1.\" Copyright (c) 1985, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)inetd.8 6.7 (Berkeley) 03/16/91 7.\" 8.Dd 9.Dt INETD 8 10.Os BSD 4.3 11.Sh NAME 12.Nm inetd 13.Nd internet 14.Dq super-server 15.Sh SYNOPSIS 16.Nm inetd 17.Op Fl d 18.Op Ar configuration file 19.Sh DESCRIPTION 20.Nm Inetd 21should be run at boot time by 22.Pa /etc/rc.local 23(see 24.Xr rc 8 ) . 25It then listens for connections on certain 26internet sockets. When a connection is found on one 27of its sockets, it decides what service the socket 28corresponds to, and invokes a program to service the request. 29After the program is 30finished, it continues to listen on the socket (except in some cases which 31will be described below). Essentially, 32.Nm inetd 33allows running one daemon to invoke several others, 34reducing load on the system. 35.Pp 36The option available for 37.Nm inetd: 38.Bl -tag -width Ds 39.It Fl d 40Turns on debugging. 41.El 42.Pp 43Upon execution, 44.Nm inetd 45reads its configuration information from a configuration 46file which, by default, is 47.Pa /etc/inetd.conf . 48There must be an entry for each field of the configuration 49file, with entries for each field separated by a tab or 50a space. Comments are denoted by a ``#'' at the beginning 51of a line. There must be an entry for each field. The 52fields of the configuration file are as follows: 53.Pp 54.Bd -unfilled -offset indent -compact 55service name 56socket type 57protocol 58wait/nowait 59user 60server program 61server program arguments 62.Ed 63.Pp 64The 65.Em service-name 66entry is the name of a valid service in 67the file 68.Pa /etc/services . 69For 70.Dq internal 71services (discussed below), the service 72name 73.Em must 74be the official name of the service (that is, the first entry in 75.Pa /etc/services ) . 76.Pp 77The 78.Em socket-type 79should be one of 80.Dq stream , 81.Dq dgram , 82.Dq raw , 83.Dq rdm , 84or 85.Dq seqpacket , 86depending on whether the socket is a stream, datagram, raw, 87reliably delivered message, or sequenced packet socket. 88.Pp 89The 90.Em protocol 91must be a valid protocol as given in 92.Pa /etc/protocols . 93Examples might be 94.Dq tcp 95or 96.Dq udp . 97.Pp 98The 99.Em wait/nowait 100entry is applicable to datagram sockets only (other sockets should 101have a 102.Dq nowait 103entry in this space). If a datagram server connects 104to its peer, freeing the socket so 105.Nm inetd 106can received further messages on the socket, it is said to be 107a 108.Dq multi-threaded 109server, and should use the 110.Dq nowait 111entry. For datagram servers which process all incoming datagrams 112on a socket and eventually time out, the server is said to be 113.Dq single-threaded 114and should use a 115.Dq wait 116entry. 117.Xr Comsat 8 118.Pq Xr biff 1 119and 120.Xr talkd 8 121are both examples of the latter type of 122datagram server. 123.Xr Tftpd 8 124is an exception; it is a datagram server that establishes pseudo-connections. 125It must be listed as 126.Dq wait 127in order to avoid a race; 128the server reads the first packet, creates a new socket, 129and then forks and exits to allow 130.Nm inetd 131to check for new service requests to spawn new servers. 132.Pp 133The 134.Em user 135entry should contain the user name of the user as whom the server 136should run. This allows for servers to be given less permission 137than root. 138.Pp 139The 140.Em server-program 141entry should contain the pathname of the program which is to be 142executed by 143.Nm inetd 144when a request is found on its socket. If 145.Nm inetd 146provides this service internally, this entry should 147be 148.Dq internal . 149.Pp 150The 151.Em server program arguments 152should be just as arguments 153normally are, starting with argv[0], which is the name of 154the program. If the service is provided internally, the 155word 156.Dq internal 157should take the place of this entry. 158.Pp 159.Nm Inetd 160provides several 161.Dq trivial 162services internally by use of 163routines within itself. These services are 164.Dq echo , 165.Dq discard , 166.Dq chargen 167(character generator), 168.Dq daytime 169(human readable time), and 170.Dq time 171(machine readable time, 172in the form of the number of seconds since midnight, January 1731, 1900). All of these services are tcp based. For 174details of these services, consult the appropriate 175.Tn RFC 176from the Network Information Center. 177.Pp 178.Nm Inetd 179rereads its configuration file when it receives a hangup signal, 180.Dv SIGHUP . 181Services may be added, deleted or modified when the configuration file 182is reread. 183.Sh SEE ALSO 184.Xr comsat 8 , 185.Xr fingerd 8 , 186.Xr ftpd 8 , 187.Xr rexecd 8 , 188.Xr rlogind 8 , 189.Xr rshd 8 , 190.Xr telnetd 8 , 191.Xr tftpd 8 192.Sh HISTORY 193The 194.Nm 195command appeared in 196.Bx 4.3 . 197