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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
#!/usr/bin/env python3
#
# Manipulations with qcow2 image
#
# 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:])
|
