Add option to ignore Probe Request frames on 2.4 GHz from dualband STA
The new no_probe_resp_if_seen_on=<ifname> parameter can now be used to
configure hostapd to not reply to group-addressed Probe Request from a
station that was seen on another radio.
This can be used with enabled track_sta_max_num configuration on another
interface controlled by the same hostapd process to restrict Probe
Request frame handling from replying to group-addressed Probe Request
frames from a station that has been detected to be capable of operating
on another band, e.g., to try to reduce likelihood of the station
selecting a 2.4 GHz BSS when the AP operates both a 2.4 GHz and 5 GHz
BSS concurrently.
Note: Enabling this can cause connectivity issues and increase latency
for discovering the AP.
Signed-off-by: Jouni Malinen <j@w1.fi>
diff --git a/hostapd/config_file.c b/hostapd/config_file.c
index 336eba9..57ccbc6 100644
--- a/hostapd/config_file.c
+++ b/hostapd/config_file.c
@@ -3403,6 +3403,9 @@
conf->track_sta_max_num = atoi(pos);
} else if (os_strcmp(buf, "track_sta_max_age") == 0) {
conf->track_sta_max_age = atoi(pos);
+ } else if (os_strcmp(buf, "no_probe_resp_if_seen_on") == 0) {
+ os_free(bss->no_probe_resp_if_seen_on);
+ bss->no_probe_resp_if_seen_on = os_strdup(pos);
} else {
wpa_printf(MSG_ERROR,
"Line %d: unknown configuration item '%s'",
diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
index d912197..43e81ca 100644
--- a/hostapd/hostapd.conf
+++ b/hostapd/hostapd.conf
@@ -1289,6 +1289,21 @@
# Default: 180
#track_sta_max_age=180
+# Do not reply to group-addressed Probe Request from a station that was seen on
+# another radio.
+# Default: Disabled
+#
+# This can be used with enabled track_sta_max_num configuration on another
+# interface controlled by the same hostapd process to restrict Probe Request
+# frame handling from replying to group-addressed Probe Request frames from a
+# station that has been detected to be capable of operating on another band,
+# e.g., to try to reduce likelihood of the station selecting a 2.4 GHz BSS when
+# the AP operates both a 2.4 GHz and 5 GHz BSS concurrently.
+#
+# Note: Enabling this can cause connectivity issues and increase latency for
+# discovering the AP.
+#no_probe_resp_if_seen_on=wlan1
+
##### Wi-Fi Protected Setup (WPS) #############################################
# WPS state
diff --git a/src/ap/ap_config.c b/src/ap/ap_config.c
index be2fa8b..96f8651 100644
--- a/src/ap/ap_config.c
+++ b/src/ap/ap_config.c
@@ -566,6 +566,8 @@
wpabuf_free(conf->own_ie_override);
#endif /* CONFIG_TESTING_OPTIONS */
+ os_free(conf->no_probe_resp_if_seen_on);
+
os_free(conf);
}
diff --git a/src/ap/ap_config.h b/src/ap/ap_config.h
index 3434214..d821f27 100644
--- a/src/ap/ap_config.h
+++ b/src/ap/ap_config.h
@@ -554,6 +554,8 @@
int radio_measurements;
int vendor_vht;
+
+ char *no_probe_resp_if_seen_on;
};
diff --git a/src/ap/beacon.c b/src/ap/beacon.c
index 46fff82..651ee74 100644
--- a/src/ap/beacon.c
+++ b/src/ap/beacon.c
@@ -622,6 +622,29 @@
}
+static int sta_track_seen_on(struct hostapd_iface *iface, const u8 *addr,
+ const char *ifname)
+{
+ struct hapd_interfaces *interfaces = iface->interfaces;
+ size_t i, j;
+
+ for (i = 0; i < interfaces->count; i++) {
+ iface = interfaces->iface[i];
+ for (j = 0; j < iface->num_bss; j++) {
+ struct hostapd_data *hapd = iface->bss[j];
+
+ if (os_strcmp(ifname, hapd->conf->iface) == 0)
+ break;
+ }
+
+ if (j < iface->num_bss && sta_track_get(iface, addr))
+ return 1;
+ }
+
+ return 0;
+}
+
+
void handle_probe_req(struct hostapd_data *hapd,
const struct ieee80211_mgmt *mgmt, size_t len,
int ssi_signal)
@@ -787,6 +810,18 @@
/* TODO: verify that supp_rates contains at least one matching rate
* with AP configuration */
+ if (hapd->conf->no_probe_resp_if_seen_on &&
+ is_multicast_ether_addr(mgmt->da) &&
+ is_multicast_ether_addr(mgmt->bssid) &&
+ sta_track_seen_on(hapd->iface, mgmt->sa,
+ hapd->conf->no_probe_resp_if_seen_on)) {
+ wpa_printf(MSG_MSGDUMP, "%s: Ignore Probe Request from " MACSTR
+ " since STA has been seen on %s",
+ hapd->conf->iface, MAC2STR(mgmt->sa),
+ hapd->conf->no_probe_resp_if_seen_on);
+ return;
+ }
+
#ifdef CONFIG_TESTING_OPTIONS
if (hapd->iconf->ignore_probe_probability > 0.0 &&
drand48() < hapd->iconf->ignore_probe_probability) {
