[0m


FTPD(8)             UNIX Programmer's Manual		  FTPD(8)



[1mNAME
     [0mftpd - DARPA Internet File Transfer Protocol server

[1mSYNOPSIS
     /usr/sbin/ftpd [0m[ [1m-d [0m] [ [1m-l [0m] [ [1m-t[0mtimeout ] [ [1m-T[0mmaxtimeout ]

[1mDESCRIPTION
     [0m_F_t_p_d is the DARPA Internet File Transfer Protocol server
     process.  The server uses the TCP protocol and listens at
     the port specified in the ``ftp'' service specification; see
     _s_e_r_v_i_c_e_s(5).

     If the [1m-d [0moption is specified, debugging information is
     written to the syslog.

     If the [1m-l [0moption is specified, each ftp session is logged in
     the syslog.

     The ftp server will timeout an inactive session after 15
     minutes.  If the [1m-t [0moption is specified, the inactivity
     timeout period will be set to _t_i_m_e_o_u_t seconds.  A client may
     also request a different timeout period; the maximum period
     allowed may be set to _t_i_m_e_o_u_t seconds with the [1m-T [0moption.
     The default limit is 2 hours.

     The ftp server currently supports the following ftp
     requests; case is not distinguished.

     [1mRequest	    Description
     [0mABOR	    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
     HELP	    give help information
     LIST	    give list files in a directory (``ls -lgA'')
     MKD	    make a directory
     MDTM	    show last modification time of file
     MODE	    specify data transfer _m_o_d_e
     NLST	    give name list of files in directory
     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



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FTPD(8)             UNIX Programmer's Manual		  FTPD(8)



     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 _s_t_r_u_c_t_u_r_e
     SYST	    show operating system type of server system
     TYPE	    specify data transfer _t_y_p_e
     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.

     [1mRequest	    Description
     [0mUMASK	    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. _E._g. SITE HELP

     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 Tel-
     net 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.

     _F_t_p_d interprets file names according to the ``globbing''
     conventions used by _c_s_h(1).  This allows users to utilize
     the metacharacters ``*?[]{}~''.

     _F_t_p_d authenticates users according to three rules.

     1)   The user name must be in the password data base,
	  /_e_t_c/_p_a_s_s_w_d, 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
	  /_e_t_c/_f_t_p_u_s_e_r_s.

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



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FTPD(8)             UNIX Programmer's Manual		  FTPD(8)



     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
	  this is given as the client host's name).

     In the last case, _f_t_p_d takes special measures to restrict
     the client's access privileges.  The server performs a
     _c_h_r_o_o_t(2) command to the home directory of the ``ftp'' user.
     In order that system security is not breached, it is recom-
     mended that the ``ftp'' subtree be constructed with care;
     the following rules are recommended.

     ~ftp)
	  Make the home directory owned by ``ftp'' and unwritable
	  by anyone.

     ~ftp/bin)
	  Make this directory owned by the super-user and unwrit-
	  able by anyone.  The program _l_s(1) must be present to
	  support the list command.  This program should have
	  mode 111.

     ~ftp/etc)
	  Make this directory owned by the super-user and unwrit-
	  able by anyone.  The files _p_a_s_s_w_d(5) and _g_r_o_u_p(5) must
	  be present for the _l_s command to be able to produce
	  owner names rather than numbers.  The password field in
	  _p_a_s_s_w_d is not used, and should not contain real
	  encrypted passwords.	These files should be mode 444.

     ~ftp/pub)
	  Make this directory mode 777 and owned by ``ftp''.
	  Users should then place files which are to be accessi-
	  ble via the anonymous account in this directory.

[1mSEE ALSO
     [0mftp(1C), getusershell(3), syslogd(8)

[1mBUGS
     [0mThe anonymous account is inherently dangerous and should
     avoided when possible.

     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 incom-
     plete.






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[0m