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 <[email protected]>
   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                 value = int(opt[1])
 103             except ValueError:
 104                 value = opt[1]
 105             qmpcmd['arguments'][opt[0]] = value
 106         return qmpcmd
 107
 108     def _execute_cmd(self, cmdline):
 109         try:
 110             qmpcmd = self.__build_cmd(cmdline)
 111         except:
 112             print 'command format: <command-name> ',
 113             print '[arg-name1=arg1] ... [arg-nameN=argN]'
 114             return True
 115         resp = self.cmd_obj(qmpcmd)
 116         if resp is None:
 117             print 'Disconnected'
 118             return False
 119
 120         if self._pp is not None:
 121             self._pp.pprint(resp)
 122         else:
 123             print resp
 124         return True
 125
 126     def connect(self):
 127         self._greeting = qmp.QEMUMonitorProtocol.connect(self)
 128         self.__completer_setup()
 129
 130     def show_banner(self, msg='Welcome to the QMP low-level shell!'):
 131         print msg
 132         version = self._greeting['QMP']['version']['qemu']
 133         print 'Connected to QEMU %d.%d.%d\n' % (version['major'],version['minor'],version['micro'])
 134
 135     def read_exec_command(self, prompt):
 136         """
 137         Read and execute a command.
 138
 139         @return True if execution was ok, return False if disconnected.
 140         """
 141         try:
 142             cmdline = raw_input(prompt)
 143         except EOFError:
 144             print
 145             return False
 146         if cmdline == '':
 147             for ev in self.get_events():
 148                 print ev
 149             self.clear_events()
 150             return True
 151         else:
 152             return self._execute_cmd(cmdline)
 153
 154 class HMPShell(QMPShell):
 155     def __init__(self, address):
 156         QMPShell.__init__(self, address)
 157         self.__cpu_index = 0
 158
 159     def __cmd_completion(self):
 160         for cmd in self.__cmd_passthrough('help')['return'].split('\r\n'):
 161             if cmd and cmd[0] != '[' and cmd[0] != '\t':
 162                 name = cmd.split()[0] # drop help text
 163                 if name == 'info':
 164                     continue
 165                 if name.find('|') != -1:
 166                     # Command in the form 'foobar|f' or 'f|foobar', take the
 167                     # full name
 168                     opt = name.split('|')
 169                     if len(opt[0]) == 1:
 170                         name = opt[1]
 171                     else:
 172                         name = opt[0]
 173                 self._completer.append(name)
 174                 self._completer.append('help ' + name) # help completion
 175
 176     def __info_completion(self):
 177         for cmd in self.__cmd_passthrough('info')['return'].split('\r\n'):
 178             if cmd:
 179                 self._completer.append('info ' + cmd.split()[1])
 180
 181     def __other_completion(self):
 182         # special cases
 183         self._completer.append('help info')
 184
 185     def _fill_completion(self):
 186         self.__cmd_completion()
 187         self.__info_completion()
 188         self.__other_completion()
 189
 190     def __cmd_passthrough(self, cmdline, cpu_index = 0):
 191         return self.cmd_obj({ 'execute': 'human-monitor-command', 'arguments':
 192                               { 'command-line': cmdline,
 193                                 'cpu-index': cpu_index } })
 194
 195     def _execute_cmd(self, cmdline):
 196         if cmdline.split()[0] == "cpu":
 197             # trap the cpu command, it requires special setting
 198             try:
 199                 idx = int(cmdline.split()[1])
 200                 if not 'return' in self.__cmd_passthrough('info version', idx):
 201                     print 'bad CPU index'
 202                     return True
 203                 self.__cpu_index = idx
 204             except ValueError:
 205                 print 'cpu command takes an integer argument'
 206                 return True
 207         resp = self.__cmd_passthrough(cmdline, self.__cpu_index)
 208         if resp is None:
 209             print 'Disconnected'
 210             return False
 211         assert 'return' in resp or 'error' in resp
 212         if 'return' in resp:
 213             # Success
 214             if len(resp['return']) > 0:
 215                 print resp['return'],
 216         else:
 217             # Error
 218             print '%s: %s' % (resp['error']['class'], resp['error']['desc'])
 219         return True
 220
 221     def show_banner(self):
 222         QMPShell.show_banner(self, msg='Welcome to the HMP shell!')
 223
 224 def die(msg):
 225     sys.stderr.write('ERROR: %s\n' % msg)
 226     sys.exit(1)
 227
 228 def fail_cmdline(option=None):
 229     if option:
 230         sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
 231     sys.stderr.write('qemu-shell [ -p ] [ -H ] < UNIX socket path> | < TCP address:port >\n')
 232     sys.exit(1)
 233
 234 def main():
 235     addr = ''
 236     qemu = None
 237     hmp = False
 238     pp = None
 239
 240     try:
 241         for arg in sys.argv[1:]:
 242             if arg == "-H":
 243                 if qemu is not None:
 244                     fail_cmdline(arg)
 245                 hmp = True
 246             elif arg == "-p":
 247                 if pp is not None:
 248                     fail_cmdline(arg)
 249                 pp = pprint.PrettyPrinter(indent=4)
 250             else:
 251                 if qemu is not None:
 252                     fail_cmdline(arg)
 253                 if hmp:
 254                     qemu = HMPShell(arg)
 255                 else:
 256                     qemu = QMPShell(arg, pp)
 257                 addr = arg
 258
 259         if qemu is None:
 260             fail_cmdline()
 261     except QMPShellBadPort:
 262         die('bad port number in command-line')
 263
 264     try:
 265         qemu.connect()
 266     except qmp.QMPConnectError:
 267         die('Didn\'t get QMP greeting message')
 268     except qmp.QMPCapabilitiesError:
 269         die('Could not negotiate capabilities')
 270     except qemu.error:
 271         die('Could not connect to %s' % addr)
 272
 273     qemu.show_banner()
 274     while qemu.read_exec_command('(QEMU) '):
 275         pass
 276     qemu.close()
 277
 278 if __name__ == '__main__':
 279     main()