Fix reply on nonfunctional nic

If a nic was up but without IPv4,
do not reply even if the kernel is
'helping' us to be in the ballpark.

confluent_server/confluent/discovery/protocols/pxe.py

@@ -469,6 +469,9 @@ def check_reply(node, info, packet, sock, cfg, reqview):
     gateway = None
     netmask = None
     niccfg = netutil.get_nic_config(cfg, node, ifidx=info['netinfo']['ifidx'])
+    if niccfg.get('ipv4_broken', False):
+        # Received a request over a nic with no ipv4 configured, ignore it
+        return
     clipn = None
     if niccfg['ipv4_address']:
         clipn = socket.inet_aton(niccfg['ipv4_address'])

confluent_server/confluent/netutil.py

@@ -177,6 +177,8 @@ def get_nic_config(configmanager, node, ip=None, mac=None, ifidx=None,
     if ifidx is not None:
         dhcprequested = False
         nets = list(idxtonets(ifidx))
+        if not nets:
+            cfgdata['ipv4_broken'] = True
     if serverip is not None:
         needsvrip = True
         dhcprequested = False