used to read the data from virExec stdout/err file descriptors

* src/util/util.c src/util/util.h: not static anymore and export it
* src/libvirt_private.syms: allow access internally

Add dummy bodies for HAVE_GETPWUID_R and HAVE_MNTENT_H dependent
functions for MinGW builds.

* global: patch created by running:
for f in $(git ls-files '*.[ch]') ; do
    cppi $f > $f.t && mv $f.t $f
done

It turns out it is also useful to be able to perform other operations
on a file created while running as a different uid (eg, write things
to that file), and possibly to do this to a file that already
exists. This patch adds an optional hook function to the renamed (for
more accuracy of purpose) virFileOperation; the hook will be called
after the file has been opened (possibly created) and gid/mode
checked/set, before closing it.

As with the other operations on the file, if the VIR_FILE_OP_AS_UID
flag is set, this hook function will be called in the context of a
child process forked from the process that called virFileOperation.
The implication here is that, while all data in memory is available to
this hook function, any modification to that data will not be seen by
the caller - the only indication in memory of what happened in the
hook will be the return value (which the hook should set to 0 on
success, or one of the standard errno values on failure).

Another piece of making the function more flexible was to add an
"openflags" argument. This arg should contain exactly the flags to be
passed to open(2), eg O_RDWR | O_EXCL, etc.

In the process of adding the hook to virFileOperation, I also realized
that the bits to fix up file owner/group/mode settings after creation
were being done in the parent process, which could fail, so I moved
them to the child process where they should be.

* src/util/util.[ch]: rename and rework virFileCreate-->virFileOperation,
  and redo flags in virDirCreate
* storage/storage_backend.c, storage/storage_backend_fs.c: update the
  calls to virFileOperation/virDirCreate to reflect changes in the API,
  but don't yet take advantage of the hook.

If the hostname as returned by "gethostname" resolves
to "localhost" (as it does with the broken Fedora-12
installer), then live migration will fail because the
source will try to migrate to itself.  Detect this
situation up-front and abort the live migration before
we do any real work.

* src/util/util.h src/util/util.c: add a new virGetHostnameLocalhost
  with an optional localhost check, and rewire virGetHostname() to use
  it
* src/libvirt_private.syms: expose the new function
* src/qemu/qemu_driver.c: use it in qemudDomainMigratePrepare2()

virFork() contains bookkeeping that must be done any time a process
forks. Currently this includes:

1) Call virLogLock() prior to fork() and virLogUnlock() just after,
   to avoid a deadlock if some other thread happens to hold that lock
   during the fork.

2) Reset the logging hooks and send all child process log messages to
   stderr.

3) Block all signals prior to fork(), then either a) reset the signal
   mask for the parent process, or b) clear the signal mask for the
   child process.

Note that the signal mask handling in __virExec erroneously fails to
restore the signal mask when fork() fails. virFork() fixes this
problem.

Other than this, it attempts to behave as closely to fork() as
possible (including preserving errno for the caller), with a couple
exceptions:

1) The return value is 0 (success) or -1 (failure), while the pid is
   returned via the pid_t* argument. Like fork(), if pid < 0 there is
   no child process, otherwise both the child and the parent will
   return to the caller, and both should look at the return value,
   which will indicate if some of the extra processing outlined above
   encountered an error.

2) If virFork() returns with pid < 0 or with a return value < 0
   indicating an error condition, the error has already been
   reported. You can log an additional message if you like, but it
   isn't necessary, and may be awkwardly extraneous.

Note that virFork()'s child process will *never* call _exit() - if a
child process is created, it will return to the caller.

* util.c util.h: add virFork() function, based on what is currently
                 done in __virExec().

* src/util/util.h (virAsprintf): Remove ATTRIBUTE_RETURN_CHECK, since
it is perfectly fine to ignore the return value, now that the pointer
is guaranteed to be set to NULL upon failure.
* src/util/storage_file.c (absolutePathFromBaseFile): Remove now-
unnecessary use of ignore_value.

It was used for error reporting only.

These functions create a new file or directory with the given
uid/gid. If the flag VIR_FILE_CREATE_AS_UID is given, they do this by
forking a new process, calling setuid/setgid in the new process, and
then creating the file. This is better than simply calling open then
fchown, because in the latter case, a root-squashing nfs server would
create the new file as user nobody, then refuse to allow fchown.

If VIR_FILE_CREATE_AS_UID is not specified, the simpler tactic of
creating the file/dir, then chowning is is used. This gives better
results in cases where the parent directory isn't on a root-squashing
NFS server, but doesn't give permission for the specified uid/gid to
create files. (Note that if the fork/setuid method fails to create the
file due to access privileges, the parent process will make a second
attempt using this simpler method.)

If the bit VIR_FILE_CREATE_ALLOW_EXIST is set in the flags, an
existing file/directory will not cause an error; in this case, the
function will simply set the permissions of the file/directory to
those requested. If VIR_FILE_CREATE_ALLOW_EXIST is not specified, an
existing file/directory is considered (and reported as) an error.

Return from both of these functions is 0 on success, or the value of
errno if there was a failure.

* src/util/util.[ch]: add the 2 new util functions

* src/util/util.[ch]: similar to virExecWithHook, but waits for child to
  exit. Useful for doing things like setuid after the fork but before the
  exec.

Found while trying to cross-compile libvirt on Fedora 12 for Windows.
gnulib redefines 'close' to 'close_used_without_including_unistd_h'
in sys/socket.h if winsock2.h is present and unistd.h has not been
included before sys/socket.h. Reorder some includes to fix this.

esxVMX_IndexToDiskName handles indices up to 701. This limit comes
from a mapping gap in virDiskNameToIndex:

  sdzy -> 700
  sdzz -> 701
  sdaaa -> 728
  sdaab -> 729

This line in virDiskNameToIndex causes this gap:

  idx = (idx + i) * 26;

Fixing it by altering this line to:

  idx = (idx + (i < 1 ? 0 : 1)) * 26;

Also add a new version of virIndexToDiskName that handles the inverse
mapping for arbitrary indices.

* src/esx/esx_vmx.[ch]: remove esxVMX_IndexToDiskName
* src/util/util.[ch]: add virIndexToDiskName and fix mapping gap
* tests/esxutilstest.c: update test to verify that the gap is fixed

* configure.in: add new --with-udev, disabled by default, and requiring
  libudev > 145
* src/node_device/node_device_udev.c src/node_device/node_device_udev.h:
  the new node device backend
* src/node_device/node_device_linux_sysfs.c: moved node_device_hal_linux.c
  to a better file name
* src/conf/node_device_conf.c src/conf/node_device_conf.h: add a couple
  of fields in node device definitions, and an API to look them up,
  remove a couple of unused fields from previous patch.
* src/node_device/node_device_driver.c src/node_device/node_device_driver.h:
  plug the new driver
* po/POTFILES.in src/Makefile.am src/libvirt_private.syms: add the new
  files and symbols
* src/util/util.h src/util/util.c: add a new convenience macro
  virBuildPath and virBuildPathInternal() function

All drivers have copy + pasted inadequate error reporting which wraps
util.c:virGetHostname. Move all error reporting to this function, and improve
what we report.

Changes from v1:
  Drop the driver wrappers around virGetHostname. This means we still need
  to keep the new conn argument to virGetHostname, but I think it's worth
  it.

Nearly all of the methods in src/util/util.h have error codes that
must be checked by the caller to correct detect & report failure.
Add ATTRIBUTE_RETURN_CHECK to ensure compile time validation of
this

* daemon/libvirtd.c: Add explicit check on return value of virAsprintf
* src/conf/domain_conf.c: Add missing check on virParseMacAddr return
  value status & report error
* src/network/bridge_driver.c: Add missing OOM check on virAsprintf
  and report error
* src/qemu/qemu_conf.c: Add missing check on virParseMacAddr return
  value status & report error
* src/security/security_selinux.c: Remove call to virRandomInitialize
  that's done in libvirt.c already
* src/storage/storage_backend_logical.c: Add check & log on virRun
  return status
* src/util/util.c: Add missing checks on virAsprintf/Run status
* src/util/util.h: Annotate all methods with ATTRIBUTE_RETURN_CHECK
  if they return an error status code
* src/vbox/vbox_tmpl.c: Add missing check on virParseMacAddr
* src/xen/xm_internal.c: Add missing checks on virAsprintf
* tests/qemuargv2xmltest.c: Remove bogus call to virRandomInitialize()

* src/util/util.[ch]: Add virFileAbsPath() function to ensure an
  absolute path for a potentially realtive path.
* src/libvirt_private.syms: add it in libvirt private symbols

Seems standard to include internal.h in order to pull in libvirt.h

* src/util/util.h: include internal.h

Add the virStrncpy function, which takes a dst string, source string,
the number of bytes to copy and the number of bytes available in the
dest string.  If the source string is too large to fit into the
destination string, including the \0 byte, then no data is copied and
the function returns NULL.  Otherwise, this function copies n bytes
from source into dst, including the \0, and returns a pointer to the
dst string.  This function is intended to replace all unsafe uses
of strncpy in the code base, since strncpy does *not* guarantee that
the buffer terminates with a \0.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

* src/bridge.c, src/bridge.h, src/buf.c, src/buf.h, src/cgroup.c,
  src/cgroup.h, src/conf.c, src/conf.h, src/event.c, src/event.h,
  src/hash.c, src/hash.h, src/hostusb.c, src/hostusb.h,
  src/iptables.c, src/iptables.h, src/logging.c, src/logging.h,
  src/memory.c, src/memory.h, src/pci.c, src/pci.h, src/qparams.c,
  src/qparams.h, src/stats_linux.c, src/stats_linux.h,
  src/threads-pthread.c, src/threads-pthread.h, src/threads-win32.c,
  src/threads-win32.h, src/threads.c, src/threads.h, src/util.c,
  src/util.h, src/uuid.c, src/uuid.h, src/virterror.c,
  src/virterror_internal.h, src/xml.c, src/xml.h: Move all files
  into src/util/
* daemon/Makefile.am: Add -Isrc/util/ to build flags
* src/Makefile.am: Add -Isrc/util/ to build flags and update for
  moved files
* src/libvirt_private.syms: Export cgroup APIs since they're now
  in util rather than linking directly to drivers
* src/xen/xs_internal.c: Disable bogus virEventRemoveHandle call
  when built under PROXY
* proxy/Makefile.am: Update for changed file locations. Remove
  bogus build of event.c
* tools/Makefile.am, tests/Makefile.am: Add -Isrc/util/ to build flags

Remove the bogus dependancy between node_device.c & storage_backend.c
by moving the virWaitForDevices into util.h where it can be shared
safely

* src/storage_backend_disk.c, src/storage_backend_logical.c,
  src/storage_backend_mpath.c, src/storage_backend_scsi.c: Replace
  virStorageBackendWaitForDevices with virFileWaitForDevices
* src/storage_backend.c, src/storage_backend.h: Remove
  virStorageBackendWaitForDevices, virWaitForDevices
* src/util.h, src/util.c: Add virFileWaitForDevices
* configure.in: Move xmlrpc check further down after pkgconfig
  is detected
* src/Makefile.am: Add missing XMLRPC_CFLAGS/LIBS to opennebula
* src/libvirt_private.syms: Add many missing exports

Add option to domain XML for

     <memoryBacking>
        <hugepages/>
     </memoryBacking>

* configure.in: Add check for mntent.h
* qemud/libvirtd_qemu.aug, qemud/test_libvirtd_qemu.aug, src/qemu.conf
  Add 'hugetlbfs_mount' config parameter
* src/qemu_conf.c, src/qemu_conf.h: Check for -mem-path flag in QEMU,
  and pass it when hugepages are requested.
  Load hugetlbfs_mount config parameter, search for mount if not given.
* src/qemu_driver.c: Free hugetlbfs_mount/path parameter in driver shutdown.
  Create directory for QEMU hugepage usage, chowning if required.
* docs/formatdomain.html.in: Document memoryBacking/hugepages elements
* docs/schemas/domain.rng: Add memoryBacking/hugepages elements to schema
* src/util.c, src/util.h, src/libvirt_private.syms: Add virFileFindMountPoint
  helper API
* tests/qemuhelptest.c: Add -mem-path constants
* tests/qemuxml2argvtest.c, tests/qemuxml2xmltest.c: Add tests for hugepage
  handling
* tests/qemuxml2argvdata/qemuxml2argv-hugepages.xml,
  tests/qemuxml2argvdata/qemuxml2argv-hugepages.args: Data files for
  hugepage tests

* src/qemu_driver.c:  Add driver methods qemuGetSchedulerType,
  qemuGetSchedulerParameters, qemuSetSchedulerParameters
* src/lxc_driver.c: Fix to use unsigned long long consistently
  for schedular parameters
* src/cgroup.h, src/cgroup.c: Fix cpu_shares to take unsigned
  long long
* src/util.c, src/util.h, src/libvirt_private.syms: Add a
  virStrToDouble helper
* src/virsh.c: Fix handling of --set arg to schedinfo command
  to honour the designated data type of each schedular tunable
  as declared by the driver

Allow the driver level cgroup to be managed explicitly by the
hypervisor drivers, in order to detect whether to enable or
disable cgroup support for domains. Provides better error
reporting of failures. Also allow for creation of cgroups for
unprivileged drivers if controller is accessible by the user.

* src/cgroup.c, src/cgroup.h: Add an API to obtain a driver cgroup
* src/lxc_conf.h, src/lxc_controller.c, src/lxc_driver.c:
  Obtain a driver cgroup at startup and use that instead of
  re-creating everytime.
* src/util.c, src/util.h, src/libvirt_private.syms: Add a
  virGetUserName() helper

GCC >= 4.4 assumes the 'printf' attribute refers to the native
runtime libraries format specifiers. Thanks to gnulib, libvirt
has GNU format specifiers everywhere.  This means we need to
use 'gnu_printf' with GCC >= 4.4 to get correct compiler
checking of printf format specifiers.

* HACKING: Document new rules for ATTRIBUTE_FMT_PRINTF
* autobuild.sh, mingw32-libvirt.spec.in: Disable OpenNebula
  driver on mingw32 builds
* qemud/dispatch.h, qemud/qemu.h, src/buf.h src/internal.h,
  src/logging.h, src/security.h, src/sexpr.h, src/util.h,
  src/virterror_internal.h, src/xend_internal.c: Change
  over to ATTRIBUTE_FMT_PRINTF.
* src/virsh.c: Disable 'cd' and 'pwd' commands on Win32
  since they don't compile
* src/threads-win32.c: Add missing return value check

* configure.in: Add --with-qemu-user and --with-qemu-group args
* libvirt.spec.in: use 'qemu' for user/group for Fedora >= 12
* qemud/libvirtd_qemu.arg, qemud/test_libvirtd_qemu.aug,
  src/qemu.conf: Add 'user' and 'group' args for configuration
* src/Makefile.am: Create %localstatedir/cache/libvirt/qemu
* src/qemu_conf.c, src/qemu_conf.h: Load user/group from config
* src/qemu_driver.c: Change user ID/group ID when launching QEMU
  guests. Change user/group ownership on disks/usb/pci devs.
  Put memory dumps in %localstatedir/cache/libvirt/qemu
* src/util.c, src/util.h: Add convenient APIs for converting
  username/groupname to user ID / group ID

* configure.in src/libvirt_private.syms src/storage_backend_fs.c
  src/util.c src/util.h: find and use kvm-img, qemu-img or qcow-create
  dynamically at runtime, patch by Doug Goldstein
* AUTHORS: add Doug Goldstein
Daniel

virExec will write out the pid of the daemonized process only. Use this
in the QEMU driver, rather than QEMU's pidfile, so we can catch errors we
might miss if the emulator bails early.

Wraps __virExec with the VIR_EXEC_DAEMON flag. Waits on the intermediate
process to ensure we don't end up with any zombies, and differentiates between
original process errors and intermediate process errors.

* src/libvirt_private.syms src/storage_backend_fs.c src/util.c
  src/util.h: use posix_fallocate() on supported systems to
  allocate diskspace faster, patches by Amit Shah
Daniel

Re-factor the code from networkEnableIpForwarding() into a
utility function in preparation for code which writes to
sysfs files.

* src/qemu_driver.c: Use virSetCloseExec and virSetNonBlock,
rather than qemuSet* functions.  Suggested by Daniel P. Berrange.
* src/util.c (virSetCloseExec): Publicize.
* src/util.h (virSetCloseExec): Declare
* src/libvirt_private.syms: Add virSetCloseExec.

* Makefile.cfg (local-checks-to-skip): Remove sc_redundant_const.
* src/lxc_controller.c: Remove redundant "const"(s).
* src/storage_backend_fs.c: Likewise.
* src/util.h: Likewise.
* src/xen_internal.c: Likewise.
* tests/qparamtest.c: Likewise.

  src/uml_driver.c src/util.c src/util.h src/xen_unified.c:
  unify hostname lookup using virGetHostname convenience function,
  patch by David Lutterkort
daniel