xref: /freebsd/libexec/tftpd/tftpd.8 (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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32.\"	@(#)tftpd.8	8.1 (Berkeley) 6/4/93
33.\" $FreeBSD$
34.\"
35.Dd June 4, 1993
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 l
45.Op Fl n
46.Op Fl s Ar directory
47.Op Ar directory ...
48.Sh DESCRIPTION
49.Nm Tftpd
50is a server which supports the
51Internet Trivial File Transfer
52Protocol (\c
53.Tn RFC 783).
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 chroot option provides additional security by restricting access
94of
95.Nm
96to only a chroot'd file system.  This is useful when moving
97from an OS that supported
98.Fl s
99as a boot server.  Because chroot is restricted to root, you must run
100.Nm
101as root.  However, if you chroot, then
102.Nm
103will set its user id to nobody.
104.Pp
105The options are:
106.Bl -tag -width Ds
107.It Fl l
108Log all requests using
109.Xr syslog 3
110with the facility of LOG_FTP.  Note: Logging of LOG_FTP messages
111will also need to be enabled in the syslog configuration file
112.Xr syslog.conf 5 .
113.It Fl n
114Suppress negative acknowledgement of requests for nonexistent
115relative filenames.
116.It Fl s Ar directory
117Cause
118.Nm
119to chroot to
120.Pa directory
121before accepting commands.  In addition, the user id is set to
122nobody.
123.Pp
124If you are not running
125.Fl s ,
126no user id change will be
127attempted.  You should not run
128.Nm
129as root unless you are using
130.Fl s .
131.El
132.Sh SEE ALSO
133.Xr tftp 1 ,
134.Xr inetd 8 ,
135.Xr syslogd 8
136.Sh HISTORY
137The
138.Nm
139command appeared in
140.Bx 4.2 .
141