ensure consistent req init for vcl switching

Merges #2447

bin/varnishd/cache/cache_req_fsm.c

@@ -738,35 +738,15 @@ cnt_restart(struct worker *wrk, struct req *req)
 	return (REQ_FSM_MORE);
 }
 
-/*--------------------------------------------------------------------
- * We have a complete request, set everything up and start it.
- * We can come here both with a request from the client and with
- * a interior request during ESI delivery.
+/*
+ * prepare the request for vcl_recv, either initially or after a reset
+ * e.g. due to vcl switching
  */
 
-static enum req_fsm_nxt
-cnt_recv(struct worker *wrk, struct req *req)
+static void
+cnt_recv_prep(struct req *req, const char *ci)
 {
-	unsigned recv_handling;
-	struct VSHA256Context sha256ctx;
 	const char *xff;
-	const char *ci, *cp;
-
-	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
-	CHECK_OBJ_NOTNULL(req, REQ_MAGIC);
-	AN(req->vcl);
-	AZ(req->objcore);
-	AZ(req->err_code);
-
-	AZ(isnan(req->t_first));
-	AZ(isnan(req->t_prev));
-	AZ(isnan(req->t_req));
-
-	ci = SES_Get_String_Attr(req->sp, SA_CLIENT_IP);
-	cp = SES_Get_String_Attr(req->sp, SA_CLIENT_PORT);
-	VSLb(req->vsl, SLT_ReqStart, "%s %s", ci, cp);
-
-	http_VSL_log(req->http);
 
 	if (req->restarts == 0) {
 		/*
@@ -784,7 +764,6 @@ cnt_recv(struct worker *wrk, struct req *req)
 		http_CollectHdr(req->http, H_Cache_Control);
 
 		/* By default we use the first backend */
-		AZ(req->director_hint);
 		req->director_hint = VCL_DefaultDirector(req->vcl);
 		AN(req->director_hint);
 
@@ -798,6 +777,37 @@ cnt_recv(struct worker *wrk, struct req *req)
 
 	req->vdc->retval = 0;
 	req->is_hit = 0;
+}
+/*--------------------------------------------------------------------
+ * We have a complete request, set everything up and start it.
+ * We can come here both with a request from the client and with
+ * a interior request during ESI delivery.
+ */
+
+static enum req_fsm_nxt
+cnt_recv(struct worker *wrk, struct req *req)
+{
+	unsigned recv_handling;
+	struct VSHA256Context sha256ctx;
+	const char *ci, *cp;
+
+	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
+	CHECK_OBJ_NOTNULL(req, REQ_MAGIC);
+	AN(req->vcl);
+	AZ(req->objcore);
+	AZ(req->err_code);
+
+	AZ(isnan(req->t_first));
+	AZ(isnan(req->t_prev));
+	AZ(isnan(req->t_req));
+
+	ci = SES_Get_String_Attr(req->sp, SA_CLIENT_IP);
+	cp = SES_Get_String_Attr(req->sp, SA_CLIENT_PORT);
+	VSLb(req->vsl, SLT_ReqStart, "%s %s", ci, cp);
+
+	http_VSL_log(req->http);
+
+	cnt_recv_prep(req, ci);
 
 	if (req->req_body_status == REQ_BODY_FAIL) {
 		req->doclose = SC_OVERLOAD;
@@ -806,10 +816,9 @@ cnt_recv(struct worker *wrk, struct req *req)
 
 	VCL_recv_method(req->vcl, wrk, req, NULL, NULL);
 	if (wrk->handling == VCL_RET_VCL && req->restarts == 0) {
-		req->director_hint = VCL_DefaultDirector(req->vcl);
 		HTTP_Copy(req->http, req->http0);
 		WS_Reset(req->ws, req->ws_req);
-		AN(req->director_hint);
+		cnt_recv_prep(req, ci);
 		VCL_recv_method(req->vcl, wrk, req, NULL, NULL);
 	}