FTPD(8C)							      FTPD(8C)

NAME
       ftpd - DARPA Internet File Transfer Protocol server

SYNOPSIS
       /usr/etc/ftpd [ -d ] [ -l ] [ -ttimeout ]

DESCRIPTION
       Ftpd  is	 the  DARPA  Internet File Transfer Prototocol server process.
       The server uses the TCP protocol and listens at the port	 specified  in
       the ``ftp'' service specification; see services(5).

       If  the -d option is specified, debugging information is written to the
       syslog.

       If the -l option is specified,  each  ftp  session  is  logged  in  the
       syslog.

       The  ftp	 server will timeout an inactive session after 15 minutes.  If
       the -t option is specified, the inactivity timeout period will  be  set
       to timeout.

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

       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
       HELP	      give help information
       LIST	      give list 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  ftp  requests  specified	 in  Internet  RFC   959   are
       recognized, but not implemented.

       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.

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

       In  the last case, ftpd takes special measures to restrict the client's
       access privileges.  The server performs a chroot(2) command 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;  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	unwritable  by
	      anyone.	The  program ls(1) must be present to support the list
	      commands.	 This program should have mode 111.

       ~ftp/etc)
	      Make this directory owned by the super-user  and	unwritable  by
	      anyone.	The  files  passwd(5) and group(5) must be present for
	      the ls command to work properly.	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 accessible  via	the  anonymous
	      account in this directory.

SEE ALSO
       ftp(1C), getusershell(3), syslogd(8)

BUGS
       The  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 incomplete.

4.2 Berkeley Distribution	April 27, 1985			      FTPD(8C)

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