$scheme variable

src/http/ngx_http_variables.c

diff --git a/src/http/ngx_http_variables.c b/src/http/ngx_http_variables.c
index d5fbfc9..7dc9cc1 100644
--- a/src/http/ngx_http_variables.c
+++ b/src/http/ngx_http_variables.c
@@ -36,6 +36,8 @@
     ngx_http_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_http_variable_server_port(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
+static ngx_int_t ngx_http_variable_scheme(ngx_http_request_t *r,
+    ngx_http_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_http_variable_document_root(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_http_variable_request_filename(ngx_http_request_t *r,
@@ -122,6 +124,8 @@
     { ngx_string("server_protocol"), NULL, ngx_http_variable_request,
       offsetof(ngx_http_request_t, http_protocol), 0, 0 },
 
+    { ngx_string("scheme"), NULL, ngx_http_variable_scheme, 0, 0, 0 },
+
     { ngx_string("request_uri"), NULL, ngx_http_variable_request,
       offsetof(ngx_http_request_t, unparsed_uri), 0, 0 },
 
@@ -772,6 +776,34 @@
 
 
 static ngx_int_t
+ngx_http_variable_scheme(ngx_http_request_t *r,
+    ngx_http_variable_value_t *v, uintptr_t data)
+{
+#if (NGX_HTTP_SSL)
+
+    if (r->connection->ssl) {
+        v->len = sizeof("https") - 1;
+        v->valid = 1;
+        v->no_cachable = 0;
+        v->not_found = 0;
+        v->data = "https";
+
+        return NGX_OK;
+    }
+
+#endif
+
+    v->len = sizeof("http") - 1;
+    v->valid = 1;
+    v->no_cachable = 0;
+    v->not_found = 0;
+    v->data = "http";
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
 ngx_http_variable_document_root(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data)
 {