Bugs in 1.14.3 krb5kdc on startup

[David Shrimpton]

Hi,

While testing a newly compiled 1.14.3 I found a few confusing things
in logs that look like small bugs in net-server.c code.

Note: the kdc.conf has kdc_tcp_ports = ""
to disable tcp . 

On startup krb5kdc logs:

Jul 27 16:12:38 myhostname krb5kdc[26223](info): setting up network...
Jul 27 16:12:38 myhostname krb5kdc[26223](info): listening on fd 7: udp 0.0.0.0.88 (pktinfo)
krb5kdc: Address family not supported by protocol - Cannot create TCP server socket on ::.88
Jul 27 16:12:38 myhostname krb5kdc[26223](info): set up 1 sockets
Jul 27 16:12:38 myhostname krb5kdc[26226](info): commencing operation

strace shows a call to socket to match the "::.88" log entry:

socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP) = -1 EAFNOSUPPORT (Address family not supported by protocol)
write(3, "krb5kdc: Address family not supp"..., 93) = 93


I think this may be showing some small bugs in lib/apputils/net-server.c.

1. The log message should show UDP not TCP as a UDP socket is being attempted
   to be created.   The code logs TCP always regardless of whether UDP or TCP
   socket is being created.  This is confusing in the situation above where
   tcp has been disabled in kdc.conf.

2. There is no time and date on the "krb5kdc: Address family not supported ..."
   log line

   strace shows:

   write(3, "krb5kdc: Address family not supp"..., 93) 

   v earlier log entry 

   write(3, "Jul 27 16:11:31

   I think this is intended to be a separate log line and not part of the previous line
   and should have time and date and hostname.

3. krb5kdc is automatically attempting to create an ipv6 socket
   but there are no ipv6 interfaces on this host to bind to this socket
   if it were created.   This is a bit confusing and  leads to the misleading
   error message  above always on startup on this host when there should be 
   no error message at all.



-- 
David Shrimpton 
Information Technology Services | The University of Queensland