--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mgw/udpsink.c	Sat Jul 09 22:51:44 2022 -0800
@@ -0,0 +1,23 @@
+/*
+ * There are times when we hold open some UDP sockets, but can't do
+ * anything with incoming packets other than discard them.  This
+ * situation holds for dummy one-sided endpoints, for gateway
+ * endpoints that haven't been fully connected yet, and for all RTCP
+ * packets at the moment.
+ *
+ * In this module we implement the generic UDP "black hole" sink.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void
+udp_sink_rcvr(fd)
+{
+	u_char buf[512];
+
+	recv(fd, buf, sizeof buf, 0);
+}