[PATCH v3 3/6] iotests: dump bitmap extension data with qcow2.py

[Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>]

Add bitmap header extension data, if any, to the dump in qcow2.py.

Header extension:         Bitmaps
magic                     0x23852875
length                    24
nb_bitmaps                2
reserved32                0
bitmap_directory_size     0x40
bitmap_directory_offset   0x100000

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 tests/qemu-iotests/qcow2.py | 42 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/tests/qemu-iotests/qcow2.py b/tests/qemu-iotests/qcow2.py
index 18e4923..8286115 100755
--- a/tests/qemu-iotests/qcow2.py
+++ b/tests/qemu-iotests/qcow2.py
@@ -4,6 +4,39 @@ import sys
 import struct
 import string
 
+
+class Qcow2BitmapExt:
+
+    uint32_t = 'I'
+    uint64_t = 'Q'
+
+    fields = [
+        [uint32_t, '%d',  'nb_bitmaps'],
+        [uint32_t, '%d',  'reserved32'],
+        [uint64_t, '%#x', 'bitmap_directory_size'],
+        [uint64_t, '%#x', 'bitmap_directory_offset']
+    ]
+
+    fmt = '>' + ''.join(field[0] for field in fields)
+
+    def __init__(self, data):
+
+        extension = struct.unpack(Qcow2BitmapExt.fmt, data)
+        self.__dict__ = dict((field[2], extension[i])
+                             for i, field in enumerate(Qcow2BitmapExt.fields))
+
+    def dump_bitmap_ext(self):
+        for f in Qcow2BitmapExt.fields:
+            value = self.__dict__[f[2]]
+            value_str = f[1] % value
+
+            print("%-25s" % f[2], value_str)
+        print("")
+
+    def dump_ext(self):
+        self.dump_bitmap_ext()
+
+
 class QcowHeaderExtension:
 
     QCOW2_EXT_MAGIC_BACKING_FORMAT = 0xE2792ACA
@@ -13,12 +46,16 @@ class QcowHeaderExtension:
     QCOW2_EXT_MAGIC_DATA_FILE = 0x44415441
 
     def __init__(self, magic, length, data):
+        self.obj = None
         data_str = data[:length]
         if all(c in string.printable.encode('ascii') for c in data_str):
             data_str = "'%s'" % data_str.decode('ascii')
         else:
             data_str = "<binary>"
 
+        if magic == self.QCOW2_EXT_MAGIC_BITMAPS:
+            self.obj = Qcow2BitmapExt(data)
+
         if length % 8 != 0:
             padding = 8 - (length % 8)
             data += b"\0" * padding
@@ -172,7 +209,10 @@ class QcowHeader:
             print("%-25s %s" % ("Header extension:", ex.name))
             print("%-25s %#x" % ("magic", ex.magic))
             print("%-25s %d" % ("length", ex.length))
-            print("%-25s %s" % ("data", ex.data_str))
+            if ex.obj is not None:
+                ex.obj.dump_ext()
+            else:
+                print("%-25s %s" % ("data", ex.data_str))
             print("")
 
 
-- 
1.8.3.1