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hostap/wpa_supplicant/bss.c
David Spinadel 1ac388633a Remove disconnected APs from BSS table if likely out-of-range 
In some cases, after a sudden AP disappearing and reconnection to
another AP in the same ESS, if another scan occurs, wpa_supplicant might
try to roam to the old AP (if it was better ranked than the new one)
because it is still saved in BSS list and the blacklist entry was
cleared in previous reconnect. This attempt is going to fail if the AP
is not present anymore and it'll cause long disconnections.

Remove an AP that is probably out of range from the BSS list to avoid
such disconnections. In particular mac80211-based drivers use the
WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY reason code in locally generated
disconnection events for cases where the AP does not reply anymore.

Signed-off-by: David Spinadel <david.spinadel@intel.com>
2016-10-01 11:14:02 +03:00

1282 lines
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/*
* BSS table
* Copyright (c) 2009-2015, Jouni Malinen <j@w1.fi>
*
* 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 "drivers/driver.h"
#include "eap_peer/eap.h"
#include "wpa_supplicant_i.h"
#include "config.h"
#include "notify.h"
#include "scan.h"
#include "bss.h"
#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_set_hessid(struct wpa_bss *bss)
{
#ifdef CONFIG_INTERWORKING
const u8 *ie = wpa_bss_get_ie(bss, WLAN_EID_INTERWORKING);
if (ie == NULL || (ie[1] != 7 && ie[1] != 9)) {
os_memset(bss->hessid, 0, ETH_ALEN);
return;
}
if (ie[1] == 7)
os_memcpy(bss->hessid, ie + 3, ETH_ALEN);
else
os_memcpy(bss->hessid, ie + 5, ETH_ALEN);
#endif /* CONFIG_INTERWORKING */
}
/**
* wpa_bss_anqp_alloc - Allocate ANQP data structure for a BSS entry
* Returns: Allocated ANQP data structure or %NULL on failure
*
* The allocated ANQP data structure has its users count set to 1. It may be
* shared by multiple BSS entries and each shared entry is freed with
* wpa_bss_anqp_free().
*/
struct wpa_bss_anqp * wpa_bss_anqp_alloc(void)
{
struct wpa_bss_anqp *anqp;
anqp = os_zalloc(sizeof(*anqp));
if (anqp == NULL)
return NULL;
#ifdef CONFIG_INTERWORKING
dl_list_init(&anqp->anqp_elems);
#endif /* CONFIG_INTERWORKING */
anqp->users = 1;
return anqp;
}
/**
* wpa_bss_anqp_clone - Clone an ANQP data structure
* @anqp: ANQP data structure from wpa_bss_anqp_alloc()
* Returns: Cloned ANQP data structure or %NULL on failure
*/
static struct wpa_bss_anqp * wpa_bss_anqp_clone(struct wpa_bss_anqp *anqp)
{
struct wpa_bss_anqp *n;
n = os_zalloc(sizeof(*n));
if (n == NULL)
return NULL;
#define ANQP_DUP(f) if (anqp->f) n->f = wpabuf_dup(anqp->f)
#ifdef CONFIG_INTERWORKING
dl_list_init(&n->anqp_elems);
ANQP_DUP(capability_list);
ANQP_DUP(venue_name);
ANQP_DUP(network_auth_type);
ANQP_DUP(roaming_consortium);
ANQP_DUP(ip_addr_type_availability);
ANQP_DUP(nai_realm);
ANQP_DUP(anqp_3gpp);
ANQP_DUP(domain_name);
#endif /* CONFIG_INTERWORKING */
#ifdef CONFIG_HS20
ANQP_DUP(hs20_capability_list);
ANQP_DUP(hs20_operator_friendly_name);
ANQP_DUP(hs20_wan_metrics);
ANQP_DUP(hs20_connection_capability);
ANQP_DUP(hs20_operating_class);
ANQP_DUP(hs20_osu_providers_list);
#endif /* CONFIG_HS20 */
#undef ANQP_DUP
return n;
}
/**
* wpa_bss_anqp_unshare_alloc - Unshare ANQP data (if shared) in a BSS entry
* @bss: BSS entry
* Returns: 0 on success, -1 on failure
*
* This function ensures the specific BSS entry has an ANQP data structure that
* is not shared with any other BSS entry.
*/
int wpa_bss_anqp_unshare_alloc(struct wpa_bss *bss)
{
struct wpa_bss_anqp *anqp;
if (bss->anqp && bss->anqp->users > 1) {
/* allocated, but shared - clone an unshared copy */
anqp = wpa_bss_anqp_clone(bss->anqp);
if (anqp == NULL)
return -1;
anqp->users = 1;
bss->anqp->users--;
bss->anqp = anqp;
return 0;
}
if (bss->anqp)
return 0; /* already allocated and not shared */
/* not allocated - allocate a new storage area */
bss->anqp = wpa_bss_anqp_alloc();
return bss->anqp ? 0 : -1;
}
/**
* wpa_bss_anqp_free - Free an ANQP data structure
* @anqp: ANQP data structure from wpa_bss_anqp_alloc() or wpa_bss_anqp_clone()
*/
static void wpa_bss_anqp_free(struct wpa_bss_anqp *anqp)
{
#ifdef CONFIG_INTERWORKING
struct wpa_bss_anqp_elem *elem;
#endif /* CONFIG_INTERWORKING */
if (anqp == NULL)
return;
anqp->users--;
if (anqp->users > 0) {
/* Another BSS entry holds a pointer to this ANQP info */
return;
}
#ifdef CONFIG_INTERWORKING
wpabuf_free(anqp->capability_list);
wpabuf_free(anqp->venue_name);
wpabuf_free(anqp->network_auth_type);
wpabuf_free(anqp->roaming_consortium);
wpabuf_free(anqp->ip_addr_type_availability);
wpabuf_free(anqp->nai_realm);
wpabuf_free(anqp->anqp_3gpp);
wpabuf_free(anqp->domain_name);
while ((elem = dl_list_first(&anqp->anqp_elems,
struct wpa_bss_anqp_elem, list))) {
dl_list_del(&elem->list);
wpabuf_free(elem->payload);
os_free(elem);
}
#endif /* CONFIG_INTERWORKING */
#ifdef CONFIG_HS20
wpabuf_free(anqp->hs20_capability_list);
wpabuf_free(anqp->hs20_operator_friendly_name);
wpabuf_free(anqp->hs20_wan_metrics);
wpabuf_free(anqp->hs20_connection_capability);
wpabuf_free(anqp->hs20_operating_class);
wpabuf_free(anqp->hs20_osu_providers_list);
#endif /* CONFIG_HS20 */
os_free(anqp);
}
static void wpa_bss_update_pending_connect(struct wpa_supplicant *wpa_s,
struct wpa_bss *old_bss,
struct wpa_bss *new_bss)
{
struct wpa_radio_work *work;
struct wpa_connect_work *cwork;
work = radio_work_pending(wpa_s, "sme-connect");
if (!work)
work = radio_work_pending(wpa_s, "connect");
if (!work)
return;
cwork = work->ctx;
if (cwork->bss != old_bss)
return;
wpa_printf(MSG_DEBUG,
"Update BSS pointer for the pending connect radio work");
cwork->bss = new_bss;
if (!new_bss)
cwork->bss_removed = 1;
}
void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
const char *reason)
{
if (wpa_s->last_scan_res) {
unsigned int i;
for (i = 0; i < wpa_s->last_scan_res_used; i++) {
if (wpa_s->last_scan_res[i] == bss) {
os_memmove(&wpa_s->last_scan_res[i],
&wpa_s->last_scan_res[i + 1],
(wpa_s->last_scan_res_used - i - 1)
* sizeof(struct wpa_bss *));
wpa_s->last_scan_res_used--;
break;
}
}
}
wpa_bss_update_pending_connect(wpa_s, bss, NULL);
dl_list_del(&bss->list);
dl_list_del(&bss->list_id);
wpa_s->num_bss--;
wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Remove id %u BSSID " MACSTR
" SSID '%s' due to %s", bss->id, MAC2STR(bss->bssid),
wpa_ssid_txt(bss->ssid, bss->ssid_len), reason);
wpas_notify_bss_removed(wpa_s, bss->bssid, bss->id);
wpa_bss_anqp_free(bss->anqp);
os_free(bss);
}
/**
* wpa_bss_get - Fetch a BSS table entry based on BSSID and SSID
* @wpa_s: Pointer to wpa_supplicant data
* @bssid: BSSID
* @ssid: SSID
* @ssid_len: Length of @ssid
* Returns: Pointer to the BSS entry or %NULL if not found
*/
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;
if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
return NULL;
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 calculate_update_time(const struct os_reltime *fetch_time,
unsigned int age_ms,
struct os_reltime *update_time)
{
os_time_t usec;
update_time->sec = fetch_time->sec;
update_time->usec = fetch_time->usec;
update_time->sec -= age_ms / 1000;
usec = (age_ms % 1000) * 1000;
if (update_time->usec < usec) {
update_time->sec--;
update_time->usec += 1000000;
}
update_time->usec -= usec;
}
static void wpa_bss_copy_res(struct wpa_bss *dst, struct wpa_scan_res *src,
struct os_reltime *fetch_time)
{
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;
dst->est_throughput = src->est_throughput;
dst->snr = src->snr;
calculate_update_time(fetch_time, src->age, &dst->last_update);
}
static int wpa_bss_is_wps_candidate(struct wpa_supplicant *wpa_s,
struct wpa_bss *bss)
{
#ifdef CONFIG_WPS
struct wpa_ssid *ssid;
struct wpabuf *wps_ie;
int pbc = 0, ret;
wps_ie = wpa_bss_get_vendor_ie_multi(bss, WPS_IE_VENDOR_TYPE);
if (!wps_ie)
return 0;
if (wps_is_selected_pbc_registrar(wps_ie)) {
pbc = 1;
} else if (!wps_is_addr_authorized(wps_ie, wpa_s->own_addr, 1)) {
wpabuf_free(wps_ie);
return 0;
}
for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
continue;
if (ssid->ssid_len &&
(ssid->ssid_len != bss->ssid_len ||
os_memcmp(ssid->ssid, bss->ssid, ssid->ssid_len) != 0))
continue;
if (pbc)
ret = eap_is_wps_pbc_enrollee(&ssid->eap);
else
ret = eap_is_wps_pin_enrollee(&ssid->eap);
wpabuf_free(wps_ie);
return ret;
}
wpabuf_free(wps_ie);
#endif /* CONFIG_WPS */
return 0;
}
static int wpa_bss_known(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
{
struct wpa_ssid *ssid;
for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
if (ssid->ssid == NULL || ssid->ssid_len == 0)
continue;
if (ssid->ssid_len == bss->ssid_len &&
os_memcmp(ssid->ssid, bss->ssid, ssid->ssid_len) == 0)
return 1;
}
return 0;
}
static int wpa_bss_in_use(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
{
if (bss == wpa_s->current_bss)
return 1;
if (wpa_s->current_bss &&
(bss->ssid_len != wpa_s->current_bss->ssid_len ||
os_memcmp(bss->ssid, wpa_s->current_bss->ssid,
bss->ssid_len) != 0))
return 0; /* SSID has changed */
return !is_zero_ether_addr(bss->bssid) &&
(os_memcmp(bss->bssid, wpa_s->bssid, ETH_ALEN) == 0 ||
os_memcmp(bss->bssid, wpa_s->pending_bssid, ETH_ALEN) == 0);
}
static int wpa_bss_remove_oldest_unknown(struct wpa_supplicant *wpa_s)
{
struct wpa_bss *bss;
dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
if (!wpa_bss_known(wpa_s, bss) &&
!wpa_bss_is_wps_candidate(wpa_s, bss)) {
wpa_bss_remove(wpa_s, bss, __func__);
return 0;
}
}
return -1;
}
static int wpa_bss_remove_oldest(struct wpa_supplicant *wpa_s)
{
struct wpa_bss *bss;
/*
* Remove the oldest entry that does not match with any configured
* network.
*/
if (wpa_bss_remove_oldest_unknown(wpa_s) == 0)
return 0;
/*
* Remove the oldest entry that isn't currently in use.
*/
dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
if (!wpa_bss_in_use(wpa_s, bss)) {
wpa_bss_remove(wpa_s, bss, __func__);
return 0;
}
}
return -1;
}
static struct wpa_bss * wpa_bss_add(struct wpa_supplicant *wpa_s,
const u8 *ssid, size_t ssid_len,
struct wpa_scan_res *res,
struct os_reltime *fetch_time)
{
struct wpa_bss *bss;
bss = os_zalloc(sizeof(*bss) + res->ie_len + res->beacon_ie_len);
if (bss == NULL)
return NULL;
bss->id = wpa_s->bss_next_id++;
bss->last_update_idx = wpa_s->bss_update_idx;
wpa_bss_copy_res(bss, res, fetch_time);
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);
wpa_bss_set_hessid(bss);
if (wpa_s->num_bss + 1 > wpa_s->conf->bss_max_count &&
wpa_bss_remove_oldest(wpa_s) != 0) {
wpa_printf(MSG_ERROR, "Increasing the MAX BSS count to %d "
"because all BSSes are in use. We should normally "
"not get here!", (int) wpa_s->num_bss + 1);
wpa_s->conf->bss_max_count = wpa_s->num_bss + 1;
}
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_dbg(wpa_s, MSG_DEBUG, "BSS: Add new id %u BSSID " MACSTR
" SSID '%s' freq %d",
bss->id, MAC2STR(bss->bssid), wpa_ssid_txt(ssid, ssid_len),
bss->freq);
wpas_notify_bss_added(wpa_s, bss->bssid, bss->id);
return bss;
}
static int are_ies_equal(const struct wpa_bss *old,
const struct wpa_scan_res *new_res, 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_res, 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_res, 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_res, 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;
}
if (!old_ie || !new_ie)
ret = !old_ie && !new_ie;
else
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_res)
{
u32 changes = 0;
int caps_diff = old->caps ^ new_res->caps;
if (old->freq != new_res->freq)
changes |= WPA_BSS_FREQ_CHANGED_FLAG;
if (old->level != new_res->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_res->ie_len &&
os_memcmp(old + 1, new_res + 1, old->ie_len) == 0)
return changes;
changes |= WPA_BSS_IES_CHANGED_FLAG;
if (!are_ies_equal(old, new_res, WPA_IE_VENDOR_TYPE))
changes |= WPA_BSS_WPAIE_CHANGED_FLAG;
if (!are_ies_equal(old, new_res, WLAN_EID_RSN))
changes |= WPA_BSS_RSNIE_CHANGED_FLAG;
if (!are_ies_equal(old, new_res, WPS_IE_VENDOR_TYPE))
changes |= WPA_BSS_WPS_CHANGED_FLAG;
if (!are_ies_equal(old, new_res, WLAN_EID_SUPP_RATES) ||
!are_ies_equal(old, new_res, 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);
wpas_notify_bss_seen(wpa_s, bss->id);
}
static struct wpa_bss *
wpa_bss_update(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
struct wpa_scan_res *res, struct os_reltime *fetch_time)
{
u32 changes;
changes = wpa_bss_compare_res(bss, res);
if (changes & WPA_BSS_FREQ_CHANGED_FLAG)
wpa_printf(MSG_DEBUG, "BSS: " MACSTR " changed freq %d --> %d",
MAC2STR(bss->bssid), bss->freq, res->freq);
bss->scan_miss_count = 0;
bss->last_update_idx = wpa_s->bss_update_idx;
wpa_bss_copy_res(bss, res, fetch_time);
/* Move the entry to the end of the list */
dl_list_del(&bss->list);
#ifdef CONFIG_P2P
if (wpa_bss_get_vendor_ie(bss, P2P_IE_VENDOR_TYPE) &&
!wpa_scan_get_vendor_ie(res, P2P_IE_VENDOR_TYPE)) {
/*
* This can happen when non-P2P station interface runs a scan
* without P2P IE in the Probe Request frame. P2P GO would reply
* to that with a Probe Response that does not include P2P IE.
* Do not update the IEs in this BSS entry to avoid such loss of
* information that may be needed for P2P operations to
* determine group information.
*/
wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Do not update scan IEs for "
MACSTR " since that would remove P2P IE information",
MAC2STR(bss->bssid));
} else
#endif /* CONFIG_P2P */
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) {
unsigned int i;
for (i = 0; i < wpa_s->last_scan_res_used; i++) {
if (wpa_s->last_scan_res[i] == bss) {
wpa_s->last_scan_res[i] = nbss;
break;
}
}
if (wpa_s->current_bss == bss)
wpa_s->current_bss = nbss;
wpa_bss_update_pending_connect(wpa_s, bss, 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);
}
if (changes & WPA_BSS_IES_CHANGED_FLAG)
wpa_bss_set_hessid(bss);
dl_list_add_tail(&wpa_s->bss, &bss->list);
notify_bss_changes(wpa_s, changes, bss);
return bss;
}
/**
* wpa_bss_update_start - Start a BSS table update from scan results
* @wpa_s: Pointer to wpa_supplicant data
*
* This function is called at the start of each BSS table update round for new
* scan results. The actual scan result entries are indicated with calls to
* wpa_bss_update_scan_res() and the update round is finished with a call to
* wpa_bss_update_end().
*/
void wpa_bss_update_start(struct wpa_supplicant *wpa_s)
{
wpa_s->bss_update_idx++;
wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Start scan result update %u",
wpa_s->bss_update_idx);
wpa_s->last_scan_res_used = 0;
}
/**
* wpa_bss_update_scan_res - Update a BSS table entry based on a scan result
* @wpa_s: Pointer to wpa_supplicant data
* @res: Scan result
* @fetch_time: Time when the result was fetched from the driver
*
* This function updates a BSS table entry (or adds one) based on a scan result.
* This is called separately for each scan result between the calls to
* wpa_bss_update_start() and wpa_bss_update_end().
*/
void wpa_bss_update_scan_res(struct wpa_supplicant *wpa_s,
struct wpa_scan_res *res,
struct os_reltime *fetch_time)
{
const u8 *ssid, *p2p, *mesh;
struct wpa_bss *bss;
if (wpa_s->conf->ignore_old_scan_res) {
struct os_reltime update;
calculate_update_time(fetch_time, res->age, &update);
if (os_reltime_before(&update, &wpa_s->scan_trigger_time)) {
struct os_reltime age;
os_reltime_sub(&wpa_s->scan_trigger_time, &update,
&age);
wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Ignore driver BSS "
"table entry that is %u.%06u seconds older "
"than our scan trigger",
(unsigned int) age.sec,
(unsigned int) age.usec);
return;
}
}
ssid = wpa_scan_get_ie(res, WLAN_EID_SSID);
if (ssid == NULL) {
wpa_dbg(wpa_s, MSG_DEBUG, "BSS: No SSID IE included for "
MACSTR, MAC2STR(res->bssid));
return;
}
if (ssid[1] > SSID_MAX_LEN) {
wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Too long SSID IE included for "
MACSTR, MAC2STR(res->bssid));
return;
}
p2p = wpa_scan_get_vendor_ie(res, P2P_IE_VENDOR_TYPE);
#ifdef CONFIG_P2P
if (p2p == NULL &&
wpa_s->p2p_group_interface != NOT_P2P_GROUP_INTERFACE) {
/*
* If it's a P2P specific interface, then don't update
* the scan result without a P2P IE.
*/
wpa_printf(MSG_DEBUG, "BSS: No P2P IE - skipping BSS " MACSTR
" update for P2P interface", MAC2STR(res->bssid));
return;
}
#endif /* CONFIG_P2P */
if (p2p && ssid[1] == P2P_WILDCARD_SSID_LEN &&
os_memcmp(ssid + 2, P2P_WILDCARD_SSID, P2P_WILDCARD_SSID_LEN) == 0)
return; /* Skip P2P listen discovery results here */
/* TODO: add option for ignoring BSSes we are not interested in
* (to save memory) */
mesh = wpa_scan_get_ie(res, WLAN_EID_MESH_ID);
if (mesh && mesh[1] <= SSID_MAX_LEN)
ssid = mesh;
bss = wpa_bss_get(wpa_s, res->bssid, ssid + 2, ssid[1]);
if (bss == NULL)
bss = wpa_bss_add(wpa_s, ssid + 2, ssid[1], res, fetch_time);
else {
bss = wpa_bss_update(wpa_s, bss, res, fetch_time);
if (wpa_s->last_scan_res) {
unsigned int i;
for (i = 0; i < wpa_s->last_scan_res_used; i++) {
if (bss == wpa_s->last_scan_res[i]) {
/* Already in the list */
return;
}
}
}
}
if (bss == NULL)
return;
if (wpa_s->last_scan_res_used >= wpa_s->last_scan_res_size) {
struct wpa_bss **n;
unsigned int siz;
if (wpa_s->last_scan_res_size == 0)
siz = 32;
else
siz = wpa_s->last_scan_res_size * 2;
n = os_realloc_array(wpa_s->last_scan_res, siz,
sizeof(struct wpa_bss *));
if (n == NULL)
return;
wpa_s->last_scan_res = n;
wpa_s->last_scan_res_size = siz;
}
if (wpa_s->last_scan_res)
wpa_s->last_scan_res[wpa_s->last_scan_res_used++] = bss;
}
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;
}
/**
* wpa_bss_update_end - End a BSS table update from scan results
* @wpa_s: Pointer to wpa_supplicant data
* @info: Information about scan parameters
* @new_scan: Whether this update round was based on a new scan
*
* This function is called at the end of each BSS table update round for new
* scan results. The start of the update was indicated with a call to
* wpa_bss_update_start().
*/
void wpa_bss_update_end(struct wpa_supplicant *wpa_s, struct scan_info *info,
int new_scan)
{
struct wpa_bss *bss, *n;
os_get_reltime(&wpa_s->last_scan);
if ((info && info->aborted) || !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_s->conf->bss_expiration_scan_count) {
wpa_bss_remove(wpa_s, bss, "no match in scan");
}
}
wpa_printf(MSG_DEBUG, "BSS: last_scan_res_used=%u/%u",
wpa_s->last_scan_res_used, wpa_s->last_scan_res_size);
}
/**
* wpa_bss_flush_by_age - Flush old BSS entries
* @wpa_s: Pointer to wpa_supplicant data
* @age: Maximum entry age in seconds
*
* Remove BSS entries that have not been updated during the last @age seconds.
*/
void wpa_bss_flush_by_age(struct wpa_supplicant *wpa_s, int age)
{
struct wpa_bss *bss, *n;
struct os_reltime t;
if (dl_list_empty(&wpa_s->bss))
return;
os_get_reltime(&t);
t.sec -= 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_reltime_before(&bss->last_update, &t)) {
wpa_bss_remove(wpa_s, bss, __func__);
} else
break;
}
}
/**
* wpa_bss_init - Initialize BSS table
* @wpa_s: Pointer to wpa_supplicant data
* Returns: 0 on success, -1 on failure
*
* This prepares BSS table lists and timer for periodic updates. The BSS table
* is deinitialized with wpa_bss_deinit() once not needed anymore.
*/
int wpa_bss_init(struct wpa_supplicant *wpa_s)
{
dl_list_init(&wpa_s->bss);
dl_list_init(&wpa_s->bss_id);
return 0;
}
/**
* wpa_bss_flush - Flush all unused BSS entries
* @wpa_s: Pointer to wpa_supplicant data
*/
void wpa_bss_flush(struct wpa_supplicant *wpa_s)
{
struct wpa_bss *bss, *n;
wpa_s->clear_driver_scan_cache = 1;
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) {
if (wpa_bss_in_use(wpa_s, bss))
continue;
wpa_bss_remove(wpa_s, bss, __func__);
}
}
/**
* wpa_bss_deinit - Deinitialize BSS table
* @wpa_s: Pointer to wpa_supplicant data
*/
void wpa_bss_deinit(struct wpa_supplicant *wpa_s)
{
wpa_bss_flush(wpa_s);
}
/**
* wpa_bss_get_bssid - Fetch a BSS table entry based on BSSID
* @wpa_s: Pointer to wpa_supplicant data
* @bssid: BSSID
* Returns: Pointer to the BSS entry or %NULL if not found
*/
struct wpa_bss * wpa_bss_get_bssid(struct wpa_supplicant *wpa_s,
const u8 *bssid)
{
struct wpa_bss *bss;
if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
return NULL;
dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0)
return bss;
}
return NULL;
}
/**
* wpa_bss_get_bssid_latest - Fetch the latest BSS table entry based on BSSID
* @wpa_s: Pointer to wpa_supplicant data
* @bssid: BSSID
* Returns: Pointer to the BSS entry or %NULL if not found
*
* This function is like wpa_bss_get_bssid(), but full BSS table is iterated to
* find the entry that has the most recent update. This can help in finding the
* correct entry in cases where the SSID of the AP may have changed recently
* (e.g., in WPS reconfiguration cases).
*/
struct wpa_bss * wpa_bss_get_bssid_latest(struct wpa_supplicant *wpa_s,
const u8 *bssid)
{
struct wpa_bss *bss, *found = NULL;
if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
return NULL;
dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
if (os_memcmp(bss->bssid, bssid, ETH_ALEN) != 0)
continue;
if (found == NULL ||
os_reltime_before(&found->last_update, &bss->last_update))
found = bss;
}
return found;
}
#ifdef CONFIG_P2P
/**
* wpa_bss_get_p2p_dev_addr - Fetch a BSS table entry based on P2P Device Addr
* @wpa_s: Pointer to wpa_supplicant data
* @dev_addr: P2P Device Address of the GO
* Returns: Pointer to the BSS entry or %NULL if not found
*/
struct wpa_bss * wpa_bss_get_p2p_dev_addr(struct wpa_supplicant *wpa_s,
const u8 *dev_addr)
{
struct wpa_bss *bss;
dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
u8 addr[ETH_ALEN];
if (p2p_parse_dev_addr((const u8 *) (bss + 1), bss->ie_len,
addr) == 0 &&
os_memcmp(addr, dev_addr, ETH_ALEN) == 0)
return bss;
}
return NULL;
}
#endif /* CONFIG_P2P */
/**
* wpa_bss_get_id - Fetch a BSS table entry based on identifier
* @wpa_s: Pointer to wpa_supplicant data
* @id: Unique identifier (struct wpa_bss::id) assigned for the entry
* Returns: Pointer to the BSS entry or %NULL if not found
*/
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;
}
/**
* wpa_bss_get_id_range - Fetch a BSS table entry based on identifier range
* @wpa_s: Pointer to wpa_supplicant data
* @idf: Smallest allowed identifier assigned for the entry
* @idf: Largest allowed identifier assigned for the entry
* Returns: Pointer to the BSS entry or %NULL if not found
*
* This function is similar to wpa_bss_get_id() but allows a BSS entry with the
* smallest id value to be fetched within the specified range without the
* caller having to know the exact id.
*/
struct wpa_bss * wpa_bss_get_id_range(struct wpa_supplicant *wpa_s,
unsigned int idf, unsigned int idl)
{
struct wpa_bss *bss;
dl_list_for_each(bss, &wpa_s->bss_id, struct wpa_bss, list_id) {
if (bss->id >= idf && bss->id <= idl)
return bss;
}
return NULL;
}
/**
* wpa_bss_get_ie - Fetch a specified information element from a BSS entry
* @bss: BSS table 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 BSS
* entry.
*/
const u8 * wpa_bss_get_ie(const struct wpa_bss *bss, u8 ie)
{
return get_ie((const u8 *) (bss + 1), bss->ie_len, ie);
}
/**
* wpa_bss_get_vendor_ie - Fetch a vendor information element from a BSS entry
* @bss: BSS table 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 BSS
* entry.
*/
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 (end - pos > 1) {
if (2 + pos[1] > end - pos)
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_bss_get_vendor_ie_beacon - Fetch a vendor information from a BSS entry
* @bss: BSS table 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 BSS
* entry.
*
* This function is like wpa_bss_get_vendor_ie(), but uses IE buffer only
* from Beacon frames instead of either Beacon or Probe Response frames.
*/
const u8 * wpa_bss_get_vendor_ie_beacon(const struct wpa_bss *bss,
u32 vendor_type)
{
const u8 *end, *pos;
if (bss->beacon_ie_len == 0)
return NULL;
pos = (const u8 *) (bss + 1);
pos += bss->ie_len;
end = pos + bss->beacon_ie_len;
while (end - pos > 1) {
if (2 + pos[1] > end - pos)
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_bss_get_vendor_ie_multi - Fetch vendor IE data from a BSS entry
* @bss: BSS table 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 BSS entry. The caller is responsible for
* freeing the returned buffer.
*/
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 (end - pos > 1) {
if (2 + pos[1] > end - pos)
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;
}
/**
* wpa_bss_get_vendor_ie_multi_beacon - Fetch vendor IE data from a BSS entry
* @bss: BSS table 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 BSS entry. The caller is responsible for
* freeing the returned buffer.
*
* This function is like wpa_bss_get_vendor_ie_multi(), but uses IE buffer only
* from Beacon frames instead of either Beacon or Probe Response frames.
*/
struct wpabuf * wpa_bss_get_vendor_ie_multi_beacon(const struct wpa_bss *bss,
u32 vendor_type)
{
struct wpabuf *buf;
const u8 *end, *pos;
buf = wpabuf_alloc(bss->beacon_ie_len);
if (buf == NULL)
return NULL;
pos = (const u8 *) (bss + 1);
pos += bss->ie_len;
end = pos + bss->beacon_ie_len;
while (end - pos > 1) {
if (2 + pos[1] > end - pos)
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;
}
/**
* wpa_bss_get_max_rate - Get maximum legacy TX rate supported in a BSS
* @bss: BSS table entry
* Returns: Maximum legacy rate in units of 500 kbps
*/
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;
}
/**
* wpa_bss_get_bit_rates - Get legacy TX rates supported in a BSS
* @bss: BSS table entry
* @rates: Buffer for returning a pointer to the rates list (units of 500 kbps)
* Returns: number of legacy TX rates or -1 on failure
*
* The caller is responsible for freeing the returned buffer with os_free() in
* case of success.
*/
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;
}
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