xref: /qemu/scripts/qmp/qmp-shell (revision ab9056ff) 
1#!/usr/bin/python
2#
3# Low-level QEMU shell on top of QMP.
4#
5# Copyright (C) 2009, 2010 Red Hat Inc.
6#
7# Authors:
8#  Luiz Capitulino <lcapitulino@redhat.com>
9#
10# This work is licensed under the terms of the GNU GPL, version 2.  See
11# the COPYING file in the top-level directory.
12#
13# Usage:
14#
15# Start QEMU with:
16#
17# # qemu [...] -qmp unix:./qmp-sock,server
18#
19# Run the shell:
20#
21# $ qmp-shell ./qmp-sock
22#
23# Commands have the following format:
24#
25#    < command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ]
26#
27# For example:
28#
29# (QEMU) device_add driver=e1000 id=net1
30# {u'return': {}}
31# (QEMU)
32#
33# key=value pairs also support Python or JSON object literal subset notations,
34# without spaces. Dictionaries/objects {} are supported as are arrays [].
35#
36#    example-command arg-name1={'key':'value','obj'={'prop':"value"}}
37#
38# Both JSON and Python formatting should work, including both styles of
39# string literal quotes. Both paradigms of literal values should work,
40# including null/true/false for JSON and None/True/False for Python.
41#
42#
43# Transactions have the following multi-line format:
44#
45#    transaction(
46#    action-name1 [ arg-name1=arg1 ] ... [arg-nameN=argN ]
47#    ...
48#    action-nameN [ arg-name1=arg1 ] ... [arg-nameN=argN ]
49#    )
50#
51# One line transactions are also supported:
52#
53#    transaction( action-name1 ... )
54#
55# For example:
56#
57#     (QEMU) transaction(
58#     TRANS> block-dirty-bitmap-add node=drive0 name=bitmap1
59#     TRANS> block-dirty-bitmap-clear node=drive0 name=bitmap0
60#     TRANS> )
61#     {"return": {}}
62#     (QEMU)
63#
64# Use the -v and -p options to activate the verbose and pretty-print options,
65# which will echo back the properly formatted JSON-compliant QMP that is being
66# sent to QEMU, which is useful for debugging and documentation generation.
67
68from __future__ import print_function
69import json
70import ast
71import readline
72import sys
73import os
74import errno
75import atexit
76import re
77
78sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
79from qemu import qmp
80
81if sys.version_info[0] == 2:
82    input = raw_input
83
84class QMPCompleter(list):
85    def complete(self, text, state):
86        for cmd in self:
87            if cmd.startswith(text):
88                if not state:
89                    return cmd
90                else:
91                    state -= 1
92
93class QMPShellError(Exception):
94    pass
95
96class QMPShellBadPort(QMPShellError):
97    pass
98
99class FuzzyJSON(ast.NodeTransformer):
100    '''This extension of ast.NodeTransformer filters literal "true/false/null"
101    values in an AST and replaces them by proper "True/False/None" values that
102    Python can properly evaluate.'''
103    def visit_Name(self, node):
104        if node.id == 'true':
105            node.id = 'True'
106        if node.id == 'false':
107            node.id = 'False'
108        if node.id == 'null':
109            node.id = 'None'
110        return node
111
112# TODO: QMPShell's interface is a bit ugly (eg. _fill_completion() and
113#       _execute_cmd()). Let's design a better one.
114class QMPShell(qmp.QEMUMonitorProtocol):
115    def __init__(self, address, pretty=False):
116        super(QMPShell, self).__init__(self.__get_address(address))
117        self._greeting = None
118        self._completer = None
119        self._pretty = pretty
120        self._transmode = False
121        self._actions = list()
122        self._histfile = os.path.join(os.path.expanduser('~'),
123                                      '.qmp-shell_history')
124
125    def __get_address(self, arg):
126        """
127        Figure out if the argument is in the port:host form, if it's not it's
128        probably a file path.
129        """
130        addr = arg.split(':')
131        if len(addr) == 2:
132            try:
133                port = int(addr[1])
134            except ValueError:
135                raise QMPShellBadPort
136            return ( addr[0], port )
137        # socket path
138        return arg
139
140    def _fill_completion(self):
141        cmds = self.cmd('query-commands')
142        if 'error' in cmds:
143            return
144        for cmd in cmds['return']:
145            self._completer.append(cmd['name'])
146
147    def __completer_setup(self):
148        self._completer = QMPCompleter()
149        self._fill_completion()
150        readline.set_history_length(1024)
151        readline.set_completer(self._completer.complete)
152        readline.parse_and_bind("tab: complete")
153        # XXX: default delimiters conflict with some command names (eg. query-),
154        # clearing everything as it doesn't seem to matter
155        readline.set_completer_delims('')
156        try:
157            readline.read_history_file(self._histfile)
158        except Exception as e:
159            if isinstance(e, IOError) and e.errno == errno.ENOENT:
160                # File not found. No problem.
161                pass
162            else:
163                print("Failed to read history '%s'; %s" % (self._histfile, e))
164        atexit.register(self.__save_history)
165
166    def __save_history(self):
167        try:
168            readline.write_history_file(self._histfile)
169        except Exception as e:
170            print("Failed to save history file '%s'; %s" % (self._histfile, e))
171
172    def __parse_value(self, val):
173        try:
174            return int(val)
175        except ValueError:
176            pass
177
178        if val.lower() == 'true':
179            return True
180        if val.lower() == 'false':
181            return False
182        if val.startswith(('{', '[')):
183            # Try first as pure JSON:
184            try:
185                return json.loads(val)
186            except ValueError:
187                pass
188            # Try once again as FuzzyJSON:
189            try:
190                st = ast.parse(val, mode='eval')
191                return ast.literal_eval(FuzzyJSON().visit(st))
192            except SyntaxError:
193                pass
194            except ValueError:
195                pass
196        return val
197
198    def __cli_expr(self, tokens, parent):
199        for arg in tokens:
200            (key, sep, val) = arg.partition('=')
201            if sep != '=':
202                raise QMPShellError("Expected a key=value pair, got '%s'" % arg)
203
204            value = self.__parse_value(val)
205            optpath = key.split('.')
206            curpath = []
207            for p in optpath[:-1]:
208                curpath.append(p)
209                d = parent.get(p, {})
210                if type(d) is not dict:
211                    raise QMPShellError('Cannot use "%s" as both leaf and non-leaf key' % '.'.join(curpath))
212                parent[p] = d
213                parent = d
214            if optpath[-1] in parent:
215                if type(parent[optpath[-1]]) is dict:
216                    raise QMPShellError('Cannot use "%s" as both leaf and non-leaf key' % '.'.join(curpath))
217                else:
218                    raise QMPShellError('Cannot set "%s" multiple times' % key)
219            parent[optpath[-1]] = value
220
221    def __build_cmd(self, cmdline):
222        """
223        Build a QMP input object from a user provided command-line in the
224        following format:
225
226            < command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ]
227        """
228        cmdargs = re.findall(r'''(?:[^\s"']|"(?:\\.|[^"])*"|'(?:\\.|[^'])*')+''', cmdline)
229
230        # Transactional CLI entry/exit:
231        if cmdargs[0] == 'transaction(':
232            self._transmode = True
233            cmdargs.pop(0)
234        elif cmdargs[0] == ')' and self._transmode:
235            self._transmode = False
236            if len(cmdargs) > 1:
237                raise QMPShellError("Unexpected input after close of Transaction sub-shell")
238            qmpcmd = { 'execute': 'transaction',
239                       'arguments': { 'actions': self._actions } }
240            self._actions = list()
241            return qmpcmd
242
243        # Nothing to process?
244        if not cmdargs:
245            return None
246
247        # Parse and then cache this Transactional Action
248        if self._transmode:
249            finalize = False
250            action = { 'type': cmdargs[0], 'data': {} }
251            if cmdargs[-1] == ')':
252                cmdargs.pop(-1)
253                finalize = True
254            self.__cli_expr(cmdargs[1:], action['data'])
255            self._actions.append(action)
256            return self.__build_cmd(')') if finalize else None
257
258        # Standard command: parse and return it to be executed.
259        qmpcmd = { 'execute': cmdargs[0], 'arguments': {} }
260        self.__cli_expr(cmdargs[1:], qmpcmd['arguments'])
261        return qmpcmd
262
263    def _print(self, qmp):
264        indent = None
265        if self._pretty:
266            indent = 4
267        jsobj = json.dumps(qmp, indent=indent)
268        print(str(jsobj))
269
270    def _execute_cmd(self, cmdline):
271        try:
272            qmpcmd = self.__build_cmd(cmdline)
273        except Exception as e:
274            print('Error while parsing command line: %s' % e)
275            print('command format: <command-name> ', end=' ')
276            print('[arg-name1=arg1] ... [arg-nameN=argN]')
277            return True
278        # For transaction mode, we may have just cached the action:
279        if qmpcmd is None:
280            return True
281        if self._verbose:
282            self._print(qmpcmd)
283        resp = self.cmd_obj(qmpcmd)
284        if resp is None:
285            print('Disconnected')
286            return False
287        self._print(resp)
288        return True
289
290    def connect(self, negotiate):
291        self._greeting = super(QMPShell, self).connect(negotiate)
292        self.__completer_setup()
293
294    def show_banner(self, msg='Welcome to the QMP low-level shell!'):
295        print(msg)
296        if not self._greeting:
297            print('Connected')
298            return
299        version = self._greeting['QMP']['version']['qemu']
300        print('Connected to QEMU %d.%d.%d\n' % (version['major'],version['minor'],version['micro']))
301
302    def get_prompt(self):
303        if self._transmode:
304            return "TRANS> "
305        return "(QEMU) "
306
307    def read_exec_command(self, prompt):
308        """
309        Read and execute a command.
310
311        @return True if execution was ok, return False if disconnected.
312        """
313        try:
314            cmdline = input(prompt)
315        except EOFError:
316            print()
317            return False
318        if cmdline == '':
319            for ev in self.get_events():
320                print(ev)
321            self.clear_events()
322            return True
323        else:
324            return self._execute_cmd(cmdline)
325
326    def set_verbosity(self, verbose):
327        self._verbose = verbose
328
329class HMPShell(QMPShell):
330    def __init__(self, address):
331        QMPShell.__init__(self, address)
332        self.__cpu_index = 0
333
334    def __cmd_completion(self):
335        for cmd in self.__cmd_passthrough('help')['return'].split('\r\n'):
336            if cmd and cmd[0] != '[' and cmd[0] != '\t':
337                name = cmd.split()[0] # drop help text
338                if name == 'info':
339                    continue
340                if name.find('|') != -1:
341                    # Command in the form 'foobar|f' or 'f|foobar', take the
342                    # full name
343                    opt = name.split('|')
344                    if len(opt[0]) == 1:
345                        name = opt[1]
346                    else:
347                        name = opt[0]
348                self._completer.append(name)
349                self._completer.append('help ' + name) # help completion
350
351    def __info_completion(self):
352        for cmd in self.__cmd_passthrough('info')['return'].split('\r\n'):
353            if cmd:
354                self._completer.append('info ' + cmd.split()[1])
355
356    def __other_completion(self):
357        # special cases
358        self._completer.append('help info')
359
360    def _fill_completion(self):
361        self.__cmd_completion()
362        self.__info_completion()
363        self.__other_completion()
364
365    def __cmd_passthrough(self, cmdline, cpu_index = 0):
366        return self.cmd_obj({ 'execute': 'human-monitor-command', 'arguments':
367                              { 'command-line': cmdline,
368                                'cpu-index': cpu_index } })
369
370    def _execute_cmd(self, cmdline):
371        if cmdline.split()[0] == "cpu":
372            # trap the cpu command, it requires special setting
373            try:
374                idx = int(cmdline.split()[1])
375                if not 'return' in self.__cmd_passthrough('info version', idx):
376                    print('bad CPU index')
377                    return True
378                self.__cpu_index = idx
379            except ValueError:
380                print('cpu command takes an integer argument')
381                return True
382        resp = self.__cmd_passthrough(cmdline, self.__cpu_index)
383        if resp is None:
384            print('Disconnected')
385            return False
386        assert 'return' in resp or 'error' in resp
387        if 'return' in resp:
388            # Success
389            if len(resp['return']) > 0:
390                print(resp['return'], end=' ')
391        else:
392            # Error
393            print('%s: %s' % (resp['error']['class'], resp['error']['desc']))
394        return True
395
396    def show_banner(self):
397        QMPShell.show_banner(self, msg='Welcome to the HMP shell!')
398
399def die(msg):
400    sys.stderr.write('ERROR: %s\n' % msg)
401    sys.exit(1)
402
403def fail_cmdline(option=None):
404    if option:
405        sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
406    sys.stderr.write('qmp-shell [ -v ] [ -p ] [ -H ] [ -N ] < UNIX socket path> | < TCP address:port >\n')
407    sys.stderr.write('    -v     Verbose (echo command sent and received)\n')
408    sys.stderr.write('    -p     Pretty-print JSON\n')
409    sys.stderr.write('    -H     Use HMP interface\n')
410    sys.stderr.write('    -N     Skip negotiate (for qemu-ga)\n')
411    sys.exit(1)
412
413def main():
414    addr = ''
415    qemu = None
416    hmp = False
417    pretty = False
418    verbose = False
419    negotiate = True
420
421    try:
422        for arg in sys.argv[1:]:
423            if arg == "-H":
424                if qemu is not None:
425                    fail_cmdline(arg)
426                hmp = True
427            elif arg == "-p":
428                pretty = True
429            elif arg == "-N":
430                negotiate = False
431            elif arg == "-v":
432                verbose = True
433            else:
434                if qemu is not None:
435                    fail_cmdline(arg)
436                if hmp:
437                    qemu = HMPShell(arg)
438                else:
439                    qemu = QMPShell(arg, pretty)
440                addr = arg
441
442        if qemu is None:
443            fail_cmdline()
444    except QMPShellBadPort:
445        die('bad port number in command-line')
446
447    try:
448        qemu.connect(negotiate)
449    except qmp.QMPConnectError:
450        die('Didn\'t get QMP greeting message')
451    except qmp.QMPCapabilitiesError:
452        die('Could not negotiate capabilities')
453    except qemu.error:
454        die('Could not connect to %s' % addr)
455
456    qemu.show_banner()
457    qemu.set_verbosity(verbose)
458    while qemu.read_exec_command(qemu.get_prompt()):
459        pass
460    qemu.close()
461
462if __name__ == '__main__':
463    main()
464