Rewrite lxcDomainAttachDeviceHostdevSubsysUSBLive function
to use the virProcessRunInMountNamespace helper. This avoids
risk of a malicious guest replacing /dev with a absolute
symlink, tricking the driver into changing the host OS
filesystem.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Rewrite lxcDomainAttachDeviceDiskLive function to use the
virProcessRunInMountNamespace helper. This avoids risk of
a malicious guest replacing /dev with a absolute symlink,
tricking the driver into changing the host OS filesystem.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Use helper virProcessRunInMountNamespace in lxcDomainShutdownFlags and
lxcDomainReboot.  Otherwise, a malicious guest could use symlinks
to force the host to manipulate the wrong file in the host's namespace.

Idea by Dan Berrange, based on an initial report by Reco
<recoverym4n@gmail.com> at
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=732394Signed-off-by: NEric Blake <eblake@redhat.com>

The check for whether the cgroup devices ACL is available is
done quite late during LXC hotplug - in fact after the device
node is already created in the container in some cases. Better
to do it upfront so we fail immediately.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The LXC disk hotplug code was allowing block or character devices
to be given as disk. A disk is always a block device.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When detaching a USB device from an LXC guest we must remove
the device from the cgroup ACL. Unfortunately we were telling
the cgroup code to use the guest /dev path, not the host /dev
path, and the guest device node had already been unlinked.
This was, however, fortunate since the code passed &priv->cgroup
instead of priv->cgroup, so would have crash if the device node
were accessible.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

After hotplugging a USB device, the LXC driver forgot
to add the device def to the virDomainDefPtr.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The LXC code missed the 'usb' component out of the path
/dev/bus/usb/$BUSNUM/$DEVNUM, so it failed to actually
setup cgroups for the device. This was in fact lucky
because the call to virLXCSetupHostUsbDeviceCgroup
was also mistakenly passing '&priv->cgroup' instead of
just 'priv->cgroup'. So once the path is fixed, libvirtd
would then crash trying to access the bogus virCgroupPtr
pointer. This would have been a security issue, were it
not for the bogus path preventing the pointer reference
being reached.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Yet another variable name frowned upon by older compilers. Introduced in
commit b73c029d.

The problem with VLAN is that the user still has to manually create the
vlan interface on the host. Then the generated configuration will use
it as a nerwork hostdev device. So the generated configurations of the
following two fragments are equivalent (see rhbz#1059637).

lxc.network.type = phys
lxc.network.link = eth0.5

lxc.network.type = vlan
lxc.network.link = eth0
lxc.network.vlan.id = 5

Some of the LXC configuration properties aren't migrated since they
would only cause problems in libvirt-lxc:
  * lxc.network.ipv[46]: LXC driver doesn't setup IP address of guests,
    see rhbz#1059624
  * lxc.network.name, see rhbz#1059630

If no network configuration is provided, LXC only provides the loopback
interface. To match this, we need to use the privnet feature. LXC will
also define a 'none' network type in its 1.0.0 version that fits
libvirt LXC driver's default.

Tmpfs relative size and default 50% size values aren't supported as
we have no idea of the available memory at the conversion time.

LXC rootfs can be either a directory or a block device or an image
file. The first two types have been implemented, but the image file is
still to be done since LXC auto-guesses the file format at mount time
and the LXC driver doesn't support the 'auto' format.

This function aims at converting LXC configuration into a libvirt
domain XML description to help users migrate from LXC to libvirt.

Here is an example of how the lxc configuration works:
virsh -c lxc:/// domxml-from-native lxc-tools /var/lib/lxc/migrate_test/config

It is possible that some parts couldn't be properly mapped into a
domain XML fragment, so users should carefully review the result
before creating the domain.

fstab files in lxc.mount lines will need to be merged into the
configuration file as lxc.mount.entry.

As we can't know the amount of memory of the host, we have to set a
default value for max_balloon that users will probably want to adjust.

https://bugzilla.redhat.com/show_bug.cgi?id=1058839

Commit f9f56340 for CVE-2014-0028 almost had the right idea - we
need to check the ACL rules to filter which events to send.  But
it overlooked one thing: the event dispatch queue is running in
the main loop thread, and therefore does not normally have a
current virIdentityPtr.  But filter checks can be based on current
identity, so when libvirtd.conf contains access_drivers=["polkit"],
we ended up rejecting access for EVERY event due to failure to
look up the current identity, even if it should have been allowed.

Furthermore, even for events that are triggered by API calls, it
is important to remember that the point of events is that they can
be copied across multiple connections, which may have separate
identities and permissions.  So even if events were dispatched
from a context where we have an identity, we must change to the
correct identity of the connection that will be receiving the
event, rather than basing a decision on the context that triggered
the event, when deciding whether to filter an event to a
particular connection.

If there were an easy way to get from virConnectPtr to the
appropriate virIdentityPtr, then object_event.c could adjust the
identity prior to checking whether to dispatch an event.  But
setting up that back-reference is a bit invasive.  Instead, it
is easier to delay the filtering check until lower down the
stack, at the point where we have direct access to the RPC
client object that owns an identity.  As such, this patch ends
up reverting a large portion of the framework of commit f9f56340.
We also have to teach 'make check' to special-case the fact that
the event registration filtering is done at the point of dispatch,
rather than the point of registration.  Note that even though we
don't actually use virConnectDomainEventRegisterCheckACL (because
the RegisterAny variant is sufficient), we still generate the
function for the purposes of documenting that the filtering
takes place.

Also note that I did not entirely delete the notion of a filter
from object_event.c; I still plan on using that for my upcoming
patch series for qemu monitor events in libvirt-qemu.so.  In
other words, while this patch changes ACL filtering to live in
remote.c and therefore we have no current client of the filtering
in object_event.c, the notion of filtering in object_event.c is
still useful down the road.

* src/check-aclrules.pl: Exempt event registration from having to
pass checkACL filter down call stack.
* daemon/remote.c (remoteRelayDomainEventCheckACL)
(remoteRelayNetworkEventCheckACL): New functions.
(remoteRelay*Event*): Use new functions.
* src/conf/domain_event.h (virDomainEventStateRegister)
(virDomainEventStateRegisterID): Drop unused parameter.
* src/conf/network_event.h (virNetworkEventStateRegisterID):
Likewise.
* src/conf/domain_event.c (virDomainEventFilter): Delete unused
function.
* src/conf/network_event.c (virNetworkEventFilter): Likewise.
* src/libxl/libxl_driver.c: Adjust caller.
* src/lxc/lxc_driver.c: Likewise.
* src/network/bridge_driver.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/remote/remote_driver.c: Likewise.
* src/test/test_driver.c: Likewise.
* src/uml/uml_driver.c: Likewise.
* src/vbox/vbox_tmpl.c: Likewise.
* src/xen/xen_driver.c: Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Coverity complains about default: label in libxl_driver.c not be able
to be reached. It's by design for the code and since it's not necessary
in the code nor does it elicit any compiler/make check warnings - just
remove it rather than adding a coverity[dead_error_begin] tag.

While I'm at it, lxc_driver.c and nodeinfo.c have the same design, so I
removed the default labels and the existing coverity tags.

The NWFilter code has as a deadlock race condition between
the virNWFilter{Define,Undefine} APIs and starting of guest
VMs due to mis-matched lock ordering.

In the virNWFilter{Define,Undefine} codepaths the lock ordering
is

  1. nwfilter driver lock
  2. virt driver lock
  3. nwfilter update lock
  4. domain object lock

In the VM guest startup paths the lock ordering is

  1. virt driver lock
  2. domain object lock
  3. nwfilter update lock

As can be seen the domain object and nwfilter update locks are
not acquired in a consistent order.

The fix used is to push the nwfilter update lock upto the top
level resulting in a lock ordering for virNWFilter{Define,Undefine}
of

  1. nwfilter driver lock
  2. nwfilter update lock
  3. virt driver lock
  4. domain object lock

and VM start using

  1. nwfilter update lock
  2. virt driver lock
  3. domain object lock

This has the effect of serializing VM startup once again, even if
no nwfilters are applied to the guest. There is also the possibility
of deadlock due to a call graph loop via virNWFilterInstantiate
and virNWFilterInstantiateFilterLate.

These two problems mean the lock must be turned into a read/write
lock instead of a plain mutex at the same time. The lock is used to
serialize changes to the "driver->nwfilters" hash, so the write lock
only needs to be held by the define/undefine methods. All other
methods can rely on a read lock which allows good concurrency.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

I noticed that we allow virDomainGetVcpusFlags even for read-only
connections, but that with a flag, it can require guest agent
interaction.  It is feasible that a malicious guest could
intentionally abuse the replies it sends over the guest agent
connection to possibly trigger a bug in libvirt's JSON parser,
or withhold an answer so as to prevent the use of the agent
in a later command such as a shutdown request.  Although we
don't know of any such exploits now (and therefore don't mind
posting this patch publicly without trying to get a CVE assigned),
it is better to err on the side of caution and explicitly require
full access to any domain where the API requires guest interaction
to operate correctly.

I audited all commands that are marked as conditionally using a
guest agent.  Note that at least virDomainFSTrim is documented
as needing a guest agent, but that such use is unconditional
depending on the hypervisor (so the existing domain:fs_trim ACL
should be sufficient there, rather than also requirng domain:write).
But when designing future APIs, such as the plans for obtaining
a domain's IP addresses, we should copy the approach of this patch
in making interaction with the guest be specified via a flag, and
use that flag to also require stricter access checks.

* src/libvirt.c (virDomainGetVcpusFlags): Forbid guest interaction
on read-only connection.
(virDomainShutdownFlags, virDomainReboot): Improve docs on agent
interaction.
* src/remote/remote_protocol.x
(REMOTE_PROC_DOMAIN_SNAPSHOT_CREATE_XML)
(REMOTE_PROC_DOMAIN_SET_VCPUS_FLAGS)
(REMOTE_PROC_DOMAIN_GET_VCPUS_FLAGS, REMOTE_PROC_DOMAIN_REBOOT)
(REMOTE_PROC_DOMAIN_SHUTDOWN_FLAGS): Require domain:write for any
conditional use of a guest agent.
* src/xen/xen_driver.c: Fix clients.
* src/libxl/libxl_driver.c: Likewise.
* src/uml/uml_driver.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/lxc/lxc_driver.c: Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Commit 399394ab removed some coverity
comments which skipped the dead code, so add them back.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

With this patch,user can set throttle blkio cgroup for
lxc domain through virsh tool.
Signed-off-by: NGuan Qiang <hzguanqiang@corp.netease.com>
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

This patch introduces virCgroupSetBlkioDeviceReadIops,
virCgroupSetBlkioDeviceWriteIops,
virCgroupSetBlkioDeviceReadBps and
virCgroupSetBlkioDeviceWriteBps,

we can use these interfaces to set up throttle
blkio cgroup for domain.

This patch also adds the new throttle blkio cgroup
elements to the test xml.
Signed-off-by: NGuan Qiang <hzguanqiang@corp.netease.com>
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

The public virConnectRef and virConnectClose API are just thin
wrappers around virObjectRef/virObjectRef, with added object
validation and an error reset.  Within our backend drivers, use
of the object validation is just an inefficiency since we always
pass valid objects.  More important to think about is what
happens with the error reset; our uses of virConnectRef happened
to be safe (since we hadn't encountered any earlier errors), but
in several cases the use of virConnectClose could lose a real
error.

Ideally, we should also avoid calling virConnectOpen() from
within backend drivers - but that is a known situation that
needs much more design work.

* src/qemu/qemu_process.c (qemuProcessReconnectHelper)
(qemuProcessReconnect): Avoid nested public API call.
* src/qemu/qemu_driver.c (qemuAutostartDomains)
(qemuStateInitialize, qemuStateStop): Likewise.
* src/qemu/qemu_migration.c (doPeer2PeerMigrate): Likewise.
* src/storage/storage_driver.c (storageDriverAutostart):
Likewise.
* src/uml/uml_driver.c (umlAutostartConfigs): Likewise.
* src/lxc/lxc_process.c (virLXCProcessAutostartAll): Likewise.
(virLXCProcessReboot): Likewise, and avoid leaking conn on error.
Signed-off-by: NEric Blake <eblake@redhat.com>

Ever since ACL filtering was added in commit 76397360 (v1.1.1), a
user could still use event registration to obtain access to a
domain that they could not normally access via virDomainLookup*
or virConnectListAllDomains and friends.  We already have the
framework in the RPC generator for creating the filter, and
previous cleanup patches got us to the point that we can now
wire the filter through the entire object event stack.

Furthermore, whether or not domain:getattr is honored, use of
global events is a form of obtaining a list of networks, which
is covered by connect:search_domains added in a93cd08f (v1.1.0).
Ideally, we'd have a way to enforce connect:search_domains when
doing global registrations while omitting that check on a
per-domain registration.  But this patch just unconditionally
requires connect:search_domains, even when no list could be
obtained, based on the following observations:
1. Administrators are unlikely to grant domain:getattr for one
or all domains while still denying connect:search_domains - a
user that is able to manage domains will want to be able to
manage them efficiently, but efficient management includes being
able to list the domains they can access.  The idea of denying
connect:search_domains while still granting access to individual
domains is therefore not adding any real security, but just
serves as a layer of obscurity to annoy the end user.
2. In the current implementation, domain events are filtered
on the client; the server has no idea if a domain filter was
requested, and must therefore assume that all domain event
requests are global.  Even if we fix the RPC protocol to
allow for server-side filtering for newer client/server combos,
making the connect:serach_domains ACL check conditional on
whether the domain argument was NULL won't benefit older clients.
Therefore, we choose to document that connect:search_domains
is a pre-requisite to any domain event management.

Network events need the same treatment, with the obvious
change of using connect:search_networks and network:getattr.

* src/access/viraccessperm.h
(VIR_ACCESS_PERM_CONNECT_SEARCH_DOMAINS)
(VIR_ACCESS_PERM_CONNECT_SEARCH_NETWORKS): Document additional
effect of the permission.
* src/conf/domain_event.h (virDomainEventStateRegister)
(virDomainEventStateRegisterID): Add new parameter.
* src/conf/network_event.h (virNetworkEventStateRegisterID):
Likewise.
* src/conf/object_event_private.h (virObjectEventStateRegisterID):
Likewise.
* src/conf/object_event.c (_virObjectEventCallback): Track a filter.
(virObjectEventDispatchMatchCallback): Use filter.
(virObjectEventCallbackListAddID): Register filter.
* src/conf/domain_event.c (virDomainEventFilter): New function.
(virDomainEventStateRegister, virDomainEventStateRegisterID):
Adjust callers.
* src/conf/network_event.c (virNetworkEventFilter): New function.
(virNetworkEventStateRegisterID): Adjust caller.
* src/remote/remote_protocol.x
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_REGISTER)
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_REGISTER_ANY)
(REMOTE_PROC_CONNECT_NETWORK_EVENT_REGISTER_ANY): Generate a
filter, and require connect:search_domains instead of weaker
connect:read.
* src/test/test_driver.c (testConnectDomainEventRegister)
(testConnectDomainEventRegisterAny)
(testConnectNetworkEventRegisterAny): Update callers.
* src/remote/remote_driver.c (remoteConnectDomainEventRegister)
(remoteConnectDomainEventRegisterAny): Likewise.
* src/xen/xen_driver.c (xenUnifiedConnectDomainEventRegister)
(xenUnifiedConnectDomainEventRegisterAny): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc): Likewise.
* src/libxl/libxl_driver.c (libxlConnectDomainEventRegister)
(libxlConnectDomainEventRegisterAny): Likewise.
* src/qemu/qemu_driver.c (qemuConnectDomainEventRegister)
(qemuConnectDomainEventRegisterAny): Likewise.
* src/uml/uml_driver.c (umlConnectDomainEventRegister)
(umlConnectDomainEventRegisterAny): Likewise.
* src/network/bridge_driver.c
(networkConnectNetworkEventRegisterAny): Likewise.
* src/lxc/lxc_driver.c (lxcConnectDomainEventRegister)
(lxcConnectDomainEventRegisterAny): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

the unix socket /var/run/libvirt/lxc/domain.sock is not created
under the selinux context which configured by <seclabel>.

If we try to connect the domain.sock under the selinux context
of domain in virtLXCProcessConnectMonitor,selinux will deny
this connect operation.

type=AVC msg=audit(1387953696.067:662): avc:  denied  { connectto } for  pid=21206 comm="libvirtd" path="/usr/local/var/run/libvirt/lxc/systemd.sock" scontext=unconfined_u:system_r:svirt_lxc_net_t:s0:c770,c848 tcontext=unconfined_u:system_r:unconfined_t:s0-s0:c0.c1023 tclass=unix_stream_socket

fix this problem by creating socket under selinux context of domain.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

The argument is --handshakefd not --handshake.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The @name variable is VIR_STRDUP()-ed into, but never freed. In fact,
there's no need to duplicate a command line argument since all places
where @name is used expect const char.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Ever since their introduction (commit 1509b802 in v0.5.0 for
virConnectDomainEventRegister, commit 44457238 in v0.8.0 for
virConnectDomainEventDeregisterAny), the event deregistration
functions have been documented as returning 0 on success;
likewise for older registration (only the newer RegisterAny
must return a non-zero callbackID).  And now that we are
adding virConnectNetworkEventDeregisterAny for v1.2.1, it
should have the same semantics.

Fortunately, all of the stateful drivers have been obeying
the docs and returning 0, thanks to the way the remote_driver
tracks things (in fact, the RPC wire protocol is unable to
send a return value for DomainEventRegisterAny, at least not
without adding a new RPC number).  Well, except for vbox,
which was always failing deregistration, due to failure to
set the return value to anything besides its initial -1.

But for local drivers, such as test:///default, we've been
returning non-zero numbers; worse, the non-zero numbers have
differed over time.  For example, in Fedora 12 (libvirt 0.8.2),
calling Register twice would return 0 and 1 [the callbackID
generated under the hood]; while in Fedora 20 (libvirt 1.1.3),
it returns 1 and 2 [the number of callbacks registered for
that event type].  Since we have changed the behavior over
time, and since it differs by local vs. remote, we can safely
argue that no one could have been reasonably relying on any
particular behavior, so we might as well obey the docs, as well
as prepare callers that might deal with older clients to not be
surprised if the docs are not strictly followed.

For consistency, this patch fixes the code for all drivers,
even though it only makes an impact for vbox and for local
drivers.  By fixing all drivers, future copy and paste from
a remote driver to a local driver is less likely to
reintroduce the bug.

Finally, update the testsuite to gain some coverage of the
issue for local drivers, including the first test of old-style
domain event registration via function pointer instead of
event id.

* src/libvirt.c (virConnectDomainEventRegister)
(virConnectDomainEventDeregister)
(virConnectDomainEventDeregisterAny): Clarify docs.
* src/libxl/libxl_driver.c (libxlConnectDomainEventRegister)
(libxlConnectDomainEventDeregister)
(libxlConnectDomainEventDeregisterAny): Match documentation.
* src/lxc/lxc_driver.c (lxcConnectDomainEventRegister)
(lxcConnectDomainEventDeregister)
(lxcConnectDomainEventDeregisterAny): Likewise.
* src/test/test_driver.c (testConnectDomainEventRegister)
(testConnectDomainEventDeregister)
(testConnectDomainEventDeregisterAny)
(testConnectNetworkEventDeregisterAny): Likewise.
* src/uml/uml_driver.c (umlConnectDomainEventRegister)
(umlConnectDomainEventDeregister)
(umlConnectDomainEventDeregisterAny): Likewise.
* src/vbox/vbox_tmpl.c (vboxConnectDomainEventRegister)
(vboxConnectDomainEventDeregister)
(vboxConnectDomainEventDeregisterAny): Likewise.
* src/xen/xen_driver.c (xenUnifiedConnectDomainEventRegister)
(xenUnifiedConnectDomainEventDeregister)
(xenUnifiedConnectDomainEventDeregisterAny): Likewise.
* src/network/bridge_driver.c
(networkConnectNetworkEventDeregisterAny): Likewise.
* tests/objecteventtest.c (testDomainCreateXMLOld): New test.
(mymain): Run it.
(testDomainCreateXML): Check return values.
Signed-off-by: NEric Blake <eblake@redhat.com>