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Diffstat (limited to 'gnu/build/marionette.scm')
| -rw-r--r-- | gnu/build/marionette.scm | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/gnu/build/marionette.scm b/gnu/build/marionette.scm new file mode 100644 index 0000000000..9399c55313 --- /dev/null +++ b/gnu/build/marionette.scm @@ -0,0 +1,206 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2016 Ludovic Courtès <ludo@gnu.org> +;;; +;;; 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 (rnrs io ports) + #:use-module (ice-9 match) + #:export (marionette? + make-marionette + marionette-eval + marionette-control + %qwerty-us-keystrokes + marionette-type)) + +;;; 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)) ;port + +(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") + "-device" "virtio-serial" + "-device" "virtconsole,chardev=repl")) + + (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) + (sigaction SIGALRM + (lambda (signum) + (display "time is up!\n") ;FIXME: break + #t)) + (alarm timeout) + + (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") + (match (accept repl) + ((repl-conn . addr) + (display "connected to guest REPL\n") + (close-port repl) + (match (read repl-conn) + ('ready + (alarm 0) + (sigaction SIGALRM SIG_DFL) + (display "marionette is ready\n") + (marionette (append command extra-options) pid + monitor-conn repl-conn))))))))))) + +(define (marionette-eval exp marionette) + "Evaluate EXP in MARIONETTE's backdoor REPL. Return the result." + (match marionette + (($ <marionette> command pid monitor repl) + (write exp repl) + (newline repl) + (read repl)))) + +(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-doc) +pcsys_monitor\")." + (match marionette + (($ <marionette> _ _ monitor) + (display command monitor) + (newline monitor) + (wait-for-monitor-prompt monitor)))) + +(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") + (#\( . "shift-9") + (#\) . "shift-0") + (#\/ . "slash") + (#\< . "less") + (#\> . "shift-less") + (#\. . "dot") + (#\, . "comma") + (#\; . "semicolon") + (#\bs . "backspace") + (#\tab . "tab"))) + +(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 " + (or (assoc-ref keystrokes chr) + (string chr))) + 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))) + +;;; marionette.scm ends here |