xref: /qemu/scripts/qmp/qmp-shell (revision a8260d38) 
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 qmp
70import json
71import ast
72import readline
73import sys
74import os
75import errno
76import atexit
77import shlex
78
79class QMPCompleter(list):
80    def complete(self, text, state):
81        for cmd in self:
82            if cmd.startswith(text):
83                if not state:
84                    return cmd
85                else:
86                    state -= 1
87
88class QMPShellError(Exception):
89    pass
90
91class QMPShellBadPort(QMPShellError):
92    pass
93
94class FuzzyJSON(ast.NodeTransformer):
95    '''This extension of ast.NodeTransformer filters literal "true/false/null"
96    values in an AST and replaces them by proper "True/False/None" values that
97    Python can properly evaluate.'''
98    def visit_Name(self, node):
99        if node.id == 'true':
100            node.id = 'True'
101        if node.id == 'false':
102            node.id = 'False'
103        if node.id == 'null':
104            node.id = 'None'
105        return node
106
107# TODO: QMPShell's interface is a bit ugly (eg. _fill_completion() and
108#       _execute_cmd()). Let's design a better one.
109class QMPShell(qmp.QEMUMonitorProtocol):
110    def __init__(self, address, pretty=False):
111        super(QMPShell, self).__init__(self.__get_address(address))
112        self._greeting = None
113        self._completer = None
114        self._pretty = pretty
115        self._transmode = False
116        self._actions = list()
117        self._histfile = os.path.join(os.path.expanduser('~'),
118                                      '.qmp-shell_history')
119
120    def __get_address(self, arg):
121        """
122        Figure out if the argument is in the port:host form, if it's not it's
123        probably a file path.
124        """
125        addr = arg.split(':')
126        if len(addr) == 2:
127            try:
128                port = int(addr[1])
129            except ValueError:
130                raise QMPShellBadPort
131            return ( addr[0], port )
132        # socket path
133        return arg
134
135    def _fill_completion(self):
136        cmds = self.cmd('query-commands')
137        if 'error' in cmds:
138            return
139        for cmd in cmds['return']:
140            self._completer.append(cmd['name'])
141
142    def __completer_setup(self):
143        self._completer = QMPCompleter()
144        self._fill_completion()
145        readline.set_history_length(1024)
146        readline.set_completer(self._completer.complete)
147        readline.parse_and_bind("tab: complete")
148        # XXX: default delimiters conflict with some command names (eg. query-),
149        # clearing everything as it doesn't seem to matter
150        readline.set_completer_delims('')
151        try:
152            readline.read_history_file(self._histfile)
153        except Exception as e:
154            if isinstance(e, IOError) and e.errno == errno.ENOENT:
155                # File not found. No problem.
156                pass
157            else:
158                print("Failed to read history '%s'; %s" % (self._histfile, e))
159        atexit.register(self.__save_history)
160
161    def __save_history(self):
162        try:
163            readline.write_history_file(self._histfile)
164        except Exception as e:
165            print("Failed to save history file '%s'; %s" % (self._histfile, e))
166
167    def __parse_value(self, val):
168        try:
169            return int(val)
170        except ValueError:
171            pass
172
173        if val.lower() == 'true':
174            return True
175        if val.lower() == 'false':
176            return False
177        if val.startswith(('{', '[')):
178            # Try first as pure JSON:
179            try:
180                return json.loads(val)
181            except ValueError:
182                pass
183            # Try once again as FuzzyJSON:
184            try:
185                st = ast.parse(val, mode='eval')
186                return ast.literal_eval(FuzzyJSON().visit(st))
187            except SyntaxError:
188                pass
189            except ValueError:
190                pass
191        return val
192
193    def __cli_expr(self, tokens, parent):
194        for arg in tokens:
195            (key, sep, val) = arg.partition('=')
196            if sep != '=':
197                raise QMPShellError("Expected a key=value pair, got '%s'" % arg)
198
199            value = self.__parse_value(val)
200            optpath = key.split('.')
201            curpath = []
202            for p in optpath[:-1]:
203                curpath.append(p)
204                d = parent.get(p, {})
205                if type(d) is not dict:
206                    raise QMPShellError('Cannot use "%s" as both leaf and non-leaf key' % '.'.join(curpath))
207                parent[p] = d
208                parent = d
209            if optpath[-1] in parent:
210                if type(parent[optpath[-1]]) is dict:
211                    raise QMPShellError('Cannot use "%s" as both leaf and non-leaf key' % '.'.join(curpath))
212                else:
213                    raise QMPShellError('Cannot set "%s" multiple times' % key)
214            parent[optpath[-1]] = value
215
216    def __build_cmd(self, cmdline):
217        """
218        Build a QMP input object from a user provided command-line in the
219        following format:
220
221            < command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ]
222        """
223        cmdargs = shlex.split(cmdline)
224
225        # Transactional CLI entry/exit:
226        if cmdargs[0] == 'transaction(':
227            self._transmode = True
228            cmdargs.pop(0)
229        elif cmdargs[0] == ')' and self._transmode:
230            self._transmode = False
231            if len(cmdargs) > 1:
232                raise QMPShellError("Unexpected input after close of Transaction sub-shell")
233            qmpcmd = { 'execute': 'transaction',
234                       'arguments': { 'actions': self._actions } }
235            self._actions = list()
236            return qmpcmd
237
238        # Nothing to process?
239        if not cmdargs:
240            return None
241
242        # Parse and then cache this Transactional Action
243        if self._transmode:
244            finalize = False
245            action = { 'type': cmdargs[0], 'data': {} }
246            if cmdargs[-1] == ')':
247                cmdargs.pop(-1)
248                finalize = True
249            self.__cli_expr(cmdargs[1:], action['data'])
250            self._actions.append(action)
251            return self.__build_cmd(')') if finalize else None
252
253        # Standard command: parse and return it to be executed.
254        qmpcmd = { 'execute': cmdargs[0], 'arguments': {} }
255        self.__cli_expr(cmdargs[1:], qmpcmd['arguments'])
256        return qmpcmd
257
258    def _print(self, qmp):
259        indent = None
260        if self._pretty:
261            indent = 4
262        jsobj = json.dumps(qmp, indent=indent)
263        print(str(jsobj))
264
265    def _execute_cmd(self, cmdline):
266        try:
267            qmpcmd = self.__build_cmd(cmdline)
268        except Exception as e:
269            print('Error while parsing command line: %s' % e)
270            print('command format: <command-name> ', end=' ')
271            print('[arg-name1=arg1] ... [arg-nameN=argN]')
272            return True
273        # For transaction mode, we may have just cached the action:
274        if qmpcmd is None:
275            return True
276        if self._verbose:
277            self._print(qmpcmd)
278        resp = self.cmd_obj(qmpcmd)
279        if resp is None:
280            print('Disconnected')
281            return False
282        self._print(resp)
283        return True
284
285    def connect(self, negotiate):
286        self._greeting = super(QMPShell, self).connect(negotiate)
287        self.__completer_setup()
288
289    def show_banner(self, msg='Welcome to the QMP low-level shell!'):
290        print(msg)
291        if not self._greeting:
292            print('Connected')
293            return
294        version = self._greeting['QMP']['version']['qemu']
295        print('Connected to QEMU %d.%d.%d\n' % (version['major'],version['minor'],version['micro']))
296
297    def get_prompt(self):
298        if self._transmode:
299            return "TRANS> "
300        return "(QEMU) "
301
302    def read_exec_command(self, prompt):
303        """
304        Read and execute a command.
305
306        @return True if execution was ok, return False if disconnected.
307        """
308        try:
309            cmdline = raw_input(prompt)
310        except EOFError:
311            print()
312            return False
313        if cmdline == '':
314            for ev in self.get_events():
315                print(ev)
316            self.clear_events()
317            return True
318        else:
319            return self._execute_cmd(cmdline)
320
321    def set_verbosity(self, verbose):
322        self._verbose = verbose
323
324class HMPShell(QMPShell):
325    def __init__(self, address):
326        QMPShell.__init__(self, address)
327        self.__cpu_index = 0
328
329    def __cmd_completion(self):
330        for cmd in self.__cmd_passthrough('help')['return'].split('\r\n'):
331            if cmd and cmd[0] != '[' and cmd[0] != '\t':
332                name = cmd.split()[0] # drop help text
333                if name == 'info':
334                    continue
335                if name.find('|') != -1:
336                    # Command in the form 'foobar|f' or 'f|foobar', take the
337                    # full name
338                    opt = name.split('|')
339                    if len(opt[0]) == 1:
340                        name = opt[1]
341                    else:
342                        name = opt[0]
343                self._completer.append(name)
344                self._completer.append('help ' + name) # help completion
345
346    def __info_completion(self):
347        for cmd in self.__cmd_passthrough('info')['return'].split('\r\n'):
348            if cmd:
349                self._completer.append('info ' + cmd.split()[1])
350
351    def __other_completion(self):
352        # special cases
353        self._completer.append('help info')
354
355    def _fill_completion(self):
356        self.__cmd_completion()
357        self.__info_completion()
358        self.__other_completion()
359
360    def __cmd_passthrough(self, cmdline, cpu_index = 0):
361        return self.cmd_obj({ 'execute': 'human-monitor-command', 'arguments':
362                              { 'command-line': cmdline,
363                                'cpu-index': cpu_index } })
364
365    def _execute_cmd(self, cmdline):
366        if cmdline.split()[0] == "cpu":
367            # trap the cpu command, it requires special setting
368            try:
369                idx = int(cmdline.split()[1])
370                if not 'return' in self.__cmd_passthrough('info version', idx):
371                    print('bad CPU index')
372                    return True
373                self.__cpu_index = idx
374            except ValueError:
375                print('cpu command takes an integer argument')
376                return True
377        resp = self.__cmd_passthrough(cmdline, self.__cpu_index)
378        if resp is None:
379            print('Disconnected')
380            return False
381        assert 'return' in resp or 'error' in resp
382        if 'return' in resp:
383            # Success
384            if len(resp['return']) > 0:
385                print(resp['return'], end=' ')
386        else:
387            # Error
388            print('%s: %s' % (resp['error']['class'], resp['error']['desc']))
389        return True
390
391    def show_banner(self):
392        QMPShell.show_banner(self, msg='Welcome to the HMP shell!')
393
394def die(msg):
395    sys.stderr.write('ERROR: %s\n' % msg)
396    sys.exit(1)
397
398def fail_cmdline(option=None):
399    if option:
400        sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
401    sys.stderr.write('qmp-shell [ -v ] [ -p ] [ -H ] [ -N ] < UNIX socket path> | < TCP address:port >\n')
402    sys.stderr.write('    -v     Verbose (echo command sent and received)\n')
403    sys.stderr.write('    -p     Pretty-print JSON\n')
404    sys.stderr.write('    -H     Use HMP interface\n')
405    sys.stderr.write('    -N     Skip negotiate (for qemu-ga)\n')
406    sys.exit(1)
407
408def main():
409    addr = ''
410    qemu = None
411    hmp = False
412    pretty = False
413    verbose = False
414    negotiate = True
415
416    try:
417        for arg in sys.argv[1:]:
418            if arg == "-H":
419                if qemu is not None:
420                    fail_cmdline(arg)
421                hmp = True
422            elif arg == "-p":
423                pretty = True
424            elif arg == "-N":
425                negotiate = False
426            elif arg == "-v":
427                verbose = True
428            else:
429                if qemu is not None:
430                    fail_cmdline(arg)
431                if hmp:
432                    qemu = HMPShell(arg)
433                else:
434                    qemu = QMPShell(arg, pretty)
435                addr = arg
436
437        if qemu is None:
438            fail_cmdline()
439    except QMPShellBadPort:
440        die('bad port number in command-line')
441
442    try:
443        qemu.connect(negotiate)
444    except qmp.QMPConnectError:
445        die('Didn\'t get QMP greeting message')
446    except qmp.QMPCapabilitiesError:
447        die('Could not negotiate capabilities')
448    except qemu.error:
449        die('Could not connect to %s' % addr)
450
451    qemu.show_banner()
452    qemu.set_verbosity(verbose)
453    while qemu.read_exec_command(qemu.get_prompt()):
454        pass
455    qemu.close()
456
457if __name__ == '__main__':
458    main()
459