new file mode 100644
--- /dev/null
+++ b/src/stream/ngx_stream_variables.h
@@ -0,0 +1,109 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) Nginx, Inc.
+ */
+
+
+#ifndef _NGX_STREAM_VARIABLES_H_INCLUDED_
+#define _NGX_STREAM_VARIABLES_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_stream.h>
+
+
+typedef ngx_variable_value_t  ngx_stream_variable_value_t;
+
+#define ngx_stream_variable(v)     { sizeof(v) - 1, 1, 0, 0, 0, (u_char *) v }
+
+typedef struct ngx_stream_variable_s  ngx_stream_variable_t;
+
+typedef void (*ngx_stream_set_variable_pt) (ngx_stream_session_t *s,
+    ngx_stream_variable_value_t *v, uintptr_t data);
+typedef ngx_int_t (*ngx_stream_get_variable_pt) (ngx_stream_session_t *s,
+    ngx_stream_variable_value_t *v, uintptr_t data);
+
+
+#define NGX_STREAM_VAR_CHANGEABLE   1
+#define NGX_STREAM_VAR_NOCACHEABLE  2
+#define NGX_STREAM_VAR_INDEXED      4
+#define NGX_STREAM_VAR_NOHASH       8
+
+
+struct ngx_stream_variable_s {
+    ngx_str_t                     name;   /* must be first to build the hash */
+    ngx_stream_set_variable_pt    set_handler;
+    ngx_stream_get_variable_pt    get_handler;
+    uintptr_t                     data;
+    ngx_uint_t                    flags;
+    ngx_uint_t                    index;
+};
+
+
+ngx_stream_variable_t *ngx_stream_add_variable(ngx_conf_t *cf, ngx_str_t *name,
+    ngx_uint_t flags);
+ngx_int_t ngx_stream_get_variable_index(ngx_conf_t *cf, ngx_str_t *name);
+ngx_stream_variable_value_t *ngx_stream_get_indexed_variable(
+    ngx_stream_session_t *s, ngx_uint_t index);
+ngx_stream_variable_value_t *ngx_stream_get_flushed_variable(
+    ngx_stream_session_t *s, ngx_uint_t index);
+
+ngx_stream_variable_value_t *ngx_stream_get_variable(ngx_stream_session_t *s,
+    ngx_str_t *name, ngx_uint_t key);
+
+
+#if (NGX_PCRE)
+
+typedef struct {
+    ngx_uint_t                    capture;
+    ngx_int_t                     index;
+} ngx_stream_regex_variable_t;
+
+
+typedef struct {
+    ngx_regex_t                  *regex;
+    ngx_uint_t                    ncaptures;
+    ngx_stream_regex_variable_t  *variables;
+    ngx_uint_t                    nvariables;
+    ngx_str_t                     name;
+} ngx_stream_regex_t;
+
+
+typedef struct {
+    ngx_stream_regex_t           *regex;
+    void                         *value;
+} ngx_stream_map_regex_t;
+
+
+ngx_stream_regex_t *ngx_stream_regex_compile(ngx_conf_t *cf,
+    ngx_regex_compile_t *rc);
+ngx_int_t ngx_stream_regex_exec(ngx_stream_session_t *s, ngx_stream_regex_t *re,
+    ngx_str_t *str);
+
+#endif
+
+
+typedef struct {
+    ngx_hash_combined_t           hash;
+#if (NGX_PCRE)
+    ngx_stream_map_regex_t       *regex;
+    ngx_uint_t                    nregex;
+#endif
+} ngx_stream_map_t;
+
+
+void *ngx_stream_map_find(ngx_stream_session_t *s, ngx_stream_map_t *map,
+    ngx_str_t *match);
+
+
+ngx_int_t ngx_stream_variables_add_core_vars(ngx_conf_t *cf);
+ngx_int_t ngx_stream_variables_init_vars(ngx_conf_t *cf);
+
+
+extern ngx_stream_variable_value_t  ngx_stream_variable_null_value;
+extern ngx_stream_variable_value_t  ngx_stream_variable_true_value;
+
+
+#endif /* _NGX_STREAM_VARIABLES_H_INCLUDED_ */