Provided by: inetutils-ftpd_2.3-5_amd64 bug


     ftpd — Internet File Transfer Protocol server


     ftpd [option ...]


     ftpd is the Internet File Transfer Protocol server process.  The server uses the TCP
     protocol and listens at the port specified in the “ftp” service specification; see


     -4, --ipv4
             Restrict daemon to listen to IPv4 addresses only.

     -6, --ipv6
             Restrict daemon to listen to IPv6 addresses only.

     -d, --debug
             Debugging information is written to the syslog using LOG_FTP.

     -l, --logging
             Each successful and failed ftp(1) session is logged using syslog with a facility of
             LOG_FTP.  If this option is specified twice, the retrieve (get), store (put),
             append, delete, make directory, remove directory and rename operations and their
             filename arguments are also logged.

     -A, --anonymous-only
             Only anonymous login is allowed.

     -D, --daemon
             ftpd enters daemon-mode. That allows ftpd to be run without inetd.

     -q, --no-version
             Quiet mode. No information about the version of the ftpd is given to the client.

     -T, --max-timeout timeout
             A client may also request a different timeout period; the maximum period allowed may
             be set to timeout seconds with the -T option.  The default limit is 2 hours.

     -t, --timeout timeout
             The inactivity timeout period is set to timeout seconds (the default is 15 minutes).

     -p, --pidfile pidfile
             Change default location of pidfile.

     -a, --auth auth
             Give anonymous another login-name (anonymous and ftpd will still work).  It can be
             one of

                     Use passwd authentication.

             pam     Use PAM service 'ftp'.

             Neglect RFC 2577 by giving information on missing users.

     -u, --umask value
             Set default umask to value.

     -?, --help
             Display a help list.

             Display a short usage message.

     -V, --version
             Display program version.


     The file /etc/nologin can be used to disable ftp access.  If the file exists, ftpd displays
     it and exits.  If the file /etc/ftpwelcome exists, ftpd prints it before issuing the “ready”
     message.  If the file /etc/motd exists, ftpd prints it after a successful login.

     The ftp server currently supports the following ftp requests.  The case of the requests is

           Request    Description
           ABOR       abort previous command
           ACCT       specify account (ignored)
           ALLO       allocate storage (vacuously)
           APPE       append to a file
           CDUP       change to parent of current working directory
           CWD        change working directory
           DELE       delete a file
           EPRT       extended data connection port, RFC 2428
           EPSV       extended passive transfer request, RFC 2428
           FEAT       display command extensions
           HELP       give help information
           LIST       give list files in a directory (“ls -lgA”)
           LPRT       long data connection port, RFC 1639
           LPSV       long passive transfer request, RFC 1639
           MKD        make a directory
           MDTM       show last modification time of file
           MODE       specify data transfer mode
           NLST       give name list of files in directory
           NOOP       do nothing
           OPTS       option settings
           PASS       specify password
           PASV       prepare for server-to-server transfer
           PORT       specify data connection port
           PWD        print the current working directory
           QUIT       terminate session
           REST       restart incomplete transfer
           RETR       retrieve a file
           RMD        remove a directory
           RNFR       specify rename-from file name
           RNTO       specify rename-to file name
           SITE       non-standard commands (see next section)
           SIZE       return size of file
           STAT       return status of server
           STOR       store a file
           STOU       store a file with a unique name
           STRU       specify data transfer structure
           SYST       show operating system type of server system
           TYPE       specify data transfer type
           USER       specify user name
           XCUP       change to parent of current working directory (deprecated)
           XCWD       change working directory (deprecated)
           XMKD       make a directory (deprecated)
           XPWD       print the current working directory (deprecated)
           XRMD       remove a directory (deprecated)

     The following non-standard or UNIX specific commands are supported by the SITE request.

           Request    Description
           UMASK      change umask, e.g. SITE UMASK 002
           IDLE       set idle-timer, e.g. SITE IDLE 60
           CHMOD      change mode of a file, e.g. SITE CHMOD 755 filename
           HELP       give help information.

     The remaining ftp requests specified in Internet RFC 959 are recognized, but not
     implemented.  MDTM and SIZE are not specified in RFC 959, but will appear in the next
     updated FTP RFC.

     The ftp server will abort an active file transfer only when the ABOR command is preceded by
     a Telnet "Interrupt Process" (IP) signal and a Telnet "Synch" signal in the command Telnet
     stream, as described in Internet RFC 959.  If a STAT command is received during a data
     transfer, preceded by a Telnet IP and Synch, transfer status will be returned.

     ftpd interprets file names according to the “globbing” conventions used by csh(1).  This
     allows users to utilize the metacharacters “*?[]{}~”.

     ftpd authenticates users according to three rules.

           1.   The login name must be in the password data base, /etc/passwd, 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 login name must not appear in the file /etc/ftpusers.

           3.   The user must have a standard shell returned by getusershell(3).

           4.   If the user name is “anonymous” or “ftp”, an anonymous ftp 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 an email address for the user
                should be used as the password).

     In the last case, ftpd takes special measures to restrict the client's access privileges.
     The server performs a chroot(2) to the home directory of the “ftp” user.  In order that
     system security is not breached, it is recommended that the “ftp” subtree be constructed
     with care, following these rules:

           ~ftp      Make the home directory owned by “root” and unwritable by anyone.

           ~ftp/bin  Make this directory owned by “root” and unwritable by anyone (mode 555).
                     The program ls(1) must be present to support the list command.  This program
                     should be mode 111.

           ~ftp/etc  Make this directory owned by “root” and unwritable by anyone (mode 555).
                     The files passwd(5) and group(5) must be present for the ls command to be
                     able to produce owner names rather than numbers.  The password field in
                     passwd is not used, and should not contain real passwords.  The file motd,
                     if present, will be printed after a successful login.  These files should be
                     mode 444.

           ~ftp/pub  Make this directory mode 777 and owned by “ftp”.  Guests can then place
                     files which are to be accessible via the anonymous account in this


     /etc/ftpusers    List of unwelcome/restricted users.
     /etc/ftpwelcome  Welcome notice.
     /etc/motd        Welcome notice after login.
     /etc/nologin     Displayed and access refused.


     ftp(1), getusershell(3), syslogd(8)


     The server must run as the super-user to create sockets with privileged port numbers.  It
     maintains an effective user id of the logged in user, reverting to the super-user only when
     binding addresses to sockets.  The possible security holes have been extensively
     scrutinized, but are possibly incomplete.


     The ftpd command appeared in 4.2BSD.