qemu-e2k/scripts/qmp/qmp-shell
John Snow c4a1447fc1 scripts/qmp-shell: use @classmethod where appropriate
Methods with no self-use should belong to the class.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210607200649.1840382-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-06-18 16:10:06 -04:00

469 lines
14 KiB
Python
Executable File

#!/usr/bin/env python3
#
# Low-level QEMU shell on top of QMP.
#
# Copyright (C) 2009, 2010 Red Hat Inc.
#
# Authors:
# Luiz Capitulino <lcapitulino@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2. See
# the COPYING file in the top-level directory.
#
# Usage:
#
# Start QEMU with:
#
# # qemu [...] -qmp unix:./qmp-sock,server
#
# Run the shell:
#
# $ qmp-shell ./qmp-sock
#
# Commands have the following format:
#
# < command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ]
#
# For example:
#
# (QEMU) device_add driver=e1000 id=net1
# {u'return': {}}
# (QEMU)
#
# key=value pairs also support Python or JSON object literal subset notations,
# without spaces. Dictionaries/objects {} are supported as are arrays [].
#
# example-command arg-name1={'key':'value','obj'={'prop':"value"}}
#
# Both JSON and Python formatting should work, including both styles of
# string literal quotes. Both paradigms of literal values should work,
# including null/true/false for JSON and None/True/False for Python.
#
#
# Transactions have the following multi-line format:
#
# transaction(
# action-name1 [ arg-name1=arg1 ] ... [arg-nameN=argN ]
# ...
# action-nameN [ arg-name1=arg1 ] ... [arg-nameN=argN ]
# )
#
# One line transactions are also supported:
#
# transaction( action-name1 ... )
#
# For example:
#
# (QEMU) transaction(
# TRANS> block-dirty-bitmap-add node=drive0 name=bitmap1
# TRANS> block-dirty-bitmap-clear node=drive0 name=bitmap0
# TRANS> )
# {"return": {}}
# (QEMU)
#
# Use the -v and -p options to activate the verbose and pretty-print options,
# which will echo back the properly formatted JSON-compliant QMP that is being
# sent to QEMU, which is useful for debugging and documentation generation.
import ast
import atexit
import errno
import json
import os
import re
import readline
import sys
sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
from qemu import qmp
class QMPCompleter(list):
def complete(self, text, state):
for cmd in self:
if cmd.startswith(text):
if not state:
return cmd
else:
state -= 1
class QMPShellError(Exception):
pass
class FuzzyJSON(ast.NodeTransformer):
'''This extension of ast.NodeTransformer filters literal "true/false/null"
values in an AST and replaces them by proper "True/False/None" values that
Python can properly evaluate.'''
@classmethod
def visit_Name(cls, node):
if node.id == 'true':
node.id = 'True'
if node.id == 'false':
node.id = 'False'
if node.id == 'null':
node.id = 'None'
return node
# TODO: QMPShell's interface is a bit ugly (eg. _fill_completion() and
# _execute_cmd()). Let's design a better one.
class QMPShell(qmp.QEMUMonitorProtocol):
def __init__(self, address, pretty=False):
super(QMPShell, self).__init__(self.parse_address(address))
self._greeting = None
self._completer = None
self._pretty = pretty
self._transmode = False
self._actions = list()
self._histfile = os.path.join(os.path.expanduser('~'),
'.qmp-shell_history')
def _fill_completion(self):
cmds = self.cmd('query-commands')
if 'error' in cmds:
return
for cmd in cmds['return']:
self._completer.append(cmd['name'])
def __completer_setup(self):
self._completer = QMPCompleter()
self._fill_completion()
readline.set_history_length(1024)
readline.set_completer(self._completer.complete)
readline.parse_and_bind("tab: complete")
# NB: default delimiters conflict with some command names
# (eg. query-), clearing everything as it doesn't seem to matter
readline.set_completer_delims('')
try:
readline.read_history_file(self._histfile)
except Exception as e:
if isinstance(e, IOError) and e.errno == errno.ENOENT:
# File not found. No problem.
pass
else:
print("Failed to read history '%s'; %s" % (self._histfile, e))
atexit.register(self.__save_history)
def __save_history(self):
try:
readline.write_history_file(self._histfile)
except Exception as e:
print("Failed to save history file '%s'; %s" % (self._histfile, e))
@classmethod
def __parse_value(cls, val):
try:
return int(val)
except ValueError:
pass
if val.lower() == 'true':
return True
if val.lower() == 'false':
return False
if val.startswith(('{', '[')):
# Try first as pure JSON:
try:
return json.loads(val)
except ValueError:
pass
# Try once again as FuzzyJSON:
try:
st = ast.parse(val, mode='eval')
return ast.literal_eval(FuzzyJSON().visit(st))
except SyntaxError:
pass
except ValueError:
pass
return val
def __cli_expr(self, tokens, parent):
for arg in tokens:
(key, sep, val) = arg.partition('=')
if sep != '=':
raise QMPShellError(
f"Expected a key=value pair, got '{arg!s}'"
)
value = self.__parse_value(val)
optpath = key.split('.')
curpath = []
for p in optpath[:-1]:
curpath.append(p)
d = parent.get(p, {})
if type(d) is not dict:
msg = 'Cannot use "{:s}" as both leaf and non-leaf key'
raise QMPShellError(msg.format('.'.join(curpath)))
parent[p] = d
parent = d
if optpath[-1] in parent:
if type(parent[optpath[-1]]) is dict:
msg = 'Cannot use "{:s}" as both leaf and non-leaf key'
raise QMPShellError(msg.format('.'.join(curpath)))
else:
raise QMPShellError(f'Cannot set "{key}" multiple times')
parent[optpath[-1]] = value
def __build_cmd(self, cmdline):
"""
Build a QMP input object from a user provided command-line in the
following format:
< command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ]
"""
argument_regex = r'''(?:[^\s"']|"(?:\\.|[^"])*"|'(?:\\.|[^'])*')+'''
cmdargs = re.findall(argument_regex, cmdline)
# Transactional CLI entry/exit:
if cmdargs[0] == 'transaction(':
self._transmode = True
cmdargs.pop(0)
elif cmdargs[0] == ')' and self._transmode:
self._transmode = False
if len(cmdargs) > 1:
msg = 'Unexpected input after close of Transaction sub-shell'
raise QMPShellError(msg)
qmpcmd = {
'execute': 'transaction',
'arguments': {'actions': self._actions}
}
self._actions = list()
return qmpcmd
# Nothing to process?
if not cmdargs:
return None
# Parse and then cache this Transactional Action
if self._transmode:
finalize = False
action = {'type': cmdargs[0], 'data': {}}
if cmdargs[-1] == ')':
cmdargs.pop(-1)
finalize = True
self.__cli_expr(cmdargs[1:], action['data'])
self._actions.append(action)
return self.__build_cmd(')') if finalize else None
# Standard command: parse and return it to be executed.
qmpcmd = {'execute': cmdargs[0], 'arguments': {}}
self.__cli_expr(cmdargs[1:], qmpcmd['arguments'])
return qmpcmd
def _print(self, qmp_message):
indent = None
if self._pretty:
indent = 4
jsobj = json.dumps(qmp_message, indent=indent, sort_keys=self._pretty)
print(str(jsobj))
def _execute_cmd(self, cmdline):
try:
qmpcmd = self.__build_cmd(cmdline)
except Exception as e:
print('Error while parsing command line: %s' % e)
print('command format: <command-name> ', end=' ')
print('[arg-name1=arg1] ... [arg-nameN=argN]')
return True
# For transaction mode, we may have just cached the action:
if qmpcmd is None:
return True
if self._verbose:
self._print(qmpcmd)
resp = self.cmd_obj(qmpcmd)
if resp is None:
print('Disconnected')
return False
self._print(resp)
return True
def connect(self, negotiate: bool = True):
self._greeting = super(QMPShell, self).connect(negotiate)
self.__completer_setup()
def show_banner(self, msg='Welcome to the QMP low-level shell!'):
print(msg)
if not self._greeting:
print('Connected')
return
version = self._greeting['QMP']['version']['qemu']
print("Connected to QEMU {major}.{minor}.{micro}\n".format(**version))
def get_prompt(self):
if self._transmode:
return "TRANS> "
return "(QEMU) "
def read_exec_command(self, prompt):
"""
Read and execute a command.
@return True if execution was ok, return False if disconnected.
"""
try:
cmdline = input(prompt)
except EOFError:
print()
return False
if cmdline == '':
for ev in self.get_events():
print(ev)
self.clear_events()
return True
else:
return self._execute_cmd(cmdline)
def set_verbosity(self, verbose):
self._verbose = verbose
class HMPShell(QMPShell):
def __init__(self, address):
QMPShell.__init__(self, address)
self.__cpu_index = 0
def __cmd_completion(self):
for cmd in self.__cmd_passthrough('help')['return'].split('\r\n'):
if cmd and cmd[0] != '[' and cmd[0] != '\t':
name = cmd.split()[0] # drop help text
if name == 'info':
continue
if name.find('|') != -1:
# Command in the form 'foobar|f' or 'f|foobar', take the
# full name
opt = name.split('|')
if len(opt[0]) == 1:
name = opt[1]
else:
name = opt[0]
self._completer.append(name)
self._completer.append('help ' + name) # help completion
def __info_completion(self):
for cmd in self.__cmd_passthrough('info')['return'].split('\r\n'):
if cmd:
self._completer.append('info ' + cmd.split()[1])
def __other_completion(self):
# special cases
self._completer.append('help info')
def _fill_completion(self):
self.__cmd_completion()
self.__info_completion()
self.__other_completion()
def __cmd_passthrough(self, cmdline, cpu_index=0):
return self.cmd_obj({
'execute': 'human-monitor-command',
'arguments': {
'command-line': cmdline,
'cpu-index': cpu_index
}
})
def _execute_cmd(self, cmdline):
if cmdline.split()[0] == "cpu":
# trap the cpu command, it requires special setting
try:
idx = int(cmdline.split()[1])
if 'return' not in self.__cmd_passthrough('info version', idx):
print('bad CPU index')
return True
self.__cpu_index = idx
except ValueError:
print('cpu command takes an integer argument')
return True
resp = self.__cmd_passthrough(cmdline, self.__cpu_index)
if resp is None:
print('Disconnected')
return False
assert 'return' in resp or 'error' in resp
if 'return' in resp:
# Success
if len(resp['return']) > 0:
print(resp['return'], end=' ')
else:
# Error
print('%s: %s' % (resp['error']['class'], resp['error']['desc']))
return True
def show_banner(self, msg='Welcome to the HMP shell!'):
QMPShell.show_banner(self, msg)
def die(msg):
sys.stderr.write('ERROR: %s\n' % msg)
sys.exit(1)
def fail_cmdline(option=None):
if option:
sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
sys.stderr.write(
'qmp-shell [ -v ] [ -p ] [ -H ] [ -N ] '
'< UNIX socket path> | < TCP address:port >\n'
)
sys.stderr.write(' -v Verbose (echo command sent and received)\n')
sys.stderr.write(' -p Pretty-print JSON\n')
sys.stderr.write(' -H Use HMP interface\n')
sys.stderr.write(' -N Skip negotiate (for qemu-ga)\n')
sys.exit(1)
def main():
addr = ''
qemu = None
hmp = False
pretty = False
verbose = False
negotiate = True
try:
for arg in sys.argv[1:]:
if arg == "-H":
if qemu is not None:
fail_cmdline(arg)
hmp = True
elif arg == "-p":
pretty = True
elif arg == "-N":
negotiate = False
elif arg == "-v":
verbose = True
else:
if qemu is not None:
fail_cmdline(arg)
if hmp:
qemu = HMPShell(arg)
else:
qemu = QMPShell(arg, pretty)
addr = arg
if qemu is None:
fail_cmdline()
except qmp.QMPBadPortError:
die('bad port number in command-line')
try:
qemu.connect(negotiate)
except qmp.QMPConnectError:
die('Didn\'t get QMP greeting message')
except qmp.QMPCapabilitiesError:
die('Could not negotiate capabilities')
except OSError:
die('Could not connect to %s' % addr)
qemu.show_banner()
qemu.set_verbosity(verbose)
while qemu.read_exec_command(qemu.get_prompt()):
pass
qemu.close()
if __name__ == '__main__':
main()