[Qemu-devel] Re: [PATCH] rev4: support colon in filenames

[Jan Kiszka <jan.kiszka@siemens.com>]

Ram Pai wrote:
> Problem: It is impossible to feed filenames with the character colon because
> qemu interprets such names as a protocol. For example filename scsi:0, is
> interpreted as a protocol by name "scsi".
> 
> This patch allows user to espace colon characters. For example the above
> filename can now be expressed either as 'scsi\:0' or as file:scsi:0
> 
> anything following the "file:" tag is interpreted verbatin. However if "file:"
> tag is omitted then any colon characters in the string must be escaped using
> backslash.
> 
> Here are couple of examples:
> 
> scsi\:0\:abc is a local file scsi:0:abc
> http\://myweb is a local file by name http://myweb
> file:scsi:0:abc is a local file scsi:0:abc
> file:http://myweb is a local file by name http://myweb
> 
> fat:c:\path\to\dir\:floppy\:  is a fat file by name \path\to\dir:floppy:
> NOTE:The above example cannot be expressed using the "file:" protocol.
> 
> 
> Changelog w.r.t to iteration 0:
>    1) removes flexibility added to nbd semantics  eg -- nbd:\::9999
>    2) introduce the file: protocol to indicate local file
> 
> Changelog w.r.t to iteration 1:
>    1) generically handles 'file:' protocol in find_protocol
>    2) centralizes 'filename' pruning before the call to open().
>    3) fixes buffer overflow seen in fill_token()
>    4) adheres to codying style
>    5) patch against upstream qemu tree
> 
> Changelog w.r.t to iteration 2:
>    1) really really fixes buffer overflow seen in 
> 	fill_token() (if not, beat me :)
>    2) the centralized 'filename' pruning had a side effect with
> 	qcow2 files and other files. Fixed it. _open() is back.
> 
> Changelog w.r.t to iteration 3:
>    1) support added to raw-win32.c (i do not have the setup to 
> 		test this change. Request help with testing)
>    2) ability to espace option values containing commas using 
> 	backslashes 
> 	eg  file=file:abc,,  can also be expressed as file=file:abc\, 
> 		where 'abc,' is a filename
>    3) fixes a bug (reported by Jan Kiszka) w.r.t support for -snapshot
>    4) renamed _open() to qemu_open() and removed dependency on PATH_MAX
> 
> the patch applies to qemu-kvm tree only. Will port the patch to qemu tree
> after successful test results.

Please focus on upstream as upstream was broken first and the fix will
flow downstream anyway. And note that this patch does not apply on top
of qemu-kvm. So a rebase against qemu head would be very welcome.

Jan

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