This helps hiding VM IP for anonymous VMs (Whonix) even when some
application leak it. VM will know only some fake IP, which should be set
to something as common as possible.
The feature is mostly implemented at (Proxy)VM side using NAT in
separate network namespace. Core here is only passing arguments to it.
It is designed the way that multiple VMs can use the same IP and still
do not interfere with each other. Even more: it is possible to address
each of them (using their "native" IP), even when multiple of them share
the same "fake" IP.
Original approach (marmarek/old-qubes-core-admin#2) used network script
arguments by appending them to script name, but libxl in Xen >= 4.6
fixed that side effect and it isn't possible anymore. So use QubesDB
instead.
From user POV, this adds 3 "features":
- net/fake-ip - IP address visible in the VM
- net/fake-gateway - default gateway in the VM
- net/fake-netmask - network mask
The feature is enabled if net/fake-ip is set (to some IP address) and is
different than VM native IP. All of those "features" can be set on
template, to affect all of VMs.
Firewall rules etc in (Proxy)VM should still be applied to VM "native"
IP.
FixesQubesOS/qubes-issues#1143
Use just introduced tar writer to archive content of LVM volumes (or
more generally: block devices). Place them as 'private.img' and
'root.img' files in the backup - just like in old format. This require
support for replacing file name in tar header - another thing trivially
supported with tar writer.
tar can't write archive with _contents_ of block device. We need this to
backup LVM-based disk images. To avoid dumping image to a file first,
create a simple tar archiver just for this purpose.
Python is not the fastest possible technology, it's 3 times slower than
equivalent written in C. But it's much easier to read, much less
error-prone, and still process 1GB image under 1s (CPU time, leaving
along actual disk reads). So, it's acceptable.
Old backup metadata (old qubes.xml) does not contain info about
individual volume sizes. So, extract it from tar header (using verbose
output during restore) and resize volume accordingly.
Without this, restoring volumes larger than default would be impossible.
To ease all this, rework restore workflow: first create QubesVM objects,
and all their files (as for fresh VM), then override them with data
from backup - possibly redirecting some files to new location. This
allows generic code to create LVM volumes and then only restore its
content.
1. Add a helper function on vm.storage. This is equivalent of:
vm.storage.get_pool(vm.volumes[name]).export(vm.volumes[name])
2. Make sure the path returned by `export` on LVM volume is accessible.
First part - handling firewall.xml and rules formatting.
Specification on https://qubes-os.org/doc/vm-interface/
TODO (for dom0):
- plug into QubesVM object
- expose rules in QubesDB (including reloading)
- drop old functions (vm.get_firewall_conf etc)
QubesOS/qubes-issues#1815
