AP: Unsolicited broadcast Probe Response configuration

Add hostapd configuration options for unsolicited broadcast
Probe Response transmission for in-band discovery in 6 GHz.
Maximum allowed packet interval is 20 TUs (IEEE P802.11ax/D8.0
26.17.2.3.2, AP behavior for fast passive scanning).
Setting value to 0 disables the transmission.

Signed-off-by: Aloka Dixit <alokad@codeaurora.org>

hostapd/config_file.c

@@ -3617,6 +3617,16 @@ static int hostapd_config_fill(struct hostapd_config *conf,
 		conf->he_6ghz_rx_ant_pat = atoi(pos);
 	} else if (os_strcmp(buf, "he_6ghz_tx_ant_pat") == 0) {
 		conf->he_6ghz_tx_ant_pat = atoi(pos);
+	} else if (os_strcmp(buf, "unsol_bcast_probe_resp_interval") == 0) {
+		int val = atoi(pos);
+
+		if (val < 0 || val > 20) {
+			wpa_printf(MSG_ERROR,
+				   "Line %d: invalid unsol_bcast_probe_resp_interval value",
+				   line);
+			return 1;
+		}
+		bss->unsol_bcast_probe_resp_interval = val;
 #endif /* CONFIG_IEEE80211AX */
 	} else if (os_strcmp(buf, "max_listen_interval") == 0) {
 		bss->max_listen_interval = atoi(pos);

hostapd/hostapd.conf

@@ -933,6 +933,14 @@ wmm_ac_vo_acm=0
 #     (default)
 #he_6ghz_tx_ant_pat=1
 
+# Unsolicited broadcast Probe Response transmission settings
+# This is for the 6 GHz band only. If the interval is set to a non-zero value,
+# the AP schedules unsolicited broadcast Probe Response frames to be
+# transmitted for in-band discovery. Refer to
+# IEEE P802.11ax/D8.0 26.17.2.3.2, AP behavior for fast passive scanning.
+# Valid range: 0..20 TUs; default is 0 (disabled)
+#unsol_bcast_probe_resp_interval=0
+
 ##### IEEE 802.1X-2004 related configuration ##################################
 
 # Require IEEE 802.1X authorization

src/ap/ap_config.h

@@ -878,6 +878,8 @@ struct hostapd_bss_config {
 
 	int *pasn_groups;
 #endif /* CONFIG_PASN */
+
+	unsigned int unsol_bcast_probe_resp_interval;
 };
 
 /**

src/ap/beacon.c

@@ -1124,6 +1124,23 @@ static u8 * hostapd_probe_resp_offloads(struct hostapd_data *hapd,
 #endif /* NEED_AP_MLME */
 
 
+#ifdef CONFIG_IEEE80211AX
+/* Unsolicited broadcast Probe Response transmission, 6 GHz only */
+static u8 * hostapd_unsol_bcast_probe_resp(struct hostapd_data *hapd,
+					   struct wpa_driver_ap_params *params)
+{
+	if (!is_6ghz_op_class(hapd->iconf->op_class))
+		return NULL;
+
+	params->unsol_bcast_probe_resp_interval =
+		hapd->conf->unsol_bcast_probe_resp_interval;
+
+	return hostapd_gen_probe_resp(hapd, NULL, 0,
+				      &params->unsol_bcast_probe_resp_tmpl_len);
+}
+#endif /* CONFIG_IEEE80211AX */
+
+
 void sta_track_del(struct hostapd_sta_info *info)
 {
 #ifdef CONFIG_TAXONOMY
@@ -1719,6 +1736,10 @@ void ieee802_11_free_ap_params(struct wpa_driver_ap_params *params)
 	os_free(params->fd_frame_tmpl);
 	params->fd_frame_tmpl = NULL;
 #endif /* CONFIG_FILS */
+#ifdef CONFIG_IEEE80211AX
+	os_free(params->unsol_bcast_probe_resp_tmpl);
+	params->unsol_bcast_probe_resp_tmpl = NULL;
+#endif /* CONFIG_IEEE80211AX */
 }
 
 
@@ -1769,6 +1790,8 @@ int ieee802_11_set_beacon(struct hostapd_data *hapd)
 	params.he_bss_color = hapd->iface->conf->he_op.he_bss_color;
 	params.twt_responder = hostapd_get_he_twt_responder(hapd,
 							    IEEE80211_MODE_AP);
+	params.unsol_bcast_probe_resp_tmpl =
+		hostapd_unsol_bcast_probe_resp(hapd, &params);
 #endif /* CONFIG_IEEE80211AX */
 	hapd->reenable_beacon = 0;
 #ifdef CONFIG_SAE

src/drivers/driver.h

@@ -1561,6 +1561,21 @@ struct wpa_driver_ap_params {
 	 * FILS Discovery frame template length
 	 */
 	size_t fd_frame_tmpl_len;
+
+	/**
+	 * Unsolicited broadcast Probe Response interval in TUs
+	 */
+	unsigned int unsol_bcast_probe_resp_interval;
+
+	/**
+	 * Unsolicited broadcast Probe Response template data
+	 */
+	u8 *unsol_bcast_probe_resp_tmpl;
+
+	/**
+	 * Unsolicited broadcast Probe Response template length
+	 */
+	size_t unsol_bcast_probe_resp_tmpl_len;
 };
 
 struct wpa_driver_mesh_bss_params {