qemu-e2k/scripts/qmp/qmp-shell

483 lines
15 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 argparse
import ast
import json
import logging
import os
import re
import readline
import sys
from typing import (
Iterator,
List,
NoReturn,
Optional,
Sequence,
)
sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
from qemu import qmp
from qemu.qmp import QMPMessage
LOG = logging.getLogger(__name__)
class QMPCompleter:
# NB: Python 3.9+ will probably allow us to subclass list[str] directly,
# but pylint as of today does not know that List[str] is simply 'list'.
def __init__(self) -> None:
self._matches: List[str] = []
def append(self, value: str) -> None:
return self._matches.append(value)
def complete(self, text: str, state: int) -> Optional[str]:
for cmd in self._matches:
if cmd.startswith(text):
if state == 0:
return cmd
state -= 1
return None
class QMPShellError(Exception):
pass
class FuzzyJSON(ast.NodeTransformer):
"""
This extension of ast.NodeTransformer filters literal "true/false/null"
values in a Python AST and replaces them by proper "True/False/None" values
that Python can properly evaluate.
"""
@classmethod
def visit_Name(cls, # pylint: disable=invalid-name
node: ast.Name) -> ast.AST:
if node.id == 'true':
return ast.Constant(value=True)
if node.id == 'false':
return ast.Constant(value=False)
if node.id == 'null':
return ast.Constant(value=None)
return node
class QMPShell(qmp.QEMUMonitorProtocol):
def __init__(self, address: qmp.SocketAddrT,
pretty: bool = False, verbose: bool = False):
super().__init__(address)
self._greeting: Optional[QMPMessage] = None
self._completer = QMPCompleter()
self._transmode = False
self._actions: List[QMPMessage] = []
self._histfile = os.path.join(os.path.expanduser('~'),
'.qmp-shell_history')
self.pretty = pretty
self.verbose = verbose
def close(self) -> None:
# Hook into context manager of parent to save shell history.
self._save_history()
super().close()
def _fill_completion(self) -> None:
cmds = self.cmd('query-commands')
if 'error' in cmds:
return
for cmd in cmds['return']:
self._completer.append(cmd['name'])
def __completer_setup(self) -> None:
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 FileNotFoundError:
pass
except IOError as err:
msg = f"Failed to read history '{self._histfile}': {err!s}"
LOG.warning(msg)
def _save_history(self) -> None:
try:
readline.write_history_file(self._histfile)
except IOError as err:
msg = f"Failed to save history file '{self._histfile}': {err!s}"
LOG.warning(msg)
@classmethod
def __parse_value(cls, val: str) -> object:
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:
tree = ast.parse(val, mode='eval')
transformed = FuzzyJSON().visit(tree)
return ast.literal_eval(transformed)
except (SyntaxError, ValueError):
pass
return val
def __cli_expr(self,
tokens: Sequence[str],
parent: qmp.QMPObject) -> None:
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 path in optpath[:-1]:
curpath.append(path)
obj = parent.get(path, {})
if not isinstance(obj, dict):
msg = 'Cannot use "{:s}" as both leaf and non-leaf key'
raise QMPShellError(msg.format('.'.join(curpath)))
parent[path] = obj
parent = obj
if optpath[-1] in parent:
if isinstance(parent[optpath[-1]], dict):
msg = 'Cannot use "{:s}" as both leaf and non-leaf key'
raise QMPShellError(msg.format('.'.join(curpath)))
raise QMPShellError(f'Cannot set "{key}" multiple times')
parent[optpath[-1]] = value
def __build_cmd(self, cmdline: str) -> Optional[QMPMessage]:
"""
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)
qmpcmd: QMPMessage
# Transactional CLI entry:
if cmdargs and cmdargs[0] == 'transaction(':
self._transmode = True
self._actions = []
cmdargs.pop(0)
# Transactional CLI exit:
if cmdargs and 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}
}
return qmpcmd
# No args, or no args remaining
if not cmdargs:
return None
if self._transmode:
# Parse and cache this Transactional Action
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: object) -> None:
jsobj = json.dumps(qmp_message,
indent=4 if self.pretty else None,
sort_keys=self.pretty)
print(str(jsobj))
def _execute_cmd(self, cmdline: str) -> bool:
try:
qmpcmd = self.__build_cmd(cmdline)
except Exception as err:
print('Error while parsing command line: %s' % err)
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) -> None:
self._greeting = super().connect(negotiate)
self.__completer_setup()
def show_banner(self,
msg: str = 'Welcome to the QMP low-level shell!') -> None:
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))
@property
def prompt(self) -> str:
if self._transmode:
return 'TRANS> '
return '(QEMU) '
def read_exec_command(self) -> bool:
"""
Read and execute a command.
@return True if execution was ok, return False if disconnected.
"""
try:
cmdline = input(self.prompt)
except EOFError:
print()
return False
if cmdline == '':
for event in self.get_events():
print(event)
self.clear_events()
return True
return self._execute_cmd(cmdline)
def repl(self) -> Iterator[None]:
self.show_banner()
while self.read_exec_command():
yield
self.close()
class HMPShell(QMPShell):
def __init__(self, address: qmp.SocketAddrT,
pretty: bool = False, verbose: bool = False):
super().__init__(address, pretty, verbose)
self.__cpu_index = 0
def __cmd_completion(self) -> None:
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) -> None:
for cmd in self.__cmd_passthrough('info')['return'].split('\r\n'):
if cmd:
self._completer.append('info ' + cmd.split()[1])
def __other_completion(self) -> None:
# special cases
self._completer.append('help info')
def _fill_completion(self) -> None:
self.__cmd_completion()
self.__info_completion()
self.__other_completion()
def __cmd_passthrough(self, cmdline: str,
cpu_index: int = 0) -> QMPMessage:
return self.cmd_obj({
'execute': 'human-monitor-command',
'arguments': {
'command-line': cmdline,
'cpu-index': cpu_index
}
})
def _execute_cmd(self, cmdline: str) -> bool:
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: str = 'Welcome to the HMP shell!') -> None:
QMPShell.show_banner(self, msg)
def die(msg: str) -> NoReturn:
sys.stderr.write('ERROR: %s\n' % msg)
sys.exit(1)
def main() -> None:
parser = argparse.ArgumentParser()
parser.add_argument('-H', '--hmp', action='store_true',
help='Use HMP interface')
parser.add_argument('-N', '--skip-negotiation', action='store_true',
help='Skip negotiate (for qemu-ga)')
parser.add_argument('-v', '--verbose', action='store_true',
help='Verbose (echo commands sent and received)')
parser.add_argument('-p', '--pretty', action='store_true',
help='Pretty-print JSON')
default_server = os.environ.get('QMP_SOCKET')
parser.add_argument('qmp_server', action='store',
default=default_server,
help='< UNIX socket path | TCP address:port >')
args = parser.parse_args()
if args.qmp_server is None:
parser.error("QMP socket or TCP address must be specified")
shell_class = HMPShell if args.hmp else QMPShell
try:
address = shell_class.parse_address(args.qmp_server)
except qmp.QMPBadPortError:
parser.error(f"Bad port number: {args.qmp_server}")
return # pycharm doesn't know error() is noreturn
with shell_class(address, args.pretty, args.verbose) as qemu:
try:
qemu.connect(negotiate=not args.skip_negotiation)
except qmp.QMPConnectError:
die("Didn't get QMP greeting message")
except qmp.QMPCapabilitiesError:
die("Couldn't negotiate capabilities")
except OSError as err:
die(f"Couldn't connect to {args.qmp_server}: {err!s}")
for _ in qemu.repl():
pass
if __name__ == '__main__':
main()