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hostapd/wpa_supplicant/scan.c
Jouni Malinen b21ff9cb20 P2P: Fix WSC IE inclusion for P2P disabled case 
wpas_wps_in_use() was forcing WPS to be enabled unconditionally if P2P
support was included in the build. This is not really the correct
behavior for the case when P2P has been disabled at runtime. Change the
code here to verify runtime configuration of P2P before forcing WPS to
be enabled. This allows WSC IE to be left out from Probe Request frames
when scanning for APs without P2P or WPS being in use.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
2012-01-27 21:09:34 +02:00

1267 lines
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/*
* WPA Supplicant - Scanning
* Copyright (c) 2003-2010, 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 "config.h"
#include "wpa_supplicant_i.h"
#include "driver_i.h"
#include "wps_supplicant.h"
#include "p2p_supplicant.h"
#include "p2p/p2p.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->wps->dev.p2p = 1;
if (!wps) {
wps = 1;
*req_type = WPS_REQ_ENROLLEE_INFO;
}
}
#endif /* CONFIG_P2P */
return wps;
}
#endif /* CONFIG_WPS */
int wpa_supplicant_enabled_networks(struct wpa_config *conf)
{
struct wpa_ssid *ssid = conf->ssid;
int count = 0;
while (ssid) {
if (!ssid->disabled)
count++;
ssid = ssid->next;
}
return count;
}
static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
struct wpa_ssid *ssid)
{
while (ssid) {
if (!ssid->disabled)
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(*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;
}
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(&params->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 wpa_driver_scan_params *params)
{
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, &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;
}
static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
{
struct wpa_supplicant *wpa_s = eloop_ctx;
struct wpa_ssid *ssid;
int scan_req = 0, ret;
struct wpabuf *extra_ie;
struct wpa_driver_scan_params 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) {
wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
return;
}
if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
!wpa_s->scan_req) {
wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
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->wpa_state == WPA_SCANNING) {
wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
"while P2P operation is in progress");
wpa_supplicant_req_scan(wpa_s, 5, 0);
} else {
wpa_dbg(wpa_s, MSG_DEBUG, "Do not request scan while "
"P2P operation is in progress");
}
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 = 0;
os_memset(&params, 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 (scan_req != 2 && 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;
}
}
/* 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 != 2 && wpa_s->conf->ap_scan == 2) {
wpa_s->connect_without_scan = NULL;
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 (!ssid->disabled && 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 (tssid->disabled)
continue;
if ((params.freqs || !freqs_set) && tssid->scan_freq) {
int_array_concat(&params.freqs,
tssid->scan_freq);
} else {
os_free(params.freqs);
params.freqs = NULL;
}
freqs_set = 1;
}
int_array_sort_unique(params.freqs);
}
if (ssid) {
wpa_s->prev_scan_ssid = ssid;
if (max_ssids > 1) {
wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
"the scan request");
params.num_ssids++;
}
wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for specific "
"SSID(s)");
} else {
wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
params.num_ssids++;
wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
"SSID");
}
wpa_supplicant_optimize_freqs(wpa_s, &params);
extra_ie = wpa_supplicant_extra_ies(wpa_s, &params);
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, &params.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) {
/*
* 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 */
ret = wpa_supplicant_trigger_scan(wpa_s, &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);
wpa_supplicant_req_scan(wpa_s, 1, 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_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
*
* 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
*
* 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;
enum wpa_states prev_state;
struct wpa_ssid *ssid;
struct wpabuf *wps_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)
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 (!ssid->disabled && !ssid->scan_ssid) {
/* Use wildcard SSID to find this network */
wildcard = 1;
} else if (!ssid->disabled && ssid->ssid_len)
need_ssids++;
}
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(&params, 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);
/* 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");
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 (ssid->disabled)
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;
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;
}
if (wpa_s->wps)
wps_ie = wpa_supplicant_extra_ies(wpa_s, &params);
if (ssid || !wpa_s->first_sched_scan) {
wpa_dbg(wpa_s, MSG_DEBUG,
"Starting sched scan: interval %d (no timeout)",
wpa_s->sched_scan_interval);
} else {
wpa_dbg(wpa_s, MSG_DEBUG,
"Starting sched scan: interval %d timeout %d",
wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
}
ret = wpa_supplicant_start_sched_scan(wpa_s, &params,
wpa_s->sched_scan_interval);
wpabuf_free(wps_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);
}
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;
}
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;
}
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;
}
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;
}
struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
const struct wpa_scan_res *res, u32 vendor_type)
{
struct wpabuf *buf;
const u8 *end, *pos;
if (res->beacon_ie_len == 0)
return NULL;
buf = wpabuf_alloc(res->beacon_ie_len);
if (buf == NULL)
return NULL;
pos = (const u8 *) (res + 1);
pos += res->ie_len;
end = pos + res->beacon_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];
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);
}
}
#endif /* CONFIG_NO_STDOUT_DEBUG */
}
/**
* 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;
}
#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;
}
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;
}
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