xref: /openbmc/qemu/scripts/qmp/qmp-shell (revision 5964ed56) 
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
80if sys.version_info[0] == 2:
81    input = raw_input
82
83class QMPCompleter(list):
84    def complete(self, text, state):
85        for cmd in self:
86            if cmd.startswith(text):
87                if not state:
88                    return cmd
89                else:
90                    state -= 1
91
92class QMPShellError(Exception):
93    pass
94
95class QMPShellBadPort(QMPShellError):
96    pass
97
98class FuzzyJSON(ast.NodeTransformer):
99    '''This extension of ast.NodeTransformer filters literal "true/false/null"
100    values in an AST and replaces them by proper "True/False/None" values that
101    Python can properly evaluate.'''
102    def visit_Name(self, node):
103        if node.id == 'true':
104            node.id = 'True'
105        if node.id == 'false':
106            node.id = 'False'
107        if node.id == 'null':
108            node.id = 'None'
109        return node
110
111# TODO: QMPShell's interface is a bit ugly (eg. _fill_completion() and
112#       _execute_cmd()). Let's design a better one.
113class QMPShell(qmp.QEMUMonitorProtocol):
114    def __init__(self, address, pretty=False):
115        super(QMPShell, self).__init__(self.__get_address(address))
116        self._greeting = None
117        self._completer = None
118        self._pretty = pretty
119        self._transmode = False
120        self._actions = list()
121        self._histfile = os.path.join(os.path.expanduser('~'),
122                                      '.qmp-shell_history')
123
124    def __get_address(self, arg):
125        """
126        Figure out if the argument is in the port:host form, if it's not it's
127        probably a file path.
128        """
129        addr = arg.split(':')
130        if len(addr) == 2:
131            try:
132                port = int(addr[1])
133            except ValueError:
134                raise QMPShellBadPort
135            return ( addr[0], port )
136        # socket path
137        return arg
138
139    def _fill_completion(self):
140        cmds = self.cmd('query-commands')
141        if 'error' in cmds:
142            return
143        for cmd in cmds['return']:
144            self._completer.append(cmd['name'])
145
146    def __completer_setup(self):
147        self._completer = QMPCompleter()
148        self._fill_completion()
149        readline.set_history_length(1024)
150        readline.set_completer(self._completer.complete)
151        readline.parse_and_bind("tab: complete")
152        # XXX: default delimiters conflict with some command names (eg. query-),
153        # clearing everything as it doesn't seem to matter
154        readline.set_completer_delims('')
155        try:
156            readline.read_history_file(self._histfile)
157        except Exception as e:
158            if isinstance(e, IOError) and e.errno == errno.ENOENT:
159                # File not found. No problem.
160                pass
161            else:
162                print("Failed to read history '%s'; %s" % (self._histfile, e))
163        atexit.register(self.__save_history)
164
165    def __save_history(self):
166        try:
167            readline.write_history_file(self._histfile)
168        except Exception as e:
169            print("Failed to save history file '%s'; %s" % (self._histfile, e))
170
171    def __parse_value(self, val):
172        try:
173            return int(val)
174        except ValueError:
175            pass
176
177        if val.lower() == 'true':
178            return True
179        if val.lower() == 'false':
180            return False
181        if val.startswith(('{', '[')):
182            # Try first as pure JSON:
183            try:
184                return json.loads(val)
185            except ValueError:
186                pass
187            # Try once again as FuzzyJSON:
188            try:
189                st = ast.parse(val, mode='eval')
190                return ast.literal_eval(FuzzyJSON().visit(st))
191            except SyntaxError:
192                pass
193            except ValueError:
194                pass
195        return val
196
197    def __cli_expr(self, tokens, parent):
198        for arg in tokens:
199            (key, sep, val) = arg.partition('=')
200            if sep != '=':
201                raise QMPShellError("Expected a key=value pair, got '%s'" % arg)
202
203            value = self.__parse_value(val)
204            optpath = key.split('.')
205            curpath = []
206            for p in optpath[:-1]:
207                curpath.append(p)
208                d = parent.get(p, {})
209                if type(d) is not dict:
210                    raise QMPShellError('Cannot use "%s" as both leaf and non-leaf key' % '.'.join(curpath))
211                parent[p] = d
212                parent = d
213            if optpath[-1] in parent:
214                if type(parent[optpath[-1]]) is dict:
215                    raise QMPShellError('Cannot use "%s" as both leaf and non-leaf key' % '.'.join(curpath))
216                else:
217                    raise QMPShellError('Cannot set "%s" multiple times' % key)
218            parent[optpath[-1]] = value
219
220    def __build_cmd(self, cmdline):
221        """
222        Build a QMP input object from a user provided command-line in the
223        following format:
224
225            < command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ]
226        """
227        cmdargs = re.findall(r'''(?:[^\s"']|"(?:\\.|[^"])*"|'(?:\\.|[^'])*')+''', cmdline)
228
229        # Transactional CLI entry/exit:
230        if cmdargs[0] == 'transaction(':
231            self._transmode = True
232            cmdargs.pop(0)
233        elif cmdargs[0] == ')' and self._transmode:
234            self._transmode = False
235            if len(cmdargs) > 1:
236                raise QMPShellError("Unexpected input after close of Transaction sub-shell")
237            qmpcmd = { 'execute': 'transaction',
238                       'arguments': { 'actions': self._actions } }
239            self._actions = list()
240            return qmpcmd
241
242        # Nothing to process?
243        if not cmdargs:
244            return None
245
246        # Parse and then cache this Transactional Action
247        if self._transmode:
248            finalize = False
249            action = { 'type': cmdargs[0], 'data': {} }
250            if cmdargs[-1] == ')':
251                cmdargs.pop(-1)
252                finalize = True
253            self.__cli_expr(cmdargs[1:], action['data'])
254            self._actions.append(action)
255            return self.__build_cmd(')') if finalize else None
256
257        # Standard command: parse and return it to be executed.
258        qmpcmd = { 'execute': cmdargs[0], 'arguments': {} }
259        self.__cli_expr(cmdargs[1:], qmpcmd['arguments'])
260        return qmpcmd
261
262    def _print(self, qmp):
263        indent = None
264        if self._pretty:
265            indent = 4
266        jsobj = json.dumps(qmp, indent=indent)
267        print(str(jsobj))
268
269    def _execute_cmd(self, cmdline):
270        try:
271            qmpcmd = self.__build_cmd(cmdline)
272        except Exception as e:
273            print('Error while parsing command line: %s' % e)
274            print('command format: <command-name> ', end=' ')
275            print('[arg-name1=arg1] ... [arg-nameN=argN]')
276            return True
277        # For transaction mode, we may have just cached the action:
278        if qmpcmd is None:
279            return True
280        if self._verbose:
281            self._print(qmpcmd)
282        resp = self.cmd_obj(qmpcmd)
283        if resp is None:
284            print('Disconnected')
285            return False
286        self._print(resp)
287        return True
288
289    def connect(self, negotiate):
290        self._greeting = super(QMPShell, self).connect(negotiate)
291        self.__completer_setup()
292
293    def show_banner(self, msg='Welcome to the QMP low-level shell!'):
294        print(msg)
295        if not self._greeting:
296            print('Connected')
297            return
298        version = self._greeting['QMP']['version']['qemu']
299        print('Connected to QEMU %d.%d.%d\n' % (version['major'],version['minor'],version['micro']))
300
301    def get_prompt(self):
302        if self._transmode:
303            return "TRANS> "
304        return "(QEMU) "
305
306    def read_exec_command(self, prompt):
307        """
308        Read and execute a command.
309
310        @return True if execution was ok, return False if disconnected.
311        """
312        try:
313            cmdline = input(prompt)
314        except EOFError:
315            print()
316            return False
317        if cmdline == '':
318            for ev in self.get_events():
319                print(ev)
320            self.clear_events()
321            return True
322        else:
323            return self._execute_cmd(cmdline)
324
325    def set_verbosity(self, verbose):
326        self._verbose = verbose
327
328class HMPShell(QMPShell):
329    def __init__(self, address):
330        QMPShell.__init__(self, address)
331        self.__cpu_index = 0
332
333    def __cmd_completion(self):
334        for cmd in self.__cmd_passthrough('help')['return'].split('\r\n'):
335            if cmd and cmd[0] != '[' and cmd[0] != '\t':
336                name = cmd.split()[0] # drop help text
337                if name == 'info':
338                    continue
339                if name.find('|') != -1:
340                    # Command in the form 'foobar|f' or 'f|foobar', take the
341                    # full name
342                    opt = name.split('|')
343                    if len(opt[0]) == 1:
344                        name = opt[1]
345                    else:
346                        name = opt[0]
347                self._completer.append(name)
348                self._completer.append('help ' + name) # help completion
349
350    def __info_completion(self):
351        for cmd in self.__cmd_passthrough('info')['return'].split('\r\n'):
352            if cmd:
353                self._completer.append('info ' + cmd.split()[1])
354
355    def __other_completion(self):
356        # special cases
357        self._completer.append('help info')
358
359    def _fill_completion(self):
360        self.__cmd_completion()
361        self.__info_completion()
362        self.__other_completion()
363
364    def __cmd_passthrough(self, cmdline, cpu_index = 0):
365        return self.cmd_obj({ 'execute': 'human-monitor-command', 'arguments':
366                              { 'command-line': cmdline,
367                                'cpu-index': cpu_index } })
368
369    def _execute_cmd(self, cmdline):
370        if cmdline.split()[0] == "cpu":
371            # trap the cpu command, it requires special setting
372            try:
373                idx = int(cmdline.split()[1])
374                if not 'return' in self.__cmd_passthrough('info version', idx):
375                    print('bad CPU index')
376                    return True
377                self.__cpu_index = idx
378            except ValueError:
379                print('cpu command takes an integer argument')
380                return True
381        resp = self.__cmd_passthrough(cmdline, self.__cpu_index)
382        if resp is None:
383            print('Disconnected')
384            return False
385        assert 'return' in resp or 'error' in resp
386        if 'return' in resp:
387            # Success
388            if len(resp['return']) > 0:
389                print(resp['return'], end=' ')
390        else:
391            # Error
392            print('%s: %s' % (resp['error']['class'], resp['error']['desc']))
393        return True
394
395    def show_banner(self):
396        QMPShell.show_banner(self, msg='Welcome to the HMP shell!')
397
398def die(msg):
399    sys.stderr.write('ERROR: %s\n' % msg)
400    sys.exit(1)
401
402def fail_cmdline(option=None):
403    if option:
404        sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
405    sys.stderr.write('qmp-shell [ -v ] [ -p ] [ -H ] [ -N ] < UNIX socket path> | < TCP address:port >\n')
406    sys.stderr.write('    -v     Verbose (echo command sent and received)\n')
407    sys.stderr.write('    -p     Pretty-print JSON\n')
408    sys.stderr.write('    -H     Use HMP interface\n')
409    sys.stderr.write('    -N     Skip negotiate (for qemu-ga)\n')
410    sys.exit(1)
411
412def main():
413    addr = ''
414    qemu = None
415    hmp = False
416    pretty = False
417    verbose = False
418    negotiate = True
419
420    try:
421        for arg in sys.argv[1:]:
422            if arg == "-H":
423                if qemu is not None:
424                    fail_cmdline(arg)
425                hmp = True
426            elif arg == "-p":
427                pretty = True
428            elif arg == "-N":
429                negotiate = False
430            elif arg == "-v":
431                verbose = True
432            else:
433                if qemu is not None:
434                    fail_cmdline(arg)
435                if hmp:
436                    qemu = HMPShell(arg)
437                else:
438                    qemu = QMPShell(arg, pretty)
439                addr = arg
440
441        if qemu is None:
442            fail_cmdline()
443    except QMPShellBadPort:
444        die('bad port number in command-line')
445
446    try:
447        qemu.connect(negotiate)
448    except qmp.QMPConnectError:
449        die('Didn\'t get QMP greeting message')
450    except qmp.QMPCapabilitiesError:
451        die('Could not negotiate capabilities')
452    except qemu.error:
453        die('Could not connect to %s' % addr)
454
455    qemu.show_banner()
456    qemu.set_verbosity(verbose)
457    while qemu.read_exec_command(qemu.get_prompt()):
458        pass
459    qemu.close()
460
461if __name__ == '__main__':
462    main()
463