Basic implementation of zipflow.subreq

It does not have any effect yet

src/vmod_zipflow.c

@@ -68,6 +68,7 @@ struct zipflow_request {
 #define ZIPFLOW_REQUEST_MAGIC		0xaa175160
 	unsigned			bundle:1;
 	char				level;
+	VCL_STRING			url;
 	VCL_STRING			name;
 	unsigned			mode;
 	uint32_t			atime, mtime;
@@ -170,10 +171,16 @@ get_zipflow_request(VRT_CTX)
 VCL_VOID
 vmod_subreq(VRT_CTX, VCL_STRING url)
 {
+	struct zipflow_request *zfr;
+	struct zipflow_top *zft;
+
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+	AN(ctx->method & (VCL_MET_TASK_C));
 
-	// XXX TODO
-	(void) url;
+	zft = get_zipflow_top(ctx);
+	zfr = new_zipflow_request(ctx, zft);
+
+	zfr->url = url;
 }
 
 VCL_BOOL