sac(1M) 						  System Administration Commands						   sac(1M)

NAME

       sac - service access controller

SYNOPSIS

       sac -t sanity_interval

       /usr/lib/saf/sac

DESCRIPTION

       The Service Access Controller (SAC) is the overseer of the server machine. It is started when the server machine enters multiuser mode. The
       SAC performs several important functions as explained below.

   Customizing the SAC Environment
       When sac is invoked, it first looks for the per-system configuration script /etc/saf/_sysconfig. sac interprets _sysconfig to customize its
       own  environment.  The modifications made to the SAC environment by _sysconfig are inherited by all the children of the SAC. This inherited
       environment may be modified by the children.

   Starting Port Monitors
	After it has interpreted the _sysconfig file, the sac reads its administrative file /etc/saf/_sactab. _sactab specifies which  port  moni-
       tors  are to be started. For each port monitor to be started, sac forks a child (see fork(2)) and creates a utmpx entry with the type field
       set to LOGIN_PROCESS. Each child then interprets its per-port monitor configuration script /etc/saf/pmtag/_config ,  if	the  file  exists.
       These modifications to the environment  affect the port monitor and will be inherited by all its children. Finally, the child process execs
       the port monitor, using the command found in the _sactab entry.	(See sacadm; this is the command given with the -c option  when  the  port
       monitor is added to the system.)

   Polling Port Monitors to Detect Failure
       The -t option sets the frequency with which sac polls the port monitors on the system. This time may also be thought of as half of the max-
       imum latency required to detect that a port monitor has failed and that recovery action is necessary.

   Administrative functions
       The Service Access Controller represents the administrative point of control for port monitors.	Its  administrative  tasks  are  explained
       below.

       When  queried (sacadm with either -l or -L), the Service Access Controller returns the status  of the port monitors specified, which sacadm
       prints on the standard output. A port monitor may be in one of six states:

       ENABLED	       The port monitor is currently running and is accepting connections. See sacadm(1M) with the -e option.

       DISABLED        The port monitor is currently running and is not accepting connections. See sacadm with the -d option, and see  NOTRUNNING,
		       below.

       STARTING        The port monitor is in the process of starting up. STARTING is an intermediate state  on the way to ENABLED or DISABLED.

       FAILED	       The port monitor was unable to start and remain running.

       STOPPING        The  port  monitor  has	been manually terminated but has not completed its shutdown procedure. STOPPING is an intermediate
		       state on the way to NOTRUNNING.

       NOTRUNNING      The port monitor is not currently running. (See sacadm with -k.) This is the normal "not running" state. When a port  moni-
		       tor  is	killed,  all  ports it was monitoring are inaccessible.  It is not possible for an external user to tell whether a
		       port is not being monitored or the system is down. If the port monitor is not killed but is in the DISABLED state,  it  may
		       be  possible (depending on the port monitor being used) to write a message on the inaccessible port telling the user who is
		       trying to access the port that it is disabled. This is the advantage of having a DISABLED state as well as  the	NOTRUNNING
		       state.

       When a port monitor terminates, the SAC removes the utmpx entry for that port monitor.

       The SAC receives all requests to enable, disable, start, or stop port monitors and  takes the appropriate action.

       The SAC is responsible for restarting port monitors that terminate. Whether or not the SAC will restart a given port monitor depends on two
       things:

	 o  The restart count specified for the port monitor when the  port  monitor  was  added  by  sacadm;  this  information  is  included	in
	    /etc/saf/pmtag/_sactab.

	 o  The number of times the port monitor has already been restarted.

SECURITY

       sac  uses  pam(3PAM)  for session management.  The PAM configuration policy, listed through /etc/pam.conf, specifies the session management
       module to be used for sac. Here is a partial pam.conf file with entries for sac using the UNIX session management module.

       sac  session   required	 pam_unix_session.so.1

       If there are no entries for the sac service, then the entries for the "other" service will be used.

OPTIONS

       -t sanity_interval      Sets the frequency (sanity_interval) with which sac polls the port monitors on the system.

FILES

       /etc/saf/_sactab

       /etc/saf/_sysconfig

       /var/adm/utmpx

       /var/saf/_log

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       pmadm(1M), sacadm(1M), fork(2)  pam(3PAM),  pam.conf(4),  attributes(5),  pam_authtok_check(5),	pam_authtok_get(5),  pam_authtok_store(5),
       pam_dhkeys(5), pam_passwd_auth(5), pam_unix_account(5), pam_unix_auth(5), pam_unix_session(5)

NOTES

       The  pam_unix(5)  module  is  no longer supported. Similar functionality is provided by pam_authtok_check(5), pam_authtok_get(5), pam_auth-
       tok_store(5), pam_dhkeys(5), pam_passwd_auth(5), pam_unix_account(5), pam_unix_auth(5), and pam_unix_session(5).

SunOS 5.10							    23 Oct 2002 							   sac(1M)