.\" $OpenBSD: identd.8,v 1.20 2003/02/03 17:46:56 jmc Exp $ .\" .\" Copyright (c) 1997, Jason Downs. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgment: .\" This product includes software developed by Jason Downs for the .\" OpenBSD system. .\" 4. Neither the name(s) of the author(s) nor the name OpenBSD .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS .\" OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED .\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE .\" DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, .\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES .\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR .\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER .\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)identd.8 1.9 92/02/11 Lysator .\" Copyright (c) 1992 Peter Eriksson, Lysator, Linkoping University. .\" This software has been released into the public domain. .\" .Dd July 27, 1997 .Dt IDENTD 8 .Os .Sh NAME .Nm identd .Nd TCP/IP IDENT protocol server .Sh SYNOPSIS .Nm identd .Bk -words .Op Fl i | w | b .Op Fl t Ar seconds .Op Fl u Ar uid .Op Fl g Ar gid .Op Fl p Ar port .Op Fl a Ar address .Op Fl c Ar charset .Op Fl noelvmNUdh .Ek .Sh DESCRIPTION .Nm is a server which implements the .Tn TCP/IP proposed standard .Tn IDENT user identification protocol as specified in the .Tn RFC 1413 document. .Pp .Nm operates by looking up specific .Tn TCP/IP connections and returning the user name of the process owning the connection. .Pp The options are as follows: .Bl -tag -width Ds .It Fl i Tells .Nm identd to run as a process started from .Xr inetd 8 with the "nowait" option in the .Pa /etc/inetd.conf file. Use of this mode will make .Xr inetd 8 start one .Nm daemon for each connection request. This is the default mode of operation. .It Fl w Tells .Nm identd to run as a process started from .Xr inetd 8 with the "wait" option in the .Pa /etc/inetd.conf file. This mode of operation will start a copy of .Nm at the first connection request and then .Nm will handle subsequent requests. Previous versions listed this as the preferred mode of operation due to the initial overhead of parsing the kernel nlist. This version does not use kmem or nlist parsing, so this reasoning is no longer valid. .It Fl b Specify operation as a stand-alone daemon. .It Fl h Hide the actual information about the user by providing an opaque token instead. This token is entered into the local system logs so that the administrator can later discover who the real user was. .It Fl H Hide information about non existing users (e.g., connections through NAT) as well as existing users. Implies .Fl h . .It Fl t Ar seconds Specifies an idle timeout in seconds where a daemon running in "wait" mode will timeout and exit. The default is no timeout. .It Fl u Ar uid Specify a user ID number or user name which the .Nm identd server should switch to after binding itself to the .Tn TCP/IP port if running as a stand-alone daemon. .It Fl g Ar gid Specify a group ID number or group name which the .Nm server should switch to after binding itself to the .Tn TCP/IP port if running as a stand-alone daemon. .It Fl p Ar port Specify an alternative port number or service name on which to listen when running as a stand-alone daemon. Default is "auth" (113). .It Fl a Ar address Specify a local IP address in dotted quad format to bind the listen socket to if running as a stand-alone daemon. By default the daemon listens on all local IP addresses. .It Fl l Use .Xr syslogd 8 for logging purposes. .It Fl v Log every request to syslog if .Fl l above is specified. .It Fl o Do not reveal operating system type; always return .Dq OTHER instead. .It Fl e Always return .Dq UNKNOWN-ERROR instead of the .Dq NO-USER or .Dq INVALID-PORT errors. .It Fl c Ar charset Specify an optional character set designator to be included in replies. .Ar charset should be a valid character set as described in the .Tn MIME RFC in upper case characters. .It Fl n Always return uid numbers instead of usernames. .It Fl N When replying with a user name or ID, first check for a file .Pa .noident in the user's home directory. If this file is accessible, return .Dq HIDDEN-USER instead of the normal USERID response. .It Fl U When replying with a user name or ID, first check for a file .Pa .ident in the user's home directory. If this file is accessible, return the contents of the file instead of the normal USERID response. .It Fl m Allow multiple requests to be processed per session. Each request is specified one per line and the responses will be returned one per line. The connection will not be closed until the client closes its end of the connection. PLEASE NOTE THAT THIS MODE VIOLATES THE PROTOCOL SPECIFICATION AS IT CURRENTLY STANDS. .It Fl d This flag enables some debugging code that normally should NOT be enabled since that breaks the protocol and may reveal information that should not be available to outsiders. .El .Sh SEE ALSO .Xr inetd.conf 5 .Sh NOTES .Nm uses the .Li LOG_DAEMON .Xr syslogd 8 facility to log messages. .Pp Unlike previous versions of .Nm identd , this version uses .Xr sysctl 3 to obtain information from the kernel instead of parsing kmem. This version does not require privilege beyond what is needed to bind the listen port if running as a stand-alone daemon. .Sh BUGS Since .Nm identd should typically not be run as a privileged user or group, .Pa .ident files for use when running with the .Fl U flag will need to be world accessible. The same applies for .Pa .noident files when running with the .Fl N flag.