- if (!found) {
- wpa_dbg(wpa_s, MSG_DEBUG,
- "WNM: No transition candidate matches existing scan results");
- return 0;
- }
-
- bss = compare_scan_neighbor_results(wpa_s, WNM_SCAN_RESULT_AGE, NULL);
- if (!bss) {
- wpa_dbg(wpa_s, MSG_DEBUG,
- "WNM: Comparison of scan results against transition candidates did not find matches");
- return 0;
- }
-
- /* Associate to the network */
- wnm_bss_tm_connect(wpa_s, bss, ssid, 0);
- return 1;
-}
-
-
static void ieee802_11_rx_bss_trans_mgmt_req(struct wpa_supplicant *wpa_s,
const u8 *pos, const u8 *end,
int reply)
os_memcpy(wpa_s->wnm_cand_from_bss, wpa_s->bssid, ETH_ALEN);
/*
- * Fetch the latest scan results from the kernel and check for
- * candidates based on those results first. This can help in
- * finding more up-to-date information should the driver has
- * done some internal scanning operations after the last scan
- * result update in wpa_supplicant.
- */
- if (wnm_fetch_scan_results(wpa_s) > 0)
+ * Try fetching the latest scan results from the kernel.
+ * This can help in finding more up-to-date information should
+ * the driver have done some internal scanning operations after
+ * the last scan result update in wpa_supplicant.
+ *
+ * It is not a new scan, this does not update the last_scan
+ * timestamp nor will it expire old BSSs.
+ */
+ wpa_supplicant_update_scan_results(wpa_s);
+ if (wnm_scan_process(wpa_s, true) > 0)
return;
-
- /*
- * Try to use previously received scan results, if they are
- * recent enough to use for a connection.
- */
- if (wpa_s->last_scan_res_used > 0) {
- struct os_reltime now;
-
- os_get_reltime(&now);
- if (!os_reltime_expired(&now, &wpa_s->last_scan, 10)) {
- wpa_printf(MSG_DEBUG,
- "WNM: Try to use recent scan results");
- if (wnm_scan_process(wpa_s, 0) > 0)
- return;
- wpa_printf(MSG_DEBUG,
- "WNM: No match in previous scan results - try a new scan");
- }
- }
+ wpa_printf(MSG_DEBUG,
+ "WNM: No valid match in previous scan results - try a new scan");
wnm_set_scan_freqs(wpa_s);
if (wpa_s->wnm_num_neighbor_report == 1) {
projects / thirdparty / hostap.git / commitdiff
