scripts/qmp/qmp-shell

   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 import qmp
  34 import json
  35 import readline
  36 import sys
  37 import pprint
  38
  39 class QMPCompleter(list):
  40     def complete(self, text, state):
  41         for cmd in self:
  42             if cmd.startswith(text):
  43                 if not state:
  44                     return cmd
  45                 else:
  46                     state -= 1
  47
  48 class QMPShellError(Exception):
  49     pass
  50
  51 class QMPShellBadPort(QMPShellError):
  52     pass
  53
  54 # TODO: QMPShell's interface is a bit ugly (eg. _fill_completion() and
  55 #       _execute_cmd()). Let's design a better one.
  56 class QMPShell(qmp.QEMUMonitorProtocol):
  57     def __init__(self, address, pp=None):
  58         qmp.QEMUMonitorProtocol.__init__(self, self.__get_address(address))
  59         self._greeting = None
  60         self._completer = None
  61         self._pp = pp
  62
  63     def __get_address(self, arg):
  64         """
  65         Figure out if the argument is in the port:host form, if it's not it's
  66         probably a file path.
  67         """
  68         addr = arg.split(':')
  69         if len(addr) == 2:
  70             try:
  71                 port = int(addr[1])
  72             except ValueError:
  73                 raise QMPShellBadPort
  74             return ( addr[0], port )
  75         # socket path
  76         return arg
  77
  78     def _fill_completion(self):
  79         for cmd in self.cmd('query-commands')['return']:
  80             self._completer.append(cmd['name'])
  81
  82     def __completer_setup(self):
  83         self._completer = QMPCompleter()
  84         self._fill_completion()
  85         readline.set_completer(self._completer.complete)
  86         readline.parse_and_bind("tab: complete")
  87         # XXX: default delimiters conflict with some command names (eg. query-),
  88         # clearing everything as it doesn't seem to matter
  89         readline.set_completer_delims('')
  90
  91     def __build_cmd(self, cmdline):
  92         """
  93         Build a QMP input object from a user provided command-line in the
  94         following format:
  95
  96             < command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ]
  97         """
  98         cmdargs = cmdline.split()
  99         qmpcmd = { 'execute': cmdargs[0], 'arguments': {} }
 100         for arg in cmdargs[1:]:
 101             opt = arg.split('=')
 102             try:
 103                 if(len(opt) > 2):
 104                     opt[1] = '='.join(opt[1:])
 105                 value = int(opt[1])
 106             except ValueError:
 107                 if opt[1] == 'true':
 108                     value = True
 109                 elif opt[1] == 'false':
 110                     value = False
 111                 elif opt[1].startswith('{'):
 112                     value = json.loads(opt[1])
 113                 else:
 114                     value = opt[1]
 115             optpath = opt[0].split('.')
 116             parent = qmpcmd['arguments']
 117             curpath = []
 118             for p in optpath[:-1]:
 119                 curpath.append(p)
 120                 d = parent.get(p, {})
 121                 if type(d) is not dict:
 122                     raise QMPShellError('Cannot use "%s" as both leaf and non-leaf key' % '.'.join(curpath))
 123                 parent[p] = d
 124                 parent = d
 125             if optpath[-1] in parent:
 126                 if type(parent[optpath[-1]]) is dict:
 127                     raise QMPShellError('Cannot use "%s" as both leaf and non-leaf key' % '.'.join(curpath))
 128                 else:
 129                     raise QMPShellError('Cannot set "%s" multiple times' % opt[0])
 130             parent[optpath[-1]] = value
 131         return qmpcmd
 132
 133     def _execute_cmd(self, cmdline):
 134         try:
 135             qmpcmd = self.__build_cmd(cmdline)
 136         except Exception, e:
 137             print 'Error while parsing command line: %s' % e
 138             print 'command format: <command-name> ',
 139             print '[arg-name1=arg1] ... [arg-nameN=argN]'
 140             return True
 141         resp = self.cmd_obj(qmpcmd)
 142         if resp is None:
 143             print 'Disconnected'
 144             return False
 145
 146         if self._pp is not None:
 147             self._pp.pprint(resp)
 148         else:
 149             print resp
 150         return True
 151
 152     def connect(self):
 153         self._greeting = qmp.QEMUMonitorProtocol.connect(self)
 154         self.__completer_setup()
 155
 156     def show_banner(self, msg='Welcome to the QMP low-level shell!'):
 157         print msg
 158         version = self._greeting['QMP']['version']['qemu']
 159         print 'Connected to QEMU %d.%d.%d\n' % (version['major'],version['minor'],version['micro'])
 160
 161     def read_exec_command(self, prompt):
 162         """
 163         Read and execute a command.
 164
 165         @return True if execution was ok, return False if disconnected.
 166         """
 167         try:
 168             cmdline = raw_input(prompt)
 169         except EOFError:
 170             print
 171             return False
 172         if cmdline == '':
 173             for ev in self.get_events():
 174                 print ev
 175             self.clear_events()
 176             return True
 177         else:
 178             return self._execute_cmd(cmdline)
 179
 180 class HMPShell(QMPShell):
 181     def __init__(self, address):
 182         QMPShell.__init__(self, address)
 183         self.__cpu_index = 0
 184
 185     def __cmd_completion(self):
 186         for cmd in self.__cmd_passthrough('help')['return'].split('\r\n'):
 187             if cmd and cmd[0] != '[' and cmd[0] != '\t':
 188                 name = cmd.split()[0] # drop help text
 189                 if name == 'info':
 190                     continue
 191                 if name.find('|') != -1:
 192                     # Command in the form 'foobar|f' or 'f|foobar', take the
 193                     # full name
 194                     opt = name.split('|')
 195                     if len(opt[0]) == 1:
 196                         name = opt[1]
 197                     else:
 198                         name = opt[0]
 199                 self._completer.append(name)
 200                 self._completer.append('help ' + name) # help completion
 201
 202     def __info_completion(self):
 203         for cmd in self.__cmd_passthrough('info')['return'].split('\r\n'):
 204             if cmd:
 205                 self._completer.append('info ' + cmd.split()[1])
 206
 207     def __other_completion(self):
 208         # special cases
 209         self._completer.append('help info')
 210
 211     def _fill_completion(self):
 212         self.__cmd_completion()
 213         self.__info_completion()
 214         self.__other_completion()
 215
 216     def __cmd_passthrough(self, cmdline, cpu_index = 0):
 217         return self.cmd_obj({ 'execute': 'human-monitor-command', 'arguments':
 218                               { 'command-line': cmdline,
 219                                 'cpu-index': cpu_index } })
 220
 221     def _execute_cmd(self, cmdline):
 222         if cmdline.split()[0] == "cpu":
 223             # trap the cpu command, it requires special setting
 224             try:
 225                 idx = int(cmdline.split()[1])
 226                 if not 'return' in self.__cmd_passthrough('info version', idx):
 227                     print 'bad CPU index'
 228                     return True
 229                 self.__cpu_index = idx
 230             except ValueError:
 231                 print 'cpu command takes an integer argument'
 232                 return True
 233         resp = self.__cmd_passthrough(cmdline, self.__cpu_index)
 234         if resp is None:
 235             print 'Disconnected'
 236             return False
 237         assert 'return' in resp or 'error' in resp
 238         if 'return' in resp:
 239             # Success
 240             if len(resp['return']) > 0:
 241                 print resp['return'],
 242         else:
 243             # Error
 244             print '%s: %s' % (resp['error']['class'], resp['error']['desc'])
 245         return True
 246
 247     def show_banner(self):
 248         QMPShell.show_banner(self, msg='Welcome to the HMP shell!')
 249
 250 def die(msg):
 251     sys.stderr.write('ERROR: %s\n' % msg)
 252     sys.exit(1)
 253
 254 def fail_cmdline(option=None):
 255     if option:
 256         sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
 257     sys.stderr.write('qemu-shell [ -p ] [ -H ] < UNIX socket path> | < TCP address:port >\n')
 258     sys.exit(1)
 259
 260 def main():
 261     addr = ''
 262     qemu = None
 263     hmp = False
 264     pp = None
 265
 266     try:
 267         for arg in sys.argv[1:]:
 268             if arg == "-H":
 269                 if qemu is not None:
 270                     fail_cmdline(arg)
 271                 hmp = True
 272             elif arg == "-p":
 273                 if pp is not None:
 274                     fail_cmdline(arg)
 275                 pp = pprint.PrettyPrinter(indent=4)
 276             else:
 277                 if qemu is not None:
 278                     fail_cmdline(arg)
 279                 if hmp:
 280                     qemu = HMPShell(arg)
 281                 else:
 282                     qemu = QMPShell(arg, pp)
 283                 addr = arg
 284
 285         if qemu is None:
 286             fail_cmdline()
 287     except QMPShellBadPort:
 288         die('bad port number in command-line')
 289
 290     try:
 291         qemu.connect()
 292     except qmp.QMPConnectError:
 293         die('Didn\'t get QMP greeting message')
 294     except qmp.QMPCapabilitiesError:
 295         die('Could not negotiate capabilities')
 296     except qemu.error:
 297         die('Could not connect to %s' % addr)
 298
 299     qemu.show_banner()
 300     while qemu.read_exec_command('(QEMU) '):
 301         pass
 302     qemu.close()
 303
 304 if __name__ == '__main__':
 305     main()