https://bugzilla.redhat.com/show_bug.cgi?id=1182074
If they're available and we need to pass secrets to qemu, then use the
qemu domain secret object in order to pass the secrets for RBD volumes
instead of passing the base64 encoded secret on the command line.
The goal is to make AES secrets the default and have no user interaction
required in order to allow using the AES mechanism. If the mechanism
is not available, then fall back to the current plain mechanism using
a base64 encoded secret.
New APIs:
qemu_domain.c:
qemuDomainGetSecretAESAlias:
Generate/return the secret object alias for an AES Secret Info type.
This will be called from qemuDomainSecretAESSetup.
qemuDomainSecretAESSetup: (private)
This API handles the details of the generation of the AES secret
and saves the pieces that need to be passed to qemu in order for
the secret to be decrypted. The encrypted secret based upon the
domain master key, an initialization vector (16 byte random value),
and the stored secret. Finally, the requirement from qemu is the IV
and encrypted secret are to be base64 encoded.
qemu_command.c:
qemuBuildSecretInfoProps: (private)
Generate/return a JSON properties object for the AES secret to
be used by both the command building and eventually the hotplug
code in order to add the secret object. Code was designed so that
in the future perhaps hotplug could use it if it made sense.
qemuBuildObjectSecretCommandLine (private)
Generate and add to the command line the -object secret for the
secret. This will be required for the subsequent RBD reference
to the object.
qemuBuildDiskSecinfoCommandLine (private)
Handle adding the AES secret object.
Adjustments:
qemu_domain.c:
The qemuDomainSecretSetup was altered to call either the AES or Plain
Setup functions based upon whether AES secrets are possible (we have
the encryption API) or not, we have secrets, and of course if the
protocol source is RBD.
qemu_command.c:
Adjust the qemuBuildRBDSecinfoURI API's in order to generate the
specific command options for an AES secret, such as:
-object secret,id=$alias,keyid=$masterKey,data=$base64encodedencrypted,
format=base64
-drive file=rbd:pool/image:id=myname:auth_supported=cephx\;none:\
mon_host=mon1.example.org\:6321,password-secret=$alias,...
where the 'id=' value is the secret object alias generated by
concatenating the disk alias and "-aesKey0". The 'keyid= $masterKey'
is the master key shared with qemu, and the -drive syntax will
reference that alias as the 'password-secret'. For the -drive
syntax, the 'id=myname' is kept to define the username, while the
'key=$base64 encoded secret' is removed.
While according to the syntax described for qemu commit '60390a21'
or as seen in the email archive:
https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg04083.html
it is possible to pass a plaintext password via a file, the qemu
commit 'ac1d8878' describes the more feature rich 'keyid=' option
based upon the shared masterKey.
Add tests for checking/comparing output.
NB: For hotplug, since the hotplug code doesn't add command line
arguments, passing the encoded secret directly to the monitor
will suffice.
For device hotplug, the new alias ID needs to be checked in the list
rather than using the count of devices. Unplugging a device that is not
last in the array will make further hotplug impossible due to alias
collision.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1324551
For device hotplug, the new alias ID needs to be checked in the list
rather than using the count of devices. Unplugging a device that is not
last in the array will make further hotplug impossible due to alias
collision.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1324551
If the -object secret capability exists, then get the path to the
masterKey file and provide that to qemu. Checking for the existence
of the file before passing to qemu could be done, but causes issues
in mock test environment.
Since the qemuDomainObjPrivate is not available when building the
command line, the qemuBuildHasMasterKey API will have to suffice
as the primary arbiter for whether the capability exists in order
to find/return the path to the master key for usage.
Created the qemuDomainGetMasterKeyAlias API which will be used by
later patches to define the 'keyid' (eg, masterKey) to be used by
other secrets to provide the id to qemu for the master key.
Starting with commit f8e712fe, if you start a domain that has an
<interface type='hostdev' (or that has <interface type='network'>
where the network is a pool of devices for hostdev assignment), when
you later try to add *another* interface (of any kind) with hotplug,
the function qemuAssignDeviceNetAlias() fails as soon as it sees a
"hostdevN" alias in the list of interfaces), causing the attach to
fail.
This is because (starting with f8e712fe) the device alias names are
assigned during the new function qemuProcessPrepareDomain(), which is
called *before* networkAllocateActualDevice() (which is called from
qemuProcessPrepareHost(), which is called from
qemuProcessLaunch()). Prior to that commit,
networkAllocateActualDevice() was called first.
The problem with this is that the alias for interfaces that are really
a hostdev (<interface type='hostdev'>) is of the form "hostdevN" (just
like other hostdevs), while other interfaces are "netN". But if you
don't know that the interface is going to be a hostdev at the time you
assign the alias name, you can't name it differently. (As far as I've
seen so far, the change in name by itself wouldn't have been a problem
(other than just an outwardly noticeable change in behavior) except
for the abovementioned failure to attach/detach new interfaces.
Rather than take the chance that there may be other not-yet-revealed
problems associated with changing the alias name, this patch changes
the way that aliases are assigned to restore the old behavior.
Old: In the past, assigning an alias to an interface was skipped if it
was seen that the interface was type='hostdev' - we knew that the
hostdev part of the interface was also in the list of hostdevs (that's
part of what happens in networkAllocateActualDevice()) and it would be
assigned when all the other hostdev aliases were assigned.
New: When assigning an alias to an interface, we haven't yet called
networkAllocateActualDevice() to construct the hostdev part of the
interface, so we can't just wait for the loop that creates aliases for
all the hostdevs (there's nothing on that list for this device
yet!). Instead we handle it immediately in the loop creating interface
aliases, by calling the new function networkGetActualType() to
determine if it is going to be hostdev, and if so calling
qemuAssignDeviceHostdevAlias() instead.
Some adjustments have to be made to both
qemuAssignDeviceHostdevAlias() and to qemuAssignDeviceNetAlias() to
accommodate this. In both of them, an error return from
qemuDomainDeviceAliasIndex() is no longer considered an error; instead
it's just ignored (because it almost certainly means that the alias
string for the device was "net" when we expected "hostdev" or vice
versa). in qemuAssignDeviceHostdevAlias() we have to look at all
interface aliases for hostdevN in addition to looking at all hostdev
aliases (this wasn't necessary in the past, because both the interface
entry and the hostdev entry for the device already pointed at the
device info; no longer the case since the hostdev entry hasn't yet
been setup).
Fortunately the buggy behavior hasn't yet been in any official release
of libvirt.
In certain cases, we need to assign a hostdevN-style alias in a case
when we don't have a virDomainHostdevDefPtr (instead we have a
virDomainNetDefPtr). Since qemuAssignDeviceHostdevAlias() doesn't use
anything in the virDomainHostdevDef except the alias string itself
anyway, this patch just changes the arguments to pass a pointer to the
alias pointer instead.
