root / snf-image-helper / disklabel.py @ 94d0a699
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#!/usr/bin/env python
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#
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# -*- coding: utf-8 -*-
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#
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# Copyright (C) 2013 GRNET S.A.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301, USA.
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"""This module provides the code for handling BSD disklabels"""
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import struct |
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import sys |
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import os |
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import cStringIO |
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import optparse |
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import abc |
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from collections import namedtuple |
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from collections import OrderedDict |
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BLOCKSIZE = 512
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LABELSECTOR = 1
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LABELOFFSET = 0
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BBSIZE = 8192 # size of boot area with label |
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SBSIZE = 8192 # max size of fs superblock |
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DISKMAGIC = 0x82564557
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class MBR(object): |
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"""Represents a Master Boot Record."""
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class Partition(object): |
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"""Represents a partition entry in MBR"""
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fmt = "<B3sB3sLL"
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def __init__(self, raw_part): |
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"""Create a Partition instance"""
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(self.status,
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self.start,
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self.type,
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self.end,
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self.first_sector,
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self.sector_count
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) = struct.unpack(self.fmt, raw_part)
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def pack(self): |
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"""Pack the partition values into a binary string"""
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return struct.pack(self.fmt, |
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self.status,
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self.start,
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self.type,
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self.end,
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self.first_sector,
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self.sector_count)
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@staticmethod
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def size(): |
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"""Returns the size of an MBR partition entry"""
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return struct.calcsize(MBR.Partition.fmt)
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def __str__(self): |
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return "%02Xh %s %02Xh %s %d %d" % (self.status, |
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self.unpack_chs(self.start), |
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self.type,
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self.unpack_chs(self.end), |
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self.first_sector,
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self.sector_count)
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@staticmethod
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def unpack_chs(chs): |
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"""Unpacks a CHS address string to a tuple."""
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assert len(chs) == 3 |
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head = struct.unpack('<B', chs[0])[0] |
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sector = struct.unpack('<B', chs[1])[0] & 0x3f |
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cylinder = (struct.unpack('<B', chs[1])[0] & 0xC0) << 2 | \ |
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struct.unpack('<B', chs[2])[0] |
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return (cylinder, head, sector)
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@staticmethod
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def pack_chs(cylinder, head, sector): |
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"""Packs a CHS tuple to an address string."""
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assert 1 <= sector < 2**6, "Invalid sector value" |
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assert 0 <= head < 2**8, "Invalid head value" |
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assert 0 <= cylinder < 2**10, "Invalid cylinder value" |
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byte0 = head |
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byte1 = (cylinder >> 2) & 0xC0 | sector |
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byte2 = cylinder & 0xff
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return struct.pack('<BBB', byte0, byte1, byte2) |
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def __init__(self, block): |
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"""Create an MBR instance"""
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self.fmt = "<444s2x16s16s16s16s2s" |
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raw_part = {} # Offset Length Contents
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(self.code_area, # 0 440(max. 446) code area |
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# 440 2(optional) disk signature
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# 444 2 Usually nulls
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raw_part[0], # 446 16 Partition 0 |
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raw_part[1], # 462 16 Partition 1 |
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raw_part[2], # 478 16 Partition 2 |
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raw_part[3], # 494 16 Partition 3 |
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self.signature # 510 2 MBR signature |
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) = struct.unpack(self.fmt, block)
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self.part = {}
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for i in range(4): |
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self.part[i] = self.Partition(raw_part[i]) |
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def size(self): |
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"""Return the size of a Master Boot Record."""
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return struct.calcsize(self.fmt) |
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def pack(self): |
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"""Pack an MBR to a binary string."""
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return struct.pack(self.fmt, |
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self.code_area,
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self.part[0].pack(), |
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self.part[1].pack(), |
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self.part[2].pack(), |
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self.part[3].pack(), |
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self.signature)
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def __str__(self): |
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"""Print the MBR"""
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ret = ""
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for i in range(4): |
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ret += "Partition %d: %s\n" % (i, self.part[i]) |
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ret += "Signature: %s %s\n" % (hex(ord(self.signature[0])), |
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hex(ord(self.signature[1]))) |
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title = "Master Boot Record"
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return "%s\n%s\n%s\n" % (title, len(title) * "=", ret) |
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class Disk(object): |
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"""Represents a BSD Disk"""
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def __init__(self, device): |
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"""Create a Disk instance"""
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self.device = device
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self.part_num = None |
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self.disklabel = None |
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with open(device, "rb") as d: |
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sector0 = d.read(BLOCKSIZE) |
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self.mbr = MBR(sector0)
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for i in range(4): |
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ptype = self.mbr.part[i].type
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if ptype in (0xa5, 0xa6, 0xa9): |
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d.seek(BLOCKSIZE * self.mbr.part[i].first_sector)
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self.part_num = i
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if ptype == 0xa5: # FreeBSD |
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self.disklabel = BSDDisklabel(d)
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elif ptype == 0xa6: # OpenBSD |
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self.disklabel = OpenBSDDisklabel(d)
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else: # NetBSD |
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self.disklabel = BSDDisklabel(d)
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break
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assert self.disklabel is not None, "No *BSD partition found" |
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def write(self): |
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"""Write the changes back to the media"""
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with open(self.device, 'rw+b') as d: |
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d.write(self.mbr.pack())
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d.seek(self.mbr.part[self.part_num].first_sector * BLOCKSIZE) |
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self.disklabel.write_to(d)
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def __str__(self): |
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"""Print the partitioning info of the Disk"""
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return str(self.mbr) + str(self.disklabel) |
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def enlarge(self, new_size): |
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"""Enlarge the disk and return the last usable sector"""
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# Fix the disklabel
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end = self.disklabel.enlarge(new_size)
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# Fix the MBR
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start = self.mbr.part[self.part_num].first_sector |
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self.mbr.part[self.part_num].sector_count = end - start + 1 |
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# There are cases where the CHS address changes although the LBA
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# address remains the same. For example when the bios is configured
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# to use a disk in LBA-Assisted translation mode, the CHS
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# representation depends on the size of the disk. When we enlarge the
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# size of the disk we may have to update the starting sector's CHS
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# address too.
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start_chs = MBR.Partition.pack_chs(*self.disklabel.lba2chs(start))
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self.mbr.part[self.part_num].start = start_chs |
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end_chs = MBR.Partition.pack_chs(*self.disklabel.lba2chs(end))
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self.mbr.part[self.part_num].end = end_chs |
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def enlarge_last_partition(self): |
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"""Enlarge the last partition to cover up all the free space"""
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self.disklabel.enlarge_last_partition()
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def get_last_partition_id(self): |
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"""Get the ID of the last partition"""
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return self.disklabel.get_last_partition_id() |
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def get_duid(self): |
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"""Get the Disklabel Unique Identifier (works only for OpenBSD)"""
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if 'uid' in self.disklabel.field: |
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return self.disklabel.field['uid'] |
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return "" |
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class DisklabelBase(object): |
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"""Disklabel base class"""
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__metaclass__ = abc.ABCMeta |
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def __init__(self, device): |
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"""Create a Disklabel instance"""
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# Subclasses need to overwrite this
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self.field = None |
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self.ptable = None |
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@abc.abstractproperty
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def fmt(self): |
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"""Fields format string for the disklabel fields"""
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pass
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def pack(self, checksum=None): |
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"""Return a binary copy of the Disklabel block"""
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out = OrderedDict() |
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for k, v in self.field.iteritems(): |
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out[k] = v |
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if checksum is not None: |
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out['checksum'] = checksum
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return struct.pack(self.fmt, * out.values() + [self.ptable.pack()]) |
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def compute_checksum(self): |
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"""Compute the checksum of the disklabel"""
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raw = cStringIO.StringIO(self.pack(0)) |
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checksum = 0
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try:
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uint16 = raw.read(2)
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while uint16 != "": |
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checksum ^= struct.unpack('<H', uint16)[0] |
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uint16 = raw.read(2)
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finally:
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raw.close() |
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return checksum
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def write_to(self, device): |
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"""Write the disklabel to a device"""
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# The disklabel starts at sector 1
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device.seek(BLOCKSIZE, os.SEEK_CUR) |
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device.write(self.pack())
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def lba2chs(self, lba, hpc=None, spt=None): |
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"""Returns the CHS address for a given LBA address"""
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assert hpc is None or hpc > 0, "Invalid heads per cylinder value" |
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assert spt is None or spt > 0, "Invalid sectors per track value" |
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if hpc is None: |
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hpc = self.field['ntracks'] |
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if spt is None: |
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spt = self.field['nsectors'] |
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# See:
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# http://en.wikipedia.org/wiki/Logical_Block_Addressing#CHS_conversion
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#
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cylinder = lba // (spt * hpc) |
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header = (lba // spt) % hpc |
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sector = (lba % spt) + 1
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return (cylinder, header, sector)
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@abc.abstractmethod
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def enlarge(self, new_size): |
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"""Enlarge the disk and return the last usable sector"""
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pass
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@abc.abstractmethod
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def enlarge_last_partition(self): |
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"""Enlarge the last partition to consume all the usable space"""
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pass
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@abc.abstractmethod
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def get_last_partition_id(self): |
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"""Get the ID of the last partition"""
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pass
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@abc.abstractmethod
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def __str__(self): |
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"""Print the Disklabel"""
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pass
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class PartitionTableBase(object): |
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"""Base Class for disklabel partition tables"""
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__metaclass__ = abc.ABCMeta |
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@abc.abstractproperty
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def fmt(self): |
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"""Partition fields format string"""
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pass
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@abc.abstractproperty
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def fields(self): |
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"""The partition fields"""
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pass
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def __init__(self, ptable, pnumber): |
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"""Create a Partition Table instance"""
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self.Partition = namedtuple('Partition', self.fields) |
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self.part = []
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size = struct.calcsize(self.fmt)
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raw = cStringIO.StringIO(ptable) |
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try:
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for _ in xrange(pnumber): |
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self.part.append(
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self.Partition(*struct.unpack(self.fmt, raw.read(size))) |
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) |
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finally:
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raw.close() |
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|
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def __str__(self): |
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"""Print the Partition table"""
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val = ""
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for i in xrange(len(self.part)): |
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val += "%c: %s\n" % (chr(ord('a') + i), str(self.part[i])) |
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return val
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|
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def pack(self): |
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"""Packs the partition table into a binary string."""
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ret = ""
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for i in xrange(len(self.part)): |
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ret += struct.pack(self.fmt, *self.part[i]) |
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return ret + ((364 - len(self.part) * 16) * '\x00') |
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class BSDDisklabel(DisklabelBase): |
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"""Represents an BSD Disklabel"""
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class PartitionTable(PartitionTableBase): |
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"""Represents a BSD Partition Table"""
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@property
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def fmt(self): |
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"""Partition fields format string"""
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return "<IIIBBH" |
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|
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@property
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def fields(self): |
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"""The partition fields"""
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return [ # Offset Length Contents |
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'size', # 0 4 Number of sectors in partition |
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'offset', # 4 4 Starting sector of the partition |
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'fsize', # 8 4 File system basic fragment size |
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'fstype', # 12 1 File system type |
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'frag', # 13 1 File system fragments per block |
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'cpg' # 14 2 File system cylinders per group |
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] |
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@property
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def fmt(self): |
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return "<IHH16s16sIIIIIIHHIHHHHIII20s20sIHHII364s" |
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|
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def __init__(self, device): |
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"""Create a BSD DiskLabel instance"""
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super(BSDDisklabel, self).__init__(device) |
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|
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# Disklabel starts at offset one
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device.seek(BLOCKSIZE, os.SEEK_CUR) |
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sector1 = device.read(BLOCKSIZE) |
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|
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d_ = OrderedDict() # Off Len Content
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(d_["magic"], # 0 4 Magic |
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d_["dtype"], # 4 2 Drive Type |
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d_["subtype"], # 6 2 Subtype |
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d_["typename"], # 8 16 Type Name |
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d_["packname"], # 24 16 Pack Identifier |
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d_["secsize"], # 32 4 Bytes per sector |
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d_["nsectors"], # 36 4 Data sectors per track |
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d_["ntracks"], # 40 4 Tracks per cylinder |
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d_["ncylinders"], # 44 4 Data cylinders per unit |
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d_["secpercyl"], # 48 4 Data sectors per cylinder |
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d_["secperunit"], # 52 4 Data sectors per unit |
| 418 |
d_["sparespertrack"], # 56 2 Spare sectors per track |
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d_["sparespercyl"], # 58 2 Spare sectors per cylinder |
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d_["acylinders"], # 60 4 Alternative cylinders per unit |
| 421 |
d_["rpm"], # 64 2 Rotation Speed |
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d_["interleave"], # 66 2 Hardware sector interleave |
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d_["trackskew"], # 68 2 Sector 0 skew, per track |
| 424 |
d_["cylskew"], # 70 2 Sector 0 skew, per cylinder |
| 425 |
d_["headswitch"], # 72 4 Head switch time |
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d_["trkseek"], # 76 4 Track-to-track seek |
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d_["flags"], # 80 4 Generic Flags |
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d_["drivedata"], # 84 5*4 Drive-type specific information |
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d_["spare"], # 104 5*4 Reserved for future use |
| 430 |
d_["magic2"], # 124 4 Magic Number |
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d_["checksum"], # 128 2 Xor of data including partitions |
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d_["npartitions"], # 130 2 Number of partitions following |
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d_["bbsize"], # 132 4 size of boot area at sn0, bytes |
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d_["sbsize"], # 136 4 Max size of fs superblock, bytes |
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ptable_raw # 140 16*16 Partition Table
|
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) = struct.unpack(self.fmt, sector1)
|
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|
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assert d_['magic'] == d_['magic2'] == DISKMAGIC, "Disklabel not valid" |
| 439 |
self.ptable = self.PartitionTable(ptable_raw, d_['npartitions']) |
| 440 |
self.field = d_
|
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|
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def enlarge(self, new_size): |
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raise NotImplementedError |
| 444 |
|
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def enlarge_last_partition(self): |
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raise NotImplementedError |
| 447 |
|
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def get_last_partition_id(self): |
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raise NotImplementedError |
| 450 |
|
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def lba2chs(self, lba, hpc=None, spt=None): |
| 452 |
"""Return the CHS address for a given LBA address"""
|
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|
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# NetBSD uses LBA-Assisted translation. The sectors per track (spt)
|
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# value is always 63 and the heads per cylinder (hpc) value depends on
|
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# the size of the disk
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|
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disk_size = self.field['secperunit'] |
| 459 |
|
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# Maximum disk size that can be addressed is 1024 * HPC* SPT
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spt = 63
|
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for hpc in 16, 32, 64, 128, 255: |
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if disk_size <= 1024 * hpc * spt: |
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break
|
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|
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chs = super(BSDDisklabel, self).lba2chs(lba, hpc, spt) |
| 467 |
|
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if chs[0] > 1023: # Cylinders overflowed |
| 469 |
assert hpc == 255 # Cylinders may overflow only for large disks |
| 470 |
return (1023, chs[1], chs[2]) |
| 471 |
|
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return chs
|
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|
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def __str__(self): |
| 475 |
"""Print the Disklabel"""
|
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|
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title = "Disklabel"
|
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|
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# Those fields may contain null bytes
|
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typename = self.field['typename'].strip('\x00').strip() |
| 481 |
packname = self.field['packname'].strip('\x00').strip() |
| 482 |
|
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return \
|
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"%s\n%s\n" % (title, len(title) * "=") + \ |
| 485 |
"Magic Number: 0x%(magic)x\n" \
|
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"Drive type: %(dtype)d\n" \
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"Subtype: %(subtype)d\n" % self.field + \ |
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"Typename: %s\n" % typename + \
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"Pack Identifier: %s\n" % packname + \
|
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"# of bytes per sector: %(secsize)d\n" \
|
| 491 |
"# of data sectors per track: %(nsectors)d\n" \
|
| 492 |
"# of tracks per cylinder: %(ntracks)d\n" \
|
| 493 |
"# of data cylinders per unit: %(ncylinders)d\n" \
|
| 494 |
"# of data sectors per cylinder: %(secpercyl)d\n" \
|
| 495 |
"# of data sectors per unit: %(secperunit)d\n" \
|
| 496 |
"# of spare sectors per track: %(sparespertrack)d\n" \
|
| 497 |
"# of spare sectors per cylinder: %(sparespercyl)d\n" \
|
| 498 |
"Alt. cylinders per unit: %(acylinders)d\n" \
|
| 499 |
"Rotational speed: %(rpm)d\n" \
|
| 500 |
"Hardware sector interleave: %(interleave)d\n" \
|
| 501 |
"Sector 0 skew, per track: %(trackskew)d\n" \
|
| 502 |
"Sector 0 skew, per cylinder: %(cylskew)d\n" \
|
| 503 |
"Head switch time, usec: %(headswitch)d\n" \
|
| 504 |
"Track-to-track seek, usec: %(trkseek)d\n" \
|
| 505 |
"Generic Flags: %(flags)r\n" \
|
| 506 |
"Drive data: %(drivedata)r\n" \
|
| 507 |
"Reserved for future use: %(spare)r\n" \
|
| 508 |
"The magic number again: 0x%(magic2)x\n" \
|
| 509 |
"Checksum: %(checksum)d\n" \
|
| 510 |
"Number of partitions: %(npartitions)d\n" \
|
| 511 |
"Size of boot aread at sn0: %(bbsize)d\n" \
|
| 512 |
"Max size of fs superblock: %(sbsize)d\n" % self.field + \ |
| 513 |
"%s" % self.ptable |
| 514 |
|
| 515 |
|
| 516 |
class OpenBSDDisklabel(DisklabelBase): |
| 517 |
"""Represents an OpenBSD Disklabel"""
|
| 518 |
|
| 519 |
class PartitionTable(PartitionTableBase): |
| 520 |
"""Reprepsents an OpenBSD Partition Table"""
|
| 521 |
|
| 522 |
@property
|
| 523 |
def fmt(self): |
| 524 |
return "<IIHHBBH" |
| 525 |
|
| 526 |
@property
|
| 527 |
def fields(self): |
| 528 |
return [ # Offset Length Contents |
| 529 |
'size', # 0 4 Number of sectors in the partition |
| 530 |
'offset', # 4 4 Starting sector of the partition |
| 531 |
'offseth', # 8 2 Starting sector (high part) |
| 532 |
'sizeh', # 10 2 Number of sectors (high part) |
| 533 |
'fstype', # 12 1 Filesystem type |
| 534 |
'frag', # 13 1 Filesystem Fragments per block |
| 535 |
'cpg' # 14 2 FS cylinders per group |
| 536 |
] |
| 537 |
|
| 538 |
def setpsize(self, i, size): |
| 539 |
"""Set size for partition i"""
|
| 540 |
tmp = self.part[i]
|
| 541 |
self.part[i] = self.Partition( |
| 542 |
size & 0xffffffff, tmp.offset, tmp.offseth, size >> 32, |
| 543 |
tmp.fstype, tmp.frag, tmp.cpg) |
| 544 |
|
| 545 |
def getpsize(self, i): |
| 546 |
"""Get size for partition i"""
|
| 547 |
return (self.part[i].sizeh << 32) + self.part[i].size |
| 548 |
|
| 549 |
def setpoffset(self, i, offset): |
| 550 |
"""Set offset for partition i"""
|
| 551 |
tmp = self.part[i]
|
| 552 |
self.part[i] = self.Partition( |
| 553 |
tmp.size, offset & 0xffffffff, offset >> 32, tmp.sizeh, |
| 554 |
tmp.frag, tmp.cpg) |
| 555 |
|
| 556 |
def getpoffset(self, i): |
| 557 |
"""Get offset for partition i"""
|
| 558 |
return (self.part[i].offseth << 32) + self.part[i].offset |
| 559 |
|
| 560 |
@property
|
| 561 |
def fmt(self): |
| 562 |
return "<IHH16s16sIIIIII8sIHHIII20sHH16sIHHII364s" |
| 563 |
|
| 564 |
def __init__(self, device): |
| 565 |
"""Create a DiskLabel instance"""
|
| 566 |
|
| 567 |
super(OpenBSDDisklabel, self).__init__(device) |
| 568 |
|
| 569 |
# Disklabel starts at offset one
|
| 570 |
device.seek(BLOCKSIZE, os.SEEK_CUR) |
| 571 |
sector1 = device.read(BLOCKSIZE) |
| 572 |
|
| 573 |
d_ = OrderedDict() # Off Len Content
|
| 574 |
(d_["magic"], # 0 4 Magic |
| 575 |
d_["dtype"], # 4 2 Drive Type |
| 576 |
d_["subtype"], # 6 2 Subtype |
| 577 |
d_["typename"], # 8 16 Type Name |
| 578 |
d_["packname"], # 24 16 Pack Identifier |
| 579 |
d_["secsize"], # 32 4 Bytes per sector |
| 580 |
d_["nsectors"], # 36 4 Data sectors per track |
| 581 |
d_["ntracks"], # 40 4 Tracks per cylinder |
| 582 |
d_["ncylinders"], # 44 4 Data cylinders per unit |
| 583 |
d_["secpercyl"], # 48 4 Data sectors per cylinder |
| 584 |
d_["secperunit"], # 52 4 Data sectors per unit |
| 585 |
d_["uid"], # 56 8 Unique label identifier |
| 586 |
d_["acylinders"], # 64 4 Alt cylinders per unit |
| 587 |
d_["bstarth"], # 68 2 Start of useable region (high part) |
| 588 |
d_["bendh"], # 70 2 Size of usable region (high part) |
| 589 |
d_["bstart"], # 72 4 Start of useable region |
| 590 |
d_["bend"], # 76 4 End of usable region |
| 591 |
d_["flags"], # 80 4 Generic Flags |
| 592 |
d_["drivedata"], # 84 5*4 Drive-type specific information |
| 593 |
d_["secperunith"], # 104 2 Number of data sectors (high part) |
| 594 |
d_["version"], # 106 2 Version |
| 595 |
d_["spare"], # 108 4*4 Reserved for future use |
| 596 |
d_["magic2"], # 124 4 Magic number |
| 597 |
d_["checksum"], # 128 2 Xor of data including partitions |
| 598 |
d_["npartitions"], # 130 2 Number of partitions in following |
| 599 |
d_["bbsize"], # 132 4 size of boot area at sn0, bytes |
| 600 |
d_["sbsize"], # 136 4 Max size of fs superblock, bytes |
| 601 |
ptable_raw # 140 16*16 Partition Table
|
| 602 |
) = struct.unpack(self.fmt, sector1)
|
| 603 |
|
| 604 |
assert d_['magic'] == d_['magic2'] == DISKMAGIC, "Disklabel not valid" |
| 605 |
self.ptable = self.PartitionTable(ptable_raw, d_['npartitions']) |
| 606 |
self.field = d_
|
| 607 |
|
| 608 |
def setdsize(self, dsize): |
| 609 |
"""Set disk size"""
|
| 610 |
self.field['secperunith'] = dsize >> 32 |
| 611 |
self.field['secperunit'] = dsize & 0xffffffff |
| 612 |
|
| 613 |
def getdsize(self): |
| 614 |
"""Get disk size"""
|
| 615 |
return (self.field['secperunith'] << 32) + self.field['secperunit'] |
| 616 |
|
| 617 |
dsize = property(getdsize, setdsize, None, "disk size") |
| 618 |
|
| 619 |
def setbstart(self, bstart): |
| 620 |
"""Set start of useable region"""
|
| 621 |
self.field['bstarth'] = bstart >> 32 |
| 622 |
self.field['bstart'] = bstart & 0xffffffff |
| 623 |
|
| 624 |
def getbstart(self): |
| 625 |
"""Get start of usable region"""
|
| 626 |
return (self.field['bstarth'] << 32) + self.field['bstart'] |
| 627 |
|
| 628 |
bstart = property(getbstart, setbstart, None, "start of usable region") |
| 629 |
|
| 630 |
def setbend(self, bend): |
| 631 |
"""Set end of useable region"""
|
| 632 |
self.field['bendh'] = bend >> 32 |
| 633 |
self.field['bend'] = bend & 0xffffffff |
| 634 |
|
| 635 |
def getbend(self): |
| 636 |
"""Get end of usable region"""
|
| 637 |
return (self.field['bendh'] << 32) + self.field['bend'] |
| 638 |
|
| 639 |
bend = property(getbend, setbend, None, "end of usable region") |
| 640 |
|
| 641 |
def enlarge(self, new_size): |
| 642 |
"""Enlarge the disk and return the last usable sector"""
|
| 643 |
|
| 644 |
assert new_size >= self.dsize, \ |
| 645 |
"New size cannot be smaller that %s" % self.dsize |
| 646 |
|
| 647 |
# Fix the disklabel
|
| 648 |
self.dsize = new_size
|
| 649 |
self.field['ncylinders'] = self.dsize // (self.field['nsectors'] * |
| 650 |
self.field['ntracks']) |
| 651 |
self.bend = (self.field['ncylinders'] * self.field['nsectors'] * |
| 652 |
self.field['ntracks']) |
| 653 |
|
| 654 |
# Partition 'c' descriptes the entire disk
|
| 655 |
self.ptable.setpsize(2, new_size) |
| 656 |
|
| 657 |
# Update the checksum
|
| 658 |
self.field['checksum'] = self.compute_checksum() |
| 659 |
|
| 660 |
# The last usable sector is the end of the usable region minus one
|
| 661 |
return self.bend - 1 |
| 662 |
|
| 663 |
def get_last_partition_id(self): |
| 664 |
"""Returns the id of the last partition"""
|
| 665 |
part = 0
|
| 666 |
end = 0
|
| 667 |
# Don't check partition 'c' which is the whole disk
|
| 668 |
for i in filter(lambda x: x != 2, range(len(self.ptable.part))): |
| 669 |
curr_end = self.ptable.getpsize(i) + self.ptable.getpoffset(i) |
| 670 |
if end < curr_end:
|
| 671 |
end = curr_end |
| 672 |
part = i |
| 673 |
|
| 674 |
assert end > 0, "No partition found" |
| 675 |
|
| 676 |
return part
|
| 677 |
|
| 678 |
def enlarge_last_partition(self): |
| 679 |
"""Enlarge the last partition to cover up all the free space"""
|
| 680 |
|
| 681 |
part_num = self.get_last_partition_id()
|
| 682 |
|
| 683 |
end = self.ptable.getpsize(part_num) + self.ptable.getpoffset(part_num) |
| 684 |
|
| 685 |
assert end > 0, "No partition found" |
| 686 |
|
| 687 |
if self.ptable.part[part_num].fstype == 1: # Swap partition. |
| 688 |
#TODO: Maybe create a warning?
|
| 689 |
return
|
| 690 |
|
| 691 |
if end > (self.bend - 1024): |
| 692 |
return
|
| 693 |
|
| 694 |
self.ptable.setpsize(
|
| 695 |
part_num, self.bend - self.ptable.getpoffset(part_num) - 1024) |
| 696 |
|
| 697 |
self.field['checksum'] = self.compute_checksum() |
| 698 |
|
| 699 |
def lba2chs(self, lba, hpc=None, spt=None): |
| 700 |
"""Returns the CHS address for a given LBA address"""
|
| 701 |
|
| 702 |
chs = super(OpenBSDDisklabel, self).lba2chs(lba, hpc, spt) |
| 703 |
|
| 704 |
# If the cylinders overflow, then OpenBSD will put the value
|
| 705 |
#(1023, 254, 63) to the tuple.
|
| 706 |
if chs[0] > 1023: |
| 707 |
return (1023, 254, 63) |
| 708 |
|
| 709 |
return chs
|
| 710 |
|
| 711 |
def __str__(self): |
| 712 |
"""Print the Disklabel"""
|
| 713 |
|
| 714 |
# Those values may contain null bytes
|
| 715 |
typename = self.field['typename'].strip('\x00').strip() |
| 716 |
packname = self.field['packname'].strip('\x00').strip() |
| 717 |
|
| 718 |
duid = "".join(x.encode('hex') for x in self.field['uid']) |
| 719 |
|
| 720 |
title = "Disklabel"
|
| 721 |
return \
|
| 722 |
"%s\n%s\n" % (title, len(title) * "=") + \ |
| 723 |
"Magic Number: 0x%(magic)x\n" \
|
| 724 |
"Drive type: %(dtype)d\n" \
|
| 725 |
"Subtype: %(subtype)d\n" % self.field + \ |
| 726 |
"Typename: %s\n" % typename + \
|
| 727 |
"Pack Identifier: %s\n" % packname + \
|
| 728 |
"# of bytes per sector: %(secsize)d\n" \
|
| 729 |
"# of data sectors per track: %(nsectors)d\n" \
|
| 730 |
"# of tracks per cylinder: %(ntracks)d\n" \
|
| 731 |
"# of data cylinders per unit: %(ncylinders)d\n" \
|
| 732 |
"# of data sectors per cylinder: %(secpercyl)d\n" \
|
| 733 |
"# of data sectors per unit: %(secperunit)d\n" % self.field + \ |
| 734 |
"DUID: %s\n" % duid + \
|
| 735 |
"Alt. cylinders per unit: %(acylinders)d\n" \
|
| 736 |
"Start of useable region (high part): %(bstarth)d\n" \
|
| 737 |
"Size of useable region (high part): %(bendh)d\n" \
|
| 738 |
"Start of useable region: %(bstart)d\n" \
|
| 739 |
"End of usable region: %(bend)d\n" \
|
| 740 |
"Generic Flags: %(flags)r\n" \
|
| 741 |
"Drive data: %(drivedata)r\n" \
|
| 742 |
"Number of data sectors (high part): %(secperunith)d\n" \
|
| 743 |
"Version: %(version)d\n" \
|
| 744 |
"Reserved for future use: %(spare)r\n" \
|
| 745 |
"The magic number again: 0x%(magic2)x\n" \
|
| 746 |
"Checksum: %(checksum)d\n" \
|
| 747 |
"Number of partitions: %(npartitions)d\n" \
|
| 748 |
"Size of boot aread at sn0: %(bbsize)d\n" \
|
| 749 |
"Max size of fs superblock: %(sbsize)d\n" % self.field + \ |
| 750 |
"%s" % self.ptable |
| 751 |
|
| 752 |
|
| 753 |
def main(): |
| 754 |
"""Main entry point"""
|
| 755 |
usage = "Usage: %prog [options] <input_media>"
|
| 756 |
parser = optparse.OptionParser(usage=usage) |
| 757 |
|
| 758 |
parser.add_option("-l", "--list", action="store_true", dest="list", |
| 759 |
default=False,
|
| 760 |
help="list the disklabel on the specified media")
|
| 761 |
parser.add_option("--get-last-partition", action="store_true", |
| 762 |
dest="last_part", default=False, |
| 763 |
help="print the label of the last partition")
|
| 764 |
parser.add_option( |
| 765 |
"--get-duid", action="store_true", dest="duid", default=False, |
| 766 |
help="print the Disklabel Unique Identifier (OpenBSD only)")
|
| 767 |
parser.add_option("-d", "--enlarge-disk", type="int", dest="disk_size", |
| 768 |
default=None, metavar="SIZE", |
| 769 |
help="Enlarge the disk to this SIZE (in sectors)")
|
| 770 |
parser.add_option( |
| 771 |
"-p", "--enlarge-partition", action="store_true", |
| 772 |
dest="enlarge_partition", default=False, |
| 773 |
help="Enlarge the last partition to cover up the free space")
|
| 774 |
|
| 775 |
options, args = parser.parse_args(sys.argv[1:])
|
| 776 |
|
| 777 |
if len(args) != 1: |
| 778 |
parser.error("Wrong number of arguments")
|
| 779 |
|
| 780 |
disk = Disk(args[0])
|
| 781 |
|
| 782 |
if options.list:
|
| 783 |
print disk
|
| 784 |
return 0 |
| 785 |
|
| 786 |
if options.duid:
|
| 787 |
print "%s" % "".join(x.encode('hex') for x in disk.get_duid()) |
| 788 |
return 0 |
| 789 |
|
| 790 |
if options.last_part:
|
| 791 |
print "%c" % chr(ord('a') + disk.get_last_partition_id()) |
| 792 |
|
| 793 |
if options.disk_size is not None: |
| 794 |
disk.enlarge(options.disk_size) |
| 795 |
|
| 796 |
if options.enlarge_partition:
|
| 797 |
disk.enlarge_last_partition() |
| 798 |
|
| 799 |
disk.write() |
| 800 |
return 0 |
| 801 |
|
| 802 |
|
| 803 |
if __name__ == '__main__': |
| 804 |
sys.exit(main()) |
| 805 |
|
| 806 |
# vim: set sta sts=4 shiftwidth=4 sw=4 et ai :
|