@@ -1,163 +1,10 @@
#!/usr/bin/env python3
-
import sys
-import struct
-import string
-
-
-class QcowHeaderExtension:
-
- def __init__(self, magic, length, data):
- if length % 8 != 0:
- padding = 8 - (length % 8)
- data += b"\0" * padding
-
- self.magic = magic
- self.length = length
- self.data = data
-
- @classmethod
- def create(cls, magic, data):
- return QcowHeaderExtension(magic, len(data), data)
-
-
-class QcowHeader:
-
- uint32_t = 'I'
- uint64_t = 'Q'
-
- fields = [
- # Version 2 header fields
- [uint32_t, '%#x', 'magic'],
- [uint32_t, '%d', 'version'],
- [uint64_t, '%#x', 'backing_file_offset'],
- [uint32_t, '%#x', 'backing_file_size'],
- [uint32_t, '%d', 'cluster_bits'],
- [uint64_t, '%d', 'size'],
- [uint32_t, '%d', 'crypt_method'],
- [uint32_t, '%d', 'l1_size'],
- [uint64_t, '%#x', 'l1_table_offset'],
- [uint64_t, '%#x', 'refcount_table_offset'],
- [uint32_t, '%d', 'refcount_table_clusters'],
- [uint32_t, '%d', 'nb_snapshots'],
- [uint64_t, '%#x', 'snapshot_offset'],
-
- # Version 3 header fields
- [uint64_t, 'mask', 'incompatible_features'],
- [uint64_t, 'mask', 'compatible_features'],
- [uint64_t, 'mask', 'autoclear_features'],
- [uint32_t, '%d', 'refcount_order'],
- [uint32_t, '%d', 'header_length'],
- ]
-
- fmt = '>' + ''.join(field[0] for field in fields)
-
- def __init__(self, fd):
-
- buf_size = struct.calcsize(QcowHeader.fmt)
-
- fd.seek(0)
- buf = fd.read(buf_size)
-
- header = struct.unpack(QcowHeader.fmt, buf)
- self.__dict__ = dict((field[2], header[i])
- for i, field in enumerate(QcowHeader.fields))
-
- self.set_defaults()
- self.cluster_size = 1 << self.cluster_bits
-
- fd.seek(self.header_length)
- self.load_extensions(fd)
-
- if self.backing_file_offset:
- fd.seek(self.backing_file_offset)
- self.backing_file = fd.read(self.backing_file_size)
- else:
- self.backing_file = None
-
- def set_defaults(self):
- if self.version == 2:
- self.incompatible_features = 0
- self.compatible_features = 0
- self.autoclear_features = 0
- self.refcount_order = 4
- self.header_length = 72
-
- def load_extensions(self, fd):
- self.extensions = []
-
- if self.backing_file_offset != 0:
- end = min(self.cluster_size, self.backing_file_offset)
- else:
- end = self.cluster_size
-
- while fd.tell() < end:
- (magic, length) = struct.unpack('>II', fd.read(8))
- if magic == 0:
- break
- else:
- padded = (length + 7) & ~7
- data = fd.read(padded)
- self.extensions.append(QcowHeaderExtension(magic, length,
- data))
-
- def update_extensions(self, fd):
-
- fd.seek(self.header_length)
- extensions = self.extensions
- extensions.append(QcowHeaderExtension(0, 0, b""))
- for ex in extensions:
- buf = struct.pack('>II', ex.magic, ex.length)
- fd.write(buf)
- fd.write(ex.data)
-
- if self.backing_file is not None:
- self.backing_file_offset = fd.tell()
- fd.write(self.backing_file)
-
- if fd.tell() > self.cluster_size:
- raise Exception("I think I just broke the image...")
-
- def update(self, fd):
- header_bytes = self.header_length
-
- self.update_extensions(fd)
-
- fd.seek(0)
- header = tuple(self.__dict__[f] for t, p, f in QcowHeader.fields)
- buf = struct.pack(QcowHeader.fmt, *header)
- buf = buf[0:header_bytes-1]
- fd.write(buf)
-
- def dump(self):
- for f in QcowHeader.fields:
- value = self.__dict__[f[2]]
- if f[1] == 'mask':
- bits = []
- for bit in range(64):
- if value & (1 << bit):
- bits.append(bit)
- value_str = str(bits)
- else:
- value_str = f[1] % value
-
- print("%-25s" % f[2], value_str)
- print("")
-
- def dump_extensions(self):
- for ex in self.extensions:
-
- data = ex.data[:ex.length]
- if all(c in string.printable.encode('ascii') for c in data):
- data = "'%s'" % data.decode('ascii')
- else:
- data = "<binary>"
- print("Header extension:")
- print("%-25s %#x" % ("magic", ex.magic))
- print("%-25s %d" % ("length", ex.length))
- print("%-25s %s" % ("data", data))
- print("")
+from qcow2_format import (
+ QcowHeader,
+ QcowHeaderExtension
+)
def cmd_dump_header(fd):
new file mode 100644
@@ -0,0 +1,157 @@
+import struct
+import string
+
+
+class QcowHeaderExtension:
+
+ def __init__(self, magic, length, data):
+ if length % 8 != 0:
+ padding = 8 - (length % 8)
+ data += b"\0" * padding
+
+ self.magic = magic
+ self.length = length
+ self.data = data
+
+ @classmethod
+ def create(cls, magic, data):
+ return QcowHeaderExtension(magic, len(data), data)
+
+
+class QcowHeader:
+
+ uint32_t = 'I'
+ uint64_t = 'Q'
+
+ fields = [
+ # Version 2 header fields
+ [uint32_t, '%#x', 'magic'],
+ [uint32_t, '%d', 'version'],
+ [uint64_t, '%#x', 'backing_file_offset'],
+ [uint32_t, '%#x', 'backing_file_size'],
+ [uint32_t, '%d', 'cluster_bits'],
+ [uint64_t, '%d', 'size'],
+ [uint32_t, '%d', 'crypt_method'],
+ [uint32_t, '%d', 'l1_size'],
+ [uint64_t, '%#x', 'l1_table_offset'],
+ [uint64_t, '%#x', 'refcount_table_offset'],
+ [uint32_t, '%d', 'refcount_table_clusters'],
+ [uint32_t, '%d', 'nb_snapshots'],
+ [uint64_t, '%#x', 'snapshot_offset'],
+
+ # Version 3 header fields
+ [uint64_t, 'mask', 'incompatible_features'],
+ [uint64_t, 'mask', 'compatible_features'],
+ [uint64_t, 'mask', 'autoclear_features'],
+ [uint32_t, '%d', 'refcount_order'],
+ [uint32_t, '%d', 'header_length'],
+ ]
+
+ fmt = '>' + ''.join(field[0] for field in fields)
+
+ def __init__(self, fd):
+
+ buf_size = struct.calcsize(QcowHeader.fmt)
+
+ fd.seek(0)
+ buf = fd.read(buf_size)
+
+ header = struct.unpack(QcowHeader.fmt, buf)
+ self.__dict__ = dict((field[2], header[i])
+ for i, field in enumerate(QcowHeader.fields))
+
+ self.set_defaults()
+ self.cluster_size = 1 << self.cluster_bits
+
+ fd.seek(self.header_length)
+ self.load_extensions(fd)
+
+ if self.backing_file_offset:
+ fd.seek(self.backing_file_offset)
+ self.backing_file = fd.read(self.backing_file_size)
+ else:
+ self.backing_file = None
+
+ def set_defaults(self):
+ if self.version == 2:
+ self.incompatible_features = 0
+ self.compatible_features = 0
+ self.autoclear_features = 0
+ self.refcount_order = 4
+ self.header_length = 72
+
+ def load_extensions(self, fd):
+ self.extensions = []
+
+ if self.backing_file_offset != 0:
+ end = min(self.cluster_size, self.backing_file_offset)
+ else:
+ end = self.cluster_size
+
+ while fd.tell() < end:
+ (magic, length) = struct.unpack('>II', fd.read(8))
+ if magic == 0:
+ break
+ else:
+ padded = (length + 7) & ~7
+ data = fd.read(padded)
+ self.extensions.append(QcowHeaderExtension(magic, length,
+ data))
+
+ def update_extensions(self, fd):
+
+ fd.seek(self.header_length)
+ extensions = self.extensions
+ extensions.append(QcowHeaderExtension(0, 0, b""))
+ for ex in extensions:
+ buf = struct.pack('>II', ex.magic, ex.length)
+ fd.write(buf)
+ fd.write(ex.data)
+
+ if self.backing_file is not None:
+ self.backing_file_offset = fd.tell()
+ fd.write(self.backing_file)
+
+ if fd.tell() > self.cluster_size:
+ raise Exception("I think I just broke the image...")
+
+ def update(self, fd):
+ header_bytes = self.header_length
+
+ self.update_extensions(fd)
+
+ fd.seek(0)
+ header = tuple(self.__dict__[f] for t, p, f in QcowHeader.fields)
+ buf = struct.pack(QcowHeader.fmt, *header)
+ buf = buf[0:header_bytes-1]
+ fd.write(buf)
+
+ def dump(self):
+ for f in QcowHeader.fields:
+ value = self.__dict__[f[2]]
+ if f[1] == 'mask':
+ bits = []
+ for bit in range(64):
+ if value & (1 << bit):
+ bits.append(bit)
+ value_str = str(bits)
+ else:
+ value_str = f[1] % value
+
+ print("%-25s" % f[2], value_str)
+ print("")
+
+ def dump_extensions(self):
+ for ex in self.extensions:
+
+ data = ex.data[:ex.length]
+ if all(c in string.printable.encode('ascii') for c in data):
+ data = "'%s'" % data.decode('ascii')
+ else:
+ data = "<binary>"
+
+ print("Header extension:")
+ print("%-25s %#x" % ("magic", ex.magic))
+ print("%-25s %d" % ("length", ex.length))
+ print("%-25s %s" % ("data", data))
+ print("")
We are going to enhance qcow2 format parsing by adding more structure classes. Let's split format parsing from utility code. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- tests/qemu-iotests/qcow2.py | 161 +---------------------------- tests/qemu-iotests/qcow2_format.py | 157 ++++++++++++++++++++++++++++ 2 files changed, 161 insertions(+), 157 deletions(-) create mode 100644 tests/qemu-iotests/qcow2_format.py