--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -152,6 +152,8 @@ typedef struct {
     ngx_array_t                     *hide_headers;
     ngx_array_t                     *pass_headers;
 
+    ngx_addr_t                      *local;
+
 #if (NGX_HTTP_CACHE)
     ngx_shm_zone_t                  *cache;
 
@@ -321,6 +323,8 @@ ngx_int_t ngx_http_upstream_create(ngx_h
 void ngx_http_upstream_init(ngx_http_request_t *r);
 ngx_http_upstream_srv_conf_t *ngx_http_upstream_add(ngx_conf_t *cf,
     ngx_url_t *u, ngx_uint_t flags);
+char *ngx_http_upsteam_bind_set_slot(ngx_conf_t *cf, ngx_command_t *cmd,
+    void *conf);
 ngx_int_t ngx_http_upstream_hide_headers_hash(ngx_conf_t *cf,
     ngx_http_upstream_conf_t *conf, ngx_http_upstream_conf_t *prev,
     ngx_str_t *default_hide_headers, ngx_hash_init_t *hash);