diff --git a/common/port.h b/common/port.h
new file mode 100644
index 0000000..f97f32e
--- /dev/null
+++ b/common/port.h
@@ -0,0 +1,76 @@
+/*	$NetBSD: port.h,v 1.1 2016/06/08 01:13:14 christos Exp $	*/
+
+/*-
+ * Copyright (c) 2016 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Christos Zoulas.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+
+#ifndef __dead
+#define __dead __attribute__((__noreturn__))
+#endif
+
+#ifndef __RCSID
+#define __RCSID(a)
+#endif
+
+#ifndef __USE
+#define __USE(a) ((void)&(a))
+#endif
+
+#ifndef __printflike
+#define __printflike(f, a)	__attribute__((__format__(__printf__, f, a)))
+#endif
+
+#ifdef __NetBSD__
+# include <util.h>
+#else
+# define pidfile(a)
+#endif
+
+#ifdef __linux__
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+
+extern char *__progname;
+static inline const char *
+getprogname(void) {
+	return __progname;
+}
+
+static inline char *
+strlcpy(char *d, const char *s, size_t l)
+{
+	if (l == 0)
+		return NULL;
+	strncpy(d, s, l);
+	d[l - 1] = '\0';
+	return d;
+}
+#endif