On Fedora and RHEL systems (and probably other systems using SELinux),
error messages will appear in the system log for all file I/O operations
from dhclient, dhcrelay, dhcpd, etc.

SELinux developers discovered what needed to be changed in the ISC
software and helped me generate the attached patch.  The problem is that
all file descriptors need to be closed-on-exec (O_CLOEXEC).

Using fopen() or fdopen(), you can add 'e' to the mode string.  When
using open(), or in O_CLOEXEC to the mode.

The attached patch uses O_CLOEXEC if it's available.  For the fopen()
and fdopen() calls, I added 'e' to the mode strings.

-- 
David Cantrell <dcantrell@redhat.com>
Red Hat / Honolulu, HI