ATFTP(1) General Commands Manual ATFTP(1)
NAME
atftp - TFTP client (RFC1350).
SYNOPSIS
atftp [options] [host [port]]
DESCRIPTION
atftp can be used interactively or in batch mode to retrieve files from TFTP servers. When used interactively, a summary of the commands
can be printed by typing 'help'. This TFTP client support all basic feature from RFC1350, RFC2347, RFC2348 and RFC2349. It also support
multicast implementation of RFC2090 and mtftp as defined in the PXE specification.
OPTIONS
This program supports both the usual GNU command line syntax, with long options starting with two dashes (`-') as well as short options.
Some options are usable in batch mode only, they have no meaning when atftp is use interactively. A description of the options is included
below.
-g, --get
Non interactive invocation only. Instruct atftp to get file.
--mget Non interactive invocation only. Used to get file from a mtftp capable server.
-p, --put
Non interactive invocation only. Instruct atftp to put file.
-l, --local-file
Non interactive invocation only. The client side file name to read or write. Must be used in conjunction with --get or --put.
-r, --remote-file
Non interactive invocation only. The server side file name to get or put. Must be used in conjunction with --get or --put.
--tftp-timeout <value>
Number of seconds for timeout, client side. Default is 5 seconds.
--option <"name value">
Set option "name" to "value". This command support exactly the same arguments as the interactive one. For example, use: --option
blksize 1428 to configure block size.
--mtftp <"name value">
Set mtftp possible options. Accept the same options as the interactive mtftp command. For example, use: --mtftp client-port 76 to
configure client side port to use.
--no-source-port-checking
See atftpd's man page.
--verbose
Instruct atftp to be verbose. It will print more information about what's going on.
--trace
This is useful for debugging purpose to display all packet going to and from the network.
-V, --version
Print version.
-h, --help
Print a summary of command line arguments.
AUTHOR
This manual page was written by Remi Lefebvre <remi@debian.org> and Jean-Pierre Lefebvre <helix@step.polymtl.ca>.
December 27, 2000 ATFTP(1)
Check Out this Related Man Page
ATFTPD(8) System Manager's Manual ATFTPD(8)
NAME
atftpd - Trivial File Transfer Protocol Server.
SYNOPSIS
atftpd [options] directory
DESCRIPTION
atftpd is a TFTP (RFC1350) server. By default it is started by inetd on most sytems, but may run as a stand alone daemon. This server is
multi-threaded and supports all options described in RFC2347 (option extension), RFC2348 (blksize), RFC2349 (tsize and timeout) and RFC2090
(multicast option). It also supports mtftp as defined in the PXE specification.
OPTIONS
This program supports both the usual GNU command line syntax, with long options starting with two dashes ('-') as well as short options. A
description of the options is included below.
-t, --tftpd-timeout <value>
Number of seconds of inactivity before the server exits. This value has meaning only when the server is started by inetd. In daemon
mode, the server never exits. Default is 300 seconds.
-r, --retry-timeout <value>
How many seconds to wait for a reply before retransmitting a packet. Default is 5 seconds. This can be overridden by the TFTP client
with the 'timeout' option.
-m, --maxthread <value>
Maximum number of concurrent threads allowed. Default is 100.
-v, --verbose[=value]
Increase or set the logging level. No arguments will increase by one the current value. Default is LOG_NOTICE, see syslog(3) for log
level. Valid value range from 0 (LOG_EMERG) to 7 (LOG_DEBUG).
--trace
When verbose level is set to 7, this will output debug information for each packet sent or received from the network.
--no-timeout
disable 'timeout' from RFC2349. This will prevent the server from acknowledging the 'timeout' option requested by the client.
--no-tsize
disable 'tsize' from RFC2349. This will prevent the server from acknowledging the 'tsize' option requested by the client.
--no-blksize
disable 'blksize' from RFC2348. This will prevent the server from acknowledging the 'blksize' request by the client.
--no-multicast
disable 'multicast' from RFC2090. This will prevent the server from acknowledging the 'multicast' request by the client.
--logfile <logfile>
Log to a specific file instead of only syslog. 'nobody' (or any user used to run the server) must have permissions on the given
file. Assuming the file is /var/log/atftpd.log, simply run: "touch /var/log/atftpd.log" and then "chown nobody.nogroup
/var/log/atftpd.log". When the server is ran in daemon mode, /dev/stdout or /dev/stderr can be used.
--pidfile
Write the PID of the server to the specified file. This may be useful when automatically starting and stopping one or more instance
of the server.
--daemon
Run as a daemon. Do not use this option if atftpd is started by inetd.
--no-fork
When --daemon is specified, this option will prevent the server from forking to background. It is useful for debugging purpose or
specialized usage.
--user <user[.group]>
By default, the server change identity to the user nobody and group nogroup. Specify an alternate user.group with this option.
--group <group>
Alternate way of specifying the group. If group is specified with --user and --group, the last option will be used.
--port <number>
Specify the port on which atftpd listens. Useful when --daemon is specified. Default is standard tftp port as determined by get-
servbyname(3).
--bind-address <IP address>
Specify the IP address which atftpd binds to. Useful when --daemon is specified. Default is to bind to all interfaces. Only one
address can be specified, the server can only listen to one or all interfaces.
--mcast-ttl
Specify the TTL to be used for multicast datagram. By default a value of 1 is used. Note that TTL has a special meaning in multicast
as it is used to determine the scope of the packets. The value of 1 means the packets don't leave the local network, see ip(4).
Scope may also be determine by the address as described RFC2365.
--mcast-addr
Specify the IP address range to be used for multicast transfer. Format string may comprise range and list of values:
"239.255.0.0-31,128-132,200". Default value is "239.255.0.0-255". This address range is proposed in RFC2365 for local scope.
--mcast-port
Specify the UDP port to use for multicast transfer. Format string may contain range and list of port number: "1758-2000,8000-9000".
default value is "1758".
--pcre <file>
Specify a pattern/replacement file to use. This allow to replace requested file name based on Perl Compatible Regular Expression.
See README.PCRE.
--pcre-test <file>
Test a pattern/replacement file. When using this option, the server will not start as usual but just read file name from stdin and
printout the substitution.
--mtftp <file>
This will start a mtftp server thread for each valid entry in the supplied file. See PXE specification for detail about mtftp. An
example file is provided in the source distribution.
--mtftp-port <port>
Port the mtftp server shall listen to for incomming request.
--no-source-port-checking
In some specific cases of networks using load balancer or other equipment performing NAT (network address translation), some needs
to disable source port checking because port number as been translated. If you want to use this feature, you must know why you need
it and the implication. Be aware that this option violate the RFC1350. This option has effect only for non-multicast transfer.
--mcast-switch-client
This option allow the server to proceed with the next multicast client as soon as the current client timeout. When the current mas-
ter client fails to send an acknowledge (ACK) to the server, the server will send an option acknowledge (OACK) to the master client
with the field MC (master client) set to false and send an OACK to the next multicast client with MC set to true. Without this
option, the server will retry the current master client up to 5 times and then mark it done, proceding with the next one.
-V, --version
Show version of program.
-h, --help
Show summary of options.
path This is the root directory used by the TFTP server. All requested files from a TFTP client must reside in this directory. If not
specified, the directory defaults to /tftpboot. Since atftpd run as the nobody user, the permission of the directory must be set
properly to allow file reading and writing.
STATS
Starting with release 0.2, the server collects some statistics. Currently the server compute system load, time between connections and
some thread statistics like number of file sent, received, number of abort... To see those stats in the logs, you need to set --verbose=6
(LOG_NOTICE) or higher.
SECURITY
TFTP by itself has no provision for security. There is no user authentication and TFTP clients get access to all files within the specified
root directory for which the server has permission.
Some level of security can be gained using atftp libwrap support. Adding proper entry to /etc/hosts.allow and /etc/hosts.deny will restrict
access to trusted hosts. Daemon name to use in these files is in.tftpd.
PCRE
The atftpd server provides a way to dynamically replace requested file name by a new one based on Perl compatible regular expression. Pairs
of pattern/replacement are read from the specified files. Upon reception of a read request, the server will first try to open the file name
requested. If it fails, then it will search for a replacement based on the content of the pattern file. If this still fails, then an error
will be sent to the client. This feature is available only for read request. It makes no sense doing this substitution for client writing
files to the server.
MTFTP
The mtftp name refer to multicasrt tftp as define by the PXE specification. See pxespec.txt for the source of the specification. Note that
this is not the same as RFC2090. PXE compliant boot implements mtftp, not RFC2090.
SEE ALSO
inetd(8),hosts_access(5),libpcre(7), RFC1350, RFC2090, RFC2347, RFC2348, RFC2349 and pxespec.pdf.
AUTHOR
This manual page was written by Remi Lefebvre <remi@debian.org> and Jean-Pierre Lefebvre <helix@step.polymtl.ca>.
December 27, 2000 ATFTPD(8)