This file documents how to use the ftp-daemon ftpd

USAGE
-----

Usage as a stand-alone daemon:

Start the daemon in a scsh (or with a script, see below) using

,config ,load modules.scm
,open ftpd
(ftpd <anonymous-home> [<port>])

(confirm open's question for opening the ftpd-structure)
where <anonymous-home> is the root-directory of the ftp-server and
<port> the port the server is listening to. Usage of relative paths in
<anonymous-home> is not encouraged. <port> defaults to 21.

For example

(ftpd (cwd) 8080)

starts the server with the current directory as anonymous home and
listening to port 8080.


Usage with the collaboration of a daemon like inetd:

Instead of FTPD, inetd uses FTPD-INETD, for example:

(ftpd-inetd (cwd))

starts the server with the current directory as anonymous home and
handling the connection (given from inetd) through the current input-
and output-ports.


Example

This is how archive.informatik.uni-tuebingen.de is called at the
university of Tuebingen:

#!/bin/sh
/afs/informatik.uni-tuebingen.de/rs_aix43/scsh-0.6-alpha/bin/scsh <<EOF
,batch on
,config ,load modules.scm
,open ftpd
,open threads
(define (archive-ftpd args)
  (with-syslog-destination
   #f
   #f
   (syslog-facility local0)
   #f
   (lambda ()
     (ftpd "/afs/informatik.uni-tuebingen.de/data/archive/"))))
(dump-scsh-program archive-ftpd "archive-ftpd.image")
;; (dump-scsh "archive-ftpd.image")
EOF

Note, that the options for the syslog are set via With
WITH-SYSLOG-DESTINATION, a scsh-command. Here, the syslog-facility is
set to local0. See man syslog for further details on syslog.


SUPPORTED COMMANDS
------------------


ftpd supports following commands according to RFC 959:

ABOR - abort connection
CDUP - move to parent directory
CWD  - move to specified directory (relative paths may be used)
DELE - delete file
LIST - list files in current directory (long format)
MDTM - deliver modification time of a regular file
MKD  - make directory
MODE - change mode (only stream mode (S) is supported)
NLST - list files in current directory (short format)
NOOP - do nothing
PASS - read in passphrase
PASV - change to passive mode
PORT - change connection port
PWD  - return name of working directory (print working directory)
QUIT - quit session
RETR - return file (GET)
RMD  - remove directory
RNFR - read in the name of a file to be renamed (use RNTO next)
RNTO - rename file mentioned before in a RNFR command
SIZE - return size of a regular file
STOR - store file (PUT)
STRU - change structure to transfer files
       (only the file structure is supported)
SYST - return system type
TYPE - change type (supported types: A = ascii mode, I, L8 = 8-bit
       binary  mode)
USER - login user (only anonymous logins allowed, use "anonymous" or
       "ftp" as user name)


SYSLOG-MESSAGES
---------------

ftpd outputs a lot of syslog-messages. A syslog-message looks like
this:

Jul 24 18:34:52 axl ftpd: (thread 21) anonymous user login (230)

The log gives you following informations (including those delivered by
the syslog-daemon):

* the date and time the log was made (here: Jul 24 18:34:52)
* the machine the log was made on (here: axl)
* the program, that output the log (ftpd)
* the thread the message concerns (here thread 21)
  Each connection is linked with a thread, that handles the commands
  of this connection. When the thread is created, there is a log
  containing the remote address and the thread number, so in future 
  logs the thread number labels the connection. As at any given time 
  the thread number is unique, this is a bijection. (Note that the 
  thread numbers are not unique over a period of time).
* the log message (here: notification about an anonymous user login)
* the reply code returned by ftpd, if any (here: 230)


The Syslog-levels used:
-----------------------


Overview:


As NOTICE are logged:

* messages concerning CONNECTIONS
* the execution of the STOR command
* internal errors
* unix errors
* reaching of actually unreachable case branches


As INFO are logged:

* messages concerning all OTHER COMMANDS, including the RETR command


As DEBUG are logged:

* all other messages, including debug messages


Details:

Messages concerning connections (establishing connection, connection
refused, closing connection due to timeout, etc.) are logged at
notice-level. 

The success of the STOR-command (PUT, i.e. somebody is putting
something on your server via ftp) is also logged at notice-level. In
fact, the log is made before the storing is started actually.

Internal errors, unix errors and the reaching of unreachable
case-branches are also logged at notice-level.

Messages concerning all other commands including the RETR-command
(GET) are logged at info-level.

All other messages including debugging-informations are logged at
debug-level. If you want to debug ftpd, put all the messages in one
single file, since the debug-messages may refer to messages of other
levels.

Success (as long as interesting) and failure of commands are logged at
info-level, except the success of the STOR-command, that is logged at
notice-level (as mentioned above).