.\" SCCSID: @(#)ftpd.8c	8.1	9/11/90.TH ftpd 8c.SH Nameftpd \- DARPA Internet File Transfer Protocol server.SH Syntax.B /usr/etc/ftpd[.B \-d] [.B \-l] [.BR \-t timeout].SH Description.NXB "ftpd server".NXR "Internet File Transfer Protocol server"The .PN ftpdserver is the DARPA Internet File Transfer Protocolserver process.  The server uses the TCP protocoland is invoked by.PN inetd(8c)when it receives a connection on the port specified in the .PN ftpservice specification.  For further information, see.PN services(5)..PPThe .PN ftpserver currently supports the following.PN ftprequests.  Case is not distinguished..PP.NXB "ftpd server" "request list".IP \fBRequest\fR 9\fBDescription\fR.IP ABOR 10Abort previous command.IP ACCT 10Specify account .IP ALLO 10 Allocate storage .IP APPE 10 Append to a file.IP CDUP 10 Change to parent of current working directory.IP CWD 10 Change working directory.IP DELE 10 Delete a file.IP HELP 10 Give help information.IP LIST 10 Give list of files in a directory (\f(CWls \-lg\fP).IP MKD 10 Make a directory.IP MODE 10 Specify data transfer \fImode\fP.IP NLST 10 Give name list of files in directory (\f(CWls\fP).IP NOOP 10 Do nothing.IP PASS 10 Specify password.IP PASV 10 Prepare for server-to-server transfer.IP PORT 10 Specify data connection port.IP PWD 10 Print the current working directory.IP QUIT 10 Terminate session.IP RETR 10 Retrieve a file.IP RMD 10 Remove a directory.IP RNFR 10 Specify rename-from file name.IP RNTO 10 Specify rename-to file name.IP STOR 10 Store a file.IP STOU 10 Store a file with a unique name.IP STRU 10 Specify data transfer \fIstructure\fP.IP TYPE 10 Specify data transfer \fItype\fP.IP USER 10 Specify user name.IP XCUP 10 Change to parent of current working directory.IP XCWD 10 Change working directory.IP XMKD 10 Make a directory.IP XPWD 10 Print the current working directory.IP XRMD 10 Remove a directory.PPThe remaining .PN ftprequests specified in Internet RFC 959 arerecognized, but not implemented..NXE "ftpd server" "request list".PPThe.PN ftpdserver interprets file names according to the globbingconventions used by.PN csh(1).This allows users to utilize the metacharacters *?[]{}~..PPThe.PN ftpdserver authenticates users according to three rules: .NXR "ftpd server" "verifying users".IP 1. 5The user name must be in the password database,.PN /etc/passwd ,and not have a null password.  In this case a passwordmust be provided by the client before any file operationsmay be performed..IP 2. 5The user name must not appear in the file.PN /etc/ftpusers ..IP 3. 5If the user name is anonymous or .PN ftp , an anonymous .PN ftpaccount must be present in the passwordfile (user \f(CWftp\fP).  In this case the user is allowedto log in by specifying any password (by convention thisis given as the client host's name)..PPIn the last case, .PN ftpdtakes special measures to restrict the client's access privileges..NXR "ftpd server" "restricting access"The server performs a .PN chroot(2)command to the home directory of the .PN ftp user. To prevent system security from being breached, it is recommendedthat the .PN ftp subtree be constructed with care.  Thus the followingrules are recommended:.IP \fB~ftp)\fR 10 Make the home directory owned by .PN ftp and unwritable by anyone..IP \fB~ftp/bin)\fR 10 Make this directory owned by the superuser and unwritable byanyone.  The program .PN ls(1)must be present to support the list commands.  Thisprogram should have mode 111..IP \fB~ftp/etc)\fR 10 Make this directory owned by the superuser and unwritable byanyone.  The files .MS passwd 5  and .MS group 5 must be present for the .PN lscommand to work properly.  These files should be mode 444..IP \fB~ftp/pub)\fR 10 Make this directory mode 777 and owned by .PN ftp.  Place the files, which are to be accessible by theanonymous account, in this directory..SH Options.IP \fB\-d\fR 5Enables certain debugging messages that are printed by ftpd. .NXR "ftpd server" "options".IP \fB\-l\fR 5Logs each ftp session to the.PN syslog ..IP \fB\-t\fR 5 Sends the inactivity timeout period to  .IR timeout; otherwise, the .PN ftp server will timeout an inactive session after 15 minutes. .SH Restrictions.NXR "ftpd server" "restricted"Support does not exist for aborting commands..PPThe use of an anonymous account is inherently dangerous and shouldbe avoided when possible..PPThe server must run as the superuserto create sockets with privileged port numbers.  The server maintainsan effective user id of the logged in user, reverting tothe superuser only when binding addresses to sockets.  Thepossible security holes have been extensivelyscrutinized, but are possibly incomplete..SH Files.TP 15.PN /etc/ftpusersContains the list of unauthorized users.SH See Alsoftp(1c), services(5), inetd(8c), syslog(8).NXE "ftpd server"