--- a/src/common/CMakeLists.txt	Sun Oct 18 13:21:29 2015 -0400
+++ b/src/common/CMakeLists.txt	Sun Oct 18 14:08:04 2015 -0400
@@ -27,6 +27,7 @@
 	assfail.c
 	attr.c
 	connsvc.c
+	error.c
 	mutex.c
 	node.c
 	oid.c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/common/error.c	Sun Oct 18 14:08:04 2015 -0400
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2015 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <nomad/error.h>
+#include <nomad/rpc.h>
+
+#define MAP_ERRNO(errno)			\
+	case errno: return NERR_##errno
+
+int errno_to_nerr(int e)
+{
+	switch (e) {
+		MAP_ERRNO(EEXIST);
+		MAP_ERRNO(ENOENT);
+		case 0:
+			return NERR_SUCCESS;
+	}
+
+	return NERR_UNKNOWN_ERROR;
+}

--- a/src/common/include/nomad/rpc.h	Sun Oct 18 13:21:29 2015 -0400
+++ b/src/common/include/nomad/rpc.h	Sun Oct 18 14:08:04 2015 -0400
@@ -25,12 +25,19 @@
 
 #include <rpc/rpc.h>
 
-/* RPC error codes */
+/*
+ * RPC error codes
+ *
+ * Note: When adding new error codes, don't forget to update errno_to_nerr
+ * in error.c!
+ */
 #define NERR_UNKNOWN_ERROR     -1
 #define NERR_SUCCESS           0
 #define NERR_ENOENT            2
 #define NERR_EEXIST            17
 
+extern int errno_to_nerr(int e);
+
 extern void xdrfd_create(XDR *xdr, int fd, enum xdr_op op);
 
 #endif