Commit | Line | Data |
---|---|---|
fd869580 KB |
1 | .\" Copyright (c) 1985 The Regents of the University of California. |
2 | .\" All rights reserved. | |
55270cae | 3 | .\" |
fd869580 KB |
4 | .\" Redistribution and use in source and binary forms are permitted |
5 | .\" provided that the above copyright notice and this paragraph are | |
6 | .\" duplicated in all such forms and that any documentation, | |
7 | .\" advertising materials, and other materials related to such | |
8 | .\" distribution and use acknowledge that the software was developed | |
9 | .\" by the University of California, Berkeley. The name of the | |
10 | .\" University may not be used to endorse or promote products derived | |
11 | .\" from this software without specific prior written permission. | |
12 | .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
13 | .\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
14 | .\" WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
15 | .\" | |
16 | .\" @(#)inetd.8 6.5 (Berkeley) %G% | |
55270cae KM |
17 | .\" |
18 | .TH INETD 8 "" | |
19 | .UC 6 | |
20 | .SH NAME | |
21 | inetd \- internet ``super\-server'' | |
22 | .SH SYNOPSIS | |
23 | .B /etc/inetd | |
24 | [ | |
25 | .B \-d | |
26 | ] [ configuration file ] | |
27 | .SH DESCRIPTION | |
28 | .I Inetd | |
29 | should be run at boot time by | |
30 | .IR /etc/rc.local . | |
31 | It then listens for connections on certain | |
32 | internet sockets. When a connection is found on one | |
33 | of its sockets, it decides what service the socket | |
34 | corresponds to, and invokes a program to service the request. | |
35 | After the program is | |
36 | finished, it continues to listen on the socket (except in some cases which | |
37 | will be described below). Essentially, | |
38 | .I inetd | |
39 | allows running one daemon to invoke several others, | |
40 | reducing load on the system. | |
41 | .PP | |
42 | Upon execution, | |
43 | .I inetd | |
44 | reads its configuration information from a configuration | |
45 | file which, by default, is | |
46 | .IR /etc/inetd.conf . | |
47 | There must be an entry for each field of the configuration | |
48 | file, with entries for each field separated by a tab or | |
49 | a space. Comments are denoted by a ``#'' at the beginning | |
50 | of a line. There must be an entry for each field. The | |
51 | fields of the configuration file are as follows: | |
52 | .br | |
53 | service name | |
54 | .br | |
55 | socket type | |
56 | .br | |
57 | protocol | |
58 | .br | |
59 | wait/nowait | |
60 | .br | |
61 | user | |
62 | .br | |
63 | server program | |
64 | .br | |
65 | server program arguments | |
66 | .PP | |
67 | The | |
68 | .I service name | |
69 | entry is the name of a valid service in | |
70 | the file | |
71 | .IR /etc/services/ . | |
72 | For ``internal'' services (discussed below), the service | |
73 | name | |
74 | .I must | |
63c183b7 | 75 | be the official name of the service (that is, the first entry in |
55270cae KM |
76 | .IR /etc/services ). |
77 | .PP | |
78 | The | |
79 | .I socket type | |
80 | should be one of ``stream'', ``dgram'', ``raw'', ``rdm'', or ``seqpacket'', | |
81 | depending on whether the socket is a stream, datagram, raw, | |
82 | reliably delivered message, or sequenced packet socket. | |
83 | .PP | |
84 | The | |
85 | .I protocol | |
86 | must be a valid protocol as given in | |
87 | .IR /etc/protocols . | |
88 | Examples might be ``tcp'' or ``udp''. | |
89 | .PP | |
90 | The | |
91 | .I wait/nowait | |
92 | entry is applicable to datagram sockets only (other sockets should | |
93 | have a ``nowait'' entry in this space). If a datagram server connects | |
94 | to its peer, freeing the socket so | |
95 | .I inetd | |
96 | can received further messages on the socket, it is said to be | |
97 | a ``multi-threaded'' server, and should use the ``nowait'' | |
98 | entry. For datagram servers which process all incoming datagrams | |
99 | on a socket and eventually time out, the server is said to be | |
63c183b7 | 100 | ``single-threaded'' and should use a ``wait'' entry. ``Comsat'' (``biff'') |
55270cae KM |
101 | and ``talk'' are both examples of the latter type of |
102 | datagram server. | |
63c183b7 MK |
103 | .I Tftpd |
104 | is an exception; it is a datagram server that establishes pseudo-connections. | |
105 | It must be listed as ``wait'' in order to avoid a race; | |
106 | the server reads the first packet, creates a new socket, | |
107 | and then forks and exits to allow | |
108 | .I inetd | |
109 | to check for new service requests to spawn new servers. | |
55270cae KM |
110 | .PP |
111 | The | |
112 | .I user | |
113 | entry should contain the user name of the user as whom the server | |
114 | should run. This allows for servers to be given less permission | |
115 | than root. | |
116 | The | |
117 | .I server program | |
118 | entry should contain the pathname of the program which is to be | |
119 | executed by | |
120 | .I inetd | |
121 | when a request is found on its socket. If | |
122 | .I inetd | |
123 | provides this service internally, this entry should | |
124 | be ``internal''. | |
125 | .PP | |
126 | The arguments to the server program should be just as they | |
127 | normally are, starting with argv[0], which is the name of | |
128 | the program. If the service is provided internally, the | |
129 | word ``internal'' should take the place of this entry. | |
130 | .PP | |
131 | .I Inetd | |
132 | provides several ``trivial'' services internally by use of | |
133 | routines within itself. These services are ``echo'', | |
134 | ``discard'', ``chargen'' (character generator), ``daytime'' | |
135 | (human readable time), and ``time'' (machine readable time, | |
136 | in the form of the number of seconds since midnight, January | |
137 | 1, 1900). All of these services are tcp based. For | |
138 | details of these services, consult the appropriate RFC | |
139 | from the Network Information Center. | |
f8cbfd03 MK |
140 | .PP |
141 | .I Inetd | |
142 | rereads its configuration file when it receives a hangup signal, SIGHUP. | |
143 | Services may be added, deleted or modified when the configuration file | |
144 | is reread. | |
55270cae | 145 | .SH "SEE ALSO" |
fd869580 KB |
146 | comsat(8), fingerd(8), ftpd(8), rexecd(8), rlogind(8), rshd(8), |
147 | telnetd(8), tftpd(8) |