ANQP: Extend ANQP_GET command to request without IEEE 802.11 elements

Previously, ANQP_GET required at least one IEEE 802.11 ANQP-element to
be requested. This is not really necessary, so allow a case where
num_ids == 0 as long as the request includes at least one Hotspot 2.0 or
MBO ANQP-element.

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

wpa_supplicant/ctrl_iface.c

@@ -6751,7 +6751,7 @@ static int get_anqp(struct wpa_supplicant *wpa_s, char *dst)
 		pos++;
 	}
 
-	if (num_id == 0)
+	if (num_id == 0 && !subtypes && !mbo_subtypes)
 		return -1;
 
 	return anqp_send_req(wpa_s, dst_addr, id, num_id, subtypes,

wpa_supplicant/interworking.c

@@ -106,10 +106,12 @@ static struct wpabuf * anqp_build_req(u16 info_ids[], size_t num_ids,
 	if (buf == NULL)
 		return NULL;
 
-	len_pos = gas_anqp_add_element(buf, ANQP_QUERY_LIST);
-	for (i = 0; i < num_ids; i++)
-		wpabuf_put_le16(buf, info_ids[i]);
-	gas_anqp_set_element_len(buf, len_pos);
+	if (num_ids > 0) {
+		len_pos = gas_anqp_add_element(buf, ANQP_QUERY_LIST);
+		for (i = 0; i < num_ids; i++)
+			wpabuf_put_le16(buf, info_ids[i]);
+		gas_anqp_set_element_len(buf, len_pos);
+	}
 	if (extra)
 		wpabuf_put_buf(buf, extra);