NAME¶
tftpd
—
DARPA Trivial File Transfer Protocol server
SYNOPSIS¶
tftpd |
[ -n ]
[-s ]
[directory
... ] |
DESCRIPTION¶
Tftpd
is a server which supports the DARPA
Trivial File Transfer Protocol. The TFTP server operates at the port indicated
in the ‘
tftp
’ service description; see
services(5). The server is normally started by
inetd(8).
The use of
tftp(1) does not require an account or
password on the remote system. Due to the lack of authentication information,
tftpd
will allow only publicly readable
files to be accessed. Files may be written only if they already exist and are
publicly writable. Note that this extends the concept of
“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.
Access to files may be controlled by invoking
tftpd
with a list of directories by
including pathnames as server program arguments in
/etc/inetd.conf. In this case access is
restricted to files whose names are prefixed by the one of the given
directories. If no directories are supplied the default is
/tftpboot. To give out access to the whole
filesystem, should this be desired for some reason, supply
/ as an argument.
Unfortunately, on multi-homed systems, it is impossible for
tftpd
to determine the address on which a
packet was received. As a result,
tftpd
uses two different mechanisms to guess the best source address to use for
replies. If the socket that
inetd(8) passed to
tftpd
is bound to a particular address,
tftpd
uses that address for replies.
Otherwise,
tftpd
uses ``UDP connect'' to
let the kernel choose the reply address based on the destination of the
replies and the routing tables. This means that most setups will work
transparently, while in cases where the reply address must be fixed, the
virtual hosting feature of
inetd(8) can be used
to ensure that replies go out from the correct address. These considerations
are important, because most tftp clients will reject reply packets that appear
to come from an unexpected address.
The options are:
-n
- Suppresses negative acknowledgement of requests for nonexistent relative
filenames.
-s
- All absolute filenames are treated as if they were preceded by the first
directory argument, or /tftpboot if
there is none.
SEE ALSO¶
tftp(1),
inetd(8)
HISTORY¶
The
tftpd
command appeared in
4.2BSD.