In a first cleanup step, make nlComm from macvtap.c commonly available
for other code to use. Since nlComm uses Linux-specific structures as
parameters it's prototype is only visible on Linux.

Files under src/util must not depend on src/conf
Solve the macvtap problem by moving the definition
of macvtap modes from domain_conf.h into macvtap.h

* src/util/macvtap.c, src/util/macvtap.h: Add enum
  for macvtap modes
* src/conf/domain_conf.c, src/conf/domain_conf.h: Remove
  enum for macvtap modes

virCommandProcessIO: It's reading from stdout or stderr of child,
but not writing.

The following patch addresses the problem that when a PASSTHROUGH
mode DIRECT NIC connection is made the MAC address of the NIC is
not automatically set and reset to the configured VM MAC and
back again.

The attached patch fixes this problem by setting and resetting the MAC
while remembering the previous setting while the VM is running.
This also works if libvirtd is restarted while the VM is running.

the patch passes make syntax-check

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

Most of the safezero() implementations return -1 on error,
setting errno. The safezero() impl using posix_fallocate()
though returned a positive errno value on error (due to
the unusual API contract of posix_fallocate() compared to
most syscall APIs).

* src/util/util.c: Ensure safezero() returns -1 and sets
  errno on error.
* src/storage/storage_backend.c: Change safezero != 0 to
  < 0 for detecting errors

Previously, the parent process opened 'null' to /dev/null, then
the child process closes 'null' as well as 'childout'.  But if
childout was set to be null, then this is a double close.  At
least the double close was confined to the child process after a
fork, and therefore there is no risk of another thread opening
an fd of the same value to be bitten by the double close, but it
is always better to avoid double-close to begin with.

Additionally, if all three fds were specified, then opening
'null' was wasted.

This patch fixes things to lazily open null on the first use,
then guarantees it gets closed exactly once.

* src/util/command.c (getDevNull): New helper function.
(virExecWithHook): Use it to avoid spurious opens and double close.

This also reduces malloc pressure for invoking a child when
VIR_DEBUG is enabled.

* src/util/command.c (virExecWithHook): Drop debug, since the only
caller (virCommandRunAsync) also prints debug info.

Push under trivial rule.

The below patch decreases the response time of libvirt to errors reported by Qemu upon startup by checking whether the qemu process is still alive while polling for the local socket to show up.

This patch also introduces a special handling of signal for the Win32 part of virKillProcess.

Coverity already saw through a NULL dereference without these
annotations, and gcc is still too puny to do good NULL analysis.
But clang still benefits (and is easier to run than coverity),
not to mention that adding this bit of documentation to the code
may help future developers remember the constraints.

* src/util/uuid.h (virGetHostUUID, virUUIDFormat): Document
restrictions, for improved static analysis.

Similar in nature to commit fd21ecfd, which shut up valgrind.

sigaction is apparently a nasty interface for analyzer tools,
at least for how many false positives it generates.

* src/util/command.c (virExecWithHook): Initialize entire var, since
coverity gripes about the (unused and non-standard) sa_restorer.

Detected by Coverity.  The code was doing math on shifted unsigned
char (which promotes to int), then promoting that to unsigned long
during assignment to size.  On 64-bit platforms, this risks sign
extending values of size > 2GiB.  Bug present since commit
489fd3 (v0.6.0).

I'm not sure if a specially-crafted bogus qcow2 image could
exploit this, although it's probably not possible, since we
were already checking for the computed results being within
range of our fixed-size buffer.

* src/util/storage_file.c (qcowXGetBackingStore): Avoid sign
extension.

Seems reasonable to have all command wrappers in the same place

v2:
    Dont move SetInherit

v3:
    Comment spelling fix
    Adjust WARN0 comment
    Remove spurious #include movement
    Don't include sys/types.h
    Combine virExec enums
Signed-off-by: NCole Robinson <crobinso@redhat.com>

v2:
    Simplify command building
    Handle command building failure

v3:
    Remove unneeded NULL check
Signed-off-by: NCole Robinson <crobinso@redhat.com>

v3:
    Remove obsolete comment
Signed-off-by: NCole Robinson <crobinso@redhat.com>

Coverity complained that infd could be -1 at the point where it is
passed to write, when in reality, this code can only be reached if
infd is non-negative.

* src/util/command.c (virCommandProcessIO): Help out coverity.

Spotted by coverity.  Triggers on failed stat, although I'm not sure
how easy that condition is, so I'm not sure if this is a runtime
memory hog.  Regression introduced in commit 8077d64f (unreleased).

* src/util/storage_file.c (virStorageFileGetMetadataFromFD):
Reduce need for malloc, avoiding a leak.

Detected by Coverity.  While it is possible on OOM condition, as
well as with bad code that passes binary == NULL, it is unlikely
to be encountered in the wild.

* src/util/command.c (virCommandNewArgList): Don't leak memory.

Define the basic framework lock manager plugins. The
basic plugin API for 3rd parties to implemented is
defined in

  src/locking/lock_driver.h

This allows dlopen()able modules for alternative locking
schemes, however, we do not install the header. This
requires lock plugins to be in-tree allowing changing of
the lock manager plugin API in future.

The libvirt code for loading & calling into plugins
is in

  src/locking/lock_manager.{c,h}

* include/libvirt/virterror.h, src/util/virterror.c: Add
  VIR_FROM_LOCKING
* src/locking/lock_driver.h: API for lock driver plugins
  to implement
* src/locking/lock_manager.c, src/locking/lock_manager.h:
  Internal API for managing locking
* src/Makefile.am: Add locking code

Allow the parent process to perform a bi-directional handshake
with the child process during fork/exec. The child process
will fork and do its initial setup. Immediately prior to the
exec(), it will stop & wait for a handshake from the parent
process. The parent process will spawn the child and wait
until the child reaches the handshake point. It will do
whatever extra setup work is required, before signalling the
child to continue.

The implementation of this is done using two pairs of blocking
pipes. The first pair is used to block the parent, until the
child writes a single byte. Then the second pair pair is used
to block the child, until the parent confirms with another
single byte.

* src/util/command.c, src/util/command.h,
  src/libvirt_private.syms: Add APIs to perform a handshake

Substitute VIR_ERR_NO_SUPPORT with VIR_ERR_INTERNAL_ERROR. Error
like following is not what user want to see.

error : pciDeviceIsAssignable:1487 : this function is not supported
by the connection driver: Device 0000:07:10.0 is behind a switch
lacking ACS and cannot be assigned

Since directories can be used for <filesystem> passthrough, they are
basically storage volumes.

v2:
    Skip ., .., lost+found dirs

v3:
    Use gnulib last_component

v4:
    Use gnulib "dirname.h", not system <dirname.h>
    Don't skip lost+found

The virSysinfoIsEqual method was mistakenly inside a #ifndef WIN32
conditional.

The existing virSysinfoFormat is also stubbed out on Win32, even
though the code works without any trouble. This breaks XML output
on Win32, so the stub is removed.

virsh migrate mistakenly had some variables inside the conditional

* src/util/sysinfo.c: Build virSysinfoIsEqual on Win32 and remove
  Win32 stub for virSysinfoFormat
* tools/virsh.c: Fix variable declaration on Win32

To allow a client app to pass in custom XML during migration
of a guest it is neccessary to ensure the guest ABI remains
unchanged. The virDomainDefCheckABIStablity method accepts
two virDomainDefPtr structs and compares everything in them
that could impact the guest machine ABI

* src/conf/domain_conf.c, src/conf/domain_conf.h,
  src/libvirt_private.syms: Add virDomainDefCheckABIStablity
* src/conf/cpu_conf.c, src/conf/cpu_conf.h: Add virCPUDefIsEqual
* src/util/sysinfo.c, src/util/sysinfo.h: Add virSysinfoIsEqual

This was necessary to get libvirt to build on Solaris 11 Express and
seems correct (as it makes this match the definition in util.c):

Coverity spotted this off-by-one.  Thankfully, no one in libvirt
was ever calling virAuditSend with an argument of 3.

* src/util/virtaudit.c (virAuditSend): Use correct comparison.

We don't use the gnulib vsnprintf replacement, which means that
on mingw, vsnprintf doesn't support %zn or %lln.

And as it turns out, VIR_GET_VAR_STR was a rather inefficient
reimplementation of virVasprintf logic.

* src/util/logging.c (VIR_GET_VAR_STR): Drop.
(virLogMessage): Inline a simpler version here.
* src/util/virterror.c (VIR_GET_VAR_STR, virRaiseErrorFull):
Likewise.
Reported by Matthias Bolte.

Two additional places need initgroups call to properly work in an
environment where the UID is allowed to open/create stuff through its
supplementary groups.

This error code has existed since the dawn of time, yet the messages it
generates are almost universally busted. Here's a small sampling:

src/conf/domain_conf.c:4889 : XML description for missing root element is not well formed or invalid
src/conf/domain_conf.c:4951 : XML description for unknown device type is not well formed or invalid
src/conf/domain_conf.c:5460 : XML description for maximum vcpus must be an integer is not well formed or invalid
src/conf/domain_conf.c:5468 : XML description for invalid maxvcpus %(count)lu is not well formed or invalid

Fix up the error code to instead be

XML error: <msg>

Adjust the few locations that were using the original correctly (or shouldn't
have been using the error code at all).

v2:
    Fix wording of error code without a passed argument

starting with kernel 2.6.38 macvtap supports a 'passthru' mode for
attaching virtual functions of a SRIOV capable network card directly to a VM.
This patch adds the capability to configure such a device.
Signed-off-by: NDirk Herrendoerfer <d.herrendoerfer@herrendoerfer.name>

* src/util/util.c: Fix virRun prototype

POSIX allows sysconf(_SC_GETPW_R_SIZE_MAX) to return -1 if there
is no fixed limit, and requires ERANGE errors to track real size.
Model our behavior after the example in POSIX itself:
http://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwuid_r.html

Also, on error for get*_r functions, errno is undefined, and the
real error was the return value.

* src/util/util.c (virGetUserEnt, virGetUserID, virGetGroupID)
(virSetUIDGID):  Cope with sysconf failure or too small buffer.
Reported by Matthias Bolte.

virRunWithHook is now unused, so we can drop it. Tested w/ raw + qcow2
volume creation and copying.

v2:
    Use opaque data to skip hook second time around
    Simply command building

v3:
    Drop explicit FindFileInPath

Mingw execve() has a broken signature. Disable this
function until gnulib fixes the signature, since we
don't really need this on Win32 anyway.

* src/util/command.c: Disable virCommandExec on Win32