tftpd, in.tftpd - TCP/IP Trivial File Transfer Protocol server
/usr/etc/in.tftpd [-s] [ homedir ]
/usr/etc/in.tftpd [-s] [-p] [ homedir ]
This program is available with the Networking software installation
option. Refer to for information on how to install optional software.
tftpd is a server that supports the TCP/IP Trivial File Transfer Proto-
col (TFTP). This server is normally started by inetd(8C) and operates
at the port indicated in the tftp Internet service description in the
/etc/inetd.conf file; see inetd.conf(5) for details. The default
/etc/inetd.conf file starts this server in secure mode, that is, with
the -s option enabled. To run unsecure tftpd, modify this file and
remove the -s option.
Before responding to a request, the server attempts to change its cur-
rent directory to homedir; the default value is /tftpboot.
The tftpd daemon acts as described above, except that it will perform
certain filename mapping operations unless instructed otherwise by the
-p command line argument or when operating in a secure environment.
This mapping affects only TFTP boot requests and will not affect
requests for existing files.
The semantics of the changes are as follows. Only filenames of the for-
mat ip-address or ip-address.arch, where ip-address is the IP address
in hex, and arch is the hosts's architecture (as returned by the
arch(1) command), that do not correspond to files in /tftpboot, are
mapped. If the address is known through a Network Information Service
(NIS) lookup, any file of the form /tftpboot/ip-address* (with or with-
out a suffix) is returned. If there are multiple such files, any one
may be returned. If the ip-address is unknown (that is if the ipalloc
(8C) service says the name service does not know the address), the
filename is mapped as follows: Names without the arch suffix are mapped
into the name pnp.SUN3, and names with the suffix are mapped into pnp.
arch. That file is returned if it exists.
-s Secure. When specified, the directory change must succeed; and
the daemon also changes its root directory to homedir. This
option is set in the default /etc/inetd.conf file.
The use of tftp 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: 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 this service.
tftpd runs with the user ID (UID) and group ID (GID) set to -2, under
the assumption that no files exist with that owner or group. However,
nothing checks this assumption or enforces this restriction.
-p Disable pnp entirely. Do not map filenames.
/tftpboot/* filenames are IP addresses
tftp(1C) inetd(8C), ipallocd(8C), netconfig(8C),
Sollins, K.R., The TFTP Protocol (Revision 2), RFC 783, Network Infor-
mation Center, SRI International, Menlo Park, Calif., June 1981.
The Network Information Service (NIS) was formerly known as Sun Yellow
Pages (YP). The functionality of the two remains the same; only the
name has changed.
A request for an ip-address from a Sun-4 can be satisfied by a file
named ip-address.386 for compatibility with some early Sun-4 PROM moni-
4.2 Berkeley Distribution 7 October 1990 TFTPD(8C)