xref: /openbmc/qemu/scripts/qmp/qmp-shell (revision 587adaca) 
1#!/usr/bin/env python3
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
68import json
69import ast
70import readline
71import sys
72import os
73import errno
74import atexit
75import re
76
77sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
78from qemu import qmp
79
80class QMPCompleter(list):
81    def complete(self, text, state):
82        for cmd in self:
83            if cmd.startswith(text):
84                if not state:
85                    return cmd
86                else:
87                    state -= 1
88
89class QMPShellError(Exception):
90    pass
91
92
93class FuzzyJSON(ast.NodeTransformer):
94    '''This extension of ast.NodeTransformer filters literal "true/false/null"
95    values in an AST and replaces them by proper "True/False/None" values that
96    Python can properly evaluate.'''
97    def visit_Name(self, node):
98        if node.id == 'true':
99            node.id = 'True'
100        if node.id == 'false':
101            node.id = 'False'
102        if node.id == 'null':
103            node.id = 'None'
104        return node
105
106# TODO: QMPShell's interface is a bit ugly (eg. _fill_completion() and
107#       _execute_cmd()). Let's design a better one.
108class QMPShell(qmp.QEMUMonitorProtocol):
109    def __init__(self, address, pretty=False):
110        super(QMPShell, self).__init__(self.parse_address(address))
111        self._greeting = None
112        self._completer = None
113        self._pretty = pretty
114        self._transmode = False
115        self._actions = list()
116        self._histfile = os.path.join(os.path.expanduser('~'),
117                                      '.qmp-shell_history')
118
119    def _fill_completion(self):
120        cmds = self.cmd('query-commands')
121        if 'error' in cmds:
122            return
123        for cmd in cmds['return']:
124            self._completer.append(cmd['name'])
125
126    def __completer_setup(self):
127        self._completer = QMPCompleter()
128        self._fill_completion()
129        readline.set_history_length(1024)
130        readline.set_completer(self._completer.complete)
131        readline.parse_and_bind("tab: complete")
132        # XXX: default delimiters conflict with some command names (eg. query-),
133        # clearing everything as it doesn't seem to matter
134        readline.set_completer_delims('')
135        try:
136            readline.read_history_file(self._histfile)
137        except Exception as e:
138            if isinstance(e, IOError) and e.errno == errno.ENOENT:
139                # File not found. No problem.
140                pass
141            else:
142                print("Failed to read history '%s'; %s" % (self._histfile, e))
143        atexit.register(self.__save_history)
144
145    def __save_history(self):
146        try:
147            readline.write_history_file(self._histfile)
148        except Exception as e:
149            print("Failed to save history file '%s'; %s" % (self._histfile, e))
150
151    def __parse_value(self, val):
152        try:
153            return int(val)
154        except ValueError:
155            pass
156
157        if val.lower() == 'true':
158            return True
159        if val.lower() == 'false':
160            return False
161        if val.startswith(('{', '[')):
162            # Try first as pure JSON:
163            try:
164                return json.loads(val)
165            except ValueError:
166                pass
167            # Try once again as FuzzyJSON:
168            try:
169                st = ast.parse(val, mode='eval')
170                return ast.literal_eval(FuzzyJSON().visit(st))
171            except SyntaxError:
172                pass
173            except ValueError:
174                pass
175        return val
176
177    def __cli_expr(self, tokens, parent):
178        for arg in tokens:
179            (key, sep, val) = arg.partition('=')
180            if sep != '=':
181                raise QMPShellError("Expected a key=value pair, got '%s'" % arg)
182
183            value = self.__parse_value(val)
184            optpath = key.split('.')
185            curpath = []
186            for p in optpath[:-1]:
187                curpath.append(p)
188                d = parent.get(p, {})
189                if type(d) is not dict:
190                    raise QMPShellError('Cannot use "%s" as both leaf and non-leaf key' % '.'.join(curpath))
191                parent[p] = d
192                parent = d
193            if optpath[-1] in parent:
194                if type(parent[optpath[-1]]) is dict:
195                    raise QMPShellError('Cannot use "%s" as both leaf and non-leaf key' % '.'.join(curpath))
196                else:
197                    raise QMPShellError('Cannot set "%s" multiple times' % key)
198            parent[optpath[-1]] = value
199
200    def __build_cmd(self, cmdline):
201        """
202        Build a QMP input object from a user provided command-line in the
203        following format:
204
205            < command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ]
206        """
207        cmdargs = re.findall(r'''(?:[^\s"']|"(?:\\.|[^"])*"|'(?:\\.|[^'])*')+''', cmdline)
208
209        # Transactional CLI entry/exit:
210        if cmdargs[0] == 'transaction(':
211            self._transmode = True
212            cmdargs.pop(0)
213        elif cmdargs[0] == ')' and self._transmode:
214            self._transmode = False
215            if len(cmdargs) > 1:
216                raise QMPShellError("Unexpected input after close of Transaction sub-shell")
217            qmpcmd = { 'execute': 'transaction',
218                       'arguments': { 'actions': self._actions } }
219            self._actions = list()
220            return qmpcmd
221
222        # Nothing to process?
223        if not cmdargs:
224            return None
225
226        # Parse and then cache this Transactional Action
227        if self._transmode:
228            finalize = False
229            action = { 'type': cmdargs[0], 'data': {} }
230            if cmdargs[-1] == ')':
231                cmdargs.pop(-1)
232                finalize = True
233            self.__cli_expr(cmdargs[1:], action['data'])
234            self._actions.append(action)
235            return self.__build_cmd(')') if finalize else None
236
237        # Standard command: parse and return it to be executed.
238        qmpcmd = { 'execute': cmdargs[0], 'arguments': {} }
239        self.__cli_expr(cmdargs[1:], qmpcmd['arguments'])
240        return qmpcmd
241
242    def _print(self, qmp):
243        indent = None
244        if self._pretty:
245            indent = 4
246        jsobj = json.dumps(qmp, indent=indent, sort_keys=self._pretty)
247        print(str(jsobj))
248
249    def _execute_cmd(self, cmdline):
250        try:
251            qmpcmd = self.__build_cmd(cmdline)
252        except Exception as e:
253            print('Error while parsing command line: %s' % e)
254            print('command format: <command-name> ', end=' ')
255            print('[arg-name1=arg1] ... [arg-nameN=argN]')
256            return True
257        # For transaction mode, we may have just cached the action:
258        if qmpcmd is None:
259            return True
260        if self._verbose:
261            self._print(qmpcmd)
262        resp = self.cmd_obj(qmpcmd)
263        if resp is None:
264            print('Disconnected')
265            return False
266        self._print(resp)
267        return True
268
269    def connect(self, negotiate):
270        self._greeting = super(QMPShell, self).connect(negotiate)
271        self.__completer_setup()
272
273    def show_banner(self, msg='Welcome to the QMP low-level shell!'):
274        print(msg)
275        if not self._greeting:
276            print('Connected')
277            return
278        version = self._greeting['QMP']['version']['qemu']
279        print('Connected to QEMU %d.%d.%d\n' % (version['major'],version['minor'],version['micro']))
280
281    def get_prompt(self):
282        if self._transmode:
283            return "TRANS> "
284        return "(QEMU) "
285
286    def read_exec_command(self, prompt):
287        """
288        Read and execute a command.
289
290        @return True if execution was ok, return False if disconnected.
291        """
292        try:
293            cmdline = input(prompt)
294        except EOFError:
295            print()
296            return False
297        if cmdline == '':
298            for ev in self.get_events():
299                print(ev)
300            self.clear_events()
301            return True
302        else:
303            return self._execute_cmd(cmdline)
304
305    def set_verbosity(self, verbose):
306        self._verbose = verbose
307
308class HMPShell(QMPShell):
309    def __init__(self, address):
310        QMPShell.__init__(self, address)
311        self.__cpu_index = 0
312
313    def __cmd_completion(self):
314        for cmd in self.__cmd_passthrough('help')['return'].split('\r\n'):
315            if cmd and cmd[0] != '[' and cmd[0] != '\t':
316                name = cmd.split()[0] # drop help text
317                if name == 'info':
318                    continue
319                if name.find('|') != -1:
320                    # Command in the form 'foobar|f' or 'f|foobar', take the
321                    # full name
322                    opt = name.split('|')
323                    if len(opt[0]) == 1:
324                        name = opt[1]
325                    else:
326                        name = opt[0]
327                self._completer.append(name)
328                self._completer.append('help ' + name) # help completion
329
330    def __info_completion(self):
331        for cmd in self.__cmd_passthrough('info')['return'].split('\r\n'):
332            if cmd:
333                self._completer.append('info ' + cmd.split()[1])
334
335    def __other_completion(self):
336        # special cases
337        self._completer.append('help info')
338
339    def _fill_completion(self):
340        self.__cmd_completion()
341        self.__info_completion()
342        self.__other_completion()
343
344    def __cmd_passthrough(self, cmdline, cpu_index = 0):
345        return self.cmd_obj({ 'execute': 'human-monitor-command', 'arguments':
346                              { 'command-line': cmdline,
347                                'cpu-index': cpu_index } })
348
349    def _execute_cmd(self, cmdline):
350        if cmdline.split()[0] == "cpu":
351            # trap the cpu command, it requires special setting
352            try:
353                idx = int(cmdline.split()[1])
354                if not 'return' in self.__cmd_passthrough('info version', idx):
355                    print('bad CPU index')
356                    return True
357                self.__cpu_index = idx
358            except ValueError:
359                print('cpu command takes an integer argument')
360                return True
361        resp = self.__cmd_passthrough(cmdline, self.__cpu_index)
362        if resp is None:
363            print('Disconnected')
364            return False
365        assert 'return' in resp or 'error' in resp
366        if 'return' in resp:
367            # Success
368            if len(resp['return']) > 0:
369                print(resp['return'], end=' ')
370        else:
371            # Error
372            print('%s: %s' % (resp['error']['class'], resp['error']['desc']))
373        return True
374
375    def show_banner(self):
376        QMPShell.show_banner(self, msg='Welcome to the HMP shell!')
377
378def die(msg):
379    sys.stderr.write('ERROR: %s\n' % msg)
380    sys.exit(1)
381
382def fail_cmdline(option=None):
383    if option:
384        sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
385    sys.stderr.write('qmp-shell [ -v ] [ -p ] [ -H ] [ -N ] < UNIX socket path> | < TCP address:port >\n')
386    sys.stderr.write('    -v     Verbose (echo command sent and received)\n')
387    sys.stderr.write('    -p     Pretty-print JSON\n')
388    sys.stderr.write('    -H     Use HMP interface\n')
389    sys.stderr.write('    -N     Skip negotiate (for qemu-ga)\n')
390    sys.exit(1)
391
392def main():
393    addr = ''
394    qemu = None
395    hmp = False
396    pretty = False
397    verbose = False
398    negotiate = True
399
400    try:
401        for arg in sys.argv[1:]:
402            if arg == "-H":
403                if qemu is not None:
404                    fail_cmdline(arg)
405                hmp = True
406            elif arg == "-p":
407                pretty = True
408            elif arg == "-N":
409                negotiate = False
410            elif arg == "-v":
411                verbose = True
412            else:
413                if qemu is not None:
414                    fail_cmdline(arg)
415                if hmp:
416                    qemu = HMPShell(arg)
417                else:
418                    qemu = QMPShell(arg, pretty)
419                addr = arg
420
421        if qemu is None:
422            fail_cmdline()
423    except qmp.QMPBadPortError:
424        die('bad port number in command-line')
425
426    try:
427        qemu.connect(negotiate)
428    except qmp.QMPConnectError:
429        die('Didn\'t get QMP greeting message')
430    except qmp.QMPCapabilitiesError:
431        die('Could not negotiate capabilities')
432    except qemu.error:
433        die('Could not connect to %s' % addr)
434
435    qemu.show_banner()
436    qemu.set_verbosity(verbose)
437    while qemu.read_exec_command(qemu.get_prompt()):
438        pass
439    qemu.close()
440
441if __name__ == '__main__':
442    main()
443