/* * WPA Supplicant - Scanning * Copyright (c) 2003-2012, Jouni Malinen * * This software may be distributed under the terms of the BSD license. * See README for more details. */ #include "utils/includes.h" #include "utils/common.h" #include "utils/eloop.h" #include "common/ieee802_11_defs.h" #include "config.h" #include "wpa_supplicant_i.h" #include "driver_i.h" #include "wps_supplicant.h" #include "p2p_supplicant.h" #include "p2p/p2p.h" #include "hs20_supplicant.h" #include "notify.h" #include "bss.h" #include "scan.h" static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s) { struct wpa_ssid *ssid; union wpa_event_data data; ssid = wpa_supplicant_get_ssid(wpa_s); if (ssid == NULL) return; if (wpa_s->current_ssid == NULL) { wpa_s->current_ssid = ssid; if (wpa_s->current_ssid != NULL) wpas_notify_network_changed(wpa_s); } wpa_supplicant_initiate_eapol(wpa_s); wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured " "network - generating associated event"); os_memset(&data, 0, sizeof(data)); wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data); } #ifdef CONFIG_WPS static int wpas_wps_in_use(struct wpa_supplicant *wpa_s, enum wps_request_type *req_type) { struct wpa_ssid *ssid; int wps = 0; for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) { if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS)) continue; wps = 1; *req_type = wpas_wps_get_req_type(ssid); if (!ssid->eap.phase1) continue; if (os_strstr(ssid->eap.phase1, "pbc=1")) return 2; } #ifdef CONFIG_P2P if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p && !wpa_s->conf->p2p_disabled) { wpa_s->wps->dev.p2p = 1; if (!wps) { wps = 1; *req_type = WPS_REQ_ENROLLEE_INFO; } } #endif /* CONFIG_P2P */ return wps; } #endif /* CONFIG_WPS */ /** * wpa_supplicant_enabled_networks - Check whether there are enabled networks * @wpa_s: Pointer to wpa_supplicant data * Returns: 0 if no networks are enabled, >0 if networks are enabled * * This function is used to figure out whether any networks (or Interworking * with enabled credentials and auto_interworking) are present in the current * configuration. */ int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s) { struct wpa_ssid *ssid = wpa_s->conf->ssid; int count = 0, disabled = 0; while (ssid) { if (!wpas_network_disabled(wpa_s, ssid)) count++; else disabled++; ssid = ssid->next; } if (wpa_s->conf->cred && wpa_s->conf->interworking && wpa_s->conf->auto_interworking) count++; if (count == 0 && disabled > 0) { wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled " "networks)", disabled); } return count; } static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s, struct wpa_ssid *ssid) { while (ssid) { if (!wpas_network_disabled(wpa_s, ssid)) break; ssid = ssid->next; } /* ap_scan=2 mode - try to associate with each SSID. */ if (ssid == NULL) { wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached " "end of scan list - go back to beginning"); wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN; wpa_supplicant_req_scan(wpa_s, 0, 0); return; } if (ssid->next) { /* Continue from the next SSID on the next attempt. */ wpa_s->prev_scan_ssid = ssid; } else { /* Start from the beginning of the SSID list. */ wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN; } wpa_supplicant_associate(wpa_s, NULL, ssid); } static int int_array_len(const int *a) { int i; for (i = 0; a && a[i]; i++) ; return i; } static void int_array_concat(int **res, const int *a) { int reslen, alen, i; int *n; reslen = int_array_len(*res); alen = int_array_len(a); n = os_realloc_array(*res, reslen + alen + 1, sizeof(int)); if (n == NULL) { os_free(*res); *res = NULL; return; } for (i = 0; i <= alen; i++) n[reslen + i] = a[i]; *res = n; } static int freq_cmp(const void *a, const void *b) { int _a = *(int *) a; int _b = *(int *) b; if (_a == 0) return 1; if (_b == 0) return -1; return _a - _b; } static void int_array_sort_unique(int *a) { int alen; int i, j; if (a == NULL) return; alen = int_array_len(a); qsort(a, alen, sizeof(int), freq_cmp); i = 0; j = 1; while (a[i] && a[j]) { if (a[i] == a[j]) { j++; continue; } a[++i] = a[j++]; } if (a[i]) i++; a[i] = 0; } /** * wpa_supplicant_trigger_scan - Request driver to start a scan * @wpa_s: Pointer to wpa_supplicant data * @params: Scan parameters * Returns: 0 on success, -1 on failure */ int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params) { int ret; wpa_supplicant_notify_scanning(wpa_s, 1); ret = wpa_drv_scan(wpa_s, params); if (ret) { wpa_supplicant_notify_scanning(wpa_s, 0); wpas_notify_scan_done(wpa_s, 0); } else { wpa_s->scan_runs++; wpa_s->normal_scans++; } return ret; } static void wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx) { struct wpa_supplicant *wpa_s = eloop_ctx; wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan"); if (wpa_supplicant_req_sched_scan(wpa_s)) wpa_supplicant_req_scan(wpa_s, 0, 0); } static void wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx) { struct wpa_supplicant *wpa_s = eloop_ctx; wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it"); wpa_s->sched_scan_timed_out = 1; wpa_supplicant_cancel_sched_scan(wpa_s); } static int wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params, int interval) { int ret; wpa_supplicant_notify_scanning(wpa_s, 1); ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000); if (ret) wpa_supplicant_notify_scanning(wpa_s, 0); else wpa_s->sched_scanning = 1; return ret; } static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s) { int ret; ret = wpa_drv_stop_sched_scan(wpa_s); if (ret) { wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!"); /* TODO: what to do if stopping fails? */ return -1; } return ret; } static struct wpa_driver_scan_filter * wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids) { struct wpa_driver_scan_filter *ssids; struct wpa_ssid *ssid; size_t count; *num_ssids = 0; if (!conf->filter_ssids) return NULL; for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) { if (ssid->ssid && ssid->ssid_len) count++; } if (count == 0) return NULL; ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter)); if (ssids == NULL) return NULL; for (ssid = conf->ssid; ssid; ssid = ssid->next) { if (!ssid->ssid || !ssid->ssid_len) continue; os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len); ssids[*num_ssids].ssid_len = ssid->ssid_len; (*num_ssids)++; } return ssids; } static void wpa_supplicant_optimize_freqs( struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params) { #ifdef CONFIG_P2P if (params->freqs == NULL && wpa_s->p2p_in_provisioning && wpa_s->go_params) { /* Optimize provisioning state scan based on GO information */ if (wpa_s->p2p_in_provisioning < 5 && wpa_s->go_params->freq > 0) { wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO " "preferred frequency %d MHz", wpa_s->go_params->freq); params->freqs = os_zalloc(2 * sizeof(int)); if (params->freqs) params->freqs[0] = wpa_s->go_params->freq; } else if (wpa_s->p2p_in_provisioning < 8 && wpa_s->go_params->freq_list[0]) { wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common " "channels"); int_array_concat(¶ms->freqs, wpa_s->go_params->freq_list); if (params->freqs) int_array_sort_unique(params->freqs); } wpa_s->p2p_in_provisioning++; } #endif /* CONFIG_P2P */ #ifdef CONFIG_WPS if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) { /* * Optimize post-provisioning scan based on channel used * during provisioning. */ wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz " "that was used during provisioning", wpa_s->wps_freq); params->freqs = os_zalloc(2 * sizeof(int)); if (params->freqs) params->freqs[0] = wpa_s->wps_freq; wpa_s->after_wps--; } if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq) { /* Optimize provisioning scan based on already known channel */ wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz", wpa_s->wps_freq); params->freqs = os_zalloc(2 * sizeof(int)); if (params->freqs) params->freqs[0] = wpa_s->wps_freq; wpa_s->known_wps_freq = 0; /* only do this once */ } #endif /* CONFIG_WPS */ } #ifdef CONFIG_INTERWORKING static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s, struct wpabuf *buf) { if (wpa_s->conf->interworking == 0) return; wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB); wpabuf_put_u8(buf, 4); wpabuf_put_u8(buf, 0x00); wpabuf_put_u8(buf, 0x00); wpabuf_put_u8(buf, 0x00); wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */ wpabuf_put_u8(buf, WLAN_EID_INTERWORKING); wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 : 1 + ETH_ALEN); wpabuf_put_u8(buf, wpa_s->conf->access_network_type); /* No Venue Info */ if (!is_zero_ether_addr(wpa_s->conf->hessid)) wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN); } #endif /* CONFIG_INTERWORKING */ static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s) { struct wpabuf *extra_ie = NULL; #ifdef CONFIG_WPS int wps = 0; enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO; #endif /* CONFIG_WPS */ #ifdef CONFIG_INTERWORKING if (wpa_s->conf->interworking && wpabuf_resize(&extra_ie, 100) == 0) wpas_add_interworking_elements(wpa_s, extra_ie); #endif /* CONFIG_INTERWORKING */ #ifdef CONFIG_WPS wps = wpas_wps_in_use(wpa_s, &req_type); if (wps) { struct wpabuf *wps_ie; wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON : DEV_PW_DEFAULT, &wpa_s->wps->dev, wpa_s->wps->uuid, req_type, 0, NULL); if (wps_ie) { if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0) wpabuf_put_buf(extra_ie, wps_ie); wpabuf_free(wps_ie); } } #ifdef CONFIG_P2P if (wps) { size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p); if (wpabuf_resize(&extra_ie, ielen) == 0) wpas_p2p_scan_ie(wpa_s, extra_ie); } #endif /* CONFIG_P2P */ #endif /* CONFIG_WPS */ return extra_ie; } #ifdef CONFIG_P2P /* * Check whether there are any enabled networks or credentials that could be * used for a non-P2P connection. */ static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s) { struct wpa_ssid *ssid; for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) { if (wpas_network_disabled(wpa_s, ssid)) continue; if (!ssid->p2p_group) return 1; } if (wpa_s->conf->cred && wpa_s->conf->interworking && wpa_s->conf->auto_interworking) return 1; return 0; } /* * Find the operating frequency of any other virtual interface that is using * the same radio concurrently. */ static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s) { const char *rn, *rn2; struct wpa_supplicant *ifs; u8 bssid[ETH_ALEN]; if (!wpa_s->driver->get_radio_name) return -1; rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv); if (rn == NULL || rn[0] == '\0') return -1; for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) { if (ifs == wpa_s || !ifs->driver->get_radio_name) continue; rn2 = ifs->driver->get_radio_name(ifs->drv_priv); if (!rn2 || os_strcmp(rn, rn2) != 0) continue; if (ifs->current_ssid == NULL || ifs->assoc_freq == 0) continue; if (ifs->current_ssid->mode == WPAS_MODE_AP || ifs->current_ssid->mode == WPAS_MODE_P2P_GO) return ifs->current_ssid->frequency; if (wpa_drv_get_bssid(ifs, bssid) == 0) return ifs->assoc_freq; } return 0; } #endif /* CONFIG_P2P */ static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx) { struct wpa_supplicant *wpa_s = eloop_ctx; struct wpa_ssid *ssid; enum scan_req_type scan_req = NORMAL_SCAN_REQ; int ret; struct wpabuf *extra_ie = NULL; struct wpa_driver_scan_params params; struct wpa_driver_scan_params *scan_params; size_t max_ssids; enum wpa_states prev_state; if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) { wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled"); return; } if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) { wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan"); wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED); return; } if (!wpa_supplicant_enabled_networks(wpa_s) && wpa_s->scan_req == NORMAL_SCAN_REQ) { wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan"); wpa_supplicant_set_state(wpa_s, WPA_INACTIVE); #ifdef CONFIG_P2P wpa_s->sta_scan_pending = 0; #endif /* CONFIG_P2P */ return; } if (wpa_s->conf->ap_scan != 0 && (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) { wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - " "overriding ap_scan configuration"); wpa_s->conf->ap_scan = 0; wpas_notify_ap_scan_changed(wpa_s); } if (wpa_s->conf->ap_scan == 0) { wpa_supplicant_gen_assoc_event(wpa_s); return; } #ifdef CONFIG_P2P if (wpas_p2p_in_progress(wpa_s)) { if (wpa_s->sta_scan_pending && wpas_p2p_in_progress(wpa_s) == 2 && wpa_s->global->p2p_cb_on_scan_complete) { wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station " "mode scan during P2P search"); } else { wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan " "while P2P operation is in progress"); wpa_s->sta_scan_pending = 1; wpa_supplicant_req_scan(wpa_s, 5, 0); return; } } #endif /* CONFIG_P2P */ if (wpa_s->conf->ap_scan == 2) max_ssids = 1; else { max_ssids = wpa_s->max_scan_ssids; if (max_ssids > WPAS_MAX_SCAN_SSIDS) max_ssids = WPAS_MAX_SCAN_SSIDS; } scan_req = wpa_s->scan_req; wpa_s->scan_req = NORMAL_SCAN_REQ; os_memset(¶ms, 0, sizeof(params)); prev_state = wpa_s->wpa_state; if (wpa_s->wpa_state == WPA_DISCONNECTED || wpa_s->wpa_state == WPA_INACTIVE) wpa_supplicant_set_state(wpa_s, WPA_SCANNING); /* * If autoscan has set its own scanning parameters */ if (wpa_s->autoscan_params != NULL) { scan_params = wpa_s->autoscan_params; goto scan; } if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) { for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) { if (ssid == wpa_s->connect_without_scan) break; } wpa_s->connect_without_scan = NULL; if (ssid) { wpa_printf(MSG_DEBUG, "Start a pre-selected network " "without scan step"); wpa_supplicant_associate(wpa_s, NULL, ssid); return; } } #ifdef CONFIG_P2P if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) && wpa_s->go_params) { wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during " "P2P group formation"); params.ssids[0].ssid = wpa_s->go_params->ssid; params.ssids[0].ssid_len = wpa_s->go_params->ssid_len; params.num_ssids = 1; goto ssid_list_set; } #endif /* CONFIG_P2P */ /* Find the starting point from which to continue scanning */ ssid = wpa_s->conf->ssid; if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) { while (ssid) { if (ssid == wpa_s->prev_scan_ssid) { ssid = ssid->next; break; } ssid = ssid->next; } } if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) { wpa_s->connect_without_scan = NULL; wpa_s->prev_scan_wildcard = 0; wpa_supplicant_assoc_try(wpa_s, ssid); return; } else if (wpa_s->conf->ap_scan == 2) { /* * User-initiated scan request in ap_scan == 2; scan with * wildcard SSID. */ ssid = NULL; } else { struct wpa_ssid *start = ssid, *tssid; int freqs_set = 0; if (ssid == NULL && max_ssids > 1) ssid = wpa_s->conf->ssid; while (ssid) { if (!wpas_network_disabled(wpa_s, ssid) && ssid->scan_ssid) { wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID", ssid->ssid, ssid->ssid_len); params.ssids[params.num_ssids].ssid = ssid->ssid; params.ssids[params.num_ssids].ssid_len = ssid->ssid_len; params.num_ssids++; if (params.num_ssids + 1 >= max_ssids) break; } ssid = ssid->next; if (ssid == start) break; if (ssid == NULL && max_ssids > 1 && start != wpa_s->conf->ssid) ssid = wpa_s->conf->ssid; } for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) { if (wpas_network_disabled(wpa_s, tssid)) continue; if ((params.freqs || !freqs_set) && tssid->scan_freq) { int_array_concat(¶ms.freqs, tssid->scan_freq); } else { os_free(params.freqs); params.freqs = NULL; } freqs_set = 1; } int_array_sort_unique(params.freqs); } if (ssid && max_ssids == 1) { /* * If the driver is limited to 1 SSID at a time interleave * wildcard SSID scans with specific SSID scans to avoid * waiting a long time for a wildcard scan. */ if (!wpa_s->prev_scan_wildcard) { params.ssids[0].ssid = NULL; params.ssids[0].ssid_len = 0; wpa_s->prev_scan_wildcard = 1; wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for " "wildcard SSID (Interleave with specific)"); } else { wpa_s->prev_scan_ssid = ssid; wpa_s->prev_scan_wildcard = 0; wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for specific SSID: %s", wpa_ssid_txt(ssid->ssid, ssid->ssid_len)); } } else if (ssid) { /* max_ssids > 1 */ wpa_s->prev_scan_ssid = ssid; wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in " "the scan request"); params.num_ssids++; } else { wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN; params.num_ssids++; wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard " "SSID"); } #ifdef CONFIG_P2P ssid_list_set: #endif /* CONFIG_P2P */ wpa_supplicant_optimize_freqs(wpa_s, ¶ms); extra_ie = wpa_supplicant_extra_ies(wpa_s); #ifdef CONFIG_HS20 if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0) wpas_hs20_add_indication(extra_ie); #endif /* CONFIG_HS20 */ if (params.freqs == NULL && wpa_s->next_scan_freqs) { wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously " "generated frequency list"); params.freqs = wpa_s->next_scan_freqs; } else os_free(wpa_s->next_scan_freqs); wpa_s->next_scan_freqs = NULL; params.filter_ssids = wpa_supplicant_build_filter_ssids( wpa_s->conf, ¶ms.num_filter_ssids); if (extra_ie) { params.extra_ies = wpabuf_head(extra_ie); params.extra_ies_len = wpabuf_len(extra_ie); } #ifdef CONFIG_P2P if (wpa_s->p2p_in_provisioning || (wpa_s->show_group_started && wpa_s->go_params)) { /* * The interface may not yet be in P2P mode, so we have to * explicitly request P2P probe to disable CCK rates. */ params.p2p_probe = 1; } #endif /* CONFIG_P2P */ scan_params = ¶ms; scan: #ifdef CONFIG_P2P /* * If the driver does not support multi-channel concurrency and a * virtual interface that shares the same radio with the wpa_s interface * is operating there may not be need to scan other channels apart from * the current operating channel on the other virtual interface. Filter * out other channels in case we are trying to find a connection for a * station interface when we are not configured to prefer station * connection and a concurrent operation is already in process. */ if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ && !scan_params->freqs && !params.freqs && wpas_is_p2p_prioritized(wpa_s) && !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) && wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE && non_p2p_network_enabled(wpa_s)) { int freq = shared_vif_oper_freq(wpa_s); if (freq > 0) { wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current " "operating channel (%d MHz) since driver does " "not support multi-channel concurrency", freq); params.freqs = os_zalloc(sizeof(int) * 2); if (params.freqs) params.freqs[0] = freq; scan_params->freqs = params.freqs; } } #endif /* CONFIG_P2P */ ret = wpa_supplicant_trigger_scan(wpa_s, scan_params); wpabuf_free(extra_ie); os_free(params.freqs); os_free(params.filter_ssids); if (ret) { wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan"); if (prev_state != wpa_s->wpa_state) wpa_supplicant_set_state(wpa_s, prev_state); /* Restore scan_req since we will try to scan again */ wpa_s->scan_req = scan_req; wpa_supplicant_req_scan(wpa_s, 1, 0); } else { wpa_s->scan_for_connection = 0; } } void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec) { struct os_time remaining, new_int; int cancelled; cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL, &remaining); new_int.sec = sec; new_int.usec = 0; if (cancelled && os_time_before(&remaining, &new_int)) { new_int.sec = remaining.sec; new_int.usec = remaining.usec; } eloop_register_timeout(new_int.sec, new_int.usec, wpa_supplicant_scan, wpa_s, NULL); wpa_s->scan_interval = sec; } /** * wpa_supplicant_req_scan - Schedule a scan for neighboring access points * @wpa_s: Pointer to wpa_supplicant data * @sec: Number of seconds after which to scan * @usec: Number of microseconds after which to scan * * This function is used to schedule a scan for neighboring access points after * the specified time. */ void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec) { /* If there's at least one network that should be specifically scanned * then don't cancel the scan and reschedule. Some drivers do * background scanning which generates frequent scan results, and that * causes the specific SSID scan to get continually pushed back and * never happen, which causes hidden APs to never get probe-scanned. */ if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) && wpa_s->conf->ap_scan == 1) { struct wpa_ssid *ssid = wpa_s->conf->ssid; while (ssid) { if (!wpas_network_disabled(wpa_s, ssid) && ssid->scan_ssid) break; ssid = ssid->next; } if (ssid) { wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to " "ensure that specific SSID scans occur"); return; } } wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec", sec, usec); eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL); eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL); } /** * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan * @wpa_s: Pointer to wpa_supplicant data * @sec: Number of seconds after which to scan * @usec: Number of microseconds after which to scan * Returns: 0 on success or -1 otherwise * * This function is used to schedule periodic scans for neighboring * access points after the specified time. */ int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s, int sec, int usec) { if (!wpa_s->sched_scan_supported) return -1; eloop_register_timeout(sec, usec, wpa_supplicant_delayed_sched_scan_timeout, wpa_s, NULL); return 0; } /** * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan * @wpa_s: Pointer to wpa_supplicant data * Returns: 0 is sched_scan was started or -1 otherwise * * This function is used to schedule periodic scans for neighboring * access points repeating the scan continuously. */ int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s) { struct wpa_driver_scan_params params; struct wpa_driver_scan_params *scan_params; enum wpa_states prev_state; struct wpa_ssid *ssid = NULL; struct wpabuf *extra_ie = NULL; int ret; unsigned int max_sched_scan_ssids; int wildcard = 0; int need_ssids; if (!wpa_s->sched_scan_supported) return -1; if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS) max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS; else max_sched_scan_ssids = wpa_s->max_sched_scan_ssids; if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload) return -1; if (wpa_s->sched_scanning) { wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning"); return 0; } need_ssids = 0; for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) { if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) { /* Use wildcard SSID to find this network */ wildcard = 1; } else if (!wpas_network_disabled(wpa_s, ssid) && ssid->ssid_len) need_ssids++; #ifdef CONFIG_WPS if (!wpas_network_disabled(wpa_s, ssid) && ssid->key_mgmt == WPA_KEY_MGMT_WPS) { /* * Normal scan is more reliable and faster for WPS * operations and since these are for short periods of * time, the benefit of trying to use sched_scan would * be limited. */ wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of " "sched_scan for WPS"); return -1; } #endif /* CONFIG_WPS */ } if (wildcard) need_ssids++; if (wpa_s->normal_scans < 3 && (need_ssids <= wpa_s->max_scan_ssids || wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) { /* * When normal scan can speed up operations, use that for the * first operations before starting the sched_scan to allow * user space sleep more. We do this only if the normal scan * has functionality that is suitable for this or if the * sched_scan does not have better support for multiple SSIDs. */ wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of " "sched_scan for initial scans (normal_scans=%d)", wpa_s->normal_scans); return -1; } os_memset(¶ms, 0, sizeof(params)); /* If we can't allocate space for the filters, we just don't filter */ params.filter_ssids = os_zalloc(wpa_s->max_match_sets * sizeof(struct wpa_driver_scan_filter)); prev_state = wpa_s->wpa_state; if (wpa_s->wpa_state == WPA_DISCONNECTED || wpa_s->wpa_state == WPA_INACTIVE) wpa_supplicant_set_state(wpa_s, WPA_SCANNING); if (wpa_s->autoscan_params != NULL) { scan_params = wpa_s->autoscan_params; goto scan; } /* Find the starting point from which to continue scanning */ ssid = wpa_s->conf->ssid; if (wpa_s->prev_sched_ssid) { while (ssid) { if (ssid == wpa_s->prev_sched_ssid) { ssid = ssid->next; break; } ssid = ssid->next; } } if (!ssid || !wpa_s->prev_sched_ssid) { wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list"); if (wpa_s->sched_scan_interval == 0) wpa_s->sched_scan_interval = 10; wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2; wpa_s->first_sched_scan = 1; ssid = wpa_s->conf->ssid; wpa_s->prev_sched_ssid = ssid; } if (wildcard) { wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan"); params.num_ssids++; } while (ssid) { if (wpas_network_disabled(wpa_s, ssid)) goto next; if (params.num_filter_ssids < wpa_s->max_match_sets && params.filter_ssids && ssid->ssid && ssid->ssid_len) { wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s", wpa_ssid_txt(ssid->ssid, ssid->ssid_len)); os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid, ssid->ssid, ssid->ssid_len); params.filter_ssids[params.num_filter_ssids].ssid_len = ssid->ssid_len; params.num_filter_ssids++; } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len) { wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID " "filter for sched_scan - drop filter"); os_free(params.filter_ssids); params.filter_ssids = NULL; params.num_filter_ssids = 0; } if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) { if (params.num_ssids == max_sched_scan_ssids) break; /* only room for broadcast SSID */ wpa_dbg(wpa_s, MSG_DEBUG, "add to active scan ssid: %s", wpa_ssid_txt(ssid->ssid, ssid->ssid_len)); params.ssids[params.num_ssids].ssid = ssid->ssid; params.ssids[params.num_ssids].ssid_len = ssid->ssid_len; params.num_ssids++; if (params.num_ssids >= max_sched_scan_ssids) { wpa_s->prev_sched_ssid = ssid; do { ssid = ssid->next; } while (ssid && (wpas_network_disabled(wpa_s, ssid) || !ssid->scan_ssid)); break; } } next: wpa_s->prev_sched_ssid = ssid; ssid = ssid->next; } if (params.num_filter_ssids == 0) { os_free(params.filter_ssids); params.filter_ssids = NULL; } extra_ie = wpa_supplicant_extra_ies(wpa_s); if (extra_ie) { params.extra_ies = wpabuf_head(extra_ie); params.extra_ies_len = wpabuf_len(extra_ie); } scan_params = ¶ms; scan: if (ssid || !wpa_s->first_sched_scan) { wpa_dbg(wpa_s, MSG_DEBUG, "Starting sched scan: interval %d timeout %d", wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout); } else { wpa_dbg(wpa_s, MSG_DEBUG, "Starting sched scan: interval %d (no timeout)", wpa_s->sched_scan_interval); } ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params, wpa_s->sched_scan_interval); wpabuf_free(extra_ie); os_free(params.filter_ssids); if (ret) { wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan"); if (prev_state != wpa_s->wpa_state) wpa_supplicant_set_state(wpa_s, prev_state); return ret; } /* If we have more SSIDs to scan, add a timeout so we scan them too */ if (ssid || !wpa_s->first_sched_scan) { wpa_s->sched_scan_timed_out = 0; eloop_register_timeout(wpa_s->sched_scan_timeout, 0, wpa_supplicant_sched_scan_timeout, wpa_s, NULL); wpa_s->first_sched_scan = 0; wpa_s->sched_scan_timeout /= 2; wpa_s->sched_scan_interval *= 2; } return 0; } /** * wpa_supplicant_cancel_scan - Cancel a scheduled scan request * @wpa_s: Pointer to wpa_supplicant data * * This function is used to cancel a scan request scheduled with * wpa_supplicant_req_scan(). */ void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s) { wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request"); eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL); } /** * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans * @wpa_s: Pointer to wpa_supplicant data * * This function is used to stop a periodic scheduled scan. */ void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s) { if (!wpa_s->sched_scanning) return; wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan"); eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL); wpa_supplicant_stop_sched_scan(wpa_s); } /** * wpa_supplicant_notify_scanning - Indicate possible scan state change * @wpa_s: Pointer to wpa_supplicant data * @scanning: Whether scanning is currently in progress * * This function is to generate scanning notifycations. It is called whenever * there may have been a change in scanning (scan started, completed, stopped). * wpas_notify_scanning() is called whenever the scanning state changed from the * previously notified state. */ void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s, int scanning) { if (wpa_s->scanning != scanning) { wpa_s->scanning = scanning; wpas_notify_scanning(wpa_s); } } static int wpa_scan_get_max_rate(const struct wpa_scan_res *res) { int rate = 0; const u8 *ie; int i; ie = wpa_scan_get_ie(res, 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_scan_get_ie(res, 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; } /** * wpa_scan_get_ie - Fetch a specified information element from a scan result * @res: Scan result entry * @ie: Information element identitifier (WLAN_EID_*) * Returns: Pointer to the information element (id field) or %NULL if not found * * This function returns the first matching information element in the scan * result. */ const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie) { const u8 *end, *pos; pos = (const u8 *) (res + 1); end = pos + res->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; } /** * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result * @res: Scan result entry * @vendor_type: Vendor type (four octets starting the IE payload) * Returns: Pointer to the information element (id field) or %NULL if not found * * This function returns the first matching information element in the scan * result. */ const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res, u32 vendor_type) { const u8 *end, *pos; pos = (const u8 *) (res + 1); end = pos + res->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; } /** * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result * @res: Scan result entry * @vendor_type: Vendor type (four octets starting the IE payload) * Returns: Pointer to the information element payload or %NULL if not found * * This function returns concatenated payload of possibly fragmented vendor * specific information elements in the scan result. The caller is responsible * for freeing the returned buffer. */ struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res, u32 vendor_type) { struct wpabuf *buf; const u8 *end, *pos; buf = wpabuf_alloc(res->ie_len); if (buf == NULL) return NULL; pos = (const u8 *) (res + 1); end = pos + res->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; } /* * Channels with a great SNR can operate at full rate. What is a great SNR? * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general * rule of thumb is that any SNR above 20 is good." This one * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a * conservative value. */ #define GREAT_SNR 30 /* Compare function for sorting scan results. Return >0 if @b is considered * better. */ static int wpa_scan_result_compar(const void *a, const void *b) { #define IS_5GHZ(n) (n > 4000) #define MIN(a,b) a < b ? a : b struct wpa_scan_res **_wa = (void *) a; struct wpa_scan_res **_wb = (void *) b; struct wpa_scan_res *wa = *_wa; struct wpa_scan_res *wb = *_wb; int wpa_a, wpa_b, maxrate_a, maxrate_b; int snr_a, snr_b; /* WPA/WPA2 support preferred */ wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL || wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL; wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL || wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL; if (wpa_b && !wpa_a) return 1; if (!wpa_b && wpa_a) return -1; /* privacy support preferred */ if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 && (wb->caps & IEEE80211_CAP_PRIVACY)) return 1; if ((wa->caps & IEEE80211_CAP_PRIVACY) && (wb->caps & IEEE80211_CAP_PRIVACY) == 0) return -1; if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) && !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) { snr_a = MIN(wa->level - wa->noise, GREAT_SNR); snr_b = MIN(wb->level - wb->noise, GREAT_SNR); } else { /* Not suitable information to calculate SNR, so use level */ snr_a = wa->level; snr_b = wb->level; } /* best/max rate preferred if SNR close enough */ if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) || (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) { maxrate_a = wpa_scan_get_max_rate(wa); maxrate_b = wpa_scan_get_max_rate(wb); if (maxrate_a != maxrate_b) return maxrate_b - maxrate_a; if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq)) return IS_5GHZ(wa->freq) ? -1 : 1; } /* use freq for channel preference */ /* all things being equal, use SNR; if SNRs are * identical, use quality values since some drivers may only report * that value and leave the signal level zero */ if (snr_b == snr_a) return wb->qual - wa->qual; return snr_b - snr_a; #undef MIN #undef IS_5GHZ } #ifdef CONFIG_WPS /* Compare function for sorting scan results when searching a WPS AP for * provisioning. Return >0 if @b is considered better. */ static int wpa_scan_result_wps_compar(const void *a, const void *b) { struct wpa_scan_res **_wa = (void *) a; struct wpa_scan_res **_wb = (void *) b; struct wpa_scan_res *wa = *_wa; struct wpa_scan_res *wb = *_wb; int uses_wps_a, uses_wps_b; struct wpabuf *wps_a, *wps_b; int res; /* Optimization - check WPS IE existence before allocated memory and * doing full reassembly. */ uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL; uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL; if (uses_wps_a && !uses_wps_b) return -1; if (!uses_wps_a && uses_wps_b) return 1; if (uses_wps_a && uses_wps_b) { wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE); wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE); res = wps_ap_priority_compar(wps_a, wps_b); wpabuf_free(wps_a); wpabuf_free(wps_b); if (res) return res; } /* * Do not use current AP security policy as a sorting criteria during * WPS provisioning step since the AP may get reconfigured at the * completion of provisioning. */ /* all things being equal, use signal level; if signal levels are * identical, use quality values since some drivers may only report * that value and leave the signal level zero */ if (wb->level == wa->level) return wb->qual - wa->qual; return wb->level - wa->level; } #endif /* CONFIG_WPS */ static void dump_scan_res(struct wpa_scan_results *scan_res) { #ifndef CONFIG_NO_STDOUT_DEBUG size_t i; if (scan_res->res == NULL || scan_res->num == 0) return; wpa_printf(MSG_EXCESSIVE, "Sorted scan results"); for (i = 0; i < scan_res->num; i++) { struct wpa_scan_res *r = scan_res->res[i]; u8 *pos; if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID)) == WPA_SCAN_LEVEL_DBM) { int snr = r->level - r->noise; wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d " "noise=%d level=%d snr=%d%s flags=0x%x", MAC2STR(r->bssid), r->freq, r->qual, r->noise, r->level, snr, snr >= GREAT_SNR ? "*" : "", r->flags); } else { wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d " "noise=%d level=%d flags=0x%x", MAC2STR(r->bssid), r->freq, r->qual, r->noise, r->level, r->flags); } pos = (u8 *) (r + 1); if (r->ie_len) wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len); pos += r->ie_len; if (r->beacon_ie_len) wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs", pos, r->beacon_ie_len); } #endif /* CONFIG_NO_STDOUT_DEBUG */ } /** * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed * @wpa_s: Pointer to wpa_supplicant data * @bssid: BSSID to check * Returns: 0 if the BSSID is filtered or 1 if not * * This function is used to filter out specific BSSIDs from scan reslts mainly * for testing purposes (SET bssid_filter ctrl_iface command). */ int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s, const u8 *bssid) { size_t i; if (wpa_s->bssid_filter == NULL) return 1; for (i = 0; i < wpa_s->bssid_filter_count; i++) { if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid, ETH_ALEN) == 0) return 1; } return 0; } static void filter_scan_res(struct wpa_supplicant *wpa_s, struct wpa_scan_results *res) { size_t i, j; if (wpa_s->bssid_filter == NULL) return; for (i = 0, j = 0; i < res->num; i++) { if (wpa_supplicant_filter_bssid_match(wpa_s, res->res[i]->bssid)) { res->res[j++] = res->res[i]; } else { os_free(res->res[i]); res->res[i] = NULL; } } if (res->num != j) { wpa_printf(MSG_DEBUG, "Filtered out %d scan results", (int) (res->num - j)); res->num = j; } } /** * wpa_supplicant_get_scan_results - Get scan results * @wpa_s: Pointer to wpa_supplicant data * @info: Information about what was scanned or %NULL if not available * @new_scan: Whether a new scan was performed * Returns: Scan results, %NULL on failure * * This function request the current scan results from the driver and updates * the local BSS list wpa_s->bss. The caller is responsible for freeing the * results with wpa_scan_results_free(). */ struct wpa_scan_results * wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s, struct scan_info *info, int new_scan) { struct wpa_scan_results *scan_res; size_t i; int (*compar)(const void *, const void *) = wpa_scan_result_compar; scan_res = wpa_drv_get_scan_results2(wpa_s); if (scan_res == NULL) { wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results"); return NULL; } filter_scan_res(wpa_s, scan_res); #ifdef CONFIG_WPS if (wpas_wps_in_progress(wpa_s)) { wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS " "provisioning rules"); compar = wpa_scan_result_wps_compar; } #endif /* CONFIG_WPS */ qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *), compar); dump_scan_res(scan_res); wpa_bss_update_start(wpa_s); for (i = 0; i < scan_res->num; i++) wpa_bss_update_scan_res(wpa_s, scan_res->res[i]); wpa_bss_update_end(wpa_s, info, new_scan); return scan_res; } /** * wpa_supplicant_update_scan_results - Update scan results from the driver * @wpa_s: Pointer to wpa_supplicant data * Returns: 0 on success, -1 on failure * * This function updates the BSS table within wpa_supplicant based on the * currently available scan results from the driver without requesting a new * scan. This is used in cases where the driver indicates an association * (including roaming within ESS) and wpa_supplicant does not yet have the * needed information to complete the connection (e.g., to perform validation * steps in 4-way handshake). */ int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s) { struct wpa_scan_results *scan_res; scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0); if (scan_res == NULL) return -1; wpa_scan_results_free(scan_res); return 0; }