new file mode 100644
--- /dev/null
+++ b/src/http/modules/proxy/ngx_http_proxy_upstream.c
@@ -0,0 +1,43 @@
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_event.h>
+#include <ngx_event_connect.h>
+#include <ngx_event_pipe.h>
+#include <ngx_http.h>
+#include <ngx_http_proxy_handler.h>
+
+
+void ngx_http_proxy_reinit_upstream(ngx_http_proxy_ctx_t *p)
+{
+    ngx_chain_t             *cl;
+    ngx_output_chain_ctx_t  *octx;
+
+    octx = p->output_chain_ctx;
+
+    /* reinit the request chain */
+
+    for (cl = p->request->request_hunks; cl; cl = cl->next) {
+        cl->hunk->pos = cl->hunk->start;
+    }
+
+    /* reinit ngx_output_chain() context */
+
+    octx->hunk = NULL;
+    octx->in = NULL;
+    octx->free = NULL;
+    octx->busy = NULL;
+
+    /* reinit r->header_in buffer */
+
+    if (p->header_in) {
+        if (p->cache) {
+            p->header_in->pos = p->header_in->start + p->cache->ctx.header.size;
+            p->header_in->last = p->header_in->pos;
+
+        } else {
+            p->header_in->pos = p->header_in->start;
+            p->header_in->last = p->header_in->start;
+        }
+    }
+}