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32 .\" @(#)tftpd.8 8.1 (Berkeley) 6/4/93
40 .Nd Internet Trivial File Transfer Protocol server
44 .Op Fl F Ar strftime-format
52 utility is a server which supports the
53 Internet Trivial File Transfer
59 at the port indicated in the
64 The server is normally started by
69 does not require an account or password on the remote system.
70 Due to the lack of authentication information,
72 will allow only publicly readable files to be
74 Files containing the string
79 Files may be written only if they already exist and are publicly writable.
80 Note that this extends the concept of
83 all users on all hosts that can be reached through the network;
84 this may not be appropriate on all systems, and its implications
85 should be considered before enabling tftp service.
86 The server should have the user ID with the lowest possible privilege.
88 Access to files may be restricted by invoking
90 with a list of directories by including up to 20 pathnames
91 as server program arguments in
93 In this case access is restricted to files whose
94 names are prefixed by the one of the given directories.
95 The given directories are also treated as a search path for
96 relative filename requests.
100 option provides additional security by changing
101 the root directory of
103 thereby prohibiting accesses to outside of the specified
107 requires super-user privileges,
111 However, after performing the
115 will set its user ID to that of the specified
126 Changes the default root directory of a connecting host via
128 based on the connecting IP address.
129 This prevents multiple clients from writing to the same file at the same time.
130 If the directory does not exist, the client connection is refused.
133 option is required for
141 except it falls back to
145 if a directory does not exist for the client's IP.
149 compatible format string for the creation of the suffix if
152 By default the string "%Y%m%d" is used.
153 .It Fl d, d Ar [value]
154 Enables debug output.
157 is not specified, then the debug level is increased by one
164 is specified, then the debug level is set to
166 The debug level is a bitmask implemented in
167 .Pa src/libexec/tftpd/tftp-utils.h .
168 Valid values are 0 (DEBUG_NONE), 1 (DEBUG_PACKETS), 2, (DEBUG_SIMPLE),
169 4 (DEBUG_OPTIONS), and 8 (DEBUG_ACCESS). Multiple debug values can be combined
170 in the bitmask by logically OR'ing the values. For example, specifying
173 will enable all the debug values.
175 Log all requests using
183 must also be enabled in the syslog configuration file,
186 Suppress negative acknowledgement of requests for nonexistent
189 Disable support for RFC2347 style TFTP Options.
190 .It Fl s Ar directory
193 to change its root directory to
195 After doing that but before accepting commands,
197 will switch credentials to an unprivileged user.
199 Switch credentials to
206 The user must be specified by name, not a numeric UID.
210 for newly created files.
212 .Pq Dv S_IWGRP | S_IWOTH .
214 Allow write requests to create new files.
217 requires that the file specified in a write request exist.
218 Note that this only works in directories writable by the user
225 but append a YYYYMMDD.nn sequence number to the end of the filename.
226 Note that the string YYYYMMDD can be changed with the
239 The following RFC's are supported:
241 .%T RFC 1350: The TFTP Protocol (Revision 2)
244 .%T RFC 2347: TFTP Option Extension
247 .%T RFC 2348: TFTP Blocksize Option
250 .%T RFC 2349: TFTP Timeout Interval and Transfer Size Options
257 TFTP options are mentioned here:
260 .%U http://www.compuphase.com/tftp.htm
269 option was introduced in
273 option was introduced in
277 option was introduced in
283 options were introduced in
286 Support for Timeout Interval and Transfer Size Options (RFC2349)
289 support for the TFTP Blocksize Option (RFC2348) and the blksize2 option
293 Edwin Groothuis <edwin@FreeBSD.org> performed a major rewrite of the
297 code to support RFC2348.
299 Files larger than 33,553,919 octets (65535 blocks, last one <512
300 octets) cannot be correctly transferred without client and server
301 supporting blocksize negotiation (RFCs 2347 and 2348),
302 or the non-standard TFTP rollover option.
305 accepts a sequence of block number which wrap to zero after 65535,
306 even if the rollover option is not specified.
308 Many tftp clients will not transfer files over 16,776,703 octets
309 (32767 blocks), as they incorrectly count the block number using
310 a signed rather than unsigned 16-bit integer.