mirror of
https://github.com/freebsd/freebsd-src.git
synced 2024-11-30 04:22:44 +00:00
79c342aaf8
Some checks are pending
Cross-build Kernel / ${{ matrix.target_arch }} ${{ matrix.os }} (${{ matrix.compiler }}) (clang-14, /usr/lib/llvm-14/bin, ubuntu-22.04, bmake libarchive-dev clang-14 lld-14, amd64, amd64) (push) Waiting to run
Cross-build Kernel / ${{ matrix.target_arch }} ${{ matrix.os }} (${{ matrix.compiler }}) (clang-14, /usr/lib/llvm-14/bin, ubuntu-22.04, bmake libarchive-dev clang-14 lld-14, arm64, aarch64) (push) Waiting to run
Cross-build Kernel / ${{ matrix.target_arch }} ${{ matrix.os }} (${{ matrix.compiler }}) (clang-18, /opt/homebrew/opt/llvm@18/bin, macos-latest, bmake libarchive llvm@18, amd64, amd64) (push) Waiting to run
Cross-build Kernel / ${{ matrix.target_arch }} ${{ matrix.os }} (${{ matrix.compiler }}) (clang-18, /opt/homebrew/opt/llvm@18/bin, macos-latest, bmake libarchive llvm@18, arm64, aarch64) (push) Waiting to run
Cross-build Kernel / ${{ matrix.target_arch }} ${{ matrix.os }} (${{ matrix.compiler }}) (clang-18, /usr/lib/llvm-18/bin, ubuntu-24.04, bmake libarchive-dev clang-18 lld-18, amd64, amd64) (push) Waiting to run
Cross-build Kernel / ${{ matrix.target_arch }} ${{ matrix.os }} (${{ matrix.compiler }}) (clang-18, /usr/lib/llvm-18/bin, ubuntu-24.04, bmake libarchive-dev clang-18 lld-18, arm64, aarch64) (push) Waiting to run
The tftpd tests all follow the same pattern: 1. open a UDP socket, 2. fork a child to exec tftpd, which subsequently handles requests on the socket, 3. use a client socket to send some message to the tftpd daemon. However, tftpd's first action is to mark its socket as non-blocking and then read a request from it. If no data is present in the socket, tftpd exits immediately with an error. So, there is a race; we often see tftpd test timeouts when running tests in parallel. These timeouts also arise periodically in CI runs. One solution is to restructure each test to create the server socket, then write the request to the client socket, then fork tftpd. This closes the race. However, this involves a lot of churn. This patch fixes the problem a different way, by adding a new -b flag to tftpd which makes it block to read the initial request. Each test is modified to use -b, closing the race. Reviewed by: imp, asomers MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D47404
334 lines
8.1 KiB
Groff
334 lines
8.1 KiB
Groff
.\" Copyright (c) 1983, 1991, 1993
|
|
.\" The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
|
|
.\"
|
|
.Dd November 3, 2024
|
|
.Dt TFTPD 8
|
|
.Os
|
|
.Sh NAME
|
|
.Nm tftpd
|
|
.Nd Internet Trivial File Transfer Protocol server
|
|
.Sh SYNOPSIS
|
|
.Nm tftpd
|
|
.Op Fl bCcdlnoSw
|
|
.Op Fl F Ar strftime-format
|
|
.Op Fl s Ar directory
|
|
.Op Fl U Ar umask
|
|
.Op Fl u Ar user
|
|
.Op Ar directory ...
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
utility is a server which supports the
|
|
Internet Trivial File Transfer
|
|
Protocol
|
|
.Pq Tn RFC 1350 .
|
|
The
|
|
.Tn TFTP
|
|
server operates
|
|
at the port indicated in the
|
|
.Ql tftp
|
|
service description;
|
|
see
|
|
.Xr services 5 .
|
|
The server is normally started by
|
|
.Xr inetd 8 .
|
|
.Pp
|
|
The use of
|
|
.Xr tftp 1
|
|
does not require an account or password on the remote system.
|
|
Due to the lack of authentication information,
|
|
.Nm
|
|
will allow only publicly readable files to be
|
|
accessed.
|
|
Files containing the string
|
|
.Dq Li "/../"
|
|
or starting with
|
|
.Dq Li "../"
|
|
are not allowed.
|
|
Files may be written only if they already exist (unless the
|
|
.Fl w
|
|
option is used) and are publicly writable (unless chrooted and the
|
|
.Fl S
|
|
option is used).
|
|
Note that this extends the concept of
|
|
.Dq public
|
|
to include
|
|
all users on all hosts that can be reached through the network;
|
|
this may not be appropriate on all systems, and its implications
|
|
should be considered before enabling tftp service.
|
|
The server should have the user ID with the lowest possible privilege.
|
|
.Pp
|
|
Access to files may be restricted by invoking
|
|
.Nm
|
|
with a list of directories by including up to 20 pathnames
|
|
as server program arguments in
|
|
.Xr inetd.conf 5 .
|
|
In this case access is restricted to files whose
|
|
names are prefixed by the one of the given directories.
|
|
The given directories are also treated as a search path for
|
|
relative filename requests.
|
|
.Pp
|
|
The
|
|
.Fl s
|
|
option provides additional security by changing
|
|
the root directory of
|
|
.Nm ,
|
|
thereby prohibiting accesses to outside of the specified
|
|
.Ar directory .
|
|
Because
|
|
.Xr chroot 2
|
|
requires super-user privileges,
|
|
.Nm
|
|
must be run as
|
|
.Li root .
|
|
However, after performing the
|
|
.Xr chroot 2
|
|
call,
|
|
.Nm
|
|
will set its user ID to that of the specified
|
|
.Ar user ,
|
|
or
|
|
.Dq Li nobody
|
|
if no
|
|
.Fl u
|
|
option is specified.
|
|
.Pp
|
|
The options are:
|
|
.Bl -tag -width Ds
|
|
.It Fl b
|
|
By default,
|
|
.Nm
|
|
expects an initial message to be available on its input socket.
|
|
If no data is available, the server exits immediately.
|
|
If
|
|
.Fl b
|
|
is specified,
|
|
.Nm
|
|
will block waiting for the initial message.
|
|
.It Fl c
|
|
Changes the default root directory of a connecting host via
|
|
.Xr chroot 2
|
|
based on the connecting IP address.
|
|
This prevents multiple clients from writing to the same file at the same time.
|
|
If the directory does not exist, the client connection is refused.
|
|
The
|
|
.Fl s
|
|
option is required for
|
|
.Fl c
|
|
and the specified
|
|
.Ar directory
|
|
is used as a base.
|
|
.It Fl C
|
|
Operates the same as
|
|
.Fl c
|
|
except it falls back to
|
|
.Ar directory
|
|
specified via
|
|
.Fl s
|
|
if a directory does not exist for the client's IP.
|
|
.It Fl F
|
|
Use this
|
|
.Xr strftime 3
|
|
compatible format string for the creation of the suffix if
|
|
.Fl W
|
|
is specified.
|
|
By default the string "%Y%m%d" is used.
|
|
.It Fl d, d Ar [value]
|
|
Enables debug output.
|
|
If
|
|
.Ar value
|
|
is not specified, then the debug level is increased by one
|
|
for each instance of
|
|
.Fl d
|
|
which is specified.
|
|
.Pp
|
|
If
|
|
.Ar value
|
|
is specified, then the debug level is set to
|
|
.Ar value .
|
|
The debug level is a bitmask implemented in
|
|
.Pa src/libexec/tftpd/tftp-utils.h .
|
|
Valid values are 0 (DEBUG_NONE), 1 (DEBUG_PACKETS), 2, (DEBUG_SIMPLE),
|
|
4 (DEBUG_OPTIONS), and 8 (DEBUG_ACCESS). Multiple debug values can be combined
|
|
in the bitmask by logically OR'ing the values. For example, specifying
|
|
.Fl d
|
|
.Ar 15
|
|
will enable all the debug values.
|
|
.It Fl l
|
|
Log all requests using
|
|
.Xr syslog 3
|
|
with the facility of
|
|
.Dv LOG_FTP .
|
|
.Sy Note :
|
|
Logging of
|
|
.Dv LOG_FTP
|
|
messages
|
|
must also be enabled in the syslog configuration file,
|
|
.Xr syslog.conf 5 .
|
|
.It Fl n
|
|
Suppress negative acknowledgement of requests for nonexistent
|
|
relative filenames.
|
|
.It Fl o
|
|
Disable support for RFC2347 style TFTP Options.
|
|
.It Fl s Ar directory
|
|
Cause
|
|
.Nm
|
|
to change its root directory to
|
|
.Ar directory .
|
|
After doing that but before accepting commands,
|
|
.Nm
|
|
will switch credentials to an unprivileged user.
|
|
.It Fl S
|
|
If
|
|
.Nm
|
|
runs chrooted, the option allows write requests according to generic
|
|
file permissions, skipping requirement for files to be publicly writable.
|
|
The option is ignored for non-chrooted run.
|
|
.It Fl u Ar user
|
|
Switch credentials to
|
|
.Ar user
|
|
(default
|
|
.Dq Li nobody )
|
|
when the
|
|
.Fl s
|
|
option is used.
|
|
The user must be specified by name, not a numeric UID.
|
|
.It Fl U Ar umask
|
|
Set the
|
|
.Ar umask
|
|
for newly created files.
|
|
The default is 022
|
|
.Pq Dv S_IWGRP | S_IWOTH .
|
|
.It Fl w
|
|
Allow write requests to create new files.
|
|
By default
|
|
.Nm
|
|
requires that the file specified in a write request exist.
|
|
Note that this only works in directories writable by the user
|
|
specified with
|
|
.Fl u
|
|
option
|
|
.It Fl W
|
|
As
|
|
.Fl w
|
|
but append a YYYYMMDD.nn sequence number to the end of the filename.
|
|
Note that the string YYYYMMDD can be changed with the
|
|
.Fl F
|
|
option.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr tftp 1 ,
|
|
.Xr chroot 2 ,
|
|
.Xr syslog 3 ,
|
|
.Xr inetd.conf 5 ,
|
|
.Xr services 5 ,
|
|
.Xr syslog.conf 5 ,
|
|
.Xr inetd 8
|
|
.Pp
|
|
The following RFC's are supported:
|
|
.Rs
|
|
.%T RFC 1350: The TFTP Protocol (Revision 2)
|
|
.Re
|
|
.Rs
|
|
.%T RFC 2347: TFTP Option Extension
|
|
.Re
|
|
.Rs
|
|
.%T RFC 2348: TFTP Blocksize Option
|
|
.Re
|
|
.Rs
|
|
.%T RFC 2349: TFTP Timeout Interval and Transfer Size Options
|
|
.Re
|
|
.Rs
|
|
.%T RFC 7440: TFTP Windowsize Option
|
|
.Re
|
|
.Pp
|
|
The non-standard
|
|
.Cm rollover
|
|
and
|
|
.Cm blksize2
|
|
TFTP options are mentioned here:
|
|
.Rs
|
|
.%T Extending TFTP
|
|
.%U http://www.compuphase.com/tftp.htm
|
|
.Re
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
utility appeared in
|
|
.Bx 4.2 ;
|
|
the
|
|
.Fl s
|
|
option was introduced in
|
|
.Fx 2.2 ,
|
|
the
|
|
.Fl u
|
|
option was introduced in
|
|
.Fx 4.2 ,
|
|
the
|
|
.Fl c
|
|
option was introduced in
|
|
.Fx 4.3 ,
|
|
the
|
|
.Fl F
|
|
and
|
|
.Fl W
|
|
options were introduced in
|
|
.Fx 7.4 ,
|
|
and the
|
|
.Fl S
|
|
option was introduced in
|
|
.Fx 13.3 .
|
|
.Pp
|
|
Support for Timeout Interval and Transfer Size Options (RFC2349)
|
|
was introduced in
|
|
.Fx 5.0 ,
|
|
support for the TFTP Blocksize Option (RFC2348) and the blksize2 option
|
|
was introduced in
|
|
.Fx 7.4 .
|
|
.Pp
|
|
Edwin Groothuis <edwin@FreeBSD.org> performed a major rewrite of the
|
|
.Nm
|
|
and
|
|
.Xr tftp 1
|
|
code to support RFC2348.
|
|
.Pp
|
|
Support for the windowsize option (RFC7440) was introduced in
|
|
.Fx 13.0 .
|
|
.Sh NOTES
|
|
Files larger than 33,553,919 octets (65535 blocks, last one <512
|
|
octets) cannot be correctly transferred without client and server
|
|
supporting blocksize negotiation (RFCs 2347 and 2348),
|
|
or the non-standard TFTP rollover option.
|
|
As a kludge,
|
|
.Nm
|
|
accepts a sequence of block number which wrap to zero after 65535,
|
|
even if the rollover option is not specified.
|
|
.Pp
|
|
Many tftp clients will not transfer files over 16,776,703 octets
|
|
(32767 blocks), as they incorrectly count the block number using
|
|
a signed rather than unsigned 16-bit integer.
|