Based on 4212a3375e03fd12cb407b34cab59dbe4ed9f4eb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Sun, 3 Aug 2014 01:28:21 -0400
Subject: [PATCH] nspawn: fix truncation of machine names in interface names

Based on patch by Michael Marineau <michael.marineau@coreos.com>:

When deriving the network interface name from machine name strncpy was
not properly null terminating the string and the maximum string size as
returned by strlen() is actually IFNAMSIZ-1, not IFNAMSIZ.
---
 src/nspawn/nspawn.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

--- src/nspawn/nspawn.c
+++ src/nspawn/nspawn.c	2014-08-22 10:18:20.390235611 +0000
@@ -1383,12 +1383,8 @@ static int setup_veth(pid_t pid, char if
 
         /* Use two different interface name prefixes depending whether
          * we are in bridge mode or not. */
-        if (arg_network_bridge)
-                memcpy(iface_name, "vb-", 3);
-        else
-                memcpy(iface_name, "ve-", 3);
-
-        strncpy(iface_name+3, arg_machine, IFNAMSIZ - 3);
+        snprintf(iface_name, IFNAMSIZ, "%s-%s",
+                arg_network_bridge ? "vb" : "ve", arg_machine);
 
         r = sd_rtnl_open(&rtnl, 0);
         if (r < 0) {
