1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)tftpd.8 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD$ 34.\" 35.Dd September 14, 2000 36.Dt TFTPD 8 37.Os BSD 4.2 38.Sh NAME 39.Nm tftpd 40.Nd 41Internet Trivial File Transfer Protocol server 42.Sh SYNOPSIS 43.Nm /usr/libexec/tftpd 44.Op Fl ln 45.Op Fl s Ar directory 46.Op Fl u Ar user 47.Op Ar directory ... 48.Sh DESCRIPTION 49.Nm Tftpd 50is a server which supports the 51Internet Trivial File Transfer 52Protocol 53.Pq Tn RFC 1350 . 54The 55.Tn TFTP 56server operates 57at the port indicated in the 58.Ql tftp 59service description; 60see 61.Xr services 5 . 62The server is normally started by 63.Xr inetd 8 . 64.Pp 65The use of 66.Xr tftp 1 67does not require an account or password on the remote system. 68Due to the lack of authentication information, 69.Nm 70will allow only publicly readable files to be 71accessed. 72Files containing the string ``/\|\fB.\|.\fP\|/'' or starting with 73``\|\fB.\|.\fP\|/'' are not allowed. 74Files may be written only if they already exist and are publicly writable. 75Note that this extends the concept of 76.Dq public 77to include 78all users on all hosts that can be reached through the network; 79this may not be appropriate on all systems, and its implications 80should be considered before enabling tftp service. 81The server should have the user ID with the lowest possible privilege. 82.Pp 83Access to files may be restricted by invoking 84.Nm 85with a list of directories by including up to 20 pathnames 86as server program arguments in 87.Pa /etc/inetd.conf . 88In this case access is restricted to files whose 89names are prefixed by the one of the given directories. 90The given directories are also treated as a search path for 91relative filename requests. 92.Pp 93The 94.Fl s 95option provides additional security by changing 96.Nm Ns No 's 97root directory, thereby prohibiting accesses outside of the specified 98.Ar directory . 99Because 100.Xr chroot 2 101requires super-user privileges, 102.Nm 103must be run as root. 104However, after performing the 105.Fn chroot , 106.Nm 107will set its user id to that of the specified 108.Ar user , 109or 110.Dq nobody 111if no 112.Fl u 113option is specified. 114.Pp 115The options are: 116.Bl -tag -width Ds 117.It Fl l 118Log all requests using 119.Xr syslog 3 120with the facility of 121.Dv LOG_FTP . 122Note: Logging of 123.Dv LOG_FTP 124messages 125must also be enabled in the syslog configuration file, 126.Xr syslog.conf 5 . 127.It Fl n 128Suppress negative acknowledgement of requests for nonexistent 129relative filenames. 130.It Fl s Ar directory 131Cause 132.Nm 133to change its root directory to 134.Pa directory . 135After changing roots but before accepting commands, 136.Nm 137will switch credentials to an unprivileged user. 138.It Fl u Ar user 139Switch credentials to 140.Ar user 141(default 142.Dq nobody ) 143when the 144.Fl s 145option is used. 146The user must be specified by name, not a numeric UID. 147.El 148.Sh SEE ALSO 149.Xr tftp 1 , 150.Xr chroot 2 , 151.Xr inetd 8 , 152.Xr syslogd 8 153.Rs 154.%A K. R. Sollins 155.%T The TFTP Protocol (Revision 2) 156.%D July 1992 157.%O RFC 1350, STD 33 158.Re 159.Sh HISTORY 160The 161.Nm 162command appeared in 163.Bx 4.2 ; 164the 165.Fl s 166option was introduced in 167.Fx 2.2 , 168and the 169.Fl u 170option was introduced in 171.Fx 4.2 . 172