The first operation returns a token, which can be passed to the second
one to actually perform clone operation. This way the caller needs have
power over both source and destination VMs (or at least appropriate
volumes), so it's easier to enforce appropriate qrexec policy.
The pending tokens are stored on Qubes() instance (as QubesAdminAPI is
not persistent). It is design choice to keep them in RAM only - those
are one time use and this way restarting qubesd is a simple way to
invalidate all of them. Otherwise we'd need some additional calls like
CloneCancel or such.
QubesOS/qubes-issues#2622
In the end firewall is implemented as .Get and .Set rules, with policy
statically set to 'drop'. This way allow atomic firewall updates.
Since we already have appropriate firewall format handling in
qubes.firewall module - reuse it from there, but adjust the code to be
prepared for potentially malicious input. And also mark such variables
with untrusted_ prefix.
There is also third method: .Reload - which cause firewall reload
without making any change.
QubesOS/qubes-issues#2622FixesQubesOS/qubes-issues#2869
Drop DeviceInfo.data - device extension should provide a subclass with
proper individual fields.
Drop DeviceAssignment.frontend_domain - this information is redundant -
frontend domain is defined by where DeviceAssignment is attached.
Rename DeviceCollection.devclass to bus - devclass if confusing here,
because this term is also used for DeviceInfo subclass.
Implement this in two parts:
1. Permissions checks, getting a path from appropriate storage pool
2. Actual data import
The first part is done by qubesd in a standard way, but then, instead of
accepting all the data (which may be several GB), return a path to which
a shell script (in practice: `dd` command) will write the data.
Then the script call back to qubesd again to report success/failure and
qubesd response from that call is actually returned to the user.
This way we do not pass all the data through qubesd, but still can
control the process from there in a meaningful way. Note that the last
part (second call to qubesd) may perform all kind of verification (like
a signature check on the data, or so) and can also prevent VM from
starting (hooking also domain-pre-start event) from not verified image.
QubesOS/qubes-issues#2622
Accessing non-existing property is a common action (for example
hasattr() do try to access the property). So, introduce specific
exception, inheriting from AttributeError. It will behave very similar
to standard (non-Admin-API) property access.
This exception is reported to the Admin API user, so it will be possible
to distinguish between non-existing property and access denied. But it
isn't any significant information leak, as list of valid properties is
publicly available in the source code.
QubesOS/qubes-issues#853
