inetd(1Mtcp)

inetd -- Internet services daemon

Synopsis

inetd [-d] [-s] [-t] [configuration-file]

Description

The Internet services daemon, inetd, is normally run at boot time by the Service Access Facility (SAF). inetd listens for connections on the Internet addresses of the services specified in its configuration file. When a connection is found, inetd invokes the server daemon specified by that configuration file for the requested service. Once a server process exits, inetd continues to listen on the socket.

Rather than having several daemon processes with sparsely distributed requests each running concurrently, inetd reduces the load on the system by invoking Internet servers only as they are needed.

inetd itself provides a number of simple TCP-based services. These include echo, discard, chargen (character generator), daytime (human readable time), and time (machine readable time, in the form of the number of seconds since midnight, January 1, 1900). For details of these services, consult the appropriate RFC, as listed below, from the Network Information Center.

Files

/etc/inet/inetd.conf: the inetd configuration file
/etc/saf/inetd/_pid: the inetd process id file (if started via SAF)
/etc/protocols: protocols database
/etc/services: services database

Usage

When started, inetd reads its configuration information from configuration-file, the default being /etc/inetd.conf. See inetd.conf(4tcp) for more information on the format of this file. inetd rereads its configuration file whenever it receives a hangup signal, SIGHUP. New services can be activated, and existing services deleted or modified in between whenever the file is reread.

Options

-s: Run inetd ``stand-alone,'' outside the Service Access Facility (SAF). When the -s option is not used, inetd must be run under SAF via the sacadm(1M) command.
-d: Enable debugging. In debug mode, TCP connections will have the SO_DEBUG option enabled via setsockopt (see getsockopt(3sock)); SO_DEBUG is needed for trpt(1Mtcp). Note that when -d option is used, inetd runs in the foreground.
-t: Put inetd into calltrace mode, which produces additional syslog(3G) entries.

References

ftpd(1Mtcp), getsockopt(3sock), inetd.conf(4tcp), protocols(4tcp), rexecd(1Mtcp), rlogind(1Mtcp), rshd(1Mtcp), sacadm(1M), services(4tcp), telnetd(1Mtcp), tftpd(1Mtcp), trpt(1Mtcp)

RFC 862, RFC 863, RFC 864, RFC 867, RFC 868

Examples

To have SAF start inetd if it is not already running:

sacadm -s -p inetd

You can force inetd to re-read /etc/inetd.conf by sending it a SIGHUP signal. If inetd was started by SAF rather than from the command line, use the following command:

kill -HUP `cat /etc/saf/inetd/_pid`

ALternatively, use the SAF to stop and restart inetd:

sacadm -k -p inetd
sacadm -s -p inetd