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#!/usr/bin/env python3
#
# Manipulations with qcow2 image
#
# Copyright (C) 2012 Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
import sys
from qcow2_format import (
QcowHeader,
QcowHeaderExtension
)
def cmd_dump_header(fd):
h = QcowHeader(fd)
h.dump()
print()
h.dump_extensions()
def cmd_dump_header_exts(fd):
h = QcowHeader(fd)
h.dump_extensions()
def cmd_set_header(fd, name, value):
try:
value = int(value, 0)
except ValueError:
print("'%s' is not a valid number" % value)
sys.exit(1)
fields = (field[2] for field in QcowHeader.fields)
if name not in fields:
print("'%s' is not a known header field" % name)
sys.exit(1)
h = QcowHeader(fd)
h.__dict__[name] = value
h.update(fd)
def cmd_add_header_ext(fd, magic, data):
try:
magic = int(magic, 0)
except ValueError:
print("'%s' is not a valid magic number" % magic)
sys.exit(1)
h = QcowHeader(fd)
h.extensions.append(QcowHeaderExtension.create(magic,
data.encode('ascii')))
h.update(fd)
def cmd_add_header_ext_stdio(fd, magic):
data = sys.stdin.read()
cmd_add_header_ext(fd, magic, data)
def cmd_del_header_ext(fd, magic):
try:
magic = int(magic, 0)
except ValueError:
print("'%s' is not a valid magic number" % magic)
sys.exit(1)
h = QcowHeader(fd)
found = False
for ex in h.extensions:
if ex.magic == magic:
found = True
h.extensions.remove(ex)
if not found:
print("No such header extension")
return
h.update(fd)
def cmd_set_feature_bit(fd, group, bit):
try:
bit = int(bit, 0)
if bit < 0 or bit >= 64:
raise ValueError
except ValueError:
print("'%s' is not a valid bit number in range [0, 64)" % bit)
sys.exit(1)
h = QcowHeader(fd)
if group == 'incompatible':
h.incompatible_features |= 1 << bit
elif group == 'compatible':
h.compatible_features |= 1 << bit
elif group == 'autoclear':
h.autoclear_features |= 1 << bit
else:
print("'%s' is not a valid group, try "
"'incompatible', 'compatible', or 'autoclear'" % group)
sys.exit(1)
h.update(fd)
cmds = [
['dump-header', cmd_dump_header, 0,
'Dump image header and header extensions'],
['dump-header-exts', cmd_dump_header_exts, 0,
'Dump image header extensions'],
['set-header', cmd_set_header, 2, 'Set a field in the header'],
['add-header-ext', cmd_add_header_ext, 2, 'Add a header extension'],
['add-header-ext-stdio', cmd_add_header_ext_stdio, 1,
'Add a header extension, data from stdin'],
['del-header-ext', cmd_del_header_ext, 1, 'Delete a header extension'],
['set-feature-bit', cmd_set_feature_bit, 2, 'Set a feature bit'],
]
def main(filename, cmd, args):
fd = open(filename, "r+b")
try:
for name, handler, num_args, desc in cmds:
if name != cmd:
continue
elif len(args) != num_args:
usage()
return
else:
handler(fd, *args)
return
print("Unknown command '%s'" % cmd)
finally:
fd.close()
def usage():
print("Usage: %s <file> <cmd> [<arg>, ...]" % sys.argv[0])
print("")
print("Supported commands:")
for name, handler, num_args, desc in cmds:
print(" %-20s - %s" % (name, desc))
if __name__ == '__main__':
if len(sys.argv) < 3:
usage()
sys.exit(1)
main(sys.argv[1], sys.argv[2], sys.argv[3:])
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