Add test option for specifying hardcoded BSS Load element

The new bss_load_test parameter can be used to configure hostapd to
advertise a fixed BSS Load element in Beacon and Probe Response frames
for testing purposes. This functionality is disabled in the build by
default and can be enabled with CONFIG_TESTING_OPTIONS=y.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>

hostapd/config_file.c

@@ -3002,6 +3002,25 @@ static int hostapd_config_fill(struct hostapd_config *conf,
 		PARSE_TEST_PROBABILITY(ignore_assoc_probability)
 		PARSE_TEST_PROBABILITY(ignore_reassoc_probability)
 		PARSE_TEST_PROBABILITY(corrupt_gtk_rekey_mic_probability)
+		} else if (os_strcmp(buf, "bss_load_test") == 0) {
+			WPA_PUT_LE16(bss->bss_load_test, atoi(pos));
+			pos = os_strchr(pos, ':');
+			if (pos == NULL) {
+				wpa_printf(MSG_ERROR, "Line %d: Invalid "
+					   "bss_load_test", line);
+				return 1;
+			}
+			pos++;
+			bss->bss_load_test[2] = atoi(pos);
+			pos = os_strchr(pos, ':');
+			if (pos == NULL) {
+				wpa_printf(MSG_ERROR, "Line %d: Invalid "
+					   "bss_load_test", line);
+				return 1;
+			}
+			pos++;
+			WPA_PUT_LE16(&bss->bss_load_test[3], atoi(pos));
+			bss->bss_load_test_set = 1;
 #endif /* CONFIG_TESTING_OPTIONS */
 		} else if (os_strcmp(buf, "vendor_elements") == 0) {
 			struct wpabuf *elems;

hostapd/hostapd.conf

@@ -416,6 +416,12 @@ wmm_ac_vo_acm=0
 # associated stations in the BSS. By default, this bridging is allowed.
 #ap_isolate=1
 
+# Fixed BSS Load value for testing purposes
+# This field can be used to configure hostapd to add a fixed BSS Load element
+# into Beacon and Probe Response frames for testing purposes. The format is
+# <station count>:<channel utilization>:<available admission capacity>
+#bss_load_test=12:80:20000
+
 ##### IEEE 802.11n related configuration ######################################
 
 # ieee80211n: Whether IEEE 802.11n (HT) is enabled

src/ap/ap_config.h

@@ -467,6 +467,11 @@ struct hostapd_bss_config {
 
 	unsigned int sae_anti_clogging_threshold;
 	int *sae_groups;
+
+#ifdef CONFIG_TESTING_OPTIONS
+	u8 bss_load_test[5];
+	u8 bss_load_test_set;
+#endif /* CONFIG_TESTING_OPTIONS */
 };
 
 

src/ap/beacon.c

@@ -38,6 +38,22 @@
 
 #ifdef NEED_AP_MLME
 
+static u8 * hostapd_eid_bss_load(struct hostapd_data *hapd, u8 *eid, size_t len)
+{
+#ifdef CONFIG_TESTING_OPTIONS
+	if (hapd->conf->bss_load_test_set) {
+		if (2 + 5 > len)
+			return eid;
+		*eid++ = WLAN_EID_BSS_LOAD;
+		*eid++ = 5;
+		os_memcpy(eid, hapd->conf->bss_load_test, 5);
+		eid += 5;
+	}
+#endif /* CONFIG_TESTING_OPTIONS */
+	return eid;
+}
+
+
 static u8 ieee802_11_erp_info(struct hostapd_data *hapd)
 {
 	u8 erp = 0;
@@ -251,6 +267,8 @@ static u8 * hostapd_gen_probe_resp(struct hostapd_data *hapd,
 	/* RSN, MDIE, WPA */
 	pos = hostapd_eid_wpa(hapd, pos, epos - pos);
 
+	pos = hostapd_eid_bss_load(hapd, pos, epos - pos);
+
 #ifdef CONFIG_IEEE80211N
 	pos = hostapd_eid_ht_capabilities(hapd, pos);
 	pos = hostapd_eid_ht_operation(hapd, pos);
@@ -662,6 +680,9 @@ void ieee802_11_set_beacon(struct hostapd_data *hapd)
 	tailpos = hostapd_eid_wpa(hapd, tailpos, tail + BEACON_TAIL_BUF_SIZE -
 				  tailpos);
 
+	tailpos = hostapd_eid_bss_load(hapd, tailpos,
+				       tail + BEACON_TAIL_BUF_SIZE - tailpos);
+
 #ifdef CONFIG_IEEE80211N
 	tailpos = hostapd_eid_ht_capabilities(hapd, tailpos);
 	tailpos = hostapd_eid_ht_operation(hapd, tailpos);