TTY Monitor and Network Listener Port Monitors

Though the SAF provides a generic means for administering any future or third-party port monitors, only two port monitors are implemented in the Solaris Operating System: ttymon and listen.

TTY Port Monitor (ttymon)

The ttymon port monitor is STREAMS-based and does the following:

  • Monitors ports

  • Sets terminal modes, baud rates, and line disciplines

  • Invokes the login process

The ttymon port monitor provides Solaris users the same services that the getty port monitor did under previous versions of SunOS 4.1 software.

The ttymon port monitor runs under the SAC program and is configured with the sacadm command. Each instance of ttymon can monitor multiple ports. These ports are specified in the port monitor's administrative file. The administrative file is configured by using the pmadm and ttyadm commands.

ttymon and the Console Port

Console services are not managed by the Service Access Controller (SAC), nor by any explicit ttymon administration file. ttymon invocations are managed by SMF. As a result, you can no longer invoke ttymon by adding an entry to the /etc/inittab file. A property group with the type, application, and the name ttymon, has been added to the SMF service, svc:/system/console-login:default. The properties within this property group are used by the method script, /lib/svc/method/console-login. This script uses the property values as arguments to the ttymon invocation. Usually, if the values are empty, or if the values are not defined for any of the properties, then the value is not used for ttymon. However, if the ttymon device value is empty, or not set, then /dev/console is used as the default to enable ttymon to run.

The following properties are available under the SMF service, svc:/system/console-login:default:

ttymon/nohangup

Specifies the nohangup property. If set to true, do not force a line hang up by setting the line speed to zero before setting the default or specified speed.

ttymon/prompt

Specifies the prompt string for the console port.

ttymon/terminal_type

Specifies the default terminal type for the console.

ttymon/device

Specifies the console device.

ttymon/label

Specifies the TTY label in the /etc/ttydefs line.

ttymon-Specific Administrative Command (ttyadm)

The ttymon administrative file is updated by the sacadm and pmadm commands, as well as by the ttyadm command. The ttyadm command formats ttymon-specific information and writes it to standard output, providing a means for presenting formatted ttymon-specific data to the sacadm and pmadm commands.

Thus, the ttyadm command does not administer ttymon directly. The ttyadm command complements the generic administrative commands, sacadm and pmadm. For more information, see the ttyadm ( 1M ) man page.

Network Listener Service (listen)

The listen port monitor runs under the SAC and does the following:

  • Monitors the network for service requests

  • Accepts requests when they arrive

  • Invokes servers in response to those service requests

The listen port monitor is configured by using the sacadm command. Each instance of listen can provide multiple services. These services are specified in the port monitor's administrative file. This administrative file is configured by using the pmadm and nlsadmin commands.

The network listener process can be used with any connection-oriented transport provider that conforms to the Transport Layer Interface (TLI) specification. In the Solaris Operating System, listen port monitors can provide additional network services not provided by the inetd service.

Special listen-Specific Administrative Command (nlsadmin)

The listen port monitor's administrative file is updated by the sacadm and pmadm commands, as well as by the nlsadmin command. The nlsadmin command formats listen-specific information and writes it to standard output, providing a means of presenting formatted listen-specific data to the sacadm and pmadm commands.

Thus, the nlsadmin command does not administer listen directly. The command complements the generic administrative commands, sacadm and pmadm.

Each network, configured separately, can have at least one instance of the network listener process associated with it. The nlsadmin command controls the operational states of listen port monitors.

The nlsadmin command can establish a listen port monitor for a given network, configure the specific attributes of that port monitor, and start and kill the monitor. The nlsadmin command can also report on the listen port monitors on a machine.

For more information, see the nlsadmin ( 1M ) man page.