[Pkg-libburnia-devel] Bug#1010098: xorriso: please allow -cut-out directly from block devices

[Thomas Schmitt]

Hi,

i decided to regard a device with 0 lseekable size as not suitable for
-cut_out. The test for suitable type rejects S_ISDIR, S_ISLNK, S_ISFIFO, and
S_ISSOCK. So if an operating system offers non-POSIX types, it will be
possible to test whether they are elsewise suitable.

Please give the code a thorough test, especially with weird -cut_out
arguments.

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Committed are:

https://dev.lovelyhq.com/libburnia/libisofs.git

commit 011e2e85e6dfe6e5d882d198c29fd15c02d38e5e
Author: Thomas Schmitt <scdbackup at gmx.net>
Date:   Tue Apr 26 12:12:15 2022 +0200

    Allowed lseekable device files with iso_tree_add_new_cut_out_node(). Proof-of-concept by Ivan Shmakov.

commit f457a4f8b9a59906cde1b6577e7116944a37d2d0
Author: Thomas Schmitt <scdbackup at gmx.net>
Date:   Tue Apr 26 12:06:18 2022 +0200

    Added missing stream type names to a diagnostic function

commit 2af17490a08c29b033942da42d27b5bda076ad05
Author: Thomas Schmitt <scdbackup at gmx.net>
Date:   Tue Apr 26 12:03:53 2022 +0200

    Bug fix: The lseek methods of IsoFileSource for local filesystem and loaded ISO returned libisofs error codes as positive off_t numbers

https://dev.lovelyhq.com/libburnia/libisoburn.git

commit fc587966d3c770be8b71e57e924cb5cbf7121f76
Author: Thomas Schmitt <scdbackup at gmx.net>
Date:   Tue Apr 26 12:17:22 2022 +0200

    Allowed lseekable device files with -cut_out. Proof-of-concept by Ivan Shmakov.

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Mentioning in man xorriso:
===========================================================================

Map a byte interval of a regular disk file or of a device file into a regular
file in the ISO image. The file depicted by disk_path has to support random
read access.
...
Another use case is copying the content of a device file as interval or as
a whole into the emerging ISO filesystem. The fact that the byte_count is
allowed to be unreasonably high enables copying of a whole device:
 -cut_out /dev/sdd3 0 1000g /content_of_sdd3

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Behavior with the various file types and situations:
===========================================================================
Intentional failures:
---------------------------------------------------------------------------
S_IFIFO:

xorriso : ERRFILE : /home/test/fifo
xorriso : FAILURE : -cut_out: File type (name_pipe) is not suitable for this command: '/home/test/fifo'

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S_IFLNK:

xorriso : ERRFILE : /home/test/link
xorriso : FAILURE : -cut_out: File type (symbolic_link) is not suitable for this command: '/home/test/link'

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S_IFSOCK:

xorriso : ERRFILE : /run/user/1000/pulse/native
xorriso : FAILURE : -cut_out: File type (unix_socket) is not suitable for this command: '/run/user/1000/pulse/native'

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S_IFDIR:

xorriso : ERRFILE : /run/user/1000/pulse
xorriso : FAILURE : -cut_out: File type (directory) is not suitable for this command: '/run/user/1000/pulse'

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S_IFREG not large enough:

xorriso : ERRFILE : /home/x
xorriso : SORRY : -cut_out: Byte offset 32768 larger than addressable file size 1209 : '/home/x'

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S_IFCHR (tests are made on Linux):

xorriso : FAILURE : -cut_out: Special file with addressable size range of 0 encountered
xorriso : ERRFILE : /dev/zero
xorriso : FAILURE : -cut_out: File (char_device) does not support random read access: '/dev/zero'

---------------------------------------------------------------------------
S_IFBLK without read permission:

xorriso : FAILURE : Determination of random-access readable capacity failed: '/dev/sdb' : Permission denied
xorriso : ERRFILE : /dev/sdb
xorriso : FAILURE : -cut_out: File (block_device) does not support random read access: '/dev/sdb'

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S_IFBLK not large enough:

xorriso : ERRFILE : /dev/sdc
xorriso : FAILURE : -cut_out: Byte offset 4294967296 larger than addressable file size 2004877312 : '/dev/sdc'

===========================================================================
Successes:
---------------------------------------------------------------------------
S_IFBLK of sufficient size:

(only a message of severity DEBUG appears, like with the others too:
xorriso : DEBUG : -cut_out from /dev/sdc , byte 1024 to 3072, and graft as /sdc
)

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S_IFREG of sufficient size:

(only a message of severity DEBUG appears, like with the others too:
xorriso : DEBUG : -cut_out from /home/x , byte 1024 to 3072, and graft as /x
)

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Have a nice day :)

Thomas