xref: /freebsd/usr.bin/tftp/tftp.1 (revision 8eb2bee6c0f4957c6c1cea826e59cda4d18a2a64)
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28.\"     @(#)tftp.1	8.2 (Berkeley) 4/18/94
29.\" $FreeBSD$
30.\"
31.Dd March 2, 2020
32.Dt TFTP 1
33.Os
34.Sh NAME
35.Nm tftp
36.Nd trivial file transfer program
37.Sh SYNOPSIS
38.Nm
39.Op Ar host Op Ar port
40.Sh DESCRIPTION
41The
42.Nm
43utility is the user interface to the Internet
44.Tn TFTP
45(Trivial File Transfer Protocol),
46which allows users to transfer files to and from a remote machine.
47The remote
48.Ar host
49may be specified on the command line, in which case
50.Nm
51uses
52.Ar host
53as the default host for future transfers (see the
54.Cm connect
55command below).
56.Sh COMMANDS
57Once
58.Nm
59is running, it issues the prompt
60.Dq Li tftp>
61and recognizes the following commands:
62.Pp
63.Bl -tag -width verbose -compact
64.It Cm \&? Ar command-name ...
65Print help information.
66.Pp
67.It Cm ascii
68Shorthand for "mode ascii"
69.Pp
70.It Cm binary
71Shorthand for "mode binary"
72.Pp
73.It Cm blocksize Ar [size]
74Sets the TFTP blksize option in TFTP Read Request or Write Request packets
75to
76.Ar [size]
77as specified in RFC 2348.
78Valid values are between 8 and 65464.
79If no blocksize is specified, then by default a blocksize of 512 bytes
80will be used.
81.Pp
82.It Cm blocksize2 Ar [size]
83Sets the TFTP blksize2 option in TFTP Read Request or Write Request packets
84to
85.Ar [size] .
86Values are restricted to powers of 2 between 8 and 32768.
87This is a non-standard TFTP option.
88.Pp
89.It Cm connect Ar host Op Ar port
90Set the
91.Ar host
92(and optionally
93.Ar port )
94for transfers.
95Note that the
96.Tn TFTP
97protocol, unlike the
98.Tn FTP
99protocol,
100does not maintain connections between transfers; thus, the
101.Cm connect
102command does not actually create a connection,
103but merely remembers what host is to be used for transfers.
104You do not have to use the
105.Cm connect
106command; the remote host can be specified as part of the
107.Cm get
108or
109.Cm put
110commands.
111.Pp
112.It Cm debug Ar level
113Enable or disable debugging levels during verbose output.
114The value of
115.Ar level
116can be one of
117.Cm packet , simple , options ,
118or
119.Cm access .
120.Pp
121.It Cm get Oo Ar host : Oc Ns Ar file Op Ar localname
122.It Cm get Xo
123.Oo Ar host1 : Oc Ns Ar file1
124.Oo Ar host2 : Oc Ns Ar file2 ...
125.Oo Ar hostN : Oc Ns Ar fileN
126.Xc
127Get one or more files from the remote host.
128When using the
129.Ar host
130argument, the
131.Ar host
132will be used as default host for future transfers.
133If
134.Ar localname
135is specified, the file is stored locally as
136.Ar localname ,
137otherwise the original filename is used.
138Note that it is not possible to download two files at a time, only
139one, three, or more than three files, at a time.
140.Pp
141To specify an IPv6 numeric address for a host, wrap it using square
142brackets like
143.Dq Li [3ffe:2900:e00c:ffee::1234] : Ns Ar file
144to disambiguate the
145colons used in the IPv6 address from the colon separating the host and
146the filename.
147.Pp
148.It Cm mode Ar transfer-mode
149Set the mode for transfers;
150.Ar transfer-mode
151may be one of
152.Em ascii
153or
154.Em binary .
155The default is
156.Em binary .
157.Pp
158.It Cm packetdrop [arg]
159Randomly drop
160.Ar arg
161out of 100 packets during a transfer.
162This is a debugging feature.
163.Pp
164.It Cm put Ar file Op Oo Ar host : Oc Ns Ar remotename
165.It Cm put Ar file1 file2 ... fileN Op Oo Ar host : Oc Ns Ar remote-directory
166Put a file or set of files to the remote host.
167When
168.Ar remotename
169is specified, the file is stored remotely as
170.Ar remotename ,
171otherwise the original filename is used.
172If the
173.Ar remote-directory
174argument is used, the remote host is assumed to be a
175.Ux
176machine.
177To specify an IPv6 numeric address for a
178.Ar host ,
179see the example under the
180.Cm get
181command.
182.Pp
183.It Cm options Ar [arg]
184Enable or disable support for TFTP options.
185The valid values of
186.Ar arg
187are
188.Cm on
189(enable RFC 2347 options),
190.Cm off
191(disable RFC 2347 options), and
192.Cm extra
193(toggle support for non-RFC defined options).
194.Pp
195.It Cm quit
196Exit
197.Nm .
198An end of file also exits.
199.Pp
200.It Cm rexmt Ar retransmission-timeout
201Set the per-packet retransmission timeout, in seconds.
202.Pp
203.It Cm rollover [arg]
204Specify the rollover option in TFTP Read Request or Write
205Request packets.
206After 65535 packets have been transmitted, set the block counter to
207.Ar arg .
208Valid values of
209.Ar arg
210are 0 and 1.  This is a non-standard TFTP option.
211.Pp
212.It Cm status
213Show current status.
214.Pp
215.It Cm timeout Ar total-transmission-timeout
216Set the total transmission timeout, in seconds.
217.Pp
218.It Cm trace
219Toggle packet tracing.
220.Pp
221.It Cm verbose
222Toggle verbose mode.
223.Pp
224.It Cm windowsize Op Ar size
225Sets the TFTP windowsize option in TFTP Read Request or Write Request packets to
226.Op Ar size
227blocks as specified in RFC 7440.
228Valid values are between 1 and 65535.
229If no windowsize is specified,
230then the default windowsize of 1 block will be used.
231.El
232.Sh SEE ALSO
233.Xr tftpd 8
234.Pp
235The following RFC's are supported:
236.Rs
237.%T RFC 1350: The TFTP Protocol (Revision 2)
238.Re
239.Rs
240.%T RFC 2347: TFTP Option Extension
241.Re
242.Rs
243.%T RFC 2348: TFTP Blocksize Option
244.Re
245.Rs
246.%T RFC 2349: TFTP Timeout Interval and Transfer Size Options
247.Re
248.Rs
249.%T RFC 3617: Uniform Resource Identifier (URI) Scheme and Applicability Statement for the Trivial File Transfer Protocol (TFTP)
250.Re
251.Rs
252.%T RFC 7440: TFTP Windowsize Option
253.Re
254.Pp
255The non-standard
256.Cm rollover
257and
258.Cm blksize2
259TFTP options are mentioned here:
260.Rs
261.%T Extending TFTP
262.%U https://www.compuphase.com/tftp.htm
263.Re
264.Sh HISTORY
265The
266.Nm
267command appeared in
268.Bx 4.3 .
269.Pp
270Edwin Groothuis <edwin@FreeBSD.org> performed a major rewrite of the
271.Xr tftpd 8
272and
273.Nm
274code to support RFC2348.
275.Sh NOTES
276Because there is no user-login or validation within
277the
278.Tn TFTP
279protocol, the remote site will probably have some
280sort of file-access restrictions in place.
281The
282exact methods are specific to each site and therefore
283difficult to document here.
284.Pp
285Files larger than 33488896 octets (65535 blocks) cannot be transferred
286without client and server supporting the TFTP blocksize option (RFC2348),
287or the non-standard TFTP rollover option.
288