tftpd.1m (2010 09)

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tftpd(1M) tftpd(1M)

NAME

tftpd - trivial ﬁle transfer protocol server

SYNOPSIS

/usr/lbin/tftpd

[-l ][-R retran-seconds][

-r blksize|timeout|tsize

][-s]

[

-T total-seconds][

-L port ][-U port ][path ...]

DESCRIPTION

tftpd is a server that supports the Internet Trivial File Transfer Protocol (RFC783). The TFTP server

operates at the port indicated in the tftp

service description (see services (4)). The server is normally

started by

inetd using the /etc/inetd.conf

ﬁle (see inetd (1M) and inetd.conf (4)).

Options

tftpd supports the following options:

-l This option writes the debugging information into the syslog ﬁle.

-R This option speciﬁes the per-packet retransmission timeout, in seconds. The default

value is 5 seconds.

-r blksize|timeout|tsize

This option disables the client side options: blksize (blocksize),

timeout (retransmission timeout), and

tsize (transfer ﬁle size) individually. By

default, these options are enabled. For example, to disable timeout negotiation between a

client and the server, start the server with the following command:

tftpd -r timeout

-s This option enables tftpd to work in the Service Guard environment. This option is

required for some tftp clients. These clients reject the tftp reply received from a

different IP address than the one requested when the server’s interface is conﬁgured with

an alias IP address.

-T This option speciﬁes the total retransmission timeout, in seconds. The default value is 25

seconds.

-L port This option speciﬁes the lower limit of the port range for data transfer.

-U port This option speciﬁes the upper limit of the port range for data transfer.

NOTE: The

NDD tunables should be considered before deﬁning the -L and -U options.

If the -L option is deﬁned without using the -U option, the upper limit is set to 65535. If

the -U option is deﬁned without using the -L option, the lower limit is set to 1024.

The path parameter has the following effects:

•

tftpd operates in either of two modes or their combination. The ﬁrst mode requires a deﬁned

home directory for the pseudo-user tftp, and looks for ﬁles relative to that path. The second

mode requires one or more paths be speciﬁed on the command line, and allows access only to ﬁles

whose paths match or begin with one of the command line speciﬁcations. The ﬁrst mode is

backward-compatible with previous releases of HP-UX and supports somewhat tighter security.

The second mode is compatible with other vendors’ implementations of tftpd and allows greater

ﬂexibility in accessing ﬁles.

• If no path is speciﬁed on the command line,

tftpd requires an entry in the /etc/passwd data-

base (see passwd (4)) for an account (pseudo-user) named tftp. The password ﬁeld should be *,

the group membership should be guest, and the login shell should be /usr/bin/false.For

example (assuming the guest group ID is 101):

tftp:*:510:101:tftp server:/home/tftpdir:/usr/bin/false

tftpd uses a call to chroot() to change its root directory to be the same as the home directory

of the pseudo-user tftp. This restricts access by tftp clients to only those ﬁles found below the

tftp home directory (see chroot (2)). Furthermore, tftp clients can only read ﬁles in that direc-

tory if they are readable by the pseudo-user tftp, and tftp clients can only write ﬁles in that

directory if they exist and are writable by the pseudo-user tftp.

• If any path is speciﬁed on the command line,

tftpd does not require that a pseudo-user named

tftp exist in /etc/passwd. The speciﬁed path s control access to ﬁles by tftp clients. Each

path is treated as being relative to / (not the tftp home directory), and can be either a directory

HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1

Summary of content (2 pages)

PAGE 1
tftpd(1M) tftpd(1M) NAME tftpd - trivial file transfer protocol server SYNOPSIS /usr/lbin/tftpd [-l ] [-R retran-seconds] [-r blksize|timeout|tsize] [-s] [-T total-seconds] [-L port ] [-U port ] [path ...] DESCRIPTION tftpd is a server that supports the Internet Trivial File Transfer Protocol (RFC783). The TFTP server operates at the port indicated in the tftp service description (see services (4)). The server is normally started by inetd using the /etc/inetd.conf file (see inetd (1M) and inetd.
PAGE 2
tftpd(1M) tftpd(1M) or a file. tftpd disallows a client access to any file that does not match entirely or in its initial components one of the restriction path s. It also disallows access to any file path containing ‘‘..’’. However, an accessed file can be a symbolic link that points outside the set of restricted paths. • If any path is specified on the command line and the tftp home directory is defined and is not /, tftpd first looks for a file relative to (under) the home directory.