MBO: Add MBO IE to BSS Transition Management Response frame

When rejecting a BSS Transition Management Request frame, add MBO IE to
the BSS Transition Management Response frame to specify the transition
rejection reason.

Signed-off-by: David Spinadel <david.spinadel@intel.com>
Signed-off-by: Avraham Stern <avraham.stern@intel.com>

wpa_supplicant/mbo.c

@@ -716,3 +716,17 @@ fail:
 	wpa_printf(MSG_DEBUG, "MBO IE parsing failed (id=%u len=%u left=%zu)",
 		   id, elen, len);
 }
+
+
+size_t wpas_mbo_ie_bss_trans_reject(struct wpa_supplicant *wpa_s, u8 *pos,
+				    size_t len,
+				    enum mbo_transition_reject_reason reason)
+{
+	u8 reject_attr[3];
+
+	reject_attr[0] = MBO_ATTR_ID_TRANSITION_REJECT_REASON;
+	reject_attr[1] = 1;
+	reject_attr[2] = reason;
+
+	return mbo_add_ie(pos, len, reject_attr, sizeof(reject_attr));
+}

wpa_supplicant/wnm_sta.c

@@ -620,6 +620,14 @@ static void wnm_send_bss_transition_mgmt_resp(
 		pos += ETH_ALEN;
 	}
 
+#ifdef CONFIG_MBO
+	if (status != WNM_BSS_TM_ACCEPT) {
+		pos += wpas_mbo_ie_bss_trans_reject(
+			wpa_s, pos, buf + sizeof(buf) - pos,
+			MBO_TRANSITION_REJECT_REASON_UNSPECIFIED);
+	}
+#endif /* CONFIG_MBO */
+
 	len = pos - (u8 *) &mgmt->u.action.category;
 
 	res = wpa_drv_send_action(wpa_s, wpa_s->assoc_freq, 0, wpa_s->bssid,

wpa_supplicant/wpa_supplicant_i.h

@@ -1164,6 +1164,9 @@ int wpas_mbo_supp_op_class_ie(struct wpa_supplicant *wpa_s, int freq, u8 *pos,
 			      size_t len);
 void wpas_mbo_ie_trans_req(struct wpa_supplicant *wpa_s, const u8 *ie,
 			   size_t len);
+size_t wpas_mbo_ie_bss_trans_reject(struct wpa_supplicant *wpa_s, u8 *pos,
+				    size_t len,
+				    enum mbo_transition_reject_reason reason);
 
 /**
  * wpa_supplicant_ctrl_iface_ctrl_rsp_handle - Handle a control response