.\" Copyright 1987 by the Massachusetts Institute of Technology
.\" All rights reserved.  The file /usr/include/zephyr/mit-copyright.h
.\" specifies the terms and conditions for redistribution.
.\"
.\"	$Source$
.\"	$Header$
.\"
.TH ZEPHYRD 8 "July 27, 1987"
.FM quote "MIT Project Athena"
.SH NAME
zephyrd \- Zephyr server daemon
.SH SYNOPSIS
.I /usr/etc/zephyrd
.SH DESCRIPTION
.I zephyrd
is the central server for the Zephyr Notification System.
It maintains a location database of all currently logged-in users, and a
subscription database for each user's Zephyr clients.
.PP
.I zephyrd 
communicates with daemons running on other Zephyr server hosts, to
provide a reliable service.
.PP
When a
.B zephyrd
is executed, it requests a list of server machines from Hesiod and
initializes its state from any
\fIzephyrd\fRs executing on the other known servers.  This initialization
is only performed after the \fIzephyrd\fRs have authenticated themselves
to each other via Kerberos.
The server then enters a dispatch loop, servicing requests from clients and
other servers.
.SH ACCESS CONTROL
Certain notice classes are restricted by the Zephyr server.  Each such
class has access control lists enumerating who may transmit (xmt-*.acl) or
subscribe to that particular class.  Subscriptions may be
restricted either absolutely (sub-*.acl files), or by instance restrictions.
iws-*.acl files control subscriptions to wildcarded instances.
iui-*.acl files control subscriptions to instances which are not the
Kerberos principal identity of the subscriber.
If an access control list of a given type is absent, there is no
restriction of that type on the class, except that any notices of the
class must be authenticated.
The class registry lists all classes which are restricted.
.SH FILES
.TP \w'/usr/athena/lib/zephyr/class-registry.acl'u+4n
/usr/athena/lib/zephyr/class-registry.acl
List of classes which are restricted
.TP
/usr/athena/lib/zephyr/iws-*.acl
Access Control Lists for instance-wildcard restrictions
.TP
/usr/athena/lib/zephyr/iui-*.acl
Access Control Lists for instance-identity restrictions
.TP
/usr/athena/lib/zephyr/sub-*.acl
Access Control Lists for subscribing
.TP
/usr/athena/lib/zephyr/xmt-*.acl
Access Control Lists for transmitting
.TP
/usr/athena/lib/zephyr/srvtab
Kerberos Service keys
.TP
/usr/athena/lib/zephyr/ztkts
Current kerberos tickets for exchange with other servers 
.SH SEE ALSO
zephyr(1), zhm(8), kerberos(?), hesiod(?), access_control_lists(?)
.br
Athena Technical Plan, Sections E.4.1 (Zephyr Notification Service) and
E.2.1 (Kerberos Authentication and Authorization System)
.SH AUTHOR
.PP
John T. Kohl, MIT Project Athena
.sp
Copyright (c) 1987,1988 by the Massachusetts Institute of Technology
.br
See
.I zephyr(1)
for a full copyright notice.