Ubuntu Manpage: ftpd - Tcl FTP server implementation

NAME

       ftpd - Tcl FTP server implementation

SYNOPSIS

       package require Tcl  8.3

       package require ftpd  ?1.3?

       ::ftpd::server ?myaddr?

       ::ftpd::config ?option value? ?option value ...?

       fsCmd append path

       fsCmd delete path channel

       fsCmd dlist path style channel

       fsCmd exists path

       fsCmd mkdir path channel

       fsCmd mtime path channel

       fsCmd permissions path

       fsCmd rename path newpath channel

       fsCmd retr path

       fsCmd rmdir path channel

       fsCmd size path channel

       fsCmd store path

________________________________________________________________________________________________________________

DESCRIPTION

       The  ftpd  package provides a simple Tcl-only server library for the FTP protocol as specified in RFC 959
       (http://www.rfc-editor.org/rfc/rfc959.txt).  It works by listening on  the  standard  FTP  socket.   Most
       server  errors  are  returned  as  error  messages with the appropriate code attached to them.  Since the
       server code for the ftp daemon is executed in the event loop, it is  possible  that  a  bgerror  will  be
       thrown on the server if there are problems with the code in the module.

COMMANDS

::ftpd::server ?myaddr?
Open a listening socket to listen to and accept ftp connections. myaddr is an optional argument.
myaddr is the domain-style name or numerical IP address of the client-side network interface to
use for the connection.

::ftpd::config ?option value? ?option value ...?
The value is always the name of the command to call as the callback. The option specifies which
callback should be configured. See section CALLBACKS for descriptions of the arguments and return
values for each of the callbacks.

-authIpCmd proc
Callback to authenticate new connections based on the ip-address of the peer.

-authUsrCmd proc
Callback to authenticate new connections based on the user logging in (and the users
password).

-authFileCmd proc
Callback to accept or deny a users access to read and write to a specific path or file.

-logCmd proc
Callback for log information generated by the FTP engine.

-fsCmd proc
Callback to connect the engine to the filesystem it operates on.

-closeCmd proc
Callback to be called when a connection is closed. This allows the embedding application to
perform its own cleanup operations.

-xferDoneCmd proc
Callback for transfer completion notification. In other words, it is called whenever a
transfer of data to or from the client has completed.

CALLBACKS

authIpCmd callback
The authIpCmd receives the ip-address of the peer attempting to connect to the ftp server as its
argument. It returns a 1 to allow users from the specified IP to attempt to login and a 0 to
reject the login attempt from the specified IP.

authUsrCmd callback
The authUsrCmd receives the username and password as its two arguments. It returns a 1 to accept
the attempted login to the ftpd and a 0 to reject the attempted login.

authFileCmd callback
The authFileCmd receives the user (that is currently logged in), the path or filename that is
about to be read or written, and read or write as its three arguments. It returns a 1 to allow
the path or filename to be read or written, and a 0 to reject the attempted read or write with a
permissions error code.

logCmd callback
The logCmd receives a severity and a message as its two arguments. The severities used within the
ftpd package are note, debug, and error. The logCmd doesn't return anything.

fsCmd callback
The fsCmd receives a subcommand, a filename or path, and optional additional arguments (depending
on the subcommand).

The subcommands supported by the fsCmd are:

fsCmd append path
The append subcommand receives the filename to append to as its argument. It returns a
writable tcl channel as its return value.

fsCmd delete path channel
The delete subcommand receives the filename to delete, and a channel to write to as its two
arguments. The file specified is deleted and the appropriate ftp message is written to the
channel that is passed as the second argument. The delete subcommand returns nothing.

fsCmd dlist path style channel
The dlist subcommand receives the path that it should list the files that are in, the style
in which the files should be listed which is either nlst or list, and a channel to write to
as its three arguments. The files in the specified path are printed to the specified
channel one per line. If the style is nlst only the name of the file is printed to the
channel. If the style is list then the file permissions, number of links to the file, the
name of the user that owns the file, the name of the group that owns the file, the size (in
bytes) of the file, the modify time of the file, and the filename are printed out to the
channel in a formatted space separated format. The dlist subcommand returns nothing.

fsCmd exists path
The exists subcommand receives the name of a file to check the existence of as its only
argument. The exists subcommand returns a 1 if the path specified exists and the path is
not a directory.

fsCmd mkdir path channel
The mkdir subcommand receives the path of a directory to create and a channel to write to
as its two arguments. The mkdir subcommand creates the specified directory if necessary
and possible. The mkdir subcommand then prints the appropriate success or failure message
to the channel. The mkdir subcommand returns nothing.

fsCmd mtime path channel
The mtime subcommand receives the path of a file to check the modify time on and a channel
as its two arguments. If the file exists the mtime is printed to the channel in the proper
FTP format, otherwise an appropriate error message and code are printed to the channel.
The mtime subcommand returns nothing.

fsCmd permissions path
The permissions subcommand receives the path of a file to retrieve the permissions of. The
permissions subcommand returns the octal file permissions of the specified file. The file
is expected to exist.

fsCmd rename path newpath channel
The rename subcommand receives the path of the current file, the new file path, and a
channel to write to as its three arguments. The rename subcommand renames the current file
to the new file path if the path to the new file exists, and then prints out the
appropriate message to the channel. If the new file path doesn't exist the appropriate
error message is printed to the channel. The rename subcommand returns nothing.

fsCmd retr path
The retr subcommand receives the path of a file to read as its only argument. The retr
subcommand returns a readable channel that the specified file can be read from.

fsCmd rmdir path channel
The rmdir subcommand receives the path of a directory to remove and a channel to write to
as its two arguments. The rmdir subcommand removes the specified directory (if possible)
and prints the appropriate message to the channel (which may be an error if the specified
directory does not exist or is not empty). The rmdir subcommand returns nothing.

fsCmd size path channel
The size subcommand receives the path of a file to get the size (in bytes) of and a channel
to write to as its two arguments. The size subcommand prints the appropriate code and the
size of the file if the specified path is a file, otherwise an appropriate error code and
message are printed to the channel. The size subcommand returns nothing.

fsCmd store path
The store subcommand receives the path of a file to write as its only argument. The store
subcommand returns a writable channel.

closeCmd
The closeCmd receives no arguments when it is invoked, and any return value it may generate is
discarded.

xferDoneCmd sock sock2 file bytes filename err
The xferDoneCmd receives six arguments when invoked. These are, in this order, the channel handle
of the control socket for the connection, the channel handle of the data socket used for the
transfer (already closed), the handle of the channel containing the transfered file, the number of
bytes transfered, the path of the file which was transfered, and a (possibly empty) error message.
Any return value it may generate is discarded.

VARIABLES

       ::ftpd::cwd
              The  current  working  directory for a session when someone first connects to the FTPD or when the
              REIN ftp command is received.

       ::ftpd::contact
              The e-mail address of the person that is the contact for the ftp server.  This address is  printed
              out as part of the response to the FTP HELP command.

       ::ftpd::port
              The port that the ftp server should listen on.  If port is specified as zero, the operating system
              will allocate an unused port for use as a server socket; afterwards, the variable will contain the
              port number that was allocated.

       ::ftpd::welcome
              The message that is printed out when the user first connects to the ftp server.

       ::ftpd::CurrentSocket
              Accessible to all callbacks and all filesystem commands (which are a special form of callback) and
              contains the handle of the socket channel which was active when the callback was invoked.

BUGS, IDEAS, FEEDBACK

       This document, and the package it describes, will undoubtedly contain bugs and  other  problems.   Please
       report  such  in the category ftpd of the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist].  Please
       also report any ideas for enhancements you may have for either package and/or documentation.

       When proposing code changes, please provide unified diffs, i.e the output of diff -u.

       Note further that attachments are strongly preferred over inlined patches. Attachments  can  be  made  by
       going  to the Edit form of the ticket immediately after its creation, and then using the left-most button
       in the secondary navigation bar.

KEYWORDS

       ftp, ftpd, ftpserver, rfc 959, services