process upstream ETag header
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index b02caa6..404be48 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -161,6 +161,12 @@
offsetof(ngx_http_upstream_headers_in_t, last_modified),
ngx_http_upstream_copy_last_modified, 0, 0 },
+ { ngx_string("ETag"),
+ ngx_http_upstream_process_header_line,
+ offsetof(ngx_http_upstream_headers_in_t, etag),
+ ngx_http_upstream_copy_header_line,
+ offsetof(ngx_http_headers_out_t, etag), 0 },
+
{ ngx_string("Server"),
ngx_http_upstream_process_header_line,
offsetof(ngx_http_upstream_headers_in_t, server),
