Following the patterns established by lifecycle events, this
creates all the new RPC calls needed to pass callback IDs
for every domain event, and changes the limits in client and
server codes to use modern style when possible.

I've tested all combinations: both 'old client and new server'
and 'new client and old server' continue to work with the old
RPCs, and 'new client and new server' benefit from server-side
filtering with the new RPCs.

* src/remote/remote_protocol.x (REMOTE_PROC_DOMAIN_EVENT_*): Add
REMOTE_PROC_DOMAIN_EVENT_CALLBACK_* counterparts.
* daemon/remote.c (remoteRelayDomainEvent*): Send callbackID via
newer RPC when used with new-style registration.
(remoteDispatchConnectDomainEventCallbackRegisterAny): Extend to
cover all domain events.
* src/remote/remote_driver.c (remoteDomainBuildEvent*): Add new
Callback and Helper functions.
(remoteEvents): Match order of RPC numbers, register new handlers.
(remoteConnectDomainEventRegisterAny)
(remoteConnectDomainEventDeregisterAny): Extend to cover all
domain events.
* src/remote_protocol-structs: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

This patch adds some new RPC call numbers, but for ease of review,
they sit idle until a later patch adds the client counterpart to
drive the new RPCs.  Also for ease of review, I limited this patch
to just the lifecycle event; although converting the remaining
15 domain events will be quite mechanical.  On the server side,
we have to have a function per RPC call, largely with duplicated
bodies (the key difference being that we store in our callback
opaque pointer whether events should be fired with old or new
style); meanwhile, a single function can drive multiple RPC
messages.  With a strategic choice of XDR struct layout, we can
make the event generation code for both styles fairly compact.

I debated about adding a tri-state witness variable per
connection (values 'unknown', 'legacy', 'modern').  It would start
as 'unknown', move to 'legacy' if any RPC call is made to a legacy
event call, and move to 'modern' if the feature probe is made;
then the event code could issue an error if the witness state is
incorrect (a legacy RPC call while in 'modern', a modern RPC call
while in 'unknown' or 'legacy', and a feature probe while in
'legacy' or 'modern').  But while it might prevent odd behavior
caused by protocol fuzzing, I don't see that it would prevent
any security holes, so I considered it bloat.

Note that sticking @acl markers on the new RPCs generates unused
functions in access/viraccessapicheck.c, because there is no new
API call that needs to use the new checks; however, having a
consistent .x file is worth the dead code.

* src/libvirt_internal.h (VIR_DRV_FEATURE_REMOTE_EVENT_CALLBACK):
New feature.
* src/remote/remote_protocol.x
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_CALLBACK_REGISTER_ANY)
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_CALLBACK_DEREGISTER_ANY)
(REMOTE_PROC_DOMAIN_EVENT_CALLBACK_LIFECYCLE): New RPCs.
* daemon/remote.c (daemonClientCallback): Add field.
(remoteDispatchConnectDomainEventCallbackRegisterAny)
(remoteDispatchConnectDomainEventCallbackDeregisterAny): New
functions.
(remoteDispatchConnectDomainEventRegisterAny)
(remoteDispatchConnectDomainEventDeregisterAny): Mark legacy use.
(remoteRelayDomainEventLifecycle): Change message based on legacy
or new use.
(remoteDispatchConnectSupportsFeature): Advertise new feature.
* src/remote_protocol-structs: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

This patch continues the earlier conversion made for network
events, with a goal of introducing server-side event filtering
in a later patch.  Actual behavior is unchanged without
further RPC changes.

* daemon/libvirtd.h (daemonClientPrivate): Alter the tracking of
domain events.
* daemon/remote.c (remoteClientInitHook, remoteClientFreeFunc)
(remoteRelayDomainEvent*)
(remoteDispatchConnectDomainEventRegister)
(remoteDispatchConnectDomainEventRegisterAny): Track domain
callbacks dynamically.

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>

We haven't had a release with network events yet, so we are free
to fix the RPC so that it actually does what we want.  Doing
client-side filtering of per-network events is inefficient if a
connection is only interested in events on a single network out
of hundreds available on the server.  But to do server-side
per-network filtering, the server needs to know which network
to filter on - so we need to pass an optional network over on
registration.  Furthermore, it is possible to have a client with
both a global and per-network filter; in the existing code, the
server sends only one event and the client replicates to both
callbacks.  But with server-side filtering, the server will send
the event twice, so we need a way for the client to know which
callbackID is sending an event, to ensure that the client can
filter out events from a registration that does not match the
callbackID from the server.  Likewise, the existing style of
deregistering by eventID alone is fine; but in the new style,
we have to remember which callbackID to delete.

This patch fixes the RPC wire definition to contain all the
needed pieces of information, and hooks into the server and
client side improvements of the previous patches, in order to
switch over to full server-side filtering of network events.
Also, since we fixed this in time, all released versions of
libvirtd that support network events also support per-network
filtering, so we can hard-code that assumption into
network_event.c.

Converting domain events to server-side filtering will require
the introduction of new RPC numbers, as well as a server
feature bit that the client can use to tell whether to use
old-style (server only supports global events) or new-style
(server supports filtered events), so that is deferred to a
later set of patches.

* src/conf/network_event.c (virNetworkEventStateRegisterClient):
Assume server-side filtering.
* src/remote/remote_protocol.x
(remote_connect_network_event_register_any_args): Add network
argument.
(remote_connect_network_event_register_any_ret): Return callbackID
instead of count.
(remote_connect_network_event_deregister_any_args): Pass
callbackID instead of eventID.
(remote_connect_network_event_deregister_any_ret): Drop unused
type.
(remote_network_event_lifecycle_msg): Add callbackID.
* daemon/remote.c
(remoteDispatchConnectNetworkEventDeregisterAny): Drop unused arg,
and deal with callbackID from client.
(remoteRelayNetworkEventLifecycle): Pass callbackID.
(remoteDispatchConnectNetworkEventRegisterAny): Likewise, and
recognize non-NULL network.
* src/remote/remote_driver.c
(remoteConnectNetworkEventRegisterAny): Pass network, and track
server side id.
(remoteConnectNetworkEventDeregisterAny): Deregister by callback id.
(remoteNetworkBuildEventLifecycle): Pass remote id to event queue.
* src/remote_protocol-structs: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

Right now, the daemon side of RPC events is hard-coded to at most
one callback per eventID.  But when there are hundreds of domains
or networks coupled and multiple conections, then sending every
event to every connection that wants an event, even for the
connections that only care about events for a particular object,
is inefficient.  In order to track more than one callback in the
server, we need to store callbacks by more than just their
eventID.  This patch rearranges the daemon side to store network
callbacks in a dynamic array, which can eventually be used for
multiple callbacks of the same eventID, although actual behavior
is unchanged without further patches to the RPC protocol.  For
ease of review, domain events are saved for a later patch, as
they touch more code.

While at it, fix a bug where a malicious client could send a
negative eventID to cause network event registration to access
outside of array bounds (thankfully not a CVE, since domain
events were already doing the bounds check, and since network
events have not been released).

* daemon/libvirtd.h (daemonClientPrivate): Alter the tracking of
network events.
* daemon/remote.c (daemonClientEventCallback): New struct.
(remoteEventCallbackFree): New function.
(remoteClientInitHook, remoteRelayNetworkEventLifecycle)
(remoteClientFreeFunc)
(remoteDispatchConnectNetworkEventRegisterAny): Track network
callbacks differently.
(remoteDispatchConnectNetworkEventDeregisterAny): Enforce bounds.
Signed-off-by: NEric Blake <eblake@redhat.com>

into remoteDispatchObjectEventSend as it will later be used for both
the domain and network events.

If we fail to get domain, we had to judge whether
it's null or not when doing 'cleanup'.
Signed-off-by: NChen Hanxiao <chenhanxiao@cn.fujitsu.com>

When a client disconnects from libvirtd, all event callbacks
must be removed. This involves running the public API

  virConnectDomainEventDeregisterAny

This code does not run in normal API dispatch context, so no
identity was set. The result was that the access control drivers
denied the attempt to deregister callbacks. The callbacks thus
continued to trigger after the client was free'd causing fairly
predictable use of free memory & a crash.

This can be triggered by any client with readonly access when
the ACL drivers are active.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Signed-off-by: NGiuseppe Scrivano <gscrivan@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

The 'stats' variable was not initialized to NULL, so if some
early validation of the RPC call fails, it is possible to jump
to the 'cleanup' label and VIR_FREE an uninitialized pointer.
This is a security flaw, since the API can be called from a
readonly connection which can trigger the validation checks.

This was introduced in release v0.9.1 onwards by

  commit 158ba873
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Wed Apr 13 16:21:35 2011 +0100

    Merge all returns paths from dispatcher into single path
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

With the existing pkcheck (pid, start time) tuple for identifying
the process, there is a race condition, where a process can make
a libvirt RPC call and in another thread exec a setuid application,
causing it to change to effective UID 0. This in turn causes polkit
to do its permission check based on the wrong UID.

To address this, libvirt must get the UID the caller had at time
of connect() (from SO_PEERCRED) and pass a (pid, start time, uid)
triple to the pkcheck program.

This fix requires that libvirt is re-built against a version of
polkit that has the fix for its CVE-2013-4288, so that libvirt
can see 'pkg-config --variable pkcheck_supports_uid polkit-gobject-1'
Signed-off-by: NColin Walters <walters@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Fixes for argument layouts of various functions in daemon/remote.c

The return values for the virConnectListAllSecrets call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The return values for the virConnectListAllNWFilters call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The return values for the virConnectListAllNodeDevices call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The return values for the virConnectListAllInterfaces call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The return values for the virConnectListAllNetworks call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The return values for the virStoragePoolListAllVolumes call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The return values for the virConnectListAllStoragePools call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The return values for the virConnectListAllDomains call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The return values for the virDomain{SnapshotListAllChildren,ListAllSnapshots}
calls were not bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The return values for the virDomainGetJobStats call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The parameters for the virDomainMigrate*Params RPC calls were
not bounds checks, meaning a malicious client can cause libvirtd
to consume arbitrary memory

This issue was introduced in the 1.1.0 release of libvirt
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Since they make use of file descriptor passing, the remote protocol
methods for virDomainCreate{XML}WithFiles must be written by hand.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This patch implements extensible variants of all internal migration APIs
used for v3 migration.

This is a recurring problem for cygwin :)
For example, see commit 23a4df88.

qemu/qemu_driver.c: In function 'qemuStateInitialize':
qemu/qemu_driver.c:691:13: error: format '%d' expects type 'int', but argument 8 has type 'uid_t' [-Wformat]

* src/qemu/qemu_driver.c (qemuStateInitialize): Add casts.
* daemon/remote.c (remoteDispatchAuthList): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

CVE-2013-1962

remoteDispatchStoragePoolListAllVolumes wasn't freeing the pool.
The pool also held a reference to the connection, preventing it from
getting freed and closing the netcf interface driver, which held two
sockets open.

Commit 979e9c56 missed one case of providing the timestamp
parameter to virNetServerClientGetUNIXIdentity() when WITH_POLKIT0
is defined.

Since PIDs can be reused, polkit prefers to be given
a (PID,start time) pair. If given a PID on its own,
it will attempt to lookup the start time in /proc/pid/stat,
though this is subject to races.

It is safer if the client app resolves the PID start
time itself, because as long as the app has the client
socket open, the client PID won't be reused.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Since the 'nparams' variable passed to virTypedParametersFree is
supposed to represent the size of the 'params' array, it is bad
practice to initialize it to a non-zero value, until the array
has been allocated.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.

Ensure that the driver struct field names match the public
API names. For an API virXXXX we must have a driver struct
field xXXXX. ie strip the leading 'vir' and lowercase any
leading uppercase letters.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>