[libvirt] [PATCH v2 0/4] qemu: handle ',' and '=' in VM name

[Cole Robinson]

On 05/06/2016 07:54 AM, John Ferlan wrote:
> 
> 
> On 05/04/2016 10:56 AM, Cole Robinson wrote:
>> This series adds qemu cli comma escaping to several places that
>> are dependent on the VM name, to enable names with embedded commas.
>>
>> Patch 4 makes use of qemu -name guest=X value to allow names with
>> '=' in them.
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=639926
>> https://bugzilla.redhat.com/show_bug.cgi?id=1276485
>>
>> Note: There's likely other places that are VM name dependent that need
>> comma escaping too, but this hits the mandatory ones. I've listed some
>> more on the BiteSizedTasks page:
>>
>> http://wiki.libvirt.org/page/BiteSizedTasks#qemu:_Use_comma_escaping_for_more_command_line_values
>>
>> v2:
>>     Rebase to master
>>
>> Cole Robinson (4):
>>   qemu: command: escape commas in VM name
>>   qemu: command: escape commas in secret master path
>>   qemu: command: escape commas in chardev socket path
>>   qemu: command: Use -name guest= if available
>>
>>  src/qemu/qemu_capabilities.c                       |  2 ++
>>  src/qemu/qemu_capabilities.h                       |  1 +
>>  src/qemu/qemu_command.c                            | 22 ++++++++++++--------
>>  tests/qemucapabilitiesdata/caps_2.1.1-1.caps       |  1 +
>>  tests/qemucapabilitiesdata/caps_2.4.0-1.caps       |  1 +
>>  tests/qemucapabilitiesdata/caps_2.5.0-1.caps       |  1 +
>>  tests/qemucapabilitiesdata/caps_2.6.0-1.caps       |  1 +
>>  .../qemuxml2argvdata/qemuxml2argv-name-escape.args | 24 ++++++++++++++++++++++
>>  .../qemuxml2argvdata/qemuxml2argv-name-escape.xml  | 18 ++++++++++++++++
>>  tests/qemuxml2argvtest.c                           |  2 ++
>>  10 files changed, 65 insertions(+), 8 deletions(-)
>>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-name-escape.args
>>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-name-escape.xml
>>
> 
> ewww again ;-)
> 
> While I cannot imagine a reason for someone (other than testing perhaps)
> to want a "," or an "=" in a vm name, I suppose since it's possible to
> handle by qemu, then we should 'handle' it.
> 
> Sorry I dropped the ball after my initial pass - I guess I was wondering
> if there were any other (similar) feelings!
> 

No worries

> After reading the bz, I see why you've gone with double commas, although
> it wasn't apparent without that read...  So maybe each commit that adds
> that double comma escape could explain why the double comma works (or
> even at points in the code where it occurs?).
> 

Yeah the double comma is the qemu convention. I'll add an explicit function
like qemuBufEscapeCommas or something to make this a bit more obvious

> Searching qemu_command.c for domainChannelTargetDir and it's seems
> things are covered (good)... Searching for domainLibDir and I think
> there's one usage not covered - qemuBuildGraphicsVNCCommandLine uses it
> to build "$path_with_domainLibDir/vnc.sock".
> 

Okay, I'll add that.

> Of course finding these "one off" type issues makes me think at some
> point in the future one of those will be used for "something" and the
> double comma will be missed.  So should we generate a local "escaped"
> names for domainLibDir and domainChannelTargetDir that would include the
> double comma and that would be passed to the corresponding users?
> 

TBH I don't really think this is important enough to try and come up with a
safe generalized solution at this point. I think it will largely work itself
out if I add the explicit escaping function, and there's enough usages in
qemu_command.c that they will get cargoculted around when new code is added.

> I think as long as you cover the VNC case and add a few more words why
> the ",," can be used on the command line, then the series seems
> reasonable to me, although you may want to wait a bit to push to see if
> anyone else has angst over the two changes, especially now having
> "guest=$name" be the default for anyone using qemu 2.1 or later.
> 

I'll send a v3 anyways so we can see if anyone cares

- Cole