qemu/scripts/qmp/qom-fuse

#!/usr/bin/env python3
##
# QEMU Object Model test tools
#
# Copyright IBM, Corp. 2012
# Copyright (C) 2020 Red Hat, Inc.
#
# Authors:
#  Anthony Liguori   <aliguori@us.ibm.com>
#  Markus Armbruster <armbru@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2 or later.  See
# the COPYING file in the top-level directory.
##

import fuse, stat
from fuse import FUSE, FuseOSError, Operations
import os, posix, sys
from errno import *

sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
from qemu.qmp import QEMUMonitorProtocol

fuse.fuse_python_api = (0, 2)

class QOMFS(Operations):
    def __init__(self, qmp):
        self.qmp = qmp
        self.qmp.connect()
        self.ino_map = {}
        self.ino_count = 1

    def get_ino(self, path):
        if path in self.ino_map:
            return self.ino_map[path]
        self.ino_map[path] = self.ino_count
        self.ino_count += 1
        return self.ino_map[path]

    def is_object(self, path):
        try:
            items = self.qmp.command('qom-list', path=path)
            return True
        except:
            return False

    def is_property(self, path):
        path, prop = path.rsplit('/', 1)
        if path == '':
            path = '/'
        try:
            for item in self.qmp.command('qom-list', path=path):
                if item['name'] == prop:
                    return True
            return False
        except:
            return False

    def is_link(self, path):
        path, prop = path.rsplit('/', 1)
        if path == '':
            path = '/'
        try:
            for item in self.qmp.command('qom-list', path=path):
                if item['name'] == prop:
                    if item['type'].startswith('link<'):
                        return True
                    return False
            return False
        except:
            return False

    def read(self, path, length, offset, fh):
        if not self.is_property(path):
            return -ENOENT

        path, prop = path.rsplit('/', 1)
        if path == '':
            path = '/'
        try:
            data = self.qmp.command('qom-get', path=path, property=prop)
            data += '\n' # make values shell friendly
        except:
            raise FuseOSError(EPERM)

        if offset > len(data):
            return ''

        return bytes(data[offset:][:length], encoding='utf-8')

    def readlink(self, path):
        if not self.is_link(path):
            return False
        path, prop = path.rsplit('/', 1)
        prefix = '/'.join(['..'] * (len(path.split('/')) - 1))
        return prefix + str(self.qmp.command('qom-get', path=path,
                                             property=prop))

    def getattr(self, path, fh=None):
        if self.is_link(path):
            value = { 'st_mode': 0o755 | stat.S_IFLNK,
                      'st_ino': self.get_ino(path),
                      'st_dev': 0,
                      'st_nlink': 2,
                      'st_uid': 1000,
                      'st_gid': 1000,
                      'st_size': 4096,
                      'st_atime': 0,
                      'st_mtime': 0,
                      'st_ctime': 0 }
        elif self.is_object(path):
            value = { 'st_mode': 0o755 | stat.S_IFDIR,
                      'st_ino': self.get_ino(path),
                      'st_dev': 0,
                      'st_nlink': 2,
                      'st_uid': 1000,
                      'st_gid': 1000,
                      'st_size': 4096,
                      'st_atime': 0,
                      'st_mtime': 0,
                      'st_ctime': 0 }
        elif self.is_property(path):
            value = { 'st_mode': 0o644 | stat.S_IFREG,
                      'st_ino': self.get_ino(path),
                      'st_dev': 0,
                      'st_nlink': 1,
                      'st_uid': 1000,
                      'st_gid': 1000,
                      'st_size': 4096,
                      'st_atime': 0,
                      'st_mtime': 0,
                      'st_ctime': 0 }
        else:
            raise FuseOSError(ENOENT)
        return value

    def readdir(self, path, fh):
        yield '.'
        yield '..'
        for item in self.qmp.command('qom-list', path=path):
            yield str(item['name'])

if __name__ == '__main__':
    import os

    fuse = FUSE(QOMFS(QEMUMonitorProtocol(os.environ['QMP_SOCKET'])),
                sys.argv[1], foreground=True)