mirror of
https://github.com/libguestfs/libguestfs.git
synced 2026-03-22 07:03:38 +00:00
7b4d13626f
I saw several Windows disk images which contains strange registry entry for mapped drives: "\\DosDevices\\Y:"=hex(3):00,00,00,00,00,00,00,00,00,00,00,00 Which is decoded something like diskID = 0x0, partition starts at 0 bytes offset from the start of the disk. In addition to a Windows disk image, I have attached dummy disk and made xfs file system on a whole device without partitioning it. I mount xfs file system to a "/" and then mkdir and mount other found file systems inside (/fs1, /fs2 etc.). When we decode drive mappings we are looking for a disk with ID 0x0 (it is 4 bytes somewhere LBA0). It is appeared that dummy non-partitioned disk with xfs file system has zeros by offset where diskID is expected to be). So the disk is considered as a candidate to search for partition at offset 0. part-list command (and "parted" which is used under the hood) reports there is 1 partition on "dummy" disk which starts exactly at offset 0. And thus dummy device name and partition number are simply concatenated together and corresponding drive mapping is returned: Y => /dev/sdX1. But /dev/sdX1 is not existing block device. No matter either it is a bug in "parted" (or it works this way by-design), let's protect ourself from this situation: in addition we look for msdos partition table on a disk before making any further assumptions.
Libguestfs is tools and a library for accessing and modifying guest disk images. For more information see the home page: http://libguestfs.org/ For discussion, development, patches, etc. please use the mailing list: http://www.redhat.com/mailman/listinfo/libguestfs To find out how to build libguestfs from source, read: docs/guestfs-building.pod http://libguestfs.org/guestfs-building.1.html man docs/guestfs-building.1 Copyright (C) 2009-2018 Red Hat Inc. The library is distributed under the LGPLv2+. The programs are distributed under the GPLv2+. Please see the files COPYING and COPYING.LIB for full license information. The examples are under a very liberal license.