Network services

The port monitor administrative file: _pmtab

Each port monitor will have two directories for its exclusive use. The current directory will contain files defined by the SAF (_pmtab, _pid) and the per-service configuration scripts, if they exist. The directory /var/saf/pmtag, where pmtag is the tag of the port monitor, is available for the port monitor's private files.

Each port monitor has its own administrative file. The pmadm command should be used to add, remove, or modify service entries in this file. Each time a change is made using pmadm, the corresponding port monitor rereads its administrative file. Each entry in a port monitor's administrative file defines how the port monitor treats a specific port and what service is to be invoked on that port.

Some fields must be present for all types of port monitors. Each entry must include a unique service tag to identify the service.

NOTE: The combination of a service tag and a port monitor tag uniquely define an instance of a service. The same service tag may be used to identify a service under a different port monitor.

The record must also contain port monitor specific data (for example, for a ttymon port monitor, this will include the prompt string which is meaningful to ttymon). Each type of port monitor must provide a command that takes the necessary port monitor-specific data as arguments and outputs this data in a form suitable for storage in the file. The ttyadm(1M) command does this for ttymon, and nlsadmin(1M) does it for listen. For a user-defined port monitor, a similar administrative command must be supplied.

Each service entry in the port monitor administrative file must have the following format and contain the information listed below:

svctag:flgs:id:reserved:reserved:scheme:pmspecific#comment

svctag

A unique tag that identifies a service. This tag is unique only for the port monitor through which the service is available. Other port monitors may offer the same or other services with the same tag. A service requires both a port monitor tag and a service tag to identify it uniquely. svctag may consist of up to 14 alphanumeric characters.

flgs

Flags with the following meanings may currently be included in this field:

x: Do not enable this port. By default the port is enabled.
u: Create a utmp entry for this service. By default no utmp entry is created for the service.

Note that port monitors may ignore the u flag if creating a utmp entry for the service is not appropriate to the manner in which the service is to be invoked. Some services may not start properly unless utmp entries have been created for them (for example, login).

id

The identity under which the service is to be started. The identity has the form of a login name as it appears in /etc/passwd. If this field is empty, the identity is supplied by the authentication scheme. When an id and an authentication scheme are both specified, the port monitor performs the authentication then invokes the service under the identity specified in the id field. If neither id nor authentication scheme is supplied, an error is returned when the service is executed.

scheme

The authentication scheme for the service. If the scheme field is empty, no authentication is performed by the port monitor.

pmspecific

Examples of port monitor-specific information are addresses, the name of a process to execute, the name of a STREAMS pipe to pass a connection through, and the name of an authentication scheme or its full command line. This information will vary to meet the needs of each different type of port monitor.

comment

A comment associated with the service entry.

NOTE: Each port monitor administrative file must contain one special comment of the form:

# VERSION=value

where value is an integer that represents the port monitor's version number. The version number defines the format of the port monitor administrative file. This comment line is created automatically when a port monitor is added to the system. It appears on a line by itself, before the service entries.