tests/qemu-iotests/qcow2.py

   1 #!/usr/bin/env python3
   2 #
   3 # Manipulations with qcow2 image
   4 #
   5 # Copyright (C) 2012 Red Hat, Inc.
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; either version 2 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 #
  20
  21 import sys
  22
  23 from qcow2_format import (
  24     QcowHeader,
  25     QcowHeaderExtension
  26 )
  27
  28
  29 is_json = False
  30
  31
  32 def cmd_dump_header(fd):
  33     h = QcowHeader(fd)
  34     h.dump(is_json)
  35     print()
  36     h.dump_extensions(is_json)
  37
  38
  39 def cmd_dump_header_exts(fd):
  40     h = QcowHeader(fd)
  41     h.dump_extensions(is_json)
  42
  43
  44 def cmd_set_header(fd, name, value):
  45     try:
  46         value = int(value, 0)
  47     except ValueError:
  48         print("'%s' is not a valid number" % value)
  49         sys.exit(1)
  50
  51     fields = (field[2] for field in QcowHeader.fields)
  52     if name not in fields:
  53         print("'%s' is not a known header field" % name)
  54         sys.exit(1)
  55
  56     h = QcowHeader(fd)
  57     h.__dict__[name] = value
  58     h.update(fd)
  59
  60
  61 def cmd_add_header_ext(fd, magic, data):
  62     try:
  63         magic = int(magic, 0)
  64     except ValueError:
  65         print("'%s' is not a valid magic number" % magic)
  66         sys.exit(1)
  67
  68     h = QcowHeader(fd)
  69     h.extensions.append(QcowHeaderExtension.create(magic,
  70                                                    data.encode('ascii')))
  71     h.update(fd)
  72
  73
  74 def cmd_add_header_ext_stdio(fd, magic):
  75     data = sys.stdin.read()
  76     cmd_add_header_ext(fd, magic, data)
  77
  78
  79 def cmd_del_header_ext(fd, magic):
  80     try:
  81         magic = int(magic, 0)
  82     except ValueError:
  83         print("'%s' is not a valid magic number" % magic)
  84         sys.exit(1)
  85
  86     h = QcowHeader(fd)
  87     found = False
  88
  89     for ex in h.extensions:
  90         if ex.magic == magic:
  91             found = True
  92             h.extensions.remove(ex)
  93
  94     if not found:
  95         print("No such header extension")
  96         return
  97
  98     h.update(fd)
  99
 100
 101 def cmd_set_feature_bit(fd, group, bit):
 102     try:
 103         bit = int(bit, 0)
 104         if bit < 0 or bit >= 64:
 105             raise ValueError
 106     except ValueError:
 107         print("'%s' is not a valid bit number in range [0, 64)" % bit)
 108         sys.exit(1)
 109
 110     h = QcowHeader(fd)
 111     if group == 'incompatible':
 112         h.incompatible_features |= 1 << bit
 113     elif group == 'compatible':
 114         h.compatible_features |= 1 << bit
 115     elif group == 'autoclear':
 116         h.autoclear_features |= 1 << bit
 117     else:
 118         print("'%s' is not a valid group, try "
 119               "'incompatible', 'compatible', or 'autoclear'" % group)
 120         sys.exit(1)
 121
 122     h.update(fd)
 123
 124
 125 cmds = [
 126     ['dump-header', cmd_dump_header, 0,
 127      'Dump image header and header extensions'],
 128     ['dump-header-exts', cmd_dump_header_exts, 0,
 129      'Dump image header extensions'],
 130     ['set-header', cmd_set_header, 2, 'Set a field in the header'],
 131     ['add-header-ext', cmd_add_header_ext, 2, 'Add a header extension'],
 132     ['add-header-ext-stdio', cmd_add_header_ext_stdio, 1,
 133      'Add a header extension, data from stdin'],
 134     ['del-header-ext', cmd_del_header_ext, 1, 'Delete a header extension'],
 135     ['set-feature-bit', cmd_set_feature_bit, 2, 'Set a feature bit'],
 136 ]
 137
 138
 139 def main(filename, cmd, args):
 140     fd = open(filename, "r+b")
 141     try:
 142         for name, handler, num_args, desc in cmds:
 143             if name != cmd:
 144                 continue
 145             elif len(args) != num_args:
 146                 usage()
 147                 return
 148             else:
 149                 handler(fd, *args)
 150                 return
 151         print("Unknown command '%s'" % cmd)
 152     finally:
 153         fd.close()
 154
 155
 156 def usage():
 157     print("Usage: %s <file> <cmd> [<arg>, ...] [<key>, ...]" % sys.argv[0])
 158     print("")
 159     print("Supported commands:")
 160     for name, handler, num_args, desc in cmds:
 161         print("    %-20s - %s" % (name, desc))
 162     print("")
 163     print("Supported keys:")
 164     print("    %-20s - %s" % ('-j', 'Dump in JSON format'))
 165
 166
 167 if __name__ == '__main__':
 168     if len(sys.argv) < 3:
 169         usage()
 170         sys.exit(1)
 171
 172     is_json = '-j' in sys.argv
 173     if is_json:
 174         sys.argv.remove('-j')
 175
 176     main(sys.argv[1], sys.argv[2], sys.argv[3:])