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Fix bugs in channel shutdown handling. Add tty cooker.

This commit is contained in:
Tony Garnock-Jones 2011-10-26 00:07:38 -04:00
parent 887aada203
commit d47f553e21
3 changed files with 151 additions and 48 deletions
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67
cook-port.rkt Normal file
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@ -0,0 +1,67 @@
#lang racket/base
(require racket/port)
(provide cook-io)
(define clear-to-eol "\033[2K")
(define kill-line (string-append "\r" clear-to-eol))
(struct buffer (chars consume-next-linefeed?) #:transparent)
(define (buffer-empty? b)
(null? (buffer-chars b)))
(define (buffer-adjust b new-chars)
(struct-copy buffer b
[chars new-chars]
[consume-next-linefeed? #f]))
(define (buffer-contents b)
(list->string (reverse (buffer-chars b))))
(define (update-buffer b key prompt k-eof k-complete k-ongoing)
(case key
((#\backspace) (if (buffer-empty? b)
(k-ongoing b "")
(k-ongoing (buffer-adjust b (cdr (buffer-chars b))) "\b \b")))
((#\return) (k-complete (buffer-contents b) (buffer '() #t)))
((#\newline) (if (buffer-consume-next-linefeed? b)
(k-ongoing (struct-copy buffer b [consume-next-linefeed? #f]) "")
(k-complete (buffer-contents b) (buffer '() #f))))
((#\page) (k-ongoing b (string-append kill-line prompt (buffer-contents b))))
((#\004) ;; control-D, UNIX EOF
(if (buffer-empty? b)
(k-eof)
(k-ongoing b "")))
((#\033) ;; escape
(k-ongoing (buffer '() #f) (string-append kill-line prompt)))
(else (if (char-iso-control? key)
(k-ongoing b "")
(k-ongoing (buffer-adjust b (cons key (buffer-chars b))) (string key))))))
(define (cook-io raw-in raw-out prompt)
(define-values (cooked-in cooked-out) (make-pipe))
(thread
(lambda ()
(let loop ((b (buffer '() #f)))
(if (port-closed? cooked-out)
;; our job here is
'done
(let ((s (read-string 1 raw-in)))
(if (eof-object? s)
(begin (close-output-port cooked-out)
(loop b))
(begin (update-buffer b (string-ref s 0) prompt
(lambda ()
(close-output-port cooked-out)
(close-input-port raw-in))
(lambda (line new-b)
(write-string "\r\n" raw-out)
(write-string line cooked-out)
(newline cooked-out)
(loop new-b))
(lambda (new-b feedback)
(write-string feedback raw-out)
(loop new-b))))))))))
(values cooked-in raw-out))

61
repl-server.rkt
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@ -12,6 +12,8 @@
(require "ssh-session.rkt")
(require "standard-thread.rkt")
(require "cook-port.rkt")
(define (t-client)
(let-values (((i o) (tcp-connect "localhost"
2323
@ -21,27 +23,42 @@
(printf "Got API ~v\n" api)
(semaphore-wait (make-semaphore 0)))))
(define (repl-channel-main oob-ch in out)
(let loop ()
(sync (handle-evt oob-ch
(match-lambda
(`(notify ,type ,data)
(log-info (format "repl-channel: notify ~v ~v" type data))
(loop))
(`(request (#"shell" ,_) ,k)
(k 'ok)
(loop))
(`(request ,other ,k)
(log-info (format "repl-channel: request ~v" other))
(k 'error)
(loop))))
(handle-evt (read-line-evt in 'any)
(lambda (line)
(if (eof-object? line)
(begin (fprintf out "Goodbye\n" out)
'done)
(begin (fprintf out "You said ~s\n" line)
(loop))))))))
(define prompt "RacketSSH> ")
(define (make-repl-channel-main username)
(lambda (oob-ch in out)
(fprintf out "Hello, ~a.\r\n~a" username prompt)
(let update-channels ((in in) (out out))
(let loop ()
(sync (handle-evt oob-ch
(match-lambda
(`(notify ,type ,data)
(log-info (format "repl-channel: notify ~v ~v" type data))
(loop))
(`(request (#"shell" ,_) ,k)
(k 'ok)
(loop))
(`(request (#"pty-req" ,_) ,k)
(k 'ok)
(define-values (cooked-in cooked-out) (cook-io in out prompt))
(update-channels cooked-in cooked-out))
(`(request ,other ,k)
(log-info (format "repl-channel: request ~v" other))
(k 'error)
(loop))))
#;(handle-evt (read-bytes-evt 10000 in)
(lambda (buf)
(write-bytes buf out)
(loop)))
(handle-evt (read-line-evt in 'any)
(lambda (line)
;;(log-info (format "received ~v" line))
(if (eof-object? line)
(begin (fprintf out "\r\nGoodbye\r\n")
'done)
(begin (fprintf out "You said ~s\r\n" line)
(write-string prompt out)
(loop))))))))))
(define (t-server)
(define s (tcp-listen 2322 4 #t "localhost"))
@ -54,7 +71,7 @@
(lambda (username channel-type extra-request-data state)
(match channel-type
(#"session"
(values `(ok ,repl-channel-main #"")
(values `(ok ,(make-repl-channel-main username) #"")
state))
(else
(values `(error ,SSH_OPEN_UNKNOWN_CHANNEL_TYPE

71
ssh-session.rkt
View File

@ -937,7 +937,7 @@
;; Session API
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define (run-channel oob-ch in out handle channel-thread)
(define (run-channel oob-ch app-out-port in out handle channel-thread)
(define (close-in)
(when (not (port-closed? in))
(close-input-port in)))
@ -946,45 +946,62 @@
(close-output-port out)))
(define (close-ports)
(close-in)
(close-out))
(close-out)
'done)
(let loop ((oob-queue (make-queue))
(remaining-credit 0))
(remaining-credit 0)
(channel-thread-alive #t))
(sync (if (queue-empty? oob-queue)
never-evt
(let-values (((first rest) (dequeue oob-queue)))
(handle-evt (channel-put-evt oob-ch first)
(lambda (dummy) (loop rest remaining-credit)))))
(handle-evt (thread-dead-evt channel-thread)
(lambda (dummy)
(close-ports)
'done))
(if (and (not (port-closed? in)) (positive? remaining-credit))
(let ((buffer (make-bytes (min (channel-io-transfer-buffer-size) remaining-credit))))
(handle-evt (read-bytes-avail!-evt buffer in)
(lambda (count)
(if (eof-object? count)
(begin (close-in)
(loop oob-queue remaining-credit))
(begin (send handle say
`(data ,(sub-bit-string buffer 0 (* 8 count))))
(loop oob-queue (- remaining-credit count)))))))
(lambda (dummy) (loop rest remaining-credit channel-thread-alive)))))
(if channel-thread-alive
(handle-evt (thread-dead-evt channel-thread)
(lambda (dummy)
(when (not (port-closed? app-out-port))
(close-output-port app-out-port))
(loop oob-queue remaining-credit #f)))
never-evt)
(if (port-closed? in)
(if channel-thread-alive
never-evt
(handle-evt always-evt (lambda (dummy) (close-ports))))
(if (positive? remaining-credit)
(let ((buffer (make-bytes (min (channel-io-transfer-buffer-size)
remaining-credit))))
(handle-evt (read-bytes-avail!-evt buffer in)
(lambda (count)
(if (eof-object? count)
(begin (close-in)
(if channel-thread-alive
(loop oob-queue
remaining-credit
channel-thread-alive)
(close-ports)))
(begin (send handle say
`(data ,(sub-bit-string buffer 0 (* 8 count))))
(loop oob-queue
(- remaining-credit count)
channel-thread-alive))))))
never-evt))
(handle-evt (send handle listen-evt)
(match-lambda
((arrived _)
(loop oob-queue remaining-credit))
(loop oob-queue remaining-credit channel-thread-alive))
((departed _ _)
(close-ports)
'done)
(close-ports))
((says _ (credit _ amount) _)
(loop oob-queue (+ remaining-credit amount)))
(loop oob-queue (+ remaining-credit amount) channel-thread-alive))
((says _ `(data ,data) _)
(write-bytes data out)
;; TODO: propagate backpressure through pipes
(send handle say (credit 'session (bytes-length data)))
(loop oob-queue remaining-credit))
(loop oob-queue remaining-credit channel-thread-alive))
((says _ (and notification `(notify ,type ,data)) _)
(loop (enqueue oob-queue notification) remaining-credit))
(loop (enqueue oob-queue notification)
remaining-credit
channel-thread-alive))
((says _ (rpc-request reply-to id message) _)
(loop (enqueue oob-queue
`(request ,message
@ -992,11 +1009,12 @@
(send handle say
(rpc-reply id answer)
reply-to))))
remaining-credit)))))))
remaining-credit
channel-thread-alive)))))))
(define (start-app-channel channel-main)
(define channel-room (make-room 'channel))
(spy-on channel-room)
;;(spy-on channel-room)
(define oob-ch (make-channel))
(define-values (session-a2s app-a2s) (make-pipe))
@ -1004,6 +1022,7 @@
(standard-thread (lambda ()
(run-channel oob-ch
app-a2s
session-a2s
session-s2a
(join-room channel-room 'app)