INETD(1M)                                               INETD(1M)



     NAME
          inetd - internet ``super-server''

     SYNOPSIS
          /usr/etc/inetd [ -d ] [ configuration file ]

     DESCRIPTION
          Inetd should be run at boot time by /etc/rc2.d/S30tcp.  It
          then listens for connections on certain internet sockets.
          When a connection is found on one of its sockets, it decides
          what service the socket corresponds to, and invokes a
          program to service the request.  After the program is
          finished, it continues to listen on the socket (except in
          some cases which will be described below).  Essentially,
          inetd allows running one daemon to invoke several others,
          reducing load on the system.

          Upon execution, inetd reads its configuration information
          from a configuration file which, by default, is
          /usr/etc/inetd.conf.  There must be an entry for each field
          of the configuration file, with entries for each field
          separated by a tab or a space.  Comments are denoted by a
          ``#'' at the beginning of a line.  There must be an entry
          for each field.  The fields of the configuration file are as
          follows:
               service name or rpc specification
               socket type
               protocol
               wait/nowait
               user
               server program
               server program arguments

          The service name entry is the name of a valid service in the
          file /etc/services.  For ``internal'' services (discussed
          below), the service name must be the official name of the
          service (that is, the first entry in /etc/services).  rpc
          specifications are discussed below.

          The socket type should be one of ``stream'', ``dgram'',
          ``raw'', ``rdm'', or ``seqpacket'', depending on whether the
          socket is a stream, datagram, raw, reliably delivered
          message, or sequenced packet socket.

          The protocol must be a valid protocol as given in
          /etc/protocols.  Examples might be ``tcp'' or ``udp''.

          The wait/nowait entry is applicable to datagram sockets only
          (other sockets should have a ``nowait'' entry in this
          space).  If a datagram server connects to its peer, freeing
          the socket so inetd can received further messages on the
          socket, it is said to be a ``multi-threaded'' server, and



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     INETD(1M)                                               INETD(1M)



          should use the ``nowait'' entry.  For datagram servers which
          process all incoming datagrams on a socket and eventually
          time out, the server is said to be ``single-threaded'' and
          should use a ``wait'' entry.


          ``Comsat'' (``biff'') and ``talk'' are both examples of the
          latter type of datagram server.  Tftpd is an exception; it
          is a datagram server that establishes pseudo-connections.
          It must be listed as ``wait'' in order to avoid a race; the
          server reads the first packet, creates a new socket, and
          then forks and exits to allow inetd to check for new service
          requests to spawn new servers.

          The user entry should contain the user name of the user as
          whom the server should run.  This allows for servers to be
          given less permission than root.  The server program entry
          should contain the pathname of the program which is to be
          executed by inetd when a request is found on its socket.  If
          inetd provides this service internally, this entry should be
          ``internal''.

          The arguments to the server program should be just as they
          normally are, starting with argv[0], which is the name of
          the program.  If the service is provided internally, the
          word ``internal'' should take the place of this entry.

          Inetd provides several ``trivial'' services internally by
          use of routines within itself.  These services are ``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).  All of these services are tcp based.  For details
          of these services, consult the appropriate RFC from the
          Network Information Center.

          Inetd rereads its configuration file when it receives a
          hangup signal, SIGHUP.  Services may be added, deleted or
          modified when the configuration file is reread.

     SEE ALSO
          ftpd(1M), rexecd(1M), rlogind(1M), rshd(1M), telnetd(1M),
          tftpd(1M)

     ORIGIN
          4.3 BSD









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