[libvirt] [PATCH] qemu: Label master key file

[Cole Robinson]

On 04/14/2016 03:04 AM, Martin Kletzander wrote:
> On Wed, Apr 13, 2016 at 07:58:06PM -0400, Cole Robinson wrote:
>> On 04/13/2016 11:56 AM, Cole Robinson wrote:
>>> On 04/13/2016 11:17 AM, Martin Kletzander wrote:
>>>> When creating the master key, we used mode 0600 (which we should) but
>>>> because we were creating it as root, the file is not readable by any
>>>> qemu running as non-root.  Fortunately, it's just a matter of labelling
>>>> the file.  We are generating the file path few times already, so let's
>>>> label it in the same function that has access to the path already.
>>>>
>>>> Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
>>>> ---
>>>>  src/qemu/qemu_domain.c  | 15 ++++++++++++---
>>>>  src/qemu/qemu_domain.h  |  3 ++-
>>>>  src/qemu/qemu_process.c |  2 +-
>>>>  3 files changed, 15 insertions(+), 5 deletions(-)
>>>>
>>>
>>> ACK, makes sense and fixes things for me. One comment below
>>>
>>>> diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
>>>> index 5d54fffcfb98..83e765ef6868 100644
>>>> --- a/src/qemu/qemu_domain.c
>>>> +++ b/src/qemu/qemu_domain.c
>>>> @@ -504,11 +504,13 @@ qemuDomainGetMasterKeyFilePath(const char *libDir)
>>>>   * Returns 0 on success, -1 on failure with error message indicating failure
>>>>   */
>>>>  static int
>>>> -qemuDomainWriteMasterKeyFile(qemuDomainObjPrivatePtr priv)
>>>> +qemuDomainWriteMasterKeyFile(virQEMUDriverPtr driver,
>>>> +                             virDomainObjPtr vm)
>>>>  {
>>>>      char *path;
>>>>      int fd = -1;
>>>>      int ret = -1;
>>>> +    qemuDomainObjPrivatePtr priv = vm->privateData;
>>>>
>>>>      if (!(path = qemuDomainGetMasterKeyFilePath(priv->libDir)))
>>>>          return -1;
>>>> @@ -525,6 +527,10 @@ qemuDomainWriteMasterKeyFile(qemuDomainObjPrivatePtr
>>>> priv)
>>>>          goto cleanup;
>>>>      }
>>>>
>>>> +    if (virSecurityManagerDomainSetDirLabel(driver->securityManager,
>>>> +                                            vm->def, path) < 0)
>>>> +        goto cleanup;
>>>> +
>>>>      ret = 0;
>>>>
>>>
>>> I looked briefly at fixing this but know if there was a function to ask the
>>> security driver 'just set a on this arbitrary path'. I saw DirLabel but was
>>> thrown off by the 'Dir' name. Maybe change it to something more generic?
>>>
> 
> Yes, it's just a naming; I had to add it for similar purpose when
> labelling directories, but it "Just Works" for arbitrary path.  I'll
> rename that.
> 
>>
>> Also adding some CC, I'm guessing virt-aa-helper.c needs to be extended to to
>> allow access to $libDir/master-key.aes
>>
> 
> Actually, it shouldn't.  It's in the per-domain directory and
> everything under that should be available.
> 
> Anyway, it's a pity that we're not very likely to have a test case for
> that.  But couldn't the paths in virt-aa-helper be created from a
> security driver?  It knows all the paths, doesn't it?
> 
> I'll send a v2 with the rename.

Laine was hitting issues with this too, so I pushed this patch. The API rename
isn't blocking anyone

Thanks,
Cole