1196 lines
38 KiB
Scheme
1196 lines
38 KiB
Scheme
; RFC 959 ftp daemon
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; Mike Sperber <sperber@informatik.uni-tuebingen.de>
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; Copyright (c) 1998 Michael Sperber.
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; It doesn't support the following desirable things:
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;
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; - Login by user; this requires crypt which scsh doesn't have
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; - RESTART support
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; - Banners from files on CWD
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; - Lots of fancy stuff like ProFTPD, http://www.proftpd.org/
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; following things should be improved:
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;
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; - GET-command: ftpd reports "Can't open FILENAME for reading" if
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; file actually doesn't exist. This is confusing. Reporting
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; "FILENAME does not exist" is much better.
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(define-record session
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control-input-port
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control-output-port
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anonymous-home
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(logged-in? #f)
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(authenticated? #f)
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(anonymous? #f)
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(root-directory #f)
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(current-directory "")
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(to-be-renamed #f)
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(reverse-replies '())
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(reply-code #f) ; the last one wins
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(type 'ascii) ; PLEASE set this to bin
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(data-socket #f)
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(passive-socket #f))
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(define session (make-fluid #f))
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(define (make-fluid-selector selector)
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(lambda () (selector (fluid session))))
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(define (make-fluid-setter setter)
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(lambda (value)
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(setter (fluid session) value)))
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(define session-control-input-port (make-fluid-selector session:control-input-port))
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(define session-control-output-port (make-fluid-selector session:control-output-port))
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(define session-anonymous-home (make-fluid-selector session:anonymous-home))
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(define session-logged-in? (make-fluid-selector session:logged-in?))
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(define session-authenticated? (make-fluid-selector session:authenticated?))
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(define session-anonymous? (make-fluid-selector session:anonymous?))
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(define session-root-directory (make-fluid-selector session:root-directory))
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(define session-current-directory (make-fluid-selector session:current-directory))
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(define session-to-be-renamed (make-fluid-selector session:to-be-renamed))
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(define session-reverse-replies (make-fluid-selector session:reverse-replies))
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(define session-reply-code (make-fluid-selector session:reply-code))
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(define session-type (make-fluid-selector session:type))
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(define session-data-socket (make-fluid-selector session:data-socket))
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(define session-passive-socket (make-fluid-selector session:passive-socket))
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(define set-session-control-input-port
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(make-fluid-setter set-session:control-input-port))
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(define set-session-control-output-port
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(make-fluid-setter set-session:control-output-port))
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(define set-session-logged-in? (make-fluid-setter set-session:logged-in?))
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(define set-session-authenticated? (make-fluid-setter set-session:authenticated?))
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(define set-session-anonymous? (make-fluid-setter set-session:anonymous?))
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(define set-session-root-directory (make-fluid-setter set-session:root-directory))
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(define set-session-current-directory (make-fluid-setter set-session:current-directory))
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(define set-session-to-be-renamed (make-fluid-setter set-session:to-be-renamed))
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(define set-session-reverse-replies (make-fluid-setter set-session:reverse-replies))
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(define set-session-reply-code (make-fluid-setter set-session:reply-code))
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(define set-session-type (make-fluid-setter set-session:type))
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(define set-session-data-socket (make-fluid-setter set-session:data-socket))
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(define set-session-passive-socket (make-fluid-setter set-session:passive-socket))
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;;; LOG -------------------------------------------------------
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(define (log level format-message . args)
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(syslog level
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(apply format #f (string-append "(thread ~D) " format-message)
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(thread-uid (current-thread)) args)))
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(define (log-command level command-name . argument)
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(if (null? argument)
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(log level "handling ~A-command" command-name)
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(if (not (null? (cdr argument)))
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(log level "handling ~A-command with argument ~S"
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command-name argument)
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(log level "handling ~A-command with argument ~S" ; does this ever happen?
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command-name (car argument)))))
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;;; CONVERTERS ------------------------------------------------
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(define (protocol-family->string protocol-family)
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(cond ((= protocol-family protocol-family/unspecified)
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"unspecified")
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((= protocol-family protocol-family/internet)
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"internet")
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((= protocol-family protocol-family/unix)
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"unix")
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(else "unknown")))
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(define (socket->string socket)
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(format #f "family: ~A, ~&local address: ~A, ~&remote address: ~A, ~&input-port ~A, ~&output-port ~A"
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(protocol-family->string (socket:family socket))
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(socket-address->string (socket-local-address socket))
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(socket-address->string (socket-remote-address socket))
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(socket:inport socket)
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(socket:outport socket)))
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(define (socket-address->string socket-address)
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(call-with-values
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(lambda () (socket-address->internet-address socket-address))
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(lambda (host-address service-port)
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(format #f "~A:~A"
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(format-internet-host-address host-address)
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(format-port service-port)))))
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;;; ftpd -------------------------------------------------------
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(define (ftpd anonymous-home . maybe-port)
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(let ((port (optional maybe-port 21)))
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(with-syslog-destination
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"ftpd"
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#f
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#f
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#f
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(lambda ()
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(log (syslog-level notice)
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"starting daemon on port ~D with ~S as anonymous home"
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port (expand-file-name anonymous-home (cwd)))
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(bind-listen-accept-loop
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protocol-family/internet
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(lambda (socket address)
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(let ((remote-address (socket-address->string address)))
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(set-ftp-socket-options! socket)
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(spawn
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(spawn-to-handle-connection socket
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address
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anonymous-home
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port
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remote-address)
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remote-address))) ; use remote address as thread-name
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port)))))
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(define (spawn-to-handle-connection socket address anonymous-home port remote-address)
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(lambda ()
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(call-with-current-continuation
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(lambda (exit)
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(with-errno-handler*
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(lambda (errno packet)
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(cond
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;; I dunno why SHUTDOWN-SOCKET can die this way, but it
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;; can and does
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((or (= errno errno/notconn)
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;; this one can come out of SOCKET->STRING
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(= errno errno/inval))
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(log (syslog-level notice)
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"socket to ~A not connected any more - exiting thread"
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remote-address)
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(exit 'fick-dich-ins-knie))))
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(lambda ()
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(let ((socket-string (socket->string socket)))
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(log (syslog-level notice)
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"new connection to ~S"
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remote-address)
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(log (syslog-level debug) "socket: ~S" socket-string)
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(handle-connection (socket:inport socket)
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(socket:outport socket)
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(file-name-as-directory anonymous-home))
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(log (syslog-level debug)
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"shutting down socket ~S"
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socket-string)
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(shutdown-socket socket shutdown/sends+receives)
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(log (syslog-level notice)
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"closing connection to ~A and finishing thread" remote-address)
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(log (syslog-level debug)
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"closing socket ~S" socket-string)
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(close-socket socket))))))))
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(define (ftpd-inetd anonymous-home)
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(with-syslog-destination
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"ftpd"
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#f
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#f
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#f
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(lambda ()
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(log (syslog-level notice)
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"new connection on current input- and output-port with ~S as anonymous home"
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(expand-file-name anonymous-home (cwd)))
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(log (syslog-level debug)
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"inport: ~A, outport: ~A"
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(current-input-port)
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(current-output-port))
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(handle-connection (current-input-port)
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(current-output-port)
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(file-name-as-directory anonymous-home)))))
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(define (set-ftp-socket-options! socket)
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;; If the client closes the connection, we won't lose when we try to
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;; close the socket by trying to flush the output buffer.
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(set-port-buffering (socket:outport socket) bufpol/none)
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(set-socket-option socket level/socket socket/oob-inline #t))
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(define (handle-connection input-port output-port anonymous-home)
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(log (syslog-level debug)
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"handling connection with input-port ~A, outputport ~A and home ~A"
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input-port
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output-port
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anonymous-home)
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(call-with-current-continuation
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(lambda (escape)
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(with-handler
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(lambda (condition more)
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(log (syslog-level debug)
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"hit error condition ~A -- exiting"
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(condition-type condition))
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(display condition (current-error-port))
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(escape 'fick-dich-ins-knie))
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(lambda ()
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(let-fluid session (make-session input-port output-port
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anonymous-home)
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(lambda ()
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(display-banner)
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(handle-commands))))))))
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(define (display-banner)
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(log (syslog-level debug)
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"displaying banner (220)")
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(register-reply! 220
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(string-append
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"Scheme Untergrund ftp server ("
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*ftpd-version*
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") ready.")))
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(define-condition-type 'ftpd-quit '())
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(define ftpd-quit? (condition-predicate 'ftpd-quit))
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(define-condition-type 'ftpd-irregular-quit '())
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(define ftpd-irregular-quit? (condition-predicate 'ftpd-irregular-quit))
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(define-condition-type 'ftpd-error '())
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(define ftpd-error? (condition-predicate 'ftpd-error))
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(define (handle-commands)
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(log (syslog-level debug) "handling commands")
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(call-with-current-continuation
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(lambda (exit)
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(with-handler
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(lambda (condition more)
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(if (ftpd-quit? condition)
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(begin
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(log (syslog-level debug) "quitting (write-accept-loop)")
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(with-handler
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(lambda (condition ignore)
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(more))
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(lambda ()
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(write-replies)
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(exit 'fick-dich-ins-knie))))
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(more)))
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(lambda ()
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(log (syslog-level debug)
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"starting write-accept-loop")
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(let loop ()
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(write-replies)
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(accept-command)
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(loop)))))))
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(define (accept-command)
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(let* ((timeout-seconds 90)
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(command-line (read-crlf-line-timeout (session-control-input-port)
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#f
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(* 1000 timeout-seconds);timeout
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500))) ; max interval
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(log (syslog-level debug)
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"Command line: ~A"
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command-line)
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(cond ((eq? command-line 'timeout)
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(log (syslog-level notice) "hit timeliimit of ~D seconds (421)"
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timeout-seconds)
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(log (syslog-level debug)
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"so closing control connection and quitting")
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(register-reply!
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421
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(format #f "Timeout (~D seconds): closing control connection."
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timeout-seconds)
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(signal 'ftpd-quit)))
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(else
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(call-with-values
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(lambda () (parse-command-line command-line))
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(lambda (command arg)
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(handle-command command arg)))))))
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(define (handle-command command arg)
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; (log (syslog-level debug)
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; "handling command ~S with argument ~S"
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; command arg)
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(call-with-current-continuation
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(lambda (escape)
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(with-handler
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(lambda (condition more)
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(cond
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((error? condition)
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(log (syslog-level notice)
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"internal error occured: ~S -- replying and escaping (451)"
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condition)
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(register-reply! 451
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(format #f "Internal error: ~S"
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(condition-stuff condition)))
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(escape 'fick-dich-ins-knie))
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((ftpd-error? condition)
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; debug level because nearly every unsuccessful command ends
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; here (no args, can't change dir, etc.)
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(log (syslog-level debug)
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"ftpd error occured -- escaping")
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(escape 'fick-dich-ins-knie))
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(else
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(more))))
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(lambda ()
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(with-errno-handler*
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(lambda (errno packet)
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(let ((unix-error (car packet)))
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(log (syslog-level notice)
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"unix error occured: ~S -- replying (451) and escaping"
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unix-error)
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(register-reply! 451
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(format #f "Unix error: ~A." unix-error))
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(escape 'fick-dich-ins-knie)))
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(lambda ()
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(dispatch-command command arg))))))))
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(define (dispatch-command command arg)
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; (log (syslog-level debug)
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; "dispatching command ~S with argument ~S"
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; command arg)
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(cond
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((assoc command *command-alist*)
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=> (lambda (pair)
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(log (syslog-level debug)
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"command ~S was found in command-list and is executed with argument ~S"
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(car pair) arg)
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((cdr pair) arg)))
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(else
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(log (syslog-level debug) "rejecting unknown command ~S (500) (argument: ~S)"
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command arg)
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(register-reply! 500
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(string-append
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(format #f "Unknown command: \"~A\"" command)
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(if (string=? "" arg)
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"."
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(format #f " (argument(s) \"~A\")." arg)))))))
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(define (handle-user name)
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(log-command (syslog-level info) "USER" name)
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(cond
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((session-logged-in?)
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(log (syslog-level info) "user ~S is already logged in (230)"
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name)
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(register-reply! 230
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"You are already logged in."))
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((or (string=? "anonymous" name)
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(string=? "ftp" name))
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(handle-user-anonymous))
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(else
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(log (syslog-level info) "rejecting non-anonymous login (530)")
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(register-reply! 530
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"Only anonymous logins allowed."))))
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(define (handle-user-anonymous)
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(log (syslog-level info) "anonymous user login (230)")
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(set-session-logged-in? #t)
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(set-session-authenticated? #t)
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(set-session-anonymous? #t)
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(set-session-root-directory (session-anonymous-home))
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(set-session-current-directory "")
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(register-reply! 230 "Anonymous user logged in."))
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(define (handle-pass password)
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(log-command (syslog-level info) "PASS" password)
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(cond
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((not (session-logged-in?))
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(log (syslog-level info) "Rejecting password as user has not logged in yet. (530)")
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(register-reply! 530 "You have not logged in yet."))
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((session-anonymous?)
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(log (syslog-level info) "Accepting password as user is logged in (200)")
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(register-reply! 200 "Thank you."))
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(else
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(log (syslog-level notice) "Reached unreachable case-branch while handling password (502)")
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(register-reply! 502 "This can't happen."))))
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(define (handle-quit foo)
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(log-command (syslog-level info) "QUIT")
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(log (syslog-level debug) "quitting (221)")
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(register-reply! 221 "Goodbye! Au revoir! Auf Wiedersehen!")
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(signal 'ftpd-quit))
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(define (handle-syst foo)
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(log-command (syslog-level info) "SYST")
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(log (syslog-level debug) "telling system type (215)")
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(register-reply! 215 "UNIX Type: L8"))
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(define (handle-cwd path)
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(log-command (syslog-level info) "CWD" path)
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(ensure-authenticated-login)
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(let ((current-directory (assemble-path (session-current-directory)
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path)))
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(with-errno-handler*
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(lambda (errno packet)
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(let ((error-reason (car packet)))
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(log (syslog-level info)
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"can't change to directory \"~A\": ~A (550)"
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path error-reason)
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(signal-error! 550
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(format #f "Can't change directory to \"~A\": ~A."
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path
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error-reason))))
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(lambda ()
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(with-cwd*
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(file-name-as-directory
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(string-append (session-root-directory) current-directory))
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(lambda () ; I hate gratuitous syntax
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(log (syslog-level info)
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"changing current directory to \"/~A\" (250)"
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current-directory)
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(set-session-current-directory current-directory)
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(register-reply! 250
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(format #f "Current directory changed to \"/~A\"."
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current-directory))))))))
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(define (handle-cdup foo)
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(log-command (syslog-level info) "CDUP")
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(handle-cwd ".."))
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(define (handle-pwd foo)
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(log-command (syslog-level info) "PWD")
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(ensure-authenticated-login)
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(let ((current-directory (session-current-directory)))
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(log (syslog-level info) "replying \"/~A\" as current directory (257)"
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current-directory)
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(register-reply! 257
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(format #f "Current directory is \"/~A\"."
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current-directory))))
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(define (make-file-action-handler error-format-string action)
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(lambda (path)
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(ensure-authenticated-login)
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(if (string=? "" path)
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(begin
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(log (syslog-level info)
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"finishing processing command because of missing arguments (500)")
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(signal-error! 500 "No argument.")))
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(let ((full-path (string-append (session-root-directory)
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(assemble-path (session-current-directory)
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path))))
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(with-errno-handler*
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(lambda (errno packet)
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(let ((error-reason (car packet)))
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(log (syslog-level info)
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(string-append error-format-string " (550)") path error-reason)
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(signal-error! 550
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(format #f error-format-string
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path error-reason))))
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(lambda ()
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(action path full-path))))))
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(define handle-dele
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(make-file-action-handler
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"Could not delete \"~A\": ~A."
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(lambda (path full-path)
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(log-command (syslog-level info) "DELE" path)
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(delete-file full-path)
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(log (syslog-level info) "deleted ~S (250)" full-path)
|
|
(log (syslog-level debug) "reporting about ~S" path)
|
|
(register-reply! 250 (format #f "Deleted \"~A\"." path)))))
|
|
|
|
(define handle-mdtm
|
|
(make-file-action-handler
|
|
"Could not get info on \"~A\": ~A."
|
|
(lambda (path full-path)
|
|
(log-command (syslog-level info) "MDTM" path)
|
|
(let* ((info (file-info full-path))
|
|
(the-date (date (file-info:mtime info) 0))
|
|
(formatted-date (format-date "~Y~m~d~H~M~S" the-date)))
|
|
(log (syslog-level info) "reporting modification time of ~S: ~A (213)"
|
|
full-path
|
|
formatted-date)
|
|
(register-reply! 213
|
|
formatted-date)))))
|
|
|
|
(define handle-mkd
|
|
(make-file-action-handler
|
|
"Could not make directory \"~A\": ~A."
|
|
(lambda (path full-path)
|
|
(log-command (syslog-level info) "MKD" path)
|
|
(create-directory full-path #o755)
|
|
(log (syslog-level info) "created directory ~S (257)" full-path)
|
|
(log (syslog-level debug) "reporting about ~S" path)
|
|
(register-reply! 257
|
|
(format #f "Created directory \"~A\"." path)))))
|
|
|
|
(define handle-rmd
|
|
(make-file-action-handler
|
|
"Could not remove directory \"~A\": ~A."
|
|
(lambda (path full-path)
|
|
(log-command (syslog-level info) "RMD" path)
|
|
(delete-directory full-path)
|
|
(log (syslog-level info) "deleted directory ~S (250)" full-path)
|
|
(log (syslog-level debug) "reporting about ~S" path)
|
|
(register-reply! 250
|
|
(format #f "Deleted directory \"~A\"." path)))))
|
|
|
|
|
|
(define handle-rnfr
|
|
(make-file-action-handler
|
|
"Could not get info on file \"~A\": ~A."
|
|
(lambda (path full-path)
|
|
(log-command (syslog-level info) "RNFR" path)
|
|
(file-info full-path)
|
|
(log (syslog-level info)
|
|
"RNFR-command accepted, waiting for RNTO-command (350)")
|
|
(register-reply! 350 "RNFR accepted. Gimme a RNTO next.")
|
|
(set-session-to-be-renamed full-path))))
|
|
|
|
(define (handle-rnto path)
|
|
(log-command (syslog-level info) "RNTO" path)
|
|
(ensure-authenticated-login)
|
|
(if (not (session-to-be-renamed))
|
|
(begin
|
|
(log (syslog-level info)
|
|
"RNTO-command rejected: need RNFR-command before (503)")
|
|
(signal-error! 503 "Need RNFR before RNTO.")))
|
|
(if (string=? "" path)
|
|
(begin
|
|
(log (syslog-level info)
|
|
"No argument -- still waiting for (correct) RNTO-command (500)")
|
|
(signal-error! 500 "No argument.")))
|
|
(let ((full-path (string-append (session-root-directory)
|
|
(assemble-path (session-current-directory)
|
|
path))))
|
|
|
|
(if (file-exists? full-path)
|
|
(begin
|
|
(log (syslog-level info) "rename of ~S failed (already exists) (550)"
|
|
full-path)
|
|
(log (syslog-level debug) "reporting about ~S"
|
|
path)
|
|
(signal-error!
|
|
550
|
|
(format #f "Rename failed---\"~A\" already exists or is protected."
|
|
path))))
|
|
|
|
(with-errno-handler*
|
|
(lambda (errno packet)
|
|
(log (syslog-level info)
|
|
"failed to rename ~A (550)" path)
|
|
(signal-error! 550
|
|
(format #f "Could not rename: ~A." path)))
|
|
(lambda ()
|
|
(let ((old-name (session-to-be-renamed)))
|
|
(rename-file old-name full-path)
|
|
(log (syslog-level info)
|
|
"~S renamed to ~S - no more waiting for RNTO-command (250)"
|
|
old-name full-path)
|
|
(register-reply! 250 "File renamed.")
|
|
(set-session-to-be-renamed #f))))))
|
|
|
|
(define handle-size
|
|
(make-file-action-handler
|
|
"Could not get info on file \"~A\": ~A."
|
|
(lambda (path full-path)
|
|
(log-command (syslog-level info) "SIZE" path)
|
|
(let ((info (file-info full-path)))
|
|
(if (not (eq? 'regular (file-info:type info)))
|
|
(begin
|
|
(log (syslog-level info)
|
|
"rejecting SIZE-command as ~S is not a regular file (550)"
|
|
full-path)
|
|
(log (syslog-level debug) "reporting about ~S" path)
|
|
(signal-error! 550
|
|
(format #f "\"~A\" is not a regular file."
|
|
path))))
|
|
(let ((file-size (file-info:size info)))
|
|
(log (syslog-level info)
|
|
"reporting ~D as size of ~S (213)"
|
|
file-size full-path)
|
|
(register-reply! 213 (number->string file-size)))))))
|
|
|
|
|
|
(define (handle-type arg)
|
|
(log-command (syslog-level info) "TYPE" arg)
|
|
(cond
|
|
((string-ci=? "A" arg)
|
|
(log (syslog-level info) "changed type to ascii (200)")
|
|
(set-session-type 'ascii))
|
|
((string-ci=? "I" arg)
|
|
(log (syslog-level info) "changed type to image (8-bit binary) (200)")
|
|
(set-session-type 'image))
|
|
((string-ci=? "L8" arg)
|
|
(log (syslog-level info) "changed type to image (8-bit binary) (200)")
|
|
(set-session-type 'image))
|
|
(else
|
|
(log (syslog-level info)
|
|
"rejecting TYPE-command: unknown type (504)")
|
|
(signal-error! 504
|
|
(format #f "Unknown TYPE: ~S." arg))))
|
|
|
|
(log (syslog-level debug) "reporting new type (see above)")
|
|
(register-reply! 200
|
|
(format #f "TYPE is now ~A."
|
|
(case (session-type)
|
|
((ascii) "ASCII")
|
|
((image) "8-bit binary")
|
|
(else "somethin' weird, man")))))
|
|
|
|
(define (handle-mode arg)
|
|
(log-command (syslog-level info) "MODE" arg)
|
|
(cond
|
|
((string=? "" arg)
|
|
(log (syslog-level info) "rejecting MODE-command: no arguments (500)")
|
|
(register-reply! 500
|
|
"No arguments. Not to worry---I'd ignore them anyway."))
|
|
((string-ci=? "S" arg)
|
|
(log (syslog-level info)
|
|
"stream mode is (still) used for file-transfer (200)")
|
|
(register-reply! 200 "Using stream mode to transfer files."))
|
|
(else
|
|
(log (syslog-level info) "mode ~S is not supported (504)" arg)
|
|
(register-reply! 504 (format #f "Mode \"~A\" is not supported."
|
|
arg)))))
|
|
|
|
(define (handle-stru arg)
|
|
(log-command (syslog-level info) "STRU" arg)
|
|
(cond
|
|
((string=? "" arg)
|
|
(log (syslog-level info) "rejecting STRU-command: no arguments (500)")
|
|
(register-reply! 500
|
|
"No arguments. Not to worry---I'd ignore them anyway."))
|
|
((string-ci=? "F" arg)
|
|
(log (syslog-level info) "(still) using file structure to transfer files (200)")
|
|
(register-reply! 200 "Using file structure to transfer files."))
|
|
(else
|
|
(log (syslog-level info) "file structure ~S is not supported (504)" arg)
|
|
(register-reply! 504
|
|
(format #f "File structure \"~A\" is not supported."
|
|
arg)))))
|
|
|
|
(define (handle-noop arg)
|
|
(log-command (syslog-level info) "NOOP")
|
|
(log (syslog-level debug) "successfully done nothing (200)")
|
|
(register-reply! 200 "Done nothing, but successfully."))
|
|
|
|
(define *port-arg-regexp*
|
|
(make-regexp "^([0-9]+),([0-9]+),([0-9]+),([0-9]+),([0-9]+),([0-9]+)$"))
|
|
|
|
(define (parse-port-arg string)
|
|
(log (syslog-level debug) "parsing port-string ~S" string)
|
|
(cond
|
|
((regexp-exec *port-arg-regexp* string)
|
|
=> (lambda (match)
|
|
(let ((components
|
|
(map (lambda (match-index)
|
|
(string->number
|
|
(match:substring match match-index)))
|
|
'(1 2 3 4 5 6))))
|
|
(if (any? (lambda (component)
|
|
(> component 255))
|
|
components)
|
|
(begin
|
|
(log (syslog-level debug)
|
|
"rejecting PORT-command because of invalid arguments (port-component > 255) (501)")
|
|
(signal-error! 501
|
|
"Invalid arguments to PORT.")))
|
|
(apply
|
|
(lambda (a1 a2 a3 a4 p1 p2)
|
|
(let ((address (+ (arithmetic-shift a1 24)
|
|
(arithmetic-shift a2 16)
|
|
(arithmetic-shift a3 8)
|
|
a4))
|
|
(port (+ (arithmetic-shift p1 8) p2)))
|
|
(log (syslog-level debug)
|
|
"port-parse result: address ~D, port ~D (from compononets: address: ~A, ~A, ~A, ~A, port: ~A, ~A)"
|
|
address port
|
|
a1 a2 a3 a4 p1 p2)
|
|
(values address port)))
|
|
components))))
|
|
(else
|
|
(log (syslog-level debug) "reporting syntax error in argument (500)")
|
|
(signal-error! 500
|
|
"Syntax error in argument to PORT."))))
|
|
|
|
|
|
(define (handle-port stuff)
|
|
(log-command (syslog-level info) "PORT" stuff)
|
|
(ensure-authenticated-login)
|
|
(maybe-close-data-connection)
|
|
(call-with-values
|
|
(lambda () (parse-port-arg stuff))
|
|
(lambda (address port)
|
|
(let ((socket (create-socket protocol-family/internet
|
|
socket-type/stream)))
|
|
(log (syslog-level debug)
|
|
"created new socket (internet, stream, reusing address)")
|
|
(set-socket-option socket level/socket socket/reuse-address #t)
|
|
|
|
(connect-socket socket
|
|
(internet-address->socket-address
|
|
address port))
|
|
|
|
(set-session-data-socket socket)
|
|
|
|
(let ((formatted-internet-host-address
|
|
(format-internet-host-address address)))
|
|
(log (syslog-level info)
|
|
"connected to ~A, port ~A (200)"
|
|
formatted-internet-host-address port)
|
|
|
|
(register-reply! 200
|
|
(format #f "Connected to ~A, port ~A."
|
|
formatted-internet-host-address
|
|
port)))))))
|
|
|
|
|
|
(define (handle-pasv stuff)
|
|
(log-command (syslog-level info) "PASV")
|
|
(ensure-authenticated-login)
|
|
(maybe-close-data-connection)
|
|
(let ((socket (create-socket protocol-family/internet
|
|
socket-type/stream)))
|
|
|
|
(set-socket-option socket level/socket socket/reuse-address #t)
|
|
|
|
(bind-socket socket
|
|
(internet-address->socket-address (this-host-address)
|
|
0))
|
|
(listen-socket socket 1)
|
|
|
|
(let ((address (socket-local-address socket)))
|
|
|
|
(call-with-values
|
|
(lambda () (socket-address->internet-address address))
|
|
(lambda (host-address port)
|
|
|
|
(set-session-passive-socket socket)
|
|
|
|
|
|
(let ((formatted-this-host-address
|
|
(format-internet-host-address (this-host-address) ","))
|
|
(formatted-port (format-port port)))
|
|
(log (syslog-level info) "accepting passive mode (on ~A,~A) (227)"
|
|
formatted-this-host-address formatted-port)
|
|
(register-reply! 227
|
|
(format #f "Passive mode OK (~A,~A)"
|
|
formatted-this-host-address
|
|
formatted-port))))))))
|
|
|
|
(define (this-host-address)
|
|
(call-with-values
|
|
(lambda ()
|
|
(socket-address->internet-address
|
|
(socket-local-address (port->socket (session-control-input-port)
|
|
protocol-family/internet))))
|
|
(lambda (host-address control-port)
|
|
host-address)))
|
|
|
|
(define (format-internet-host-address address . maybe-separator)
|
|
|
|
(define (extract shift)
|
|
(number->string
|
|
(bitwise-and (arithmetic-shift address (- shift))
|
|
255)))
|
|
|
|
(let ((separator (optional maybe-separator ".")))
|
|
(string-append
|
|
(extract 24) separator (extract 16) separator
|
|
(extract 8) separator (extract 0))))
|
|
|
|
(define (format-port port)
|
|
(string-append
|
|
(number->string (bitwise-and (arithmetic-shift port -8) 255))
|
|
","
|
|
(number->string (bitwise-and port 255))))
|
|
|
|
(define (handle-nlst arg)
|
|
(log-command (syslog-level info) "NLST" arg)
|
|
(handle-listing arg '()))
|
|
|
|
(define (handle-list arg)
|
|
(log-command (syslog-level info) "LIST" arg)
|
|
(handle-listing arg '(long)))
|
|
|
|
(define (handle-listing arg preset-flags)
|
|
(ensure-authenticated-login)
|
|
(with-data-connection
|
|
(lambda ()
|
|
(let ((args (split-arguments arg)))
|
|
(call-with-values
|
|
(lambda ()
|
|
(partition-list
|
|
(lambda (arg)
|
|
(and (not (string=? "" arg))
|
|
(char=? #\- (string-ref arg 0))))
|
|
args))
|
|
(lambda (flag-args rest-args)
|
|
|
|
(if (and (not (null? rest-args))
|
|
(not (null? (cdr rest-args))))
|
|
(begin
|
|
(log (syslog-level info) "got more than one path argument - rejection (501)")
|
|
(signal-error! 501 "More than one path argument.")))
|
|
|
|
(let ((path (if (null? rest-args)
|
|
""
|
|
(car rest-args)))
|
|
(flags (arguments->ls-flags flag-args)))
|
|
|
|
(if (not flags)
|
|
(begin
|
|
(log (syslog-level info) "got invalid flags (501)")
|
|
(signal-error! 501 "Invalid flag(s).")))
|
|
(let ((all-flags (append preset-flags flags)))
|
|
(log (syslog-level info)
|
|
"sending file-listing for path ~S with flags ~A"
|
|
path all-flags)
|
|
|
|
(generate-listing path all-flags)))))))))
|
|
|
|
; Note this doesn't call ENSURE-AUTHENTICATED-LOGIN or
|
|
; ENSURE-DATA-CONNECTION.
|
|
|
|
(define (generate-listing path flags)
|
|
(let ((full-path (string-append (session-root-directory)
|
|
(assemble-path (session-current-directory)
|
|
path))))
|
|
(with-errno-handler*
|
|
(lambda (errno packet)
|
|
(let ((error-reason (car packet)))
|
|
(log (syslog-level info)
|
|
"can't access directory at ~A: ~A (451)"
|
|
path error-reason)
|
|
(signal-error! 451
|
|
(format #f "Can't access directory at ~A: ~A."
|
|
path
|
|
error-reason))))
|
|
(lambda ()
|
|
(with-cwd*
|
|
(file-name-directory full-path)
|
|
(lambda ()
|
|
(let ((nondir (file-name-nondirectory full-path)))
|
|
(ls flags
|
|
(list
|
|
;; work around OLIN BUG
|
|
(if (string=? nondir "")
|
|
"."
|
|
nondir))
|
|
(socket:outport (session-data-socket))))))))))
|
|
|
|
(define (handle-abor foo)
|
|
(log-command (syslog-level info) "ABOR")
|
|
(maybe-close-data-connection)
|
|
(log (syslog-level info) "closing data connection (226)")
|
|
(register-reply! 226 "Closing data connection."))
|
|
|
|
(define (handle-retr path)
|
|
(log-command (syslog-level info) "RETR")
|
|
(ensure-authenticated-login)
|
|
(let ((full-path (string-append (session-root-directory)
|
|
(assemble-path (session-current-directory)
|
|
path))))
|
|
(with-fatal-error-handler* ; CALL-WITH-INPUT-FILE doesn't go through ERRNO
|
|
(lambda (condition more)
|
|
(log (syslog-level info) "failed to open ~S for reading (550)" full-path)
|
|
(log (syslog-level debug) "reporting about ~S" path)
|
|
(signal-error! 550
|
|
(format #f "Can't open \"~A\" for reading."
|
|
path)))
|
|
(lambda ()
|
|
(let ((info (file-info full-path)))
|
|
(if (not (eq? 'regular (file-info:type info)))
|
|
(begin
|
|
(log (syslog-level info) "rejecting RETR-command as ~S is not a regular file (450)"
|
|
full-path)
|
|
(log (syslog-level debug) "reporting about ~S" path)
|
|
(signal-error! 450
|
|
(format #f "\"~A\" is not a regular file."
|
|
path))))
|
|
(call-with-input-file full-path
|
|
(lambda (file-port)
|
|
(with-data-connection
|
|
(lambda ()
|
|
(case (session-type)
|
|
((image)
|
|
(log (syslog-level info)
|
|
"sending file ~S (binary mode)"
|
|
full-path)
|
|
(log (syslog-level debug) "sending is from port ~S" file-port)
|
|
(copy-port->port-binary
|
|
file-port
|
|
(socket:outport (session-data-socket))))
|
|
((ascii)
|
|
(log (syslog-level info) "sending file ~S (ascii mode)"
|
|
full-path)
|
|
(log (syslog-level debug) "sending is from port ~S" file-port)
|
|
(copy-port->port-ascii
|
|
file-port
|
|
(socket:outport (session-data-socket))))))))))))))
|
|
|
|
(define (handle-stor path)
|
|
(log-command (syslog-level info) "STOR" path)
|
|
(ensure-authenticated-login)
|
|
(let ((full-path (string-append (session-root-directory)
|
|
(assemble-path (session-current-directory)
|
|
path))))
|
|
(with-fatal-error-handler*
|
|
(lambda (condition more)
|
|
(log (syslog-level info) "can't open ~S for writing (550)" full-path)
|
|
(log (syslog-level debug) "replying error for file ~S" path)
|
|
(signal-error! 550
|
|
(format #f "Can't open \"~A\" for writing."
|
|
path)))
|
|
(lambda ()
|
|
(call-with-output-file full-path
|
|
(lambda (file-port)
|
|
(with-data-connection
|
|
(lambda ()
|
|
(let ((inport (socket:inport (session-data-socket))))
|
|
(case (session-type)
|
|
((image)
|
|
(log (syslog-level notice)
|
|
"storing data to ~S (binary mode)"
|
|
full-path)
|
|
(log (syslog-level debug)
|
|
"storing comes from socket-inport ~S (binary-mode)"
|
|
inport)
|
|
(copy-port->port-binary
|
|
(socket:inport (session-data-socket))
|
|
file-port))
|
|
((ascii)
|
|
(log (syslog-level notice)
|
|
"storing data to ~S (ascii-mode)"
|
|
full-path)
|
|
(log (syslog-level debug)
|
|
"storing comes from socket-inport ~S (ascii-mode)"
|
|
inport)
|
|
(copy-ascii-port->port
|
|
(socket:inport (session-data-socket))
|
|
file-port))))))))))))
|
|
|
|
(define (assemble-path current-directory path)
|
|
(log (syslog-level debug) "assembling path ~S"
|
|
path)
|
|
(let* ((interim-path
|
|
(if (not (file-name-rooted? path))
|
|
(string-append (file-name-as-directory current-directory)
|
|
path)
|
|
path))
|
|
(complete-path (if (file-name-rooted? interim-path)
|
|
(file-name-sans-rooted interim-path)
|
|
interim-path)))
|
|
(log (syslog-level debug) "name ~S assembled to ~S"
|
|
path complete-path)
|
|
(cond
|
|
((normalize-path complete-path)
|
|
=> (lambda (assembled-path) assembled-path))
|
|
(else
|
|
(log (syslog-level debug)
|
|
"invalid pathname -- tried to pass root directory (501)")
|
|
(signal-error! 501 "Invalid pathname")))))
|
|
|
|
(define (ensure-authenticated-login)
|
|
(if (or (not (session-logged-in?))
|
|
(not (session-authenticated?)))
|
|
(begin
|
|
(log (syslog-level debug)
|
|
"login authentication failed - user is not logged in (530)")
|
|
(signal-error! 530 "You're not logged in yet."))
|
|
(log (syslog-level debug) "authenticated login ensured")))
|
|
|
|
(define (with-data-connection thunk)
|
|
(dynamic-wind ensure-data-connection
|
|
thunk
|
|
maybe-close-data-connection))
|
|
|
|
(define *window-size* 51200)
|
|
|
|
(define (ensure-data-connection)
|
|
(if (and (not (session-data-socket))
|
|
(not (session-passive-socket)))
|
|
(begin
|
|
(log (syslog-level debug) "no data connection (425)")
|
|
(signal-error! 425 "No data connection.")))
|
|
|
|
(if (session-passive-socket)
|
|
(call-with-values
|
|
(lambda () (accept-connection (session-passive-socket)))
|
|
(lambda (socket socket-address)
|
|
(set-session-data-socket socket))))
|
|
|
|
(log (syslog-level debug) "opening data connection (150)")
|
|
(register-reply! 150 "Opening data connection.")
|
|
(write-replies)
|
|
|
|
(set-socket-option (session-data-socket) level/socket
|
|
socket/send-buffer *window-size*)
|
|
(set-socket-option (session-data-socket) level/socket
|
|
socket/receive-buffer *window-size*))
|
|
|
|
(define (maybe-close-data-connection)
|
|
(if (or (session-data-socket) (session-passive-socket))
|
|
(close-data-connection)))
|
|
|
|
(define (close-data-connection)
|
|
(if (session-data-socket)
|
|
(close-socket (session-data-socket)))
|
|
(if (session-passive-socket)
|
|
(close-socket (session-passive-socket)))
|
|
(log (syslog-level debug) "closing data connection (226)")
|
|
(register-reply! 226 "Closing data connection.")
|
|
(set-session-data-socket #f)
|
|
(set-session-passive-socket #f))
|
|
|
|
(define *command-alist*
|
|
(list
|
|
(cons "NOOP" handle-noop)
|
|
(cons "USER" handle-user)
|
|
(cons "PASS" handle-pass)
|
|
(cons "QUIT" handle-quit)
|
|
(cons "SYST" handle-syst)
|
|
(cons "CWD" handle-cwd)
|
|
(cons "PWD" handle-pwd)
|
|
(cons "CDUP" handle-cdup)
|
|
(cons "DELE" handle-dele)
|
|
(cons "MDTM" handle-mdtm)
|
|
(cons "MKD" handle-mkd)
|
|
(cons "RMD" handle-rmd)
|
|
(cons "RNFR" handle-rnfr)
|
|
(cons "RNTO" handle-rnto)
|
|
(cons "SIZE" handle-size)
|
|
(cons "TYPE" handle-type)
|
|
(cons "MODE" handle-mode)
|
|
(cons "STRU" handle-stru)
|
|
(cons "PORT" handle-port)
|
|
(cons "PASV" handle-pasv)
|
|
(cons "NLST" handle-nlst)
|
|
(cons "LIST" handle-list)
|
|
(cons "RETR" handle-retr)
|
|
(cons "STOR" handle-stor)
|
|
(cons "ABOR" handle-abor)))
|
|
|
|
(define (parse-command-line line)
|
|
(if (eof-object? line) ; Netscape does this
|
|
(signal 'ftpd-irregular-quit)
|
|
(let* ((line (trim-spaces line))
|
|
(split-position (string-index line #\space)))
|
|
(if split-position
|
|
(values (upcase-string (substring line 0 split-position))
|
|
(trim-spaces (substring line
|
|
(+ 1 split-position)
|
|
(string-length line))))
|
|
(values (upcase-string line) "")))))
|
|
|
|
; Path names
|
|
|
|
; This removes all internal ..'s from a path.
|
|
; NORMALIZE-PATH returns #f if PATH points to a parent directory.
|
|
|
|
(define (normalize-path path)
|
|
(let loop ((components (split-file-name (simplify-file-name path)))
|
|
(reverse-result '()))
|
|
(cond
|
|
((null? components)
|
|
(path-list->file-name (reverse reverse-result)))
|
|
((string=? ".." (car components))
|
|
(if (null? reverse-result)
|
|
#f
|
|
(loop (cdr components) (cdr reverse-result))))
|
|
(else
|
|
(loop (cdr components) (cons (car components) reverse-result))))))
|
|
|
|
(define (file-name-rooted? file-name)
|
|
(and (not (string=? "" file-name))
|
|
(char=? #\/ (string-ref file-name 0))))
|
|
|
|
(define (file-name-sans-rooted file-name)
|
|
(substring file-name 1 (string-length file-name)))
|
|
|
|
(define split-arguments
|
|
(infix-splitter (make-regexp " +")))
|
|
|
|
; Reply handling
|
|
|
|
; Replies must be synchronous with requests and actions. Therefore,
|
|
; they are queued on generation via REGISTER-REPLY!. The messages are
|
|
; printed via WRITE-REPLIES. For the nature of the replies, see RFC
|
|
; 959.
|
|
|
|
|
|
(define (write-replies)
|
|
(if (not (null? (session-reverse-replies)))
|
|
(let loop ((messages (reverse (session-reverse-replies))))
|
|
(if (null? (cdr messages))
|
|
(write-final-reply (car messages))
|
|
(begin
|
|
(write-nonfinal-reply (car messages))
|
|
(loop (cdr messages))))))
|
|
(set-session-reverse-replies '()))
|
|
|
|
(define (write-final-reply line)
|
|
(format (session-control-output-port) "~D ~A" (session-reply-code) line)
|
|
;; (format #t "Reply: ~D ~A~%" (session-reply-code) line)
|
|
(write-crlf (session-control-output-port)))
|
|
|
|
(define (write-nonfinal-reply line)
|
|
(format (session-control-output-port) "~D-~A" (session-reply-code) line)
|
|
;; (format #t "Reply: ~D-~A~%" (session-reply-code) line)
|
|
(write-crlf (session-control-output-port)))
|
|
|
|
(define (signal-error! code message)
|
|
(register-reply! code message)
|
|
(signal 'ftpd-error))
|
|
|
|
(define (register-reply! code message)
|
|
(set-session-reverse-replies
|
|
(cons message (session-reverse-replies)))
|
|
(set-session-reply-code code))
|
|
|
|
; Version
|
|
|
|
(define *ftpd-version* "$Revision: 1.25 $")
|
|
|
|
(define (copy-port->port-binary input-port output-port)
|
|
(let ((buffer (make-string *window-size*)))
|
|
(let loop ()
|
|
(cond
|
|
((read-string! buffer input-port)
|
|
=> (lambda (length)
|
|
(write-string buffer output-port 0 length)
|
|
(loop))))))
|
|
(force-output output-port))
|
|
|
|
(define (copy-port->port-ascii input-port output-port)
|
|
(let loop ()
|
|
(let ((line (read-line input-port 'concat)))
|
|
(if (not (eof-object? line))
|
|
(let ((length (string-length line)))
|
|
(cond
|
|
((zero? length)
|
|
'fick-dich-ins-knie)
|
|
((char=? #\newline (string-ref line (- length 1)))
|
|
(write-string line output-port 0 (- length 1))
|
|
(write-crlf output-port))
|
|
(else
|
|
(write-string line output-port)))
|
|
(loop)))))
|
|
(force-output output-port))
|
|
|
|
(define (copy-ascii-port->port input-port output-port)
|
|
(let loop ()
|
|
(let* ((line (read-crlf-line input-port
|
|
#f
|
|
90000 ; timeout
|
|
500)) ; max interval
|
|
(length (string-length line)))
|
|
(if (not (eof-object? line))
|
|
(begin
|
|
(write-string line output-port 0 length)
|
|
(newline output-port)
|
|
(loop)))))
|
|
(force-output output-port))
|
|
|
|
; Utilities
|
|
|
|
(define (optional maybe-arg default-exp)
|
|
(cond
|
|
((null? maybe-arg) default-exp)
|
|
((null? (cdr maybe-arg)) (car maybe-arg))
|
|
(else (error "too many optional arguments" maybe-arg))))
|