hostapd/wpa_supplicant/scan.c
Jouni Malinen 79da74a20c WPS: Generate UUID based on MAC address, if not set
Generate a SHA1 hash -based UUID from the local MAC address if the UUID
was not configured. This makes it easier to prepare for WPS since there
is no need to generate an UUID.
2009-01-01 22:56:52 +02:00

262 lines
6.8 KiB
C

/*
* WPA Supplicant - Scanning
* Copyright (c) 2003-2008, 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 "includes.h"
#include "common.h"
#include "eloop.h"
#include "config.h"
#include "wpa_supplicant_i.h"
#include "mlme.h"
#include "wps/wps.h"
#include "wps_supplicant.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;
wpa_supplicant_initiate_eapol(wpa_s);
wpa_printf(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_config *conf, u8 *req_type)
{
struct wpa_ssid *ssid;
int wps = 0;
for (ssid = 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;
}
return wps;
}
#endif /* CONFIG_WPS */
static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
{
struct wpa_supplicant *wpa_s = eloop_ctx;
struct wpa_ssid *ssid;
int enabled, scan_req = 0, ret;
struct wpabuf *wps_ie = NULL;
const u8 *extra_ie = NULL;
size_t extra_ie_len = 0;
int wps = 0;
#ifdef CONFIG_WPS
u8 req_type = 0;
#endif /* CONFIG_WPS */
if (wpa_s->disconnected && !wpa_s->scan_req)
return;
enabled = 0;
ssid = wpa_s->conf->ssid;
while (ssid) {
if (!ssid->disabled) {
enabled++;
break;
}
ssid = ssid->next;
}
if (!enabled && !wpa_s->scan_req) {
wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
return;
}
scan_req = wpa_s->scan_req;
wpa_s->scan_req = 0;
if (wpa_s->conf->ap_scan != 0 &&
wpa_s->driver && IS_WIRED(wpa_s->driver)) {
wpa_printf(MSG_DEBUG, "Using wired authentication - "
"overriding ap_scan configuration");
wpa_s->conf->ap_scan = 0;
}
if (wpa_s->conf->ap_scan == 0) {
wpa_supplicant_gen_assoc_event(wpa_s);
return;
}
if (wpa_s->wpa_state == WPA_DISCONNECTED ||
wpa_s->wpa_state == WPA_INACTIVE)
wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
ssid = wpa_s->conf->ssid;
if (wpa_s->prev_scan_ssid != BROADCAST_SSID_SCAN) {
while (ssid) {
if (ssid == wpa_s->prev_scan_ssid) {
ssid = ssid->next;
break;
}
ssid = ssid->next;
}
}
while (ssid) {
if (!ssid->disabled &&
(ssid->scan_ssid || wpa_s->conf->ap_scan == 2))
break;
ssid = ssid->next;
}
if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
/*
* ap_scan=2 mode - try to associate with each SSID instead of
* scanning for each scan_ssid=1 network.
*/
if (ssid == NULL) {
wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
"end of scan list - go back to beginning");
wpa_s->prev_scan_ssid = BROADCAST_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 = BROADCAST_SSID_SCAN;
}
wpa_supplicant_associate(wpa_s, NULL, ssid);
return;
}
wpa_printf(MSG_DEBUG, "Starting AP scan (%s SSID)",
ssid ? "specific": "broadcast");
if (ssid) {
wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
ssid->ssid, ssid->ssid_len);
wpa_s->prev_scan_ssid = ssid;
} else
wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
#ifdef CONFIG_WPS
wps = wpas_wps_in_use(wpa_s->conf, &req_type);
#endif /* CONFIG_WPS */
if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
!wpa_s->use_client_mlme && wps != 2) {
wpa_s->scan_res_tried++;
wpa_s->scan_req = scan_req;
wpa_printf(MSG_DEBUG, "Trying to get current scan results "
"first without requesting a new scan to speed up "
"initial association");
wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
return;
}
#ifdef CONFIG_WPS
if (wps) {
wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
wpa_s->wps->uuid, req_type);
if (wps_ie) {
extra_ie = wpabuf_head(wps_ie);
extra_ie_len = wpabuf_len(wps_ie);
}
}
#endif /* CONFIG_WPS */
if (wpa_s->use_client_mlme) {
ieee80211_sta_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
ret = ieee80211_sta_req_scan(wpa_s, ssid ? ssid->ssid : NULL,
ssid ? ssid->ssid_len : 0);
} else {
wpa_drv_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
ret = wpa_drv_scan(wpa_s, ssid ? ssid->ssid : NULL,
ssid ? ssid->ssid_len : 0);
}
wpabuf_free(wps_ie);
if (ret) {
wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
wpa_supplicant_req_scan(wpa_s, 10, 0);
}
}
/**
* 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 (!ssid->disabled && ssid->scan_ssid)
break;
ssid = ssid->next;
}
if (ssid) {
wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
"ensure that specific SSID scans occur");
return;
}
}
wpa_msg(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_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_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
}