.\"	$Id$
.\"
.\" 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.
.\"
.TH ZEPHYRD 8 "July 1, 1988" "MIT Project Athena"
.ds ]W MIT Project Athena
.SH NAME
zephyrd \- Zephyr server daemon
.SH SYNOPSIS
.I /usr/etc/zephyrd
[
.BI \-d
]
.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
While running, any unusual conditions are recorded via 
.I syslog(3)
to facility local6 at various levels.
The
.BI \-d
option enables logging of additional debugging information.
.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 SIGNALS
.B SIGUSR1
enables logging of additional debugging information.
.br
.B SIGUSR2
disables the logging of additional debugging information.
.br
.B SIGHUP
causes
.I zephyrd
to re-read the default subscription file and to re-query Hesiod about
valid peers.  Any peers which are not responding and no longer
mentioned in Hesiod are flushed; any peers not previously named by
Hesiod are added.
.br
.B SIGINT \fRand\fB SIGTERM
cause
.I zephyrd
to gracefully shut down.
.br
.B SIGFPE
causes
.I zephyrd
to dump the location and subscription databases to
.I /var/tmp/zephyr.db
in an ASCII format.
.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 10
.I /usr/athena/lib/zephyr/class-registry.acl:
List of classes which are restricted
.TP
.I /usr/athena/lib/zephyr/iws-*.acl:
Access Control Lists for instance-wildcard restrictions
.TP
.I /usr/athena/lib/zephyr/iui-*.acl:
Access Control Lists for instance-identity restrictions
.TP
.I /usr/athena/lib/zephyr/sub-*.acl:
Access Control Lists for subscribing
.TP
.I /usr/athena/lib/zephyr/xmt-*.acl:
Access Control Lists for transmitting
.TP
.I /usr/athena/lib/zephyr/srvtab:
Kerberos Service keys
.TP
.I /usr/athena/lib/zephyr/ztkts:
Current Kerberos tickets for exchange with other servers 
.TP
.I /usr/tmp/zephyr.db:
File containing an ASCII dump of the database.
.SH BUGS
The current implementation of the Zephyr server (\fIzephyrd(8)\fR) makes
no distinction between realm-announced, net-visible and net-announced
exposure levels.
.SH SEE ALSO
zephyr(1), zhm(8), kerberosintro(1), hesiod(3), access_control_lists(?),
syslog(3)
.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 and Digital Equipment Corporation
.SH RESTRICTIONS
Copyright (c) 1987,1988 by the Massachusetts Institute of Technology.
All Rights Reserved.
.br
.I zephyr(1)
specifies the terms and conditions for redistribution.