[libvirt] [PATCH v2 0/2] qemu: invoke qemu-bridge-helper from libvirtd

[Paolo Bonzini]

Il 20/04/2013 11:11, Paolo Bonzini ha scritto:
> The <interface type='bridge'> is working mostly because of a peculiar
> design decision in Linux.  Ideally, QEMU would run with an empty
> capability bounding set and would not be able to do any privileged
> operation (not even by running a helper program).  This is not the case
> because dropping capabilities from the bounding set requires a capability
> of its own, CAP_SETPCAP; thus QEMU does *not* run with an empty bounding
> set if invoked via qemu:///session.  This is apparently for security
> reasons, to avoid that dropping _some_ caps but not all of them lets
> you exploit untested error paths in suid binaries.
> 
> This series lets libvirtd invoke the privileged helper program on its own,
> which is a cleaner design that would work even if the above Linux quirk
> was not there.  Also, this adds a <target dev='tap0'/> element to the
> XML of an active domain using <interface type='bridge'>.
> 
> Thanks to the patches that have already been committed, the recvfd and
> virCommand APIs make the task almost trivial.
> 
> v1->v2: OOM fix in patch 1, change label name in patch 2, rebase
> 
> Paolo Bonzini (2):
>   virnetdevtap: add virNetDevTapGetName
>   qemu: launch bridge helper from libvirtd
> 
>  src/libvirt_private.syms |   1 +
>  src/qemu/qemu_command.c  | 133 ++++++++++++++++++++++++++++++++++-------------
>  src/qemu/qemu_command.h  |   1 -
>  src/qemu/qemu_hotplug.c  |  25 +++------
>  src/util/virnetdevtap.c  |  33 ++++++++++++
>  src/util/virnetdevtap.h  |   3 ++
>  6 files changed, 143 insertions(+), 53 deletions(-)
> 

Please apply. :)

Paolo