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