ftpd(8c) ftpd(8c)
Name
ftpd - DARPA Internet File Transfer Protocol server
Syntax
/usr/etc/ftpd [ -d ] [ -l ] [ -ttimeout ]
Description
The server is the DARPA Internet File Transfer Protocol server process. The server uses the TCP protocol and is invoked by when it
receives a connection on the port specified in the service specification. For further information, see
The server currently supports the following requests. Case is not distinguished.
Request Description
ABOR Abort previous command
ACCT Specify account
ALLO Allocate storage
APPE Append to a file
CDUP Change to parent of current working directory
CWD Change working directory
DELE Delete a file
HELP Give help information
LIST Give list of files in a directory (ls -lg)
MKD Make a directory
MODE Specify data transfer mode
NLST Give name list of files in directory (ls)
NOOP Do nothing
PASS Specify password
PASV Prepare for server-to-server transfer
PORT Specify data connection port
PWD Print the current working directory
QUIT Terminate session
RETR Retrieve a file
RMD Remove a directory
RNFR Specify rename-from file name
RNTO Specify rename-to file name
STOR Store a file
STOU Store a file with a unique name
STRU Specify data transfer structure
TYPE Specify data transfer type
USER Specify user name
XCUP Change to parent of current working directory
XCWD Change working directory
XMKD Make a directory
XPWD Print the current working directory
XRMD Remove a directory
The remaining requests specified in Internet RFC 959 are recognized, but not implemented.
The server interprets file names according to the globbing conventions used by This allows users to utilize the metacharacters *?[]{}~.
The server authenticates users according to three rules:
1. The user name must be in the password database, and not have a null password. In this case a password must be provided by the client
before any file operations may be performed.
2. The user name must not appear in the file
3. If the user name is anonymous or an anonymous account must be present in the password file (user ftp). In this case the user is
allowed to log in by specifying any password (by convention this is given as the client host's name).
In the last case, takes special measures to restrict the client's access privileges. The server performs a command to the home directory
of the user. To prevent system security from being breached, it is recommended that the subtree be constructed with care. Thus the follow-
ing rules are recommended:
~ftp) Make the home directory owned by and unwritable by anyone.
~ftp/bin) Make this directory owned by the superuser and unwritable by anyone. The program must be present to support the list commands.
This program should have mode 111.
~ftp/etc) Make this directory owned by the superuser and unwritable by anyone. The files and must be present for the command to work prop-
erly. These files should be mode 444.
~ftp/pub) Make this directory mode 777 and owned by Place the files, which are to be accessible by the anonymous account, in this direc-
tory.
Options
-d Enables certain debugging messages that are printed by ftpd.
-l Logs each ftp session to the
-t Sends the inactivity timeout period to timeout; otherwise, the server will timeout an inactive session after 15 minutes.
Restrictions
Support does not exist for aborting commands.
The use of an anonymous account is inherently dangerous and should be avoided when possible.
The server must run as the superuser to create sockets with privileged port numbers. The server maintains an effective user id of the
logged in user, reverting to the superuser only when binding addresses to sockets. The possible security holes have been extensively scru-
tinized, but are possibly incomplete.
Files
Contains the list of unauthorized users
See Also
ftp(1c), services(5), inetd(8c), syslog(8)
ftpd(8c)