If a message packet for a invalid stream is received it is just
free'd. This is not good because it doesn't let the client RPC
request counter decrement. If a stream is shutdown with pending
packets the message also isn't released properly because of an
incorrect header type
* daemon/stream.c: Fix message header type
* src/rpc/virnetserverprogram.c: Send dummy reply instead of
free'ing ignored stream message
The stream code was reusing a stream message object before
it was removed from the linked list of filtered messages.
This caused any later queued messages to be completely lost.
* daemon/stream.c: Delay reuse of stream message until
after it is removed from the queue
The virNetServerClient object had a hardcoded limit of 10 requests
per client. Extend constructor to allow it to be passed in as a
configurable variable. Wire this up to the 'max_client_requests'
config parameter in libvirtd
* daemon/libvirtd.c: Pass max_client_requests into services
* src/rpc/virnetserverservice.c, src/rpc/virnetserverservice.h: Pass
nrequests_client_max to clients
* src/rpc/virnetserverclient.c, src/rpc/virnetserverclient.h: Allow
configurable request limit
Version 1.3 of <sys/sdt.h> uses this macro
#define STAP_CAST(t) (size_t)t
that breaks like this if t is a function
remote.c:1775: error: cast from function call of type 'const char *'
to non-matching type 'long unsigned int' [-Wbad-function-cast]
For that to work it should probably look like this
#define STAP_CAST(t) ((size_t)(t))
In systemtap 1.4 this was completely rewritten.
Anyway, before commit df0b57a95a t was always a variable, but now
also a function is used here, namely virNetSASLSessionGetIdentity.
Use an intermediate variable to avoid this problem.
This guts the libvirtd daemon, removing all its networking and
RPC handling code. Instead it calls out to the new virServerPtr
APIs for all its RPC & networking work
As a fallout all libvirtd daemon error reporting now takes place
via the normal internal error reporting APIs. There is no need
to call separate error reporting APIs in RPC code, nor should
code use VIR_WARN/VIR_ERROR for reporting fatal problems anymore.
* daemon/qemu_dispatch_*.h, daemon/remote_dispatch_*.h: Remove
old generated dispatcher code
* daemon/qemu_dispatch.h, daemon/remote_dispatch.h: New dispatch
code
* daemon/dispatch.c, daemon/dispatch.h: Remove obsoleted code
* daemon/remote.c, daemon/remote.h: Rewrite for new dispatch
APIs
* daemon/libvirtd.c, daemon/libvirtd.h: Remove all networking
code
* daemon/stream.c, daemon/stream.h: Update for new APIs
* daemon/Makefile.am: Link to libvirt-net-rpc-server.la
We already have a public virDomainPinVcpu, which implies that
Pin and Vcpu are treated as separate words. Unreleased commit
e261987c introduced virDomainGetVcpupinInfo as the first public
API that used Vcpupin, although we had prior internal uses of
that spelling. For consistency, change the spelling to be two
words everywhere, regardless of whether pin comes first or last.
* daemon/remote.c: Treat vcpu and pin as separate words.
* include/libvirt/libvirt.h.in: Likewise.
* src/conf/domain_conf.c: Likewise.
* src/conf/domain_conf.h: Likewise.
* src/driver.h: Likewise.
* src/libvirt.c: Likewise.
* src/libvirt_private.syms: Likewise.
* src/libvirt_public.syms: Likewise.
* src/libxl/libxl_driver.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/remote/remote_driver.c: Likewise.
* src/xen/xend_internal.c: Likewise.
* tools/virsh.c: Likewise.
* src/remote/remote_protocol.x: Likewise.
* src/remote_protocol-structs: Likewise.
Suggested by Matthias Bolte.
Integer overflow and remote code are never a nice mix.
This has existed since commit 56cd414.
* src/libvirt.c (virDomainGetVcpus): Reject overflow up front.
* src/remote/remote_driver.c (remoteDomainGetVcpus): Avoid overflow
on sending rpc.
* daemon/remote.c (remoteDispatchDomainGetVcpus): Avoid overflow on
receiving rpc.
Move the daemon/remote_generator.pl to src/rpc/gendispatch.pl
and move the src/remote/rpcgen_fix.pl to src/rpc/genprotocol.pl
* daemon/Makefile.am: Update for new name/location of generator
* src/Makefile.am: Update for new name/location of generator
Since we virEventRegisterDefaultImpl is now a public API, callers need
a way to invoke the default registered Handle and Timeout functions. We
already have general functions for these internally, so promote
them to the public API.
v2:
Actually add APIs to libvirt.h
Removes special case code from the generator and handle additional
methods.
The generated version of remoteDispatchDomainPinVcpu(Flags) has no
length check, but this check was useless anyway as it was applied to
data that was already deserialized from its XDR form.
Even though rpc uses 'unsigned int' for the _len parameter that
passes the length of item<length>, the public libvirt APIs all
use 'int' and filter out lengths < 0, except for virDomainSendKey.
* include/libvirt/libvirt.h.in (virDomainSendKey): All other APIs
use int for array length.
* src/libvirt.c (virDomainSendKey): Adjust.
* src/driver.h (virDrvDomainSendKey): Likewise.
* daemon/remote_generator.pl: Likewise.
The position of the struct parameter in the function signature
differs. Instead of hardcoding the handling for this add an annotation
to the .x file to define the position.
When an operation started by virDomainBlockPullAll completes (either with
success or with failure), raise an event to indicate the final status. This
allows an API user to avoid polling on virDomainBlockPullInfo if they would
prefer to use the event mechanism.
* daemon/remote.c: Dispatch events to client
* include/libvirt/libvirt.h.in: Define event ID and callback signature
* src/conf/domain_event.c, src/conf/domain_event.h,
src/libvirt_private.syms: Extend API to handle the new event
* src/qemu/qemu_driver.c: Connect to the QEMU monitor event
for block_stream completion and emit a libvirt block pull event
* src/remote/remote_driver.c: Receive and dispatch events to application
* src/remote/remote_protocol.x: Wire protocol definition for the event
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
src/qemu/qemu_monitor_json.c: Watch for BLOCK_STREAM_COMPLETED event
from QEMU monitor
Signed-off-by: Adam Litke <agl@us.ibm.com>
The generator can handle DomainBlockPullAll and DomainBlockPullAbort.
DomainBlockPull and DomainBlockPullInfo must be written by hand.
* src/remote/remote_protocol.x: provide defines for the new entry points
* src/remote/remote_driver.c daemon/remote.c: implement the client and
server side
* src/remote_protocol-structs: structure definitions for protocol verification
Signed-off-by: Adam Litke <agl@us.ibm.com>
Detected by Coverity. Commit ef21beda was incomplete; it solved
a leak one one path, but not on the other.
* daemon/libvirtd.c (qemudSetLogging): Avoid leak on success.
After successfull virDomainSave/virDomainManagedSave calls
the guest will no longer be active, so the domain ID must
be reset to -1
* daemon/remote_generator.pl: Special case virDomainSave &
virDomainManagedSave for same reason as virDomainDestroy
Remove some special case code that took care of mapping hyper to the
correct C types.
As the list of procedures that is allowed to map hyper to long is fixed
put it in the generator instead annotations in the .x files. This
results in simpler .x file parsing code.
Use macros for hyper to long assignments that perform overflow checks
when long is smaller than hyper. Map hyper to long long by default.
Suggested by Eric Blake.
This introduces a new domain
VIR_DOMAIN_EVENT_ID_CONTROL_ERROR
Which uses the existing generic callback
typedef void (*virConnectDomainEventGenericCallback)(virConnectPtr conn,
virDomainPtr dom,
void *opaque);
This event is intended to be emitted when there is a failure in
some part of the domain virtualization system. Whether the domain
continues to run/exist after the failure is an implementation
detail specific to the hypervisor.
The idea is that with some types of failure, hypervisors may
prefer to leave the domain running in a "degraded" mode of
operation. For example, if something goes wrong with the QEMU
monitor, it is possible to leave the guest OS running quite
happily. The mgmt app will simply loose the ability todo various
tasks. The mgmt app can then choose how/when to deal with the
failure that occured.
* daemon/remote.c: Dispatch of new event
* examples/domain-events/events-c/event-test.c: Demo catch
of event
* include/libvirt/libvirt.h.in: Define event ID and callback
* src/conf/domain_event.c, src/conf/domain_event.h: Internal
event handling
* src/remote/remote_driver.c: Receipt of new event from daemon
* src/remote/remote_protocol.x: Wire protocol for new event
* src/remote_protocol-structs: add new event for checks
In most cases this affects flags parameters that are unsigned in the
public and driver API but signed in the XDR protocol. Switch the
XDR protocol to unsigned for those.
A counterexample is virNWFilterGetXMLDesc. Its flags parameter is signed
in the public API and XDR protocol, but unsigned in the driver API.
virNodeGetFreeMemory used unsigned long long in the public API but
signed hyper in the XDR protocol. Convert the XDR protocol to use
unsigned hyper.
As explained by Eric before, this doesn't affect the on-the-wire protocol.
Several functions return values by reference parameters. This is realized
by passing the members of remote_CALL_ret by reference to the called
function.
The position of this parameters in the function signature follows some
patterns with some exceptions. This patterns and exceptions are hardcoded
in the generator.
Add an insert@<offset> annotation to the remote_CALL_ret struct members
for functions that return lists to remove some of the hardcoded patterns
and exceptions.
The current virDomainMigrateFinish3 method signature attempts to
distinguish two types of errors, by allowing return with ret== 0,
but ddomain == NULL, to indicate a failure to start the guest.
This is flawed, because when ret == 0, there is no way for the
virErrorPtr details to be sent back to the client.
Change the signature of virDomainMigrateFinish3 so it simply
returns a virDomainPtr, in the same way as virDomainMigrateFinish2
The disk locking code will protect against the only possible
failure mode this doesn't account for (loosing conenctivity to
libvirtd after Finish3 starts the CPUs, but before the client
sees the reply for Finish3).
* src/driver.h, src/libvirt.c, src/libvirt_internal.h: Change
virDomainMigrateFinish3 to return a virDomainPtr instead of int
* src/remote/remote_driver.c, src/remote/remote_protocol.x,
daemon/remote.c, src/qemu/qemu_driver.c, src/qemu/qemu_migration.c:
Update for API change
The virDomainMigratePerform3 currently has a single URI parameter
whose meaning varies. It is either
- A QEMU migration URI (normal migration)
- A libvirtd connection URI (peer2peer migration)
Unfortunately when using peer2peer migration, without also
using tunnelled migration, it is possible that both URIs are
required.
This adds a second URI parameter to the virDomainMigratePerform3
method, to cope with this scenario. Each parameter how has a fixed
meaning.
NB, there is no way to actually take advantage of this yet,
since virDomainMigrate/virDomainMigrateToURI do not have any
way to provide the 2 separate URIs
* daemon/remote.c, src/remote/remote_driver.c,
src/remote/remote_protocol.x, src/remote_protocol-structs: Add
the second URI parameter to perform3 message
* src/driver.h, src/libvirt.c, src/libvirt_internal.h: Add
the second URI parameter to Perform3 method
* src/libvirt_internal.h, src/qemu/qemu_migration.c,
src/qemu/qemu_migration.h: Update to handle URIs correctly
This extends the v3 migration protocol such that the
virDomainMigrateBegin3 and virDomainMigratePerform3
methods accept an application supplied XML config for
the target VM.
If the 'xmlin' parameter is NULL, then Begin3 uses the
current guest XML as normal. A driver implementing the
Begin3 method should either reject all non-NULL 'xmlin'
parameters, or strictly validate that the app supplied
XML does not change guest ABI.
The Perform3 method also needed the xmlin parameter to
cope with the Peer2Peer migration sequence.
NB it is not yet possible to use this capability since
neither of the public virDomainMigrate/virDomainMigrateToURI
methods have a way to pass in XML.
* daemon/remote.c, src/remote/remote_driver.c,
src/remote/remote_protocol.x, src/remote_protocol-structs:
Add 'remote_string xmlin' parameter to begin3/perform3
RPC messages
* src/libvirt.c, src/driver.h, src/libvirt_internal.h: Add
'const char *xmlin' parameter to Begin3/Perform3 methods
* src/qemu/qemu_driver.c, src/qemu/qemu_migration.c,
src/qemu/qemu_migration.h: Pass xmlin parameter around
migration methods
The on-the-wire protocol is identical; XDR guarantees that
both 'hyper' and 'unsigned hyper' are transmitted as 8 bytes.
* src/remote/remote_protocol.x (remote_get_version_ret)
(remote_get_lib_version_ret): Match public API.
* daemon/remote_generator.pl: Drop special case.
* src/remote_protocol-structs: Reflect updated type.
<sys/syslimits.h> is not standardized, so portable programs should
not need to rely on it. If there really is something that we need
where <sys/syslimits.h> provided the limit but <limits.h> did not,
then that would be a candidate for fixing in gnulib. But this patch
did not turn up any compilation failures on Linux.
* src/internal.h (includes): Drop unused header.
* daemon/libvirtd.h (includes): Likewise.
* configure.ac (AC_CHECK_HEADERS): Likewise.
Based on a report by Matthias Bolte.
virStreamNew needs to dispatch the error that virGetStream reports
on failure.
remoteCreateClientStream can fail due to virStreamNew or due to
VIR_ALLOC. Report OOM error for VIR_ALLOC failure to report errors
in all error cases.
Remove OOM error reporting from remoteCreateClientStream callers.
Extend the QEMU migration cookie structure to allow information
about the destination host graphics setup to be passed by to
the source host. This will enable seamless migration of any
connected graphics clients
* src/qemu/qemu_migration.c: Add graphics info to migration
cookies
* daemon/libvirtd.c: Always initialize gnutls to enable
x509 cert parsing in QEMU
The public API and RPC over-the-wire format have no flags argument,
so neither should the internal callback API. This simplifies the
RPC generator.
* src/driver.h (virDrvNWFilterDefineXML): Drop argument that does
not match public API.
* src/nwfilter/nwfilter_driver.c (nwfilterDefine): Likewise.
* src/libvirt.c (virNWFilterDefineXML): Likewise.
* daemon/remote_generator.pl: Drop special case.
We were 31/73 on whether to translate; since less than 50% translated
and since VIR_INFO is less than VIR_WARN which also doesn't translate,
this makes sense.
* cfg.mk (sc_prohibit_gettext_markup): Add VIR_INFO, since it
falls between WARN and DEBUG.
* daemon/libvirtd.c (qemudDispatchSignalEvent, remoteCheckAccess)
(qemudDispatchServer): Adjust offenders.
* daemon/remote.c (remoteDispatchAuthPolkit): Likewise.
* src/network/bridge_driver.c (networkReloadIptablesRules)
(networkStartNetworkDaemon, networkShutdownNetworkDaemon)
(networkCreate, networkDefine, networkUndefine): Likewise.
* src/qemu/qemu_driver.c (qemudDomainDefine)
(qemudDomainUndefine): Likewise.
* src/storage/storage_driver.c (storagePoolCreate)
(storagePoolDefine, storagePoolUndefine, storagePoolStart)
(storagePoolDestroy, storagePoolDelete, storageVolumeCreateXML)
(storageVolumeCreateXMLFrom, storageVolumeDelete): Likewise.
* src/util/bridge.c (brProbeVnetHdr): Likewise.
* po/POTFILES.in: Drop src/util/bridge.c.
glibc 2.13.90 has obsoleted its rpc implementation in favour of
the one provided by the TI-RPC library:
> * The RPC implementation in libc is obsoleted. Old programs keep working
> but new programs cannot be linked with the routines in libc anymore.
> Programs in need of RPC functionality must be linked against TI-RPC.
> The TI-RPC implemtation is IPv6 enabled and there are other benefits.
>
> Visible changes of this change include (obviously) the inability to
> link
> programs using RPC functions without referencing the TI-RPC library,
> the
> removal of the RPC headers from the glibc headers, and the lack of
> symbols defined in <rpc/netdb.h> when <netdb.h> is installed.
> Implemented by Ulrich Drepper.
(from glibc NEWS)
Thus with recent glibc, we need to try linking with -ltirpc when looking
for the XDR functions. The daemon also needs to use XDR_CFLAGS to be able
to find the XDR headers stored in /usr/include/tirpc.
When using TI-RPC, there are some warnings about redundant declarations, but
the fix probably belongs in other modules:
/usr/include/tirpc/rpc/rpcent.h:68:13: warning: redundant redeclaration of
'setrpcent' [-Wredundant-decls]
/usr/include/rpc/netdb.h:53:13: note: previous declaration of 'setrpcent'
was here
/usr/include/tirpc/rpc/rpcent.h:69:13: warning: redundant redeclaration of
'endrpcent' [-Wredundant-decls]
/usr/include/rpc/netdb.h:54:13: note: previous declaration of 'endrpcent'
was here
/usr/include/tirpc/rpc/rpc.h:84:12: warning: redundant redeclaration of
'bindresvport' [-Wredundant-decls]
/usr/include/netinet/in.h:440:12: note: previous declaration of
'bindresvport' was here
These VIR_XXXX0 APIs make us confused, use the non-0-suffix APIs instead.
How do these coversions works? The magic is using the gcc extension of ##.
When __VA_ARGS__ is empty, "##" will swallow the "," in "fmt," to
avoid compile error.
example: origin after CPP
high_level_api("%d", a_int) low_level_api("%d", a_int)
high_level_api("a string") low_level_api("a string")
About 400 conversions.
8 special conversions:
VIR_XXXX0("") -> VIR_XXXX("msg") (avoid empty format) 2 conversions
VIR_XXXX0(string_literal_with_%) -> VIR_XXXX(%->%%) 0 conversions
VIR_XXXX0(non_string_literal) -> VIR_XXXX("%s", non_string_literal)
(for security) 6 conversions
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
* daemon/Makefile.am (DAEMON_GENERATED, remote_dispatch_*.h)
(qemu_dispatch_*.h): Update to live in srcdir, since they are
distributed.
Detected by Daniel P. Berrange's autobuilder.
This matches the public API and helps to get rid of some special
case code in the remote generator.
Rename driver API functions and XDR protocol structs.
No functional change included outside of the remote generator.
Stop storing the generated files for the remote protocol client
and server in source control. The generated files will still be
included in the result of 'make dist' to avoid end-users needing
to generate the files
Signed-off-by: Eric Blake <eblake@redhat.com>
Unfortunately, this means that the strings marked for translation
in generated files are not picked up by gnulib's syntax-check,
I'm working on fixing that in gnulib.
* .gitignore, cfg.mk, po/POTFILES.in: Reflect deletion.
Always generate the rpc files, and require rpcgen during bootstrap.
* daemon/Makefile.am: Removed generated files with
maintainer-clean target
* src/Makefile.am: Removed generated files with
maintainer-clean target. Always run 'rpcgen' if
generated files are missing
In preparation for removing generated files, it is necessary
to tell automake that the generated files must be distributed
but not directly compiled (since they are included into the
body of a larger .c file that is compiled). Hence, even though
these files are code and not headers in the strict sense of
the word, it is easier to rename them to .h for automake's sake.
* daemon/remote_client_bodies.c: Rename to .h.
* daemon/qemu_client_bodies.c: Likewise.
* src/remote/remote_client_bodies.c: Likewise.
* src/remote/qemu_client_bodies.c: Likewise.
* daemon/Makefile.am (remote_dispatch_bodies.c)
(qemu_dispatch_bodies.c): Rename to .h.
(remote.c, EXTRA_DIST): Reflect rename.
* daemon/remote.c: Likewise.
* daemon/remote_generator.pl: Likewise.
* src/Makefile.am (remote/remote_driver.c): Likewise.
* src/remote/remote_driver.c: Likewise.
* po/POTFILES.in: Likewise.
* cfg.mk (exclude_file_name_regexp--sc_require_config_h)
(exclude_file_name_regexp--sc_require_config_h_first)
(exclude_file_name_regexp--sc_prohibit_empty_lines_at_EOF):
Likewise.
This patch just covers the simple functions without explicit return
values. There is more to be handled.
The generator collects the members of the XDR argument structs and uses
this information to generate the function bodies.
Exclude the generated files from offending syntax-checks.
Suggested by Richard W.M. Jones
Clang found three instances of uninitialized use of nparams in
the cleanup path. Unfortunately, one is a false positive: clang
couldn't see that ret->params.params_val is guaranteed to be
NULL unless allocated within a function, and that nparams is
guaranteed to be assigned prior to the allocation; hoisting the
assignment to nparams to be earlier in the function shuts up
that false positive. But two of the reports also happened to
highlight a real bug - the error path can dereference NULL.
Regression introduced in commit 158ba873.
* daemon/remote.c (remoteDispatchDomainGetMemoryParameters)
(remoteDispatchDomainGetBlkioParameters): Don't clear fields if
array was not allocated.
(remoteDispatchDomainGetSchedulerParameters): Initialize nparams
earlier.
Replace some occurrances of
virDomainPtr domain;
virNetworkPtr network;
With
virDomainPtr dom;
virNetworkPtr net;
* daemon/remote.c: Fix variable naming to follow standard
Replace cases of
type = virConnectGetType(conn);
if (type == NULL)
goto cleanup;
With
if (!(type = virConnectGetType(conn)))
goto cleanup;
* daemon/remote.c: Write error checks in compat form
Replace all occurrances of
if (....) {
goto cleanup;
}
With
if (.....)
goto cleanup;
to save one line of code
* daemon/remote.c: Remove curly braces on single line conditionals
The libvirt APIs reserve any negative value for indicating an
error. Thus checks
if (virXXXX() == -1)
Should instead be
if (virXXXX() < 0)
* daemon/remote.c: s/ == -1/ < 0/
The dispatcher functions have numerous places where they
return to the caller. This leads to duplicated cleanup
code, often resulting in memory leaks. It makes it harder
to ensure that errors are dispatched before freeing objects,
which may overwrite the original error.
The standard pattern is now
remoteDispatchXXX(...) {
int rv = -1;
....
if (XXX < 0)
goto cleanup;
...
if (XXXX < 0)
goto cleanup;
...
rv = 0;
cleanup:
if (rv < 0)
remoteDispatchError(rerr);
...free all other stuff..
return rv;
}
* daemon/remote.c: Centralize all cleanup paths
* daemon/stream.c: s/remoteDispatchConnError/remoteDispatchError/
* daemon/dispatch.c, daemon/dispatch.h: Replace
remoteDispatchConnError with remoteDispatchError
removing unused virConnectPtr
To install it, disable libvirtd sysv initscript:
chkconfig libvirtd off
service libvirtd stop
and enable libvirtd upstart job:
cp /usr/share/doc/libvirt-*/libvirtd.upstart \
/etc/init/libvirtd.conf
initctl reload-configuration
initctl start libvirtd
Test:
initctl status libvirtd
libvirtd start/running, process 3929
killall -9 libvirtd
initctl status libvirtd
libvirtd start/running, process 4047
I looked into the possibility to use the upstart script from Ubuntu or
at least getting inspiration from it but that's not possible. "expect
daemon" is a nice thing but it only works if the process is defined with
exec stanza instead of script ... no script. Unfortunately, with exec
stanza environment variables can only be set within upstart script
(i.e., configuration in /etc/sysconfig/libvirtd can't work). Hence, we
need to use script stanza, source sysconfig, and execute libvirtd
without --daemon. For similar reasons we can't use limit stanza and need
to handle DAEMON_COREFILE_LIMIT in job's script.
The daemon dispatcher code had an obsolete macro
#define REMOTE_DEBUG(fmt, ...) VIR_DEBUG(fmt, __VA_ARGS__)
This can be trivially removed
* daemon/remote.c: s/REMOTE_DEBUG/VIR_DEBUG/
Many functions did not check for whether a connection was
open. Replace the macro which obscures control flow, with
explicit checks, and ensure all dispatcher code has checks.
* daemon/remote.c: Add connection checks
A lot of code in libvirtd's dispatcher used the style
dom = get_nonnull_domain (conn, args->dom);
Instead of the normal libvirt style
dom = get_nonnull_domain(conn, args->dom);
* daemon/remote.c: Remove all whitelist before function brackets
The systemtap directory for tapsets is called
/usr/share/systemtap/tapset
Not
/usr/share/systemtap/tapsets
* daemon/Makefile.am,libvirt.spec.in: s/tapsets/tapset/
The daemon loops over the linked list of streams when a client
quits, closing any that the client hadn't already closed. Except
it didn't ever move to the next element in the list!
* daemon/stream.c: Fix loop over linked list of streams
The Open Nebula driver has been unmaintained since it was first
introduced. The only commits have been for tree-wide cleanups.
It also has a major design flaw, in that it only knows about guests
that it has created itself, which makes it of very limited use.
Discussions wrt evolution of the VMWare ESX driver, concluded that
it should limit itself to single-node ESX operation and not try to
manage the multi-node architecture of VirtualCenter. Open Nebula
is a cluster like Virtual Center, not a single node system, so
the same reasoning applies.
The DeltaCloud project includes an Open Nebula driver and is a much
better fit architecturally, since it is explicitly targetting the
distributed multihost cluster scenario.
Thus this patch deletes the libvirt Open Nebula driver with the
recommendation that people use DeltaCloud for managing it instead.
* configure.ac: Remove probe for xmlrpc & --with-one arg
* daemon/Makefile.am, daemon/libvirtd.c, src/Makefile.am: Remove
ONE driver build
* src/opennebula/one_client.c, src/opennebula/one_client.h,
src/opennebula/one_conf.c, src/opennebula/one_conf.h,
src/opennebula/one_driver.c, src/opennebula/one_driver.c: Delete
files
* autobuild.sh, libvirt.spec.in, mingw32-libvirt.spec.in: Remove
build rules for Open Nebula
* docs/drivers.html.in, docs/sitemap.html.in: Remove reference
to OpenNebula
* docs/drvone.html.in: Delete file
Commit f44bfb7 was supposed to make sure no additional libvirt API (esp.
*Free) is called before remoteDispatchConnError() is called on error.
However, the patch missed two instances.
Child processes don't always reach _exit(); if they die from a
signal, then any messages should still be accurate. Most users
either expect a 0 status (thankfully, if status==0, then
WIFEXITED(status) is true and WEXITSTATUS(status)==0 for all
known platforms) or were filtering on WIFEXITED before printing
a status, but a few were missing this check. Additionally,
nwfilter_ebiptables_driver was making an assumption that works
on Linux (where WEXITSTATUS shifts and WTERMSIG just masks)
but fails on other platforms (where WEXITSTATUS just masks and
WTERMSIG shifts).
* src/util/command.h (virCommandTranslateStatus): New helper.
* src/libvirt_private.syms (command.h): Export it.
* src/util/command.c (virCommandTranslateStatus): New function.
(virCommandWait): Use it to also diagnose status from signals.
* src/security/security_apparmor.c (load_profile): Likewise.
* src/storage/storage_backend.c
(virStorageBackendQEMUImgBackingFormat): Likewise.
* src/util/util.c (virExecDaemonize, virRunWithHook)
(virFileOperation, virDirCreate): Likewise.
* daemon/remote.c (remoteDispatchAuthPolkit): Likewise.
* src/nwfilter/nwfilter_ebiptables_driver.c (ebiptablesExecCLI):
Likewise.
Bug https://bugzilla.redhat.com/show_bug.cgi?id=689374 reported libvirtd
crash during error dispatch.
The reason is that libvirtd uses remoteDispatchConnError() with non-NULL
conn parameter which means that virConnGetLastError() is used instead of
its thread safe replacement virGetLastError().
So when several libvirtd threads are reporting errors at the same time,
the errors can get mixed or corrupted or in case of bad luck libvirtd
itself crashes.
Since Daniel B. is going to rewrite this code from scratch on top of his
RPC infrastructure, I tried to come up with a minimal fix. Thus,
remoteDispatchConnError() now just ignores its conn argument and always
calls virGetLastError(). However, several callers had to be touched as
well, since no libvirt API is allowed to be called before dispatching
the error. Doing so would reset the error and we would have nothing to
dispatch. As a result of that, the code is not very nice but that
doesn't really make daemon/remote.c worse than it is now :-) And it will
all die soon, which is good.
The bug report also contains a reproducer in C which detects both mixed
up error messages and libvirtd crash. Before this patch, I was able to
crash libvirtd in about 20 seconds up to 3 minutes depending on number
of CPU cores (more is better) and luck.
Add a new xen driver based on libxenlight [1], which is the primary
toolstack starting with Xen 4.1.0. The driver is stateful and runs
privileged only.
Like the existing xen-unified driver, the libxenlight driver is
accessed with xen:// URI. Driver selection is based on the status
of xend. If xend is running, the libxenlight driver will not load
and xen:// connections are handled by xen-unified. If xend is not
running *and* the libxenlight driver is available, xen://
connections are deferred to the libxenlight driver.
V6:
- Address several code style issues noted by Daniel Veillard
- Make drive work with xen:/// URI
- Hold domain object reference while domain is injected in
libvirt event loop. Race found and fixed by Markus Groß.
V5:
- Ensure events are unregistered when domain private data
is destroyed. Discovered and fixed by Markus Groß.
V4:
- Handle restart of libvirtd, reconnecting to previously
started domains
- Rebased to current master
- Tested against Xen 4.1 RC7-pre (c/s 22961:c5d121fd35c0)
V3:
- Reserve vnc port within driver when autoport=yes
V2:
- Update to Xen 4.1 RC6-pre (c/s 22940:5a4710640f81)
- Rebased to current master
- Plug memory leaks found by Stefano Stabellini and valgrind
- Handle SHUTDOWN_crash domain death event
[1] http://lists.xensource.com/archives/html/xen-devel/2009-11/msg00436.html
This is the part allowing to dynamically resize the debug log
buffer from it's default 64kB size. The buffer is now dynamically
allocated.
It adds a new API virLogSetBufferSize() which resizes the buffer
If passed a zero size, the buffer is deallocated and we do the small
optimization of not formatting messages which are not output anymore.
On the daemon side, it just adds a new option log_buffer_size to
libvirtd.conf and call virLogSetBufferSize() if needed
* src/util/logging.h src/util/logging.c src/libvirt_private.syms:
make buffer dynamic and add virLogSetBufferSize() internal API
* daemon/libvirtd.conf: document the new log_buffer_size option
* daemon/libvirtd.c: read and use the new log_buffer_size option
When building libvirt without libvirtd, I receive the following errors:
make[1]: Leaving directory `/home/wency/source/test/libvirt/src'
(cd daemon && make top_distdir=../libvirt-0.8.8 distdir=../libvirt-0.8.8/daemon \
am__remove_distdir=: am__skip_length_check=: am__skip_mode_fix=: distdir)
make[1]: Entering directory `/home/wency/source/test/libvirt/daemon'
make[1]: *** No rule to make target `libvirtd.8.in', needed by `distdir'. Stop.
This bug was caused by commit 6db98a2d.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Not all applications have an existing event loop they need
to integrate with. Forcing them to implement the libvirt
event loop integration APIs is an undue burden. This just
exposes our simple poll() based implementation for apps
to use. So instead of calling
virEventRegister(....callbacks...)
The app would call
virEventRegisterDefaultImpl()
And then have a thread somewhere calling
static bool quit = false;
....
while (!quit)
virEventRunDefaultImpl()
* daemon/libvirtd.c, tools/console.c,
tools/virsh.c: Convert to public event loop APIs
* include/libvirt/libvirt.h.in, src/libvirt_private.syms: Add
virEventRegisterDefaultImpl and virEventRunDefaultImpl
* src/util/event.c: Implement virEventRegisterDefaultImpl
and virEventRunDefaultImpl using poll() event loop
* src/util/event_poll.c: Add full error reporting
* src/util/virterror.c, include/libvirt/virterror.h: Add
VIR_FROM_EVENTS
The event loop implementation is used by more than just the
daemon, so move it into the shared area.
* daemon/event.c, src/util/event_poll.c: Renamed
* daemon/event.h, src/util/event_poll.h: Renamed
* tools/Makefile.am, tools/console.c, tools/virsh.c: Update
to use new virEventPoll APIs
* daemon/mdns.c, daemon/mdns.c, daemon/Makefile.am: Update
to use new virEventPoll APIs
The daemon code calls virEventAddHandleImpl directly instead
of calling the wrapper virEventAddHandle.
* tools/console.c, daemon/libvirtd.c, daemon/mdns.c: Convert to
use primary event APIs
In case of imminent crash or upon request (signal USR2),
dump the logging buffer to the libvirtd.log file for
post-mortem analysis
* daemon/libvirtd.c: create a sig_fatal() handler connected to
SIGFPE SIGSEGV SIGILL SIGABRT SIGBUS and SIGUSR2, just dumping
the log buffer using virLogEmergencyDumpAll
As the file may grow quite a bit especially with debug turned on.
* daemon/libvirtd.logrotate.in daemon/Makefile.am libvirt.spec.in:
add new logrotate file for the daemon log
Syslog is not the best place to go search for libvirt error
logs, change it to a default file output libvirtd.log, but
still keep standard error if not run as a daemon.
Depending on whether it's run as root or user, the log is saved
in the local state dir or in $HOME/.libvirt.
* daemon/libvirtd.c: change default logging to go to libvirtd.log
Right now, 'man libvirtd' includes information that depends on
configure results, so it must be generated on the fly and live
in $(builddir); however, requiring pod2man on all end user
machines is overkill. Meanwhile, 'man virsh' doesn't mention
any configure results, so it can be built at 'make dist' time.
If that situation changes in the future, we can generate virsh.1
in the same way that we generate libvirtd.8.
* daemon/Makefile.am (libvirtd.8.in): New rule, to run pod2man in
advance of distribution.
(libvirtd.8): Use only sed from tarball.
(EXTRA_DIST): Ship new file.
(libvirtd.pod): Delete unused rule.
(man8_MANS): Let automake know which section to use.
(CLEANFILES, MAINTAINERCLEANFILES): Adjust to new files.
* tools/Makefile.am (dist_man1_MANS): Distribute pre-built man
pages, fine since they don't require any substitution.
(virt-xml-validate.1, virt-pki-validate.1): Change input source.
(virsh.1): Build into srcdir.
(CLEANFILES, MAINTAINERCLEANFILES): Adjust to new build style.
* daemon/.gitignore: Update.
Reported by Diego Elio Pettenò.
Done mechanically with:
$ git grep -l '\bDEBUG0\? *(' | xargs -L1 sed -i 's/\bDEBUG0\? *(/VIR_&/'
followed by manual deletion of qemudDebug in daemon/libvirtd.c, along
with a single 'make syntax-check' fallout in the same file, and the
actual deletion in src/util/logging.h.
* src/util/logging.h (DEBUG, DEBUG0): Delete.
* daemon/libvirtd.h (qemudDebug): Likewise.
* global: Change remaining clients over to VIR_DEBUG counterpart.
To make it easier to investigate problems with async event
delivery, add two more debugging lines
* daemon/remote.c: Debug when an event is queued for dispatch
* src/remote/remote_driver.c: Debug when an event is received
for processing
Fixes test failure that was overlooked after commit 1e1f7a8950.
* daemon/Makefile.am (check-local): Let 'make check' fail on error.
* daemon/test_libvirtd.aug: Move qemu-specific option...
* src/qemu/test_libvirtd_qemu.aug: ...into correct test.
* src/qemu/libvirtd_qemu.aug: Parse new option.
Regression introduced in commit e6b68d7 (Nov 2010).
Prior to that point, handlesAlloc was always a multiple of
EVENT_ALLOC_EXTENT (10), and was an int (so even if the subtraction
had been able to wrap, a negative value would be less than the count
not try to free the handles array). But after that point,
VIR_RESIZE_N made handlesAlloc grow geometrically (with a pattern of
10, 20, 30, 45 for the handles array) but still freed in multiples of
EVENT_ALLOC_EXTENT; and the count changed to size_t. Which means that
after 31 handles have been created, then 30 handles destroyed,
handlesAlloc is 5 while handlesCount is 1, and since (size_t)(1 - 5)
is indeed greater than 1, this then tried to free 10 elements, which
had the awful effect of nuking the handles array while there were
still live handles.
Nuking live handles puts libvirtd in an inconsistent state, and was
easily reproducible by starting and then stopping 60 faqemu guests.
* daemon/event.c (virEventCleanupTimeouts, virEventCleanupHandles):
Avoid integer wrap-around causing us to delete the entire array
while entries are still active.
* tests/eventtest.c (mymain): Expose the bug.
Add a hook to the error reporting APIs to allow specific
error messages to be filtered out. Wire up libvirtd to
remove VIR_ERR_NO_DOMAIN & similar error codes from the
logs. They are still logged at DEBUG level.
* daemon/libvirtd.c: Filter VIR_ERR_NO_DOMAIN and friends
* src/libvirt_private.syms, src/util/virterror.c,
src/util/virterror_internal.h: Hook for changing error
reporting level
This reverts the additions in commit
abff683f78
taking us back to state where all errors are fully logged
in both libvirtd and normal clients.
THe intent was to stop VIR_ERR_NO_DOMAIN (No such domain
with UUID XXXX) messages from client apps polluting syslog
The change affected all error codes, but more seriously,
it also impacted errors from internal libvirtd infrastructure
For example guest autostart no longer logged errors. The
libvirtd network code no longer logged some errors. This
makes debugging incredibly hard
* daemon/libvirtd.c: Remove error log priority filter
* src/util/virterror.c, src/util/virterror_internal.h: Remove
callback for overriding log priority
This bug has been present since before the time that commit
f8a519 (Dec 2008) tried to make the dispatch loop re-entrant.
Dereferencing eventLoop.handles outside the lock risks crashing, since
any other thread could have reallocated the array in the meantime.
It's a narrow race window, however, and one that would have most
likely resulted in passing bogus data to the callback rather than
actually causing a segv, which is probably why it has gone undetected
this long.
* daemon/event.c (virEventDispatchHandles): Cache data while
inside the lock, as the array might be reallocated once outside.
Setting unix_sock_group to something else than default "root" in
/etc/libvirt/libvirtd.conf prevents system libvirtd from dumping core on
crash. This is because we used setgid(unix_sock_group) before binding to
/var/run/libvirt/libvirt-sock* and setgid() back to original group.
However, if a process changes its effective or filesystem group ID, it
will be forbidden from leaving core dumps unless fs.suid_dumpable sysctl
is set to something else then 0 (and it is 0 by default).
Changing socket's group ownership after bind works better. And we can do
so without introducing a race condition since we loosen access rights by
changing the group from root to something else.
* .gnulib: Update to latest.
* bootstrap.conf (gnulib_modules): Import pipe-posix and waitpid
for mingw.
* src/remote/remote_driver.c (pipe) [WIN32]: Drop dead macro.
* daemon/event.c (pipe) [WIN32]: Drop dead function.
* src/util/threads.h (virThreadID): New prototype.
* src/util/threads-pthread.c (virThreadID): New function.
* src/util/threads-win32.c (virThreadID): Likewise.
* src/libvirt_private.syms (threads.h): Export it.
* daemon/event.c (virEventInterruptLocked): Use it to avoid
warning on BSD systems.
This reverts commit
Log all errors at level INFO to stop polluting syslog
04bd0360f3.
and makes virRaiseErrorFull() log errors at debug priority
when called from inside libvirtd. This stops libvirtd from
polluting it's own log with client errors at error priority
that'll be reported and logged on the client side anyway.
libvirtd no longer deals with SIGCHLD in its signal handler
since the QEMU driver switched to always daemonize processes.
Thus remove the sigaction for it, to avoid warning log
messages
* daemon/libvirtd.c: Don't catch SIGCHLD
The virt-mem program is no longer shipped, but was still being
referenced at the bottom of the virsh and libvirtd man pages.
This patch removes it from those man pages, addressing
BZ# 639603:
https://bugzilla.redhat.com/show_bug.cgi?id=639603
* daemon/libvirtd.h (qemud_server): Change types of members
tracking array sizes, and add allocation trackers.
* daemon/event.c (virEventLoop): Likewise.
(virEventAddHandleImpl, virEventAddTimeoutImpl)
(virEventCleanupTimeouts, virEventCleanupHandles): Use
VIR_RESIZE_N instead of VIR_REALLOC_N. Tweak debug messages to
match type changes.
* daemon/libvirtd.c (qemudDispatchServer, qemudRunLoop): Likewise.
Per the gettext developer:
http://lists.gnu.org/archive/html/bug-gnu-utils/2010-10/msg00019.htmlhttp://lists.gnu.org/archive/html/bug-gnu-utils/2010-10/msg00021.html
gettext() doesn't work correctly on all platforms unless you have
called setlocale(). Furthermore, gnulib's gettext.h has provisions
for setting up a default locale, which is the preferred method for
libraries to use gettext without having to call textdomain() and
override the main program's default domain (virInitialize already
calls bindtextdomain(), but this is insufficient without the
setlocale() added in this patch; and a redundant bindtextdomain()
in this patch doesn't hurt, but serves as a good example for other
packages that need to bind a second translation domain).
This patch is needed to silence a new gnulib 'make syntax-check'
rule in the next patch.
* daemon/libvirtd.c (main): Setup locale and gettext.
* src/lxc/lxc_controller.c (main): Likewise.
* src/security/virt-aa-helper.c (main): Likewise.
* src/storage/parthelper.c (main): Likewise.
* tools/virsh.c (main): Fix exit status.
* src/internal.h (DEFAULT_TEXT_DOMAIN): Define, for gettext.h.
(_): Simplify definition accordingly.
* po/POTFILES.in: Add src/storage/parthelper.c.
Similarly to deprecating close(), I am now deprecating fclose() and
introduce VIR_FORCE_FCLOSE() and VIR_FCLOSE(). Also, fdopen() is replaced with
VIR_FDOPEN().
Most of the files are opened in read-only mode, so usage of
VIR_FORCE_CLOSE() seemed appropriate. Others that are opened in write
mode already had the fclose()< 0 check and I converted those to
VIR_FCLOSE()< 0.
I did not find occurrences of possible double-closed files on the way.
When closing open streams after a client quits, the event
callback was not removed. This mean that poll() was using
a closed FD and returning POLLNVAL in a busy-wait loop.
* daemon/stream.c: Disconnect stream callbacks
The code currently uses pthreads APIs directly. This is not
portable to Win32 threads. Switch it over to use the portability
APIs. Also add a wrapper for pipe() which is subtely different
on Win32
* daemon/event.c: Switch to use virMutex & virThread.
This provides an implementation of the virDomainOpenConsole
API for the remote driver client and server.
* daemon/remote.c: Server side impl
* src/remote/remote_driver.c: Client impl
* src/remote/remote_protocol.x: Wire definition
Using automated replacement with sed and editing I have now replaced all
occurrences of close() with VIR_(FORCE_)CLOSE() except for one, of
course. Some replacements were straight forward, others I needed to pay
attention. I hope I payed attention in all the right places... Please
have a look. This should have at least solved one more double-close
error.
Commit e8066d53 broke the build with polkit0:
remote.c: In function 'remoteDispatchAuthPolkit':
remote.c:4177: error: 'rv' undeclared (first use in this function)
Add missing identifier.
Revert most of commit a8b5f9bd27.
The audit hooks will be re-added directly in the QEMU driver code
in a future commit
* daemon/remote.c: Remove all audit logging hooks
* src/qemu/qemu_driver.c: Remove all audit logging hooks
With SystemTap 1.0 a part of the generated macros in probes.h
expands to:
volatile __typeof__(((name))) arg2 = (name);
GCC reports an 'invalid initialize' error when name has type
char[]. Therfore, add casts to char* to avoid this.
This 1-liner was actually written by Eric Blake, over IRC. It
addresses a compilation failure in make dist and make rpm for
systems without the dtrace/systemtap development libraries
installed.
It is useful to know where the client is connecting from,
so include the socket address in probe data.
* daemon/libvirtd.h: Use virSocketAddr for storing client
address and keep printable address handy for logging
* daemon/libvirtd.c: Include socket address in client
connect/disconnect probes
* daemon/probes.d: Add socket address to probes
* examples/systemtap/client.stp: Print socket address
* src/util/network.h: Add sockaddr_un to virSocketAddr union
Adds initial support for dtrace static probes in libvirtd
daemon, assuming use of systemtap dtrace compat shim on
Linux. The probes are inserted for network client connect,
disconnect, TLS handshake states and authentication protocol
states.
This can be tested by running the xample program and then
attempting to connect with any libvirt client (virsh,
virt-manager, etc).
# stap examples/systemtap/client.stp
Client fd=44 connected readonly=0
Client fd=44 auth polkit deny pid:24997,uid:500
Client fd=44 disconnected
Client fd=46 connected readonly=1
Client fd=46 auth sasl allow test
Client fd=46 disconnected
The libvirtd.stp file should also really not be required,
since it is duplicated info that is already available in
the main probes.d definition file. A script to autogenerate
the .stp file is needed, either in libvirtd tree, or better
as part of systemtap itself.
* Makefile.am: Add examples/systemtap subdir
* autobuild.sh: Disable dtrace for mingw32
* configure.ac: Add check for dtrace
* daemon/.gitignore: Ignore generated dtrace probe file
* daemon/Makefile.am: Build dtrace probe header & object
files
* daemon/libvirtd.stp: SystemTAP convenience probeset
* daemon/libvirtd.c: Add connect/disconnect & TLS probes
* daemon/remote.c: Add SASL and PolicyKit auth probes
* daemon/probes.d: Master probe definition
* daemon/libvirtd.h: Add convenience macro for probes
so that compilation is a no-op when dtrace is not available
* examples/systemtap/Makefile.am, examples/systemtap/client.stp
Example systemtap script using dtrace probe markers
* libvirt.spec.in: Enable dtrace on F13/RHEL6
* mingw32-libvirt.spec.in: Force disable dtrace
The addrToString functionality is now available via the
virSocketFormatAddrFull method.
* daemon/remote.c, src/remote/remote_driver.c: Remove
addrToString methods
If getnameinfo() with NI_NUMERICHOST set fails, there are no
grounds to expect inet_ntop to succeed, since these calls
are functionally equivalent. Remove useless inet_ntop code
in the getnameinfo() error path.
* daemon/remote.c, src/remote/remote_driver.c: Remove
calls to inet_ntop
The libvirt_util.la library was mistakenly linked into libvirtd
directly. Since libvirt_util.la is already linked to libvirt.so,
this resulted in libvirtd getting two copies of the code and
more critically 2 copies of static global variables.
Testing in turn exposed a issue with loadable modules. The
gnulib replacement functions are not exported to loadable
modules. Rather than trying to figure out the name sof all
gnulib functions & export them, just linkage all loadable
modules against libgnu.la statically.
* daemon/Makefile.am: Remove linkage of libvirt_util.la
and libvirt_driver.la
* src/Makefile.am: Link driver modules against libgnu.la
* src/libvirt.c: Don't try to load modules which were
compiled out
* src/libvirt_private.syms: Export all other internal
symbols that are required by drivers
Most operations are audited at the libvirtd level; auditing in
src/libvirt.c would result in two audit entries per operation (one in
the client, one in libvirtd).
The only exception is a domain stopping of its own will (e.g. because
the user clicks on "shutdown" inside the interface). There can often be
no client connected at the time the domain stops, so libvirtd does not
have any virConnectPtr object on which to attach an event watch. This
patch therefore adds auditing directly inside the qemu driver (other
drivers are not supported).
Integrate with libaudit.so for auditing of important operations.
libvirtd gains a couple of config entries for auditing. By
default it will enable auditing, if its enabled on the host.
It can be configured to force exit if auditing is disabled
on the host. It will can also send audit messages via libvirt
internal logging API
Places requiring audit reporting can use the VIR_AUDIT
macro to report data. This is a no-op unless auditing is
enabled
* autobuild.sh, mingw32-libvirt.spec.in: Disable audit
on mingw
* configure.ac: Add check for libaudit
* daemon/libvirtd.aug, daemon/libvirtd.conf,
daemon/test_libvirtd.aug, daemon/libvirtd.c: Add config
options to enable auditing
* include/libvirt/virterror.h, src/util/virterror.c: Add
VIR_FROM_AUDIT source
* libvirt.spec.in: Enable audit
* src/util/virtaudit.h, src/util/virtaudit.c: Simple internal
API for auditing messages
The addrToString methods were not coping with UNIX domain sockets
which have no normal host+port address. Hardcode special handling
for these so that SASL routines can work over UNIX sockets. Also
fix up SSF logic in remote client so that it presumes that a UNIX
socket is secure
* daemon/remote.c: Fix addrToString for UNIX sockets.
* src/remote/remote_driver.c: Fix addrToString for UNIX sockets
and fix SSF logic to work for TLS + UNIX sockets in the same
manner
Refactor some daemon code to facilitate the introductioin of static
probes, sanitizing function exit paths in many places
* daemon/libvirtd.c: Pass the dname string into remoteCheckDN
to let caller deal with failure paths. Add separate exit paths
to remoteCheckCertificate for auth failure vs denial. Merge
all exit paths in qemudDispatchServer to one cleanup block
* daemon/remote.c: Add separate exit paths to SASL & PolicyKit
functions for auth failure vs denial
Very occasionally during a parallel make, dispatch.c would
be compiled before the generated remote headers had been
fully written. This would cause it to compile an empty
union, and result in really wierd runtime bugs that are
near impossible to diagnose.
* daemon/Makefile.am: Fix remote build deps
If the remote daemon args/ret unions ever become zero length
(due to a build / Makefile bug) then bad stuff happens at
runtime. Add a compile time assertion to check for this kind
of problem
* daemon/remote.h: Ensure non-zero length unions
Since libvirt-guests init script and its configuration do not require
libvirtd to be running/installed, it was a bad idea to put them into
daemon directory. libvirt.spec even includes these files in
libvirt-client subpackage, which may result in build failure for
client-only builds when the whole daemon directory is just skipped.
