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.