ZEPHYRD(8)ZEPHYRD(8)NAMEzephyrd - Zephyr server daemon
SYNOPSIS
/usr/etc/zephyrd [ -d ]
DESCRIPTIONzephyrd 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.
zephyrd communicates with daemons running on other Zephyr
server hosts, to provide a reliable service.
While running, any unusual conditions are recorded via
syslog(3) to facility local6 at various levels. The -d
option enables logging of additional debugging informa
tion.
When a zephyrd is executed, it requests a list of server
machines from Hesiod and initializes its state from any
zephyrds executing on the other known servers. This ini
tialization is only performed after the zephyrds have
authenticated themselves to each other via Kerberos. The
server then enters a dispatch loop, servicing requests
from clients and other servers.
SIGNALS
SIGUSR1 enables logging of additional debugging informa
tion.
SIGUSR2 disables the logging of additional debugging
information.
SIGHUP causes 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.
SIGINT and SIGTERM cause zephyrd to gracefully shut down.
SIGFPE causes zephyrd to dump the location and subscrip
tion databases to /var/tmp/zephyr.db in an ASCII format.
ACCESS CONTROL
Certain notice classes are restricted by the Zephyr
server. Each such class has access control lists enumer
ating 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.
FILES
/usr/athena/lib/zephyr/class-registry.acl:
List of classes which are restricted
/usr/athena/lib/zephyr/iws-*.acl:
Access Control Lists for instance-wildcard
restrictions
/usr/athena/lib/zephyr/iui-*.acl:
Access Control Lists for instance-identity
restrictions
/usr/athena/lib/zephyr/sub-*.acl:
Access Control Lists for subscribing
/usr/athena/lib/zephyr/xmt-*.acl:
Access Control Lists for transmitting
/usr/athena/lib/zephyr/srvtab:
Kerberos Service keys
/usr/athena/lib/zephyr/ztkts:
Current Kerberos tickets for exchange with other
servers
/usr/tmp/zephyr.db:
File containing an ASCII dump of the database.
BUGS
The current implementation of the Zephyr server
(zephyrd(8)) makes no distinction between realm-announced,
net-visible and net-announced exposure levels.
SEE ALSOzephyr(1), zhm(8), kerberosintro(1), hesiod(3),
access_control_lists(?), syslog(3)
Athena Technical Plan, Sections E.4.1 (Zephyr Notification
Service) and E.2.1 (Kerberos Authentication and Authoriza
tion System)
AUTHOR
John T. Kohl, MIT Project Athena and Digital Equipment
Corporation
RESTRICTIONS
Copyright (c) 1987,1988 by the Massachusetts Institute of
Technology. All Rights Reserved.
zephyr(1) specifies the terms and conditions for redistri
bution.
MIT Project Athena July 1, 1988 ZEPHYRD(8)
