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-rw-r--r--tests/qemu-iotests/qcow2_format.py215
1 files changed, 198 insertions, 17 deletions
diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index cc432e7ae0..8adc9959e1 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -19,6 +19,15 @@
 
 import struct
 import string
+import json
+
+
+class ComplexEncoder(json.JSONEncoder):
+    def default(self, obj):
+        if hasattr(obj, 'to_json'):
+            return obj.to_json()
+        else:
+            return json.JSONEncoder.default(self, obj)
 
 
 class Qcow2Field:
@@ -40,6 +49,22 @@ class Flags64(Qcow2Field):
         return str(bits)
 
 
+class BitmapFlags(Qcow2Field):
+
+    flags = {
+        0x1: 'in-use',
+        0x2: 'auto'
+    }
+
+    def __str__(self):
+        bits = []
+        for bit in range(64):
+            flag = self.value & (1 << bit)
+            if flag:
+                bits.append(self.flags.get(flag, f'bit-{bit}'))
+        return f'{self.value:#x} ({bits})'
+
+
 class Enum(Qcow2Field):
 
     def __str__(self):
@@ -93,7 +118,11 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
         self.__dict__ = dict((field[2], values[i])
                              for i, field in enumerate(self.fields))
 
-    def dump(self):
+    def dump(self, is_json=False):
+        if is_json:
+            print(json.dumps(self.to_json(), indent=4, cls=ComplexEncoder))
+            return
+
         for f in self.fields:
             value = self.__dict__[f[2]]
             if isinstance(f[1], str):
@@ -103,6 +132,9 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
 
             print('{:<25} {}'.format(f[2], value_str))
 
+    def to_json(self):
+        return dict((f[2], self.__dict__[f[2]]) for f in self.fields)
+
 
 class Qcow2BitmapExt(Qcow2Struct):
 
@@ -113,6 +145,131 @@ class Qcow2BitmapExt(Qcow2Struct):
         ('u64', '{:#x}', 'bitmap_directory_offset')
     )
 
+    def __init__(self, fd, cluster_size):
+        super().__init__(fd=fd)
+        tail = struct.calcsize(self.fmt) % 8
+        if tail:
+            fd.seek(8 - tail, 1)
+        position = fd.tell()
+        self.cluster_size = cluster_size
+        self.read_bitmap_directory(fd)
+        fd.seek(position)
+
+    def read_bitmap_directory(self, fd):
+        fd.seek(self.bitmap_directory_offset)
+        self.bitmap_directory = \
+            [Qcow2BitmapDirEntry(fd, cluster_size=self.cluster_size)
+             for _ in range(self.nb_bitmaps)]
+
+    def dump(self):
+        super().dump()
+        for entry in self.bitmap_directory:
+            print()
+            entry.dump()
+
+    def to_json(self):
+        fields_dict = super().to_json()
+        fields_dict['bitmap_directory'] = self.bitmap_directory
+        return fields_dict
+
+
+class Qcow2BitmapDirEntry(Qcow2Struct):
+
+    fields = (
+        ('u64', '{:#x}', 'bitmap_table_offset'),
+        ('u32', '{}', 'bitmap_table_size'),
+        ('u32', BitmapFlags, 'flags'),
+        ('u8',  '{}', 'type'),
+        ('u8',  '{}', 'granularity_bits'),
+        ('u16', '{}', 'name_size'),
+        ('u32', '{}', 'extra_data_size')
+    )
+
+    def __init__(self, fd, cluster_size):
+        super().__init__(fd=fd)
+        self.cluster_size = cluster_size
+        # Seek relative to the current position in the file
+        fd.seek(self.extra_data_size, 1)
+        bitmap_name = fd.read(self.name_size)
+        self.name = bitmap_name.decode('ascii')
+        # Move position to the end of the entry in the directory
+        entry_raw_size = self.bitmap_dir_entry_raw_size()
+        padding = ((entry_raw_size + 7) & ~7) - entry_raw_size
+        fd.seek(padding, 1)
+        self.bitmap_table = Qcow2BitmapTable(fd=fd,
+                                             offset=self.bitmap_table_offset,
+                                             nb_entries=self.bitmap_table_size,
+                                             cluster_size=self.cluster_size)
+
+    def bitmap_dir_entry_raw_size(self):
+        return struct.calcsize(self.fmt) + self.name_size + \
+            self.extra_data_size
+
+    def dump(self):
+        print(f'{"Bitmap name":<25} {self.name}')
+        super(Qcow2BitmapDirEntry, self).dump()
+        self.bitmap_table.dump()
+
+    def to_json(self):
+        # Put the name ahead of the dict
+        return {
+            'name': self.name,
+            **super().to_json(),
+            'bitmap_table': self.bitmap_table
+        }
+
+
+class Qcow2BitmapTableEntry(Qcow2Struct):
+
+    fields = (
+        ('u64',  '{}', 'entry'),
+    )
+
+    BME_TABLE_ENTRY_RESERVED_MASK = 0xff000000000001fe
+    BME_TABLE_ENTRY_OFFSET_MASK = 0x00fffffffffffe00
+    BME_TABLE_ENTRY_FLAG_ALL_ONES = 1
+
+    def __init__(self, fd):
+        super().__init__(fd=fd)
+        self.reserved = self.entry & self.BME_TABLE_ENTRY_RESERVED_MASK
+        self.offset = self.entry & self.BME_TABLE_ENTRY_OFFSET_MASK
+        if self.offset:
+            if self.entry & self.BME_TABLE_ENTRY_FLAG_ALL_ONES:
+                self.type = 'invalid'
+            else:
+                self.type = 'serialized'
+        elif self.entry & self.BME_TABLE_ENTRY_FLAG_ALL_ONES:
+            self.type = 'all-ones'
+        else:
+            self.type = 'all-zeroes'
+
+    def to_json(self):
+        return {'type': self.type, 'offset': self.offset,
+                'reserved': self.reserved}
+
+
+class Qcow2BitmapTable:
+
+    def __init__(self, fd, offset, nb_entries, cluster_size):
+        self.cluster_size = cluster_size
+        position = fd.tell()
+        fd.seek(offset)
+        self.entries = [Qcow2BitmapTableEntry(fd) for _ in range(nb_entries)]
+        fd.seek(position)
+
+    def dump(self):
+        bitmap_table = enumerate(self.entries)
+        print(f'{"Bitmap table":<14} {"type":<15} {"size":<12} {"offset"}')
+        for i, entry in bitmap_table:
+            if entry.type == 'serialized':
+                size = self.cluster_size
+            else:
+                size = 0
+            print(f'{i:<14} {entry.type:<15} {size:<12} {entry.offset}')
+
+    def to_json(self):
+        return self.entries
+
 
 QCOW2_EXT_MAGIC_BITMAPS = 0x23852875
 
@@ -128,6 +285,9 @@ class QcowHeaderExtension(Qcow2Struct):
             0x44415441: 'Data file'
         }
 
+        def to_json(self):
+            return self.mapping.get(self.value, "<unknown>")
+
     fields = (
         ('u32', Magic, 'magic'),
         ('u32', '{}', 'length')
@@ -135,11 +295,13 @@ class QcowHeaderExtension(Qcow2Struct):
         # then padding to next multiply of 8
     )
 
-    def __init__(self, magic=None, length=None, data=None, fd=None):
+    def __init__(self, magic=None, length=None, data=None, fd=None,
+                 cluster_size=None):
         """
         Support both loading from fd and creation from user data.
         For fd-based creation current position in a file will be used to read
         the data.
+        The cluster_size value may be obtained by dependent structures.
 
         This should be somehow refactored and functionality should be moved to
         superclass (to allow creation of any qcow2 struct), but then, fields
@@ -161,28 +323,43 @@ class QcowHeaderExtension(Qcow2Struct):
         else:
             assert all(v is None for v in (magic, length, data))
             super().__init__(fd=fd)
-            padded = (self.length + 7) & ~7
-            self.data = fd.read(padded)
-            assert self.data is not None
+            if self.magic == QCOW2_EXT_MAGIC_BITMAPS:
+                self.obj = Qcow2BitmapExt(fd=fd, cluster_size=cluster_size)
+                self.data = None
+            else:
+                padded = (self.length + 7) & ~7
+                self.data = fd.read(padded)
+                assert self.data is not None
+                self.obj = None
+
+        if self.data is not None:
+            data_str = self.data[:self.length]
+            if all(c in string.printable.encode(
+                'ascii') for c in data_str):
+                data_str = f"'{ data_str.decode('ascii') }'"
+            else:
+                data_str = '<binary>'
+            self.data_str = data_str
 
-        if self.magic == QCOW2_EXT_MAGIC_BITMAPS:
-            self.obj = Qcow2BitmapExt(data=self.data)
-        else:
-            self.obj = None
 
     def dump(self):
         super().dump()
 
         if self.obj is None:
-            data = self.data[:self.length]
-            if all(c in string.printable.encode('ascii') for c in data):
-                data = f"'{ data.decode('ascii') }'"
-            else:
-                data = '<binary>'
-            print(f'{"data":<25} {data}')
+            print(f'{"data":<25} {self.data_str}')
         else:
             self.obj.dump()
 
+    def to_json(self):
+        # Put the name ahead of the dict
+        res = {'name': self.Magic(self.magic), **super().to_json()}
+        if self.obj is not None:
+            res['data'] = self.obj
+        else:
+            res['data_str'] = self.data_str
+
+        return res
+
     @classmethod
     def create(cls, magic, data):
         return QcowHeaderExtension(magic, len(data), data)
@@ -246,7 +423,7 @@ class QcowHeader(Qcow2Struct):
             end = self.cluster_size
 
         while fd.tell() < end:
-            ext = QcowHeaderExtension(fd=fd)
+            ext = QcowHeaderExtension(fd=fd, cluster_size=self.cluster_size)
             if ext.magic == 0:
                 break
             else:
@@ -280,7 +457,11 @@ class QcowHeader(Qcow2Struct):
         buf = buf[0:header_bytes-1]
         fd.write(buf)
 
-    def dump_extensions(self):
+    def dump_extensions(self, is_json=False):
+        if is_json:
+            print(json.dumps(self.extensions, indent=4, cls=ComplexEncoder))
+            return
+
         for ex in self.extensions:
             print('Header extension:')
             ex.dump()