commit ce17b1af08f3ea58d56c9168fd06f26a3094e95b
Author: Pavel Zhukov <pzhukov@redhat.com>
Date:   Mon Dec 4 16:58:57 2017 +0100

    Close the connecion if writer doesn't send data
    
    Some network monitoring tool check if service is alive by connect() to the port
    and close the connection without sending any data (ncat -z or nagios check_tcp are an
    example). As the result dhcpd leaks sockets and result is DoS.
    
    Signed-off: Martin Osvald <mosvald@redhat.com>
    
diff --git a/omapip/dispatch.c b/omapip/dispatch.c
index ba99889..d1fb57e 100644
--- a/omapip/dispatch.c
+++ b/omapip/dispatch.c
@@ -183,6 +183,10 @@ omapi_iscsock_cb(isc_task_t   *task,
 		if (status == ISC_R_INPROGRESS) {
 			return (1);
 		}
+
+		/* Writer closes the connection without data sent */
+		if (obj->reaper != NULL)
+			obj->reaper(obj->inner);
 	}
 
 	/*


-- 
PAVEL ZHUKOV
SOFTWARE ENGINEER, RHCE, RHCVA
Red Hat 
pzhukov@redhat.com    IM: IRC: landgraf