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             qmpcmd['arguments'][opt[0]] = value
 116         return qmpcmd
 117
 118     def _execute_cmd(self, cmdline):
 119         try:
 120             qmpcmd = self.__build_cmd(cmdline)
 121         except:
 122             print 'command format: <command-name> ',
 123             print '[arg-name1=arg1] ... [arg-nameN=argN]'
 124             return True
 125         resp = self.cmd_obj(qmpcmd)
 126         if resp is None:
 127             print 'Disconnected'
 128             return False
 129
 130         if self._pp is not None:
 131             self._pp.pprint(resp)
 132         else:
 133             print resp
 134         return True
 135
 136     def connect(self):
 137         self._greeting = qmp.QEMUMonitorProtocol.connect(self)
 138         self.__completer_setup()
 139
 140     def show_banner(self, msg='Welcome to the QMP low-level shell!'):
 141         print msg
 142         version = self._greeting['QMP']['version']['qemu']
 143         print 'Connected to QEMU %d.%d.%d\n' % (version['major'],version['minor'],version['micro'])
 144
 145     def read_exec_command(self, prompt):
 146         """
 147         Read and execute a command.
 148
 149         @return True if execution was ok, return False if disconnected.
 150         """
 151         try:
 152             cmdline = raw_input(prompt)
 153         except EOFError:
 154             print
 155             return False
 156         if cmdline == '':
 157             for ev in self.get_events():
 158                 print ev
 159             self.clear_events()
 160             return True
 161         else:
 162             return self._execute_cmd(cmdline)
 163
 164 class HMPShell(QMPShell):
 165     def __init__(self, address):
 166         QMPShell.__init__(self, address)
 167         self.__cpu_index = 0
 168
 169     def __cmd_completion(self):
 170         for cmd in self.__cmd_passthrough('help')['return'].split('\r\n'):
 171             if cmd and cmd[0] != '[' and cmd[0] != '\t':
 172                 name = cmd.split()[0] # drop help text
 173                 if name == 'info':
 174                     continue
 175                 if name.find('|') != -1:
 176                     # Command in the form 'foobar|f' or 'f|foobar', take the
 177                     # full name
 178                     opt = name.split('|')
 179                     if len(opt[0]) == 1:
 180                         name = opt[1]
 181                     else:
 182                         name = opt[0]
 183                 self._completer.append(name)
 184                 self._completer.append('help ' + name) # help completion
 185
 186     def __info_completion(self):
 187         for cmd in self.__cmd_passthrough('info')['return'].split('\r\n'):
 188             if cmd:
 189                 self._completer.append('info ' + cmd.split()[1])
 190
 191     def __other_completion(self):
 192         # special cases
 193         self._completer.append('help info')
 194
 195     def _fill_completion(self):
 196         self.__cmd_completion()
 197         self.__info_completion()
 198         self.__other_completion()
 199
 200     def __cmd_passthrough(self, cmdline, cpu_index = 0):
 201         return self.cmd_obj({ 'execute': 'human-monitor-command', 'arguments':
 202                               { 'command-line': cmdline,
 203                                 'cpu-index': cpu_index } })
 204
 205     def _execute_cmd(self, cmdline):
 206         if cmdline.split()[0] == "cpu":
 207             # trap the cpu command, it requires special setting
 208             try:
 209                 idx = int(cmdline.split()[1])
 210                 if not 'return' in self.__cmd_passthrough('info version', idx):
 211                     print 'bad CPU index'
 212                     return True
 213                 self.__cpu_index = idx
 214             except ValueError:
 215                 print 'cpu command takes an integer argument'
 216                 return True
 217         resp = self.__cmd_passthrough(cmdline, self.__cpu_index)
 218         if resp is None:
 219             print 'Disconnected'
 220             return False
 221         assert 'return' in resp or 'error' in resp
 222         if 'return' in resp:
 223             # Success
 224             if len(resp['return']) > 0:
 225                 print resp['return'],
 226         else:
 227             # Error
 228             print '%s: %s' % (resp['error']['class'], resp['error']['desc'])
 229         return True
 230
 231     def show_banner(self):
 232         QMPShell.show_banner(self, msg='Welcome to the HMP shell!')
 233
 234 def die(msg):
 235     sys.stderr.write('ERROR: %s\n' % msg)
 236     sys.exit(1)
 237
 238 def fail_cmdline(option=None):
 239     if option:
 240         sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
 241     sys.stderr.write('qemu-shell [ -p ] [ -H ] < UNIX socket path> | < TCP address:port >\n')
 242     sys.exit(1)
 243
 244 def main():
 245     addr = ''
 246     qemu = None
 247     hmp = False
 248     pp = None
 249
 250     try:
 251         for arg in sys.argv[1:]:
 252             if arg == "-H":
 253                 if qemu is not None:
 254                     fail_cmdline(arg)
 255                 hmp = True
 256             elif arg == "-p":
 257                 if pp is not None:
 258                     fail_cmdline(arg)
 259                 pp = pprint.PrettyPrinter(indent=4)
 260             else:
 261                 if qemu is not None:
 262                     fail_cmdline(arg)
 263                 if hmp:
 264                     qemu = HMPShell(arg)
 265                 else:
 266                     qemu = QMPShell(arg, pp)
 267                 addr = arg
 268
 269         if qemu is None:
 270             fail_cmdline()
 271     except QMPShellBadPort:
 272         die('bad port number in command-line')
 273
 274     try:
 275         qemu.connect()
 276     except qmp.QMPConnectError:
 277         die('Didn\'t get QMP greeting message')
 278     except qmp.QMPCapabilitiesError:
 279         die('Could not negotiate capabilities')
 280     except qemu.error:
 281         die('Could not connect to %s' % addr)
 282
 283     qemu.show_banner()
 284     while qemu.read_exec_command('(QEMU) '):
 285         pass
 286     qemu.close()
 287
 288 if __name__ == '__main__':
 289     main()