This file is indexed.

/usr/lib/python2.7/dist-packages/os_xenapi/dom0/etc/xapi.d/plugins/ipxe.py is in python-os-xenapi 0.3.1-0ubuntu1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
#!/usr/bin/env python

# Copyright (c) 2013 OpenStack Foundation
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
# which means the Nova xenapi plugins must use only Python 2.4 features

# TODO(sfinucan): Resolve all 'noqa' items once the above is no longer true

"""Inject network configuration into iPXE ISO for boot."""

import logging
import os
import shutil

import utils

# FIXME(sirp): should this use pluginlib from 5.6?
import dom0_pluginlib
dom0_pluginlib.configure_logging('ipxe')


ISOLINUX_CFG = """SAY iPXE ISO boot image
TIMEOUT 30
DEFAULT ipxe.krn
LABEL ipxe.krn
 KERNEL ipxe.krn
 INITRD netcfg.ipxe
"""

NETCFG_IPXE = """#!ipxe
:start
imgfree
ifclose net0
set net0/ip %(ip_address)s
set net0/netmask %(netmask)s
set net0/gateway %(gateway)s
set dns %(dns)s
ifopen net0
goto menu

:menu
chain %(boot_menu_url)s
goto boot

:boot
sanboot --no-describe --drive 0x80
"""


def _write_file(filename, data):
    # If the ISO was tampered with such that the destination is a symlink,
    # that could allow a malicious user to write to protected areas of the
    # dom0 filesystem. /HT to comstud for pointing this out.
    #
    # Short-term, checking that the destination is not a symlink should be
    # sufficient.
    #
    # Long-term, we probably want to perform all file manipulations within a
    # chroot jail to be extra safe.
    if os.path.islink(filename):
        raise RuntimeError('SECURITY: Cannot write to symlinked destination')

    logging.debug("Writing to file '%s'" % filename)
    f = open(filename, 'w')
    try:
        f.write(data)
    finally:
        f.close()


def _unbundle_iso(sr_path, filename, path):
    logging.debug("Unbundling ISO '%s'" % filename)
    read_only_path = utils.make_staging_area(sr_path)
    try:
        utils.run_command(['mount', '-o', 'loop', filename, read_only_path])
        try:
            shutil.copytree(read_only_path, path)
        finally:
            utils.run_command(['umount', read_only_path])
    finally:
        utils.cleanup_staging_area(read_only_path)


def _create_iso(mkisofs_cmd, filename, path):
    logging.debug("Creating ISO '%s'..." % filename)
    orig_dir = os.getcwd()
    os.chdir(path)
    try:
        utils.run_command([mkisofs_cmd, '-quiet', '-l', '-o', filename,
                           '-c', 'boot.cat', '-b', 'isolinux.bin',
                           '-no-emul-boot', '-boot-load-size', '4',
                           '-boot-info-table', '.'])
    finally:
        os.chdir(orig_dir)


def inject(session, sr_path, vdi_uuid, boot_menu_url, ip_address, netmask,
           gateway, dns, mkisofs_cmd):

    iso_filename = '%s.img' % os.path.join(sr_path, 'iso', vdi_uuid)

    # Create staging area so we have a unique path but remove it since
    # shutil.copytree will recreate it
    staging_path = utils.make_staging_area(sr_path)
    utils.cleanup_staging_area(staging_path)

    try:
        _unbundle_iso(sr_path, iso_filename, staging_path)

        # Write Configs
        _write_file(os.path.join(staging_path, 'netcfg.ipxe'),
                    NETCFG_IPXE % {"ip_address": ip_address,
                                   "netmask": netmask,
                                   "gateway": gateway,
                                   "dns": dns,
                                   "boot_menu_url": boot_menu_url})

        _write_file(os.path.join(staging_path, 'isolinux.cfg'),
                    ISOLINUX_CFG)

        _create_iso(mkisofs_cmd, iso_filename, staging_path)
    finally:
        utils.cleanup_staging_area(staging_path)


if __name__ == "__main__":
    utils.register_plugin_calls(inject)