summary refs log tree commit diff
path: root/gnu/build/marionette.scm
blob: 4f409166db85c4aaa10c34f7792a7f51fb3ec065 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016-2022 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2018 Chris Marusich <cmmarusich@gmail.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (gnu build marionette)
  #:use-module (srfi srfi-9)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-64)
  #:use-module (rnrs io ports)
  #:use-module (ice-9 match)
  #:use-module (ice-9 popen)
  #:use-module (ice-9 regex)
  #:export (marionette?
            make-marionette
            marionette-eval
            wait-for-file
            wait-for-tcp-port
            wait-for-unix-socket
            marionette-control
            marionette-screen-text
            wait-for-screen-text
            %qwerty-us-keystrokes
            marionette-type

            system-test-runner
            qemu-command))

;;; Commentary:
;;;
;;; Instrumentation tools for QEMU virtual machines (VMs).  A "marionette" is
;;; essentially a VM (a QEMU instance) with its monitor connected to a
;;; Unix-domain socket, and with a REPL inside the guest listening on a
;;; virtual console, which is itself connected to the host via a Unix-domain
;;; socket--these are the marionette's strings, connecting it to the almighty
;;; puppeteer.
;;;
;;; Code:

(define-record-type <marionette>
  (marionette command pid monitor repl)
  marionette?
  (command    marionette-command)                 ;list of strings
  (pid        marionette-pid)                     ;integer
  (monitor    marionette-monitor)                 ;port
  (repl       %marionette-repl))                  ;promise of a port

(define-syntax-rule (marionette-repl marionette)
  (force (%marionette-repl marionette)))

(define* (wait-for-monitor-prompt port #:key (quiet? #t))
  "Read from PORT until we have seen all of QEMU's monitor prompt.  When
QUIET? is false, the monitor's output is written to the current output port."
  (define full-prompt
    (string->list "(qemu) "))

  (let loop ((prompt full-prompt)
             (matches '())
             (prefix  '()))
    (match prompt
      (()
       ;; It's useful to set QUIET? so we don't display the echo of our own
       ;; commands.
       (unless quiet?
         (for-each (lambda (line)
                     (format #t "qemu monitor: ~a~%" line))
                   (string-tokenize (list->string (reverse prefix))
                                    (char-set-complement (char-set #\newline))))))
      ((chr rest ...)
       (let ((read (read-char port)))
         (cond ((eqv? read chr)
                (loop rest (cons read matches) prefix))
               ((eof-object? read)
                (error "EOF while waiting for QEMU monitor prompt"
                       (list->string (reverse prefix))))
               (else
                (loop full-prompt
                      '()
                      (cons read (append matches prefix))))))))))

(define* (make-marionette command
                          #:key (socket-directory "/tmp") (timeout 20))
  "Return a QEMU marionette--i.e., a virtual machine with open connections to the
QEMU monitor and to the guest's backdoor REPL."
  (define (file->sockaddr file)
    (make-socket-address AF_UNIX
                         (string-append socket-directory "/" file)))

  (define extra-options
    (list "-nographic"
          "-monitor" (string-append "unix:" socket-directory "/monitor")
          "-chardev" (string-append "socket,id=repl,path=" socket-directory
                                    "/repl")
          "-chardev" (string-append "socket,id=qga,server=on,wait=off,path="
                                    socket-directory "/qemu-ga")

          ;; See
          ;; <http://www.linux-kvm.org/page/VMchannel_Requirements#Invocation>.
          "-device" "virtio-serial"
          "-device" "virtserialport,chardev=repl,name=org.gnu.guix.port.0"
          "-device" "virtserialport,chardev=qga,name=org.qemu.guest_agent.0"))

  (define (accept* port)
    (match (select (list port) '() (list port) timeout)
      (((port) () ())
       (accept port))
      (_
       (error "timeout in 'accept'" port))))

  (let ((monitor (socket AF_UNIX SOCK_STREAM 0))
        (repl    (socket AF_UNIX SOCK_STREAM 0)))
    (bind monitor (file->sockaddr "monitor"))
    (listen monitor 1)
    (bind repl (file->sockaddr "repl"))
    (listen repl 1)

    (match (primitive-fork)
      (0
       (catch #t
         (lambda ()
           (close monitor)
           (close repl)
           (match command
             ((program . args)
              (apply execl program program
                     (append args extra-options)))))
         (lambda (key . args)
           (print-exception (current-error-port)
                            (stack-ref (make-stack #t) 1)
                            key args)
           (primitive-exit 1))))
      (pid
       (format #t "QEMU runs as PID ~a~%" pid)

       (match (accept* monitor)
         ((monitor-conn . _)
          (display "connected to QEMU's monitor\n")
          (close-port monitor)
          (wait-for-monitor-prompt monitor-conn)
          (display "read QEMU monitor prompt\n")

          (marionette (append command extra-options) pid
                      monitor-conn

                      ;; The following 'accept' call connects immediately, but
                      ;; we don't know whether the guest has connected until
                      ;; we actually receive the 'ready' message.
                      (match (accept* repl)
                        ((repl-conn . addr)
                         (display "connected to guest REPL\n")
                         (close-port repl)
                         ;; Delay reception of the 'ready' message so that the
                         ;; caller can already send monitor commands.
                         (delay
                           (match (read repl-conn)
                             ('ready
                              (display "marionette is ready\n")
                              repl-conn))))))))))))

(define (marionette-eval exp marionette)
  "Evaluate EXP in MARIONETTE's backdoor REPL.  Return the result."
  (match marionette
    (($ <marionette> command pid monitor (= force repl))
     (write exp repl)
     (newline repl)
     (read repl))))

(define* (wait-for-file file marionette
                        #:key (timeout 10) (read 'read))
  "Wait until FILE exists in MARIONETTE; READ its content and return it.  If
FILE has not shown up after TIMEOUT seconds, raise an error."
  (match (marionette-eval
          `(let loop ((i ,timeout))
             (cond ((file-exists? ,file)
                    (cons 'success (call-with-input-file ,file ,read)))
                   ((> i 0)
                    (sleep 1)
                    (loop (- i 1)))
                   (else
                    'failure)))
          marionette)
    (('success . result)
     result)
    ('failure
     (error "file didn't show up" file))))

(define* (wait-for-tcp-port port marionette
                            #:key
                            (timeout 20)
                            (address `(make-socket-address AF_INET
                                                           INADDR_LOOPBACK
                                                           ,port)))
  "Wait for up to TIMEOUT seconds for PORT to accept connections in
MARIONETTE.  ADDRESS must be an expression that returns a socket address,
typically a call to 'make-socket-address'.  Raise an error on failure."
  ;; Note: The 'connect' loop has to run within the guest because, when we
  ;; forward ports to the host, connecting to the host never raises
  ;; ECONNREFUSED.
  (match (marionette-eval
          `(let* ((address ,address)
                  (sock (socket (sockaddr:fam address) SOCK_STREAM 0)))
             (let loop ((i 0))
               (catch 'system-error
                 (lambda ()
                   (connect sock address)
                   (close-port sock)
                   'success)
                 (lambda args
                   (if (< i ,timeout)
                       (begin
                         (sleep 1)
                         (loop (+ 1 i)))
                       (list 'failure address))))))
          marionette)
    ('success #t)
    (('failure address)
     (error "nobody's listening on port"
            (list (inet-ntop (sockaddr:fam address) (sockaddr:addr address))
                  (sockaddr:port address))))))

(define* (wait-for-unix-socket file-name marionette
                                #:key (timeout 20))
  "Wait for up to TIMEOUT seconds for FILE-NAME, a Unix domain socket, to
accept connections in MARIONETTE.  Raise an error on failure."
  (match (marionette-eval
          `(begin
             (let ((sock (socket PF_UNIX SOCK_STREAM 0)))
               (let loop ((i 0))
                 (catch 'system-error
                   (lambda ()
                     (connect sock AF_UNIX ,file-name)
                     (close-port sock)
                     'success)
                   (lambda args
                     (if (< i ,timeout)
                         (begin
                           (sleep 1)
                           (loop (+ 1 i)))
                         'failure))))))
          marionette)
    ('success #t)
    ('failure
     (error "nobody's listening on unix domain socket" file-name))))

(define (marionette-control command marionette)
  "Run COMMAND in the QEMU monitor of MARIONETTE.  COMMAND is a string such as
\"sendkey ctrl-alt-f1\" or \"screendump foo.ppm\" (info \"(QEMU) QEMU
Monitor\")."
  (match marionette
    (($ <marionette> _ _ monitor)
     (display command monitor)
     (newline monitor)
     ;; The "quit" command terminates QEMU immediately, with no output.
     (unless (string=? command "quit") (wait-for-monitor-prompt monitor)))))

(define* (marionette-screen-text marionette
                                 #:key
                                 (ocrad "ocrad"))
  "Take a screenshot of MARIONETTE, perform optical character
recognition (OCR), and return the text read from the screen as a string.  Do
this by invoking OCRAD (file name for GNU Ocrad's command)"
  (define (random-file-name)
    (string-append "/tmp/marionette-screenshot-"
                   (number->string (random (expt 2 32)) 16)
                   ".ppm"))

  (let ((image (random-file-name)))
    (dynamic-wind
      (const #t)
      (lambda ()
        (marionette-control (string-append "screendump " image)
                            marionette)

        ;; Tell Ocrad to invert the image colors (make it black on white) and
        ;; to scale the image up, which significantly improves the quality of
        ;; the result.  In spite of this, be aware that OCR confuses "y" and
        ;; "V" and sometimes erroneously introduces white space.
        (let* ((pipe (open-pipe* OPEN_READ ocrad
                                 "-i" "-s" "10" image))
               (text (get-string-all pipe)))
          (unless (zero? (close-pipe pipe))
            (error "'ocrad' failed" ocrad))
          text))
      (lambda ()
        (false-if-exception (delete-file image))))))

(define* (wait-for-screen-text marionette predicate
                               #:key (timeout 30) (ocrad "ocrad"))
  "Wait for TIMEOUT seconds or until the screen text on MARIONETTE matches
PREDICATE, whichever comes first.  Raise an error when TIMEOUT is exceeded."
  (define start
    (car (gettimeofday)))

  (define end
    (+ start timeout))

  (let loop ()
    (if (> (car (gettimeofday)) end)
        (error "'wait-for-screen-text' timeout" predicate)
        (or (predicate (marionette-screen-text marionette #:ocrad ocrad))
            (begin
              (sleep 1)
              (loop))))))

(define %qwerty-us-keystrokes
  ;; Maps "special" characters to their keystrokes.
  '((#\newline . "ret")
    (#\space . "spc")
    (#\- . "minus")
    (#\+ . "shift-equal")
    (#\* . "shift-8")
    (#\= . "equal")
    (#\? . "shift-slash")
    (#\[ . "bracket_left")
    (#\] . "bracket_right")
    (#\{ . "shift-bracket_left")
    (#\} . "shift-bracket_right")
    (#\( . "shift-9")
    (#\) . "shift-0")
    (#\/ . "slash")
    (#\< . "shift-comma")
    (#\> . "shift-dot")
    (#\. . "dot")
    (#\, . "comma")
    (#\; . "semicolon")
    (#\' . "apostrophe")
    (#\" . "shift-apostrophe")
    (#\` . "grave_accent")
    (#\bs . "backspace")
    (#\tab . "tab")))

(define (character->keystroke chr keystrokes)
  "Return the keystroke for CHR according to the keyboard layout defined by
KEYSTROKES."
  (if (char-set-contains? char-set:upper-case chr)
      (string-append "shift-" (string (char-downcase chr)))
      (or (assoc-ref keystrokes chr)
          (string chr))))

(define* (string->keystroke-commands str
                                     #:optional
                                     (keystrokes
                                      %qwerty-us-keystrokes))
  "Return a list of QEMU monitor commands to send the keystrokes corresponding
to STR.  KEYSTROKES is an alist specifying a mapping from characters to
keystrokes."
  (string-fold-right (lambda (chr result)
                       (cons (string-append
                              "sendkey "
                              (character->keystroke chr keystrokes))
                             result))
                     '()
                     str))

(define* (marionette-type str marionette
                          #:key (keystrokes %qwerty-us-keystrokes))
  "Type STR on MARIONETTE's keyboard, using the KEYSTROKES alist to map characters
to actual keystrokes."
  (for-each (cut marionette-control <> marionette)
            (string->keystroke-commands str keystrokes)))


;;;
;;; Test helper.
;;;

(define* (system-test-runner #:optional log-directory)
  "Return a SRFI-64 test runner that calls 'exit' upon 'test-end'.  When
LOG-DIRECTORY is specified, create log file within it."
  (let ((runner  (test-runner-simple)))
    ;; Log to a file under LOG-DIRECTORY.
    (test-runner-on-group-begin! runner
      (let ((on-begin (test-runner-on-group-begin runner)))
        (lambda (runner suite-name count)
          (when log-directory
            (catch 'system-error
              (lambda ()
                (mkdir log-directory))
              (lambda args
                (unless (= (system-error-errno args) EEXIST)
                  (apply throw args))))
            (set! test-log-to-file
                  (string-append log-directory "/" suite-name ".log")))
          (on-begin runner suite-name count))))

    ;; The default behavior on 'test-end' is to only write a line if the test
    ;; failed.  Arrange to also write a line on success.
    (test-runner-on-test-end! runner
      (let ((on-end (test-runner-on-test-end runner)))
        (lambda (runner)
          (let* ((kind      (test-result-ref runner 'result-kind))
                 (results   (test-result-alist runner))
                 (test-name (assq-ref results 'test-name)))
            (unless (memq kind '(fail xpass))
              (format (current-output-port) "~a: ~a~%"
                      (string-upcase (symbol->string kind))
                      test-name)))

          (on-end runner))))

    ;; On 'test-end', display test results and exit with zero if and only if
    ;; there were no test failures.
    (test-runner-on-final! runner
      (lambda (runner)
        (let ((success? (= (test-runner-fail-count runner) 0)))
          (test-on-final-simple runner)

          (when (not success?)
            (let* ((log-port (test-runner-aux-value runner))
                   (log-file (port-filename log-port)))
              (format (current-error-port)
                      "\nTests failed, dumping log file '~a'.\n\n"
                      log-file)

              ;; At this point LOG-PORT is not closed yet; flush it.
              (force-output log-port)

              ;; Brute force to avoid dependency on (guix build utils) for
              ;; 'dump-port'.
              (let ((content (call-with-input-file log-file
                               get-bytevector-all)))
                (put-bytevector (current-error-port) content))))

          (exit success?))))
    runner))

(define* (qemu-command #:optional (system %host-type))
  "Return the default name of the QEMU command for SYSTEM."
  (let ((cpu (substring system 0
                        (string-index system #\-))))
    (string-append "qemu-system-"
                   (cond
                    ((string-match "^i[3456]86$" cpu) "i386")
                    ((string-match "armhf" cpu) "arm")
                    (else cpu)))))

;;; marionette.scm ends here