--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sip-in/call_list.c	Sun Sep 11 15:42:54 2022 -0800
@@ -0,0 +1,28 @@
+/*
+ * In this module we implement call list management for themwi-sip-in.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <syslog.h>
+#include "call.h"
+
+struct call *call_list;
+
+struct call *
+find_call_by_sip_id(sought_id)
+	char *sought_id;
+{
+	struct call *call;
+
+	for (call = call_list; call; call = call->next)
+		if (!strcmp(call->sip_call_id, sought_id))
+			return call;
+	return 0;
+}