# Copyright 2006 Massachusetts Institute of Technology. # All Rights Reserved. # # Export of this software from the United States of America may # require a specific license from the United States Government. # It is the responsibility of any person or organization contemplating # export to obtain such a license before exporting. # # WITHIN THAT CONSTRAINT, permission to use, copy, modify, and # distribute this software and its documentation for any purpose and # without fee is hereby granted, provided that the above copyright # notice appear in all copies and that both that copyright notice and # this permission notice appear in supporting documentation, and that # the name of M.I.T. not be used in advertising or publicity pertaining # to distribution of the software without specific, written prior # permission. Furthermore if you modify this software you must label # your software as modified software and not distribute it in such a # fashion that it might be confused with the original M.I.T. software. # M.I.T. makes no representations about the suitability of # this software for any purpose. It is provided "as is" without express # or implied warranty. # possible return values: # False: request not handled by this script, try another means # empty list: no server available, e.g., TCP KDC in realm with only UDP # ordered list of (ip-addr-string, port-number-or-string, socket-type) # # Field ip-addr-string is a numeric representation of the IPv4 or IPv6 # address. Field port-number-or-string is, for example, "88" or 88. The # socket type is also expressed numerically, SOCK_DGRAM or SOCK_STREAM. # It must agree with the supplied socktype value if that is non-zero, but # zero must not be used in the returned list. # # service enum values: kdc=1, master_kdc, kadmin, krb524, kpasswd from socket import getaddrinfo, SOCK_STREAM, SOCK_DGRAM, AF_INET, AF_INET6 def locate1 (service, realm, socktype, family): if (service == 1 or service == 2) and realm == "ATHENA.MIT.EDU": if socktype == SOCK_STREAM: return [] socktype = SOCK_DGRAM result = [] hlist = (("kerberos.mit.edu", 88), ("kerberos-1.mit.edu", 88), ("some-random-name-that-does-not-exist.mit.edu", 12345), ("kerberos.mit.edu", 750)) if service == 2: hlist = (hlist[0],) for (hname,hport) in hlist: try: alist = getaddrinfo(hname, hport, family, socktype) for a in alist: (fam, stype, proto, canonname, sa) = a if fam == AF_INET or fam == AF_INET6: addr = sa[0] port = sa[1] result = result + [(addr, port, stype)] except Exception, inst: # print "getaddrinfo error for " + hname + ":", inst pass # Enh, this is just a demo. return result if realm == "BOBO.MIT.EDU": return [] return False verbose = 0 servicenames = { 1: "kdc", 2: "master_kdc", 3: "kadmin", 4: "krb524", 5: "kpasswd" } socktypenames = { SOCK_STREAM: "STREAM", SOCK_DGRAM: "DGRAM" } familynames = { 0: "UNSPEC", AF_INET: "INET", AF_INET6: "INET6" } def locate (service, realm, socktype, family): socktypename = socktype if socktype in socktypenames: socktypename = "%s(%d)" % (socktypenames[socktype], socktype) familyname = family if family in familynames: familyname = "%s(%d)" % (familynames[family], family) servicename = service if service in servicenames: servicename = "%s(%d)" % (servicenames[service], service) if verbose: print "locate called with service", servicename, "realm", realm, "socktype", socktypename, "family", familyname result = locate1 (service, realm, socktype, family) if verbose: print "locate result is", result return result