INETD(1M) RISC/os Reference Manual INETD(1M)
NAME
inetd - internet ``super-server''
SYNOPSIS
/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 pro-
gram 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 mes-
sage, or sequenced packet socket. The socket type may be
suffixed with ``/stream'' to indicate that the service pro-
vider expects an streams connection, as opposed to a sockets
connection, and that the streams connection should conform
to the Transport Provider Interface specification. The
socket type may further be suffixed with ``/xti'' or
``/tli'' to indicate that the streams connection should be
suitable for use with the XTI facility (-lxti or -lnsl in -
systype svr3 or -systype svr4), or with ``/socket'' to indi-
cate that the streams connection should be suitable for use
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INETD(1M) RISC/os Reference Manual INETD(1M)
with the -systype svr4 sockets emulation library (-lsocket).
For example, if the service provider is implemented using
the XTI facility, and expects a virtual circuit, the socket
type should be ``stream/stream/xti''. Similarly, if the
service provider is implemented using the -systype svr4
sockets emulation library, and expects datagrams, the socket
type should be ``datagram/stream/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
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 Net-
work Information Center.
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INETD(1M) RISC/os Reference Manual INETD(1M)
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.
NOTE
/etc/routed is symbolic link to /usr/etc/routed
SEE ALSO
ftpd(1M), rexecd(1M), rlogind(1M), rshd(1M), telnetd(1M),
tftpd(1M)
ORIGIN
4.3 BSD
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