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.
ftpd [option]...
Anonymous logins will continue to work when this option is used.
syslog
using facility
‘LOG_FTP’.
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.
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 ignored.
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 -lgA”)
|
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
|
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
|
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 CHMOD0 0CHMOD1 1CHMOD2
|
HELP | give help information.
|
The remaining FTP requests specified in 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. This allows users to utilize the
metacharacters ‘*?[]{}~’.
ftpd authenticates users according to three rules.
In the last case, ftpd takes special measures to restrict the client's access privileges. The server performs a chroot 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: