The caller may not want all DBus error conditions to be turned
into libvirt errors, so provide a way for the caller to get
back the full DBusError object. They can then check the errors
and only report those that they consider to be fatal.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the DBus helper APIs require the values for an array
to be passed inline in the variadic argument list. This change
introduces support for passing arrays using a pointer to a plain
C array of the basic type. This is of particular benefit for
decoding messages when you don't know how many array elements
are being received.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The dbus_connection_send_with_reply_and_block method will
automatically call dbus_set_error_from_message for us. We
mistakenly thought we had todo it because of a flaw in the
systemd unit test mock impl. The latter should have directly
set the error object, instead of creating an error message
object.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The virDBusMessageRead method should not have side-effects on
the message parameter passed in, so unref'ing it is wrong.
The caller should unref only when they decided they are done
with it.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The test suites often have to create DBus method reply messages
with payloads. Create two helpers for simplifying the process
of creating replies with payloads.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Split the virDBusMethodCall method into a couple of new methods
virDBusCall, virDBusCreateMethod and virDBusCreateMethodV.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

virLogParseDefaultPriority's successful return value is the same as
virLogSetDefaultPriority's successful return value. So it should be 0
rather than the parsed log level.
Signed-off-by: NZhou Yimin <zhouyimin@huawei.com>

Remove the 'StorageBackend' from names of the functions and fix
indentation.

Instead of running the command asynchronously and reading the output
via fgets, let virCommand collect the output and split it with
virStringSplit.

The only storage-specific parameter is the pool object, which
is only used for passing to the callback function.

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Per the documentation, is_selinux_enabled() returns -1 on error.
Account for this. Previously when -1 was being returned the condition
would still be true. I was noticing this because on my system that has
selinux disabled I was getting this in the libvirt.log every 5
seconds:

error : virIdentityGetSystem:173 : Unable to lookup SELinux process context: Invalid argument

With this patch applied, I no longer get these messages every 5
seconds. I am submitting this in case its deemed useful for inclusion.
Anyone have any comments on this change? This is a patch off current
master.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The virSocketAddrMask method did not initialize all fields
in the sockaddr_in6 struct. In paticular the 'sin6_scope_id'
field could contain random garbage, which would in turn
affect the result of any later virSocketAddrFormat calls.
This led to ip6tables rules in the FORWARD chain which
matched on random garbage sin6_scope_id. Fortunately these
were ACCEPT rules, so the impact was merely that desired
traffic was blocked, rather than undesired traffic allowed.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

To allow for fault injection of the virCommand dry run,
add the ability to register a callback. The callback will
be passed the argv, env and stdin buffer and is expected
to return the exit status and optionally fill stdout and
stderr buffers.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

In libxl driver oldStateDir is NULL when calling
virHostdevReAttachDomainHostdevs. This is allowed.
Remove ATTRIBUTE_NONNULL setting from oldStateDir.

Introduced by commit 6225cb3d.
Signed-off-by: NChunyan Liu <cyliu@suse.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

A earlier commit changed the global log buffer so that it only
records messages that are explicitly requested via the log
filters setting. This removes the performance burden, and
improves the signal/noise ratio for messages in the global
buffer. At the same time though, it is somewhat pointless, since
all the recorded log messages are already going to be sent to an
explicit log output like syslog, stderr or the journal. The
global log buffer is thus just duplicating this data on stderr
upon crash.

The log_buffer_size config parameter is left in the augeas
lens to prevent breakage for users on upgrade. It is however
completely ignored hereafter.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the log filter strings are used in a string comparison
against the source filename each time log message is emitted.
If no log filters at all are set, there's obviously no string
comparison to be done. If any single log filter is set though,
this imposes a compute burden on every logging call even if logs
from the file in question are disabled. This string comparison
must also be done while the logging mutex is held, which has
implications for concurrency when multiple threads are emitting
log messages.

This changes the log filtering to be done based on the virLogSource
object name. The virLogSource struct is extended to contain
'serial' and 'priority' fields. Any time the global log filter
rules are changed a global serial number is incremented. When a
log message is emitted, the serial in the virLogSource instance
is compared with the global serial number. If out of date, then
the 'priority' field in the virLogSource instance is updated based
on the new filter rules. The 'priority' field is checked to see
whether the log message should be sent to the log outputs.

The comparisons of the 'serial' and 'priority' fields are done
with no locks held. So in the common case each logging call has
an overhead of 2 integer comparisons, with no locks held. Only
if the decision is made to forward the message to the log output,
or if the 'serial' value is out of date do locks need to be
acquired.

Technically the comparisons of the 'serial' and 'priority' fields
should be done with locks held, or using atomic operations. Both
of these options have a notable performance impact, however, and
since all writes a protected by a global mutex, it is believed
that worst case behaviour where the fields are read concurrently
with being written would merely result in an mistaken emission
or dropping of the log message in question. This is an acceptable
tradeoff for the performance benefit of avoiding locking.

As a quick benchmark, a demo program that registers 500 file
descriptors with the event loop (eg equiv of 500 QEMU monitor
commands), creates pending read I/O on every FD, and then runs
virEventRunDefaultImpl() took 4.6 seconds to do 51200 iterations.
After this optimization it only takes 3.3 seconds, with the log
APIs no longer being a relevant factor in the running time.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

As part of the goal to get away from doing string matching on
filenames when deciding whether to emit a log message, turn
the virLogSource enum into a struct which contains a log
"name". There will eventually be one virLogSource instance
statically declared per source file. To minimise churn in this
commit though, a single global instance is used.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The dtrace probe macros rely on the logging API. We can't make
the internal.h header include the virlog.h header though since
that'd be a circular include. Instead simply split the dtrace
probes into their own header file, since there's no compelling
reason for them to be in the main internal.h header.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The error reporting code will invoke a callback when any error
is raised and the default callback will print to stderr. The
virRaiseErrorFull method also sends all error messages on to the
logging code, which also prints to stderr by default. To avoid
duplicated data on stderr, the logging code has some logic to
skip emission when no log outputs are configured, which checks
whether the virLogSource == VIR_LOG_FROM_ERROR.

Meanwhile the libvirtd daemon can register another callback which
is used to reduce log message priority from error to a lower level.
When this is used we do want messages to end up on stderr, so the
error code will conditionally use either VIR_LOG_FROM_FILE or
VIR_LOG_FROM_ERROR depending on whether such a callback is provided.

This will all complicate later refactoring. By pushing the checks
for whether a log output is present up a level into the error code,
the special cases can be isolated in one place.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

With the vast number of log debug statements in the code, the
logging framework has a measurable performance impact on libvirt
code, particularly in the daemon event loop.

The global log buffer records every single log message triggered
whether anyone cares to see them or not. This makes it impossible
to eliminate the overhead of printf format expansions in any of
the logging code. It is possible to disable the global log buffer
in libvirtd itself, but this doesn't help client side library
code. Also even if disabled by the config file, the existence of
the feature makes other performance improvements in the logging
layer impossible.

Instead of logging every single message to the global buffer, only
log messages that pass the log filters. This if libvirtd is set
to have log_filters="1:libvirt 1:qemu" the global log buffer will
only get filled with those messages instead of everything. This
reduces the performance burden, as well as improving the signal
to noise ratio of the log buffer.

As a quick benchmark, a demo program that registers 500 file
descriptors with the event loop (eg equiv of 500 QEMU monitor
commands), creates pending read I/O on every FD, and then runs
virEventRunDefaultImpl() took 1 minute 40 seconds to do 51200
iterations with nearly all the time shown against the logging
code. After this optimization it only takes 4.6 seconds.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Commit a1cbe4b5 added a check for spaces around assignments and this
patch extends it to checks for spaces around '=='.  One exception is
virAssertCmpInt where comma after '==' is acceptable (since it is a
macro and '==' is its argument).
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Our current pidfile acquire APis (virPidFileAcquire) simply return -1 upon
failure to acquire a lock. This patch adds a parameter 'bool waitForLock'
which instructs the APIs if we want to make it block and wait for the lock
or not.

We have to explicitly destroy TAP devices on FreeBSD because
they're not freed after being closed, otherwise we end up with
orphaned TAP devices after destroying a domain.

This same set of functions is used by the qemu, xen, and lxc drivers'
connectSysInfo function.

Commit 6b306d66 converted virHostdevManager to a virObject, but
missed adding a virObject field to the virHostdevManager struct.
Result is memory corruption when taking a reference on an instance
of the object, where atomic inc is done on the stateDir field.
Later use of stateDir crashes libvirtd.

While running vircryptotest, it was found that valgrind pointed out the
following error:

==27453== Invalid write of size 1
==27453==    at 0x4C7D7C9: virCryptoHashString (vircrypto.c:76)
==27453==    by 0x401C4E: testCryptoHash (vircryptotest.c:41)
==27453==    by 0x402A11: virtTestRun (testutils.c:199)
==27453==    by 0x401AD5: mymain (vircryptotest.c:76)
==27453==    by 0x40318D: virtTestMain (testutils.c:782)
==27453==    by 0x3E6CE1ED1C: (below main) (libc-start.c:226)
==27453==  Address 0x51f0541 is 0 bytes after a block of size 65 alloc'd
==27453==    at 0x4A0577B: calloc (vg_replace_malloc.c:593)
==27453==    by 0x4C69F2E: virAllocN (viralloc.c:189)
==27453==    by 0x4C7D76B: virCryptoHashString (vircrypto.c:69)
==27453==    by 0x401C4E: testCryptoHash (vircryptotest.c:41)
==27453==    by 0x402A11: virtTestRun (testutils.c:199)
==27453==    by 0x401AD5: mymain (vircryptotest.c:76)
==27453==    by 0x40318D: virtTestMain (testutils.c:782)
==27453==    by 0x3E6CE1ED1C: (below main) (libc-start.c:226)
==27453==

...and many more.  Two observations: hashstrlen was already set
to include the trailing NUL byte (so writing to hashstrlen as
the array offset was indeed writing one byte beyond bounds), and
VIR_ALLOC_N already guarantees zero-initialization (so we already
have a trailing NUL without needing to explicitly write one).
Signed-off-by: NEric Blake <eblake@redhat.com>

Commit b4bbaeef changed char* to const char*, but omitted
the non-Linux version.

Add VIR_DOMAIN_HOSTDEV_PCI_BACKEND_XEN. For legacy xen, it will use "pciback" as
stub driver.

Mark many parameters as NONNULL and check for empty list of
hostdevs.

Changes parameter from vm def to specific hostdevs info and name info, so that
it could be used more widely, e.g, could be used without full vm def info.

Change any variable names with Usb, Pci or Scsi to use
USB, PCI and SCSI since they are abbreviations.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Some virHostdevXXXX methods included the string Hostdev again
as a suffix. Change the latter to Device instead.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Change any method names with Usb, Pci or Scsi to use
USB, PCI and SCSI since they are abbreviations.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Various methods in virnetdev.c and virhostdev.c were missing
const-ness for several char * parameters.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>