Users often edit XML file stored in configuration directory
thinking of modifying a domain/network/pool/etc. Thus it is wise
to let them know they are using the wrong way and give them hint.

Make virFileBuildPath operate on the heap instead of the stack. It
allocates a buffer instead of expecting a preexisting buffer.

This patch intentionally doesn't change indentation, in order to
make it easier to review the real changes.

* src/util/util.h (VIR_FILE_OP_RETURN_FD, virFileOperationHook):
Delete.
(virFileOperation): Rename...
(virFileOpenAs): ...and reduce parameters.
* src/util/util.c (virFileOperationNoFork, virFileOperation):
Rename and simplify.
* src/qemu/qemu_driver.c (qemudDomainSaveFlag): Adjust caller.
* src/storage/storage_backend.c (virStorageBackendCreateRaw):
Likewise.
* src/libvirt_private.syms: Reflect rename.

Currently, the hook function in virFileOperation is extremely limited:
it must be async-signal-safe, and cannot modify any memory in the
parent process.  It is much handier to return a valid fd and operate
on it in the parent than to deal with hook restrictions.

* src/util/util.h (VIR_FILE_OP_RETURN_FD): New flag.
* src/util/util.c (virFileOperationNoFork, virFileOperation):
Honor new flag.

* src/util/util.h (virSetInherit): New prototype.
* src/util/util.c (virSetCloseExec): Move guts...
(virSetInherit): ...to new function, and allow clearing.
* src/libvirt_private.syms (util.h): Export it.

* configure.ac: Check for geteuid()
* src/util/util.h: Compat for geteuid()

The virSetNonBlock() API only allows enabling non-blocking
operations. It doesn't allow turning blocking back on. Add
a new API to allow arbitrary toggling.

* src/libvirt_private.syms, src/util/util.h
  src/util/util.c: Add virSetBlocking

Remove the <stdbool.h> header from all source files / headers
and just put it into internal.h

* src/internal.h: Add <stdbool.h>

The name convention of device mapper disk is different, and 'parted'
can't be used to delete a device mapper disk partition. e.g.

Name                 Path
-----------------------------------------
3600a0b80005ad1d7000093604cae912fp1 /dev/mapper/3600a0b80005ad1d7000093604cae912fp1

Error: Expecting a partition number.

This patch introduces 'dmsetup' to fix it.

Changes:
  - New function "virIsDevMapperDevice" in "src/utils/utils.c"
  - remove "is_dm_device" in "src/storage/parthelper.c", use
    "virIsDevMapperDevice" instead.
  - Requires "device-mapper" for 'with-storage-disk" in "libvirt.spec.in"
  - Check "dmsetup" in 'configure.ac' for "with-storage-disk"
  - Changes on "src/Makefile.am" to link against libdevmapper
  - New entry for "virIsDevMapperDevice" in "src/libvirt_private.syms"

Changes from v1 to v3:
  - s/virIsDeviceMapperDevice/virIsDevMapperDevice/g
  - replace "virRun" with "virCommand"
  - sort the list of util functions in "libvirt_private.syms"
  - ATTRIBUTE_NONNULL(1) for virIsDevMapperDevice declaration.

e.g.

Name                 Path
-----------------------------------------
3600a0b80005ad1d7000093604cae912fp1 /dev/mapper/3600a0b80005ad1d7000093604cae912fp1

Vol /dev/mapper/3600a0b80005ad1d7000093604cae912fp1 deleted

Name                 Path
-----------------------------------------

It was awkward having only int conversion in the virStrToLong family,
but only long conversion in the virXPath family.  Make both families
support both types.

* src/util/util.h (virStrToLong_l, virStrToLong_ul): New
prototypes.
* src/util/xml.h (virXPathInt, virXPathUInt): Likewise.
* src/util/util.c (virStrToLong_l, virStrToLong_ul): New
functions.
* src/util/xml.c (virXPathInt, virXPathUInt): Likewise.
* src/libvirt_private.syms (util.h, xml.h): Export them.

Without this patch, at least tests/daemon-conf (which sticks
$builddir/src in the PATH) tries to execute the directory
$builddir/src/qemu rather than a real qemu binary.

* src/util/util.h (virFileExists): Adjust prototype.
(virFileIsExecutable): New prototype.
* src/util/util.c (virFindFileInPath): Reject non-executables and
directories.  Avoid huge stack allocation.
(virFileExists): Use lighter-weight syscall.
(virFileIsExecutable): New function.
* src/libvirt_private.syms (util.h): Export new function.

virSetUIDGID() sets both the real and effective group and user of the
process, and additionally calls initgroups() to assure that the
process joins all the auxiliary groups that the given uid is a member
of.

This patch adds a mode_t parameter to virFileWriteStr().
If mode is different from 0, virFileWriteStr() will try
to create the file if it doesn't exist.

* src/util/util.h (virFileWriteStr): Alter signature.
* src/util/util.c (virFileWriteStr): Allow file creation.
* src/network/bridge_driver.c (networkEnableIpForwarding)
(networkDisableIPV6): Adjust clients.
* src/node_device/node_device_driver.c
(nodeDeviceVportCreateDelete): Likewise.
* src/util/cgroup.c (virCgroupSetValueStr): Likewise.
* src/util/pci.c (pciBindDeviceToStub, pciUnBindDeviceFromStub):
Likewise.

* src/util/util.h (virVasprintf): New declaration.
* src/util/util.c (virVasprintf): New function.
(virAsprintf): Use it.
* src/util/virtaudit.c (virAuditSend): Likewise.
* src/libvirt_private.syms: Export it.
* cfg.mk (sc_prohibit_asprintf): Also prohibit vasprintf.
* .x-sc_prohibit_asprintf: Add exemption.

* src/util/util.c (saferead): Fix return type.
(safewrite): Fix indentation.

* src/util/util.h
* src/util/util.c
* src/libvirt_private.syms

virHexToBin will be used in the .vmx handling code.

We've been running into a lot of situations where
virGetHostname() is returning "localhost", where a plain
gethostname() would have returned the correct thing.  This
is because virGetHostname() is *always* trying to canonicalize
the name returned from gethostname(), even when it doesn't
have to.

This patch changes virGetHostname so that if the value returned
from gethostname() is already FQDN or localhost, it returns
that string directly.  If the value returned from gethostname()
is a shortened hostname, then we try to canonicalize it.  If
that succeeds, we returned the canonicalized hostname.  If
that fails, and/or returns "localhost", then we just return
the original string we got from gethostname() and hope for
the best.

Note that after this patch it is up to clients to check whether
"localhost" is an allowed return value.  The only place
where it's currently not is in qemu migration.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

Spurious / in a pool target path makes life difficult for apps using the
GetVolByPath, and doing other path based comparisons with pools. This
has caused a few issues for virt-manager users:

https://bugzilla.redhat.com/show_bug.cgi?id=494005
https://bugzilla.redhat.com/show_bug.cgi?id=593565

Add a new util API which removes spurious /, virFileSanitizePath. Sanitize
target paths when parsing pool XML, and for paths passed to GetVolByPath.

v2: Leading // must be preserved, properly sanitize path=/, sanitize
    away /./ -> /

v3: Properly handle starting ./ and ending /.

v4: Drop all '.' handling, just sanitize / for now.

Based on a warning from coverity.  The safe* functions
guarantee complete transactions on success, but don't guarantee
freedom from failure.

* src/util/util.h (saferead, safewrite, safezero): Add
ATTRIBUTE_RETURN_CHECK.
* src/remote/remote_driver.c (remoteIO, remoteIOEventLoop): Ignore
some failures.
(remoteIOReadBuffer): Adjust error messages on read failure.
* daemon/event.c (virEventHandleWakeup): Ignore read failure.

virParseVersionString uses virStrToLong_ui instead of sscanf.

This also fixes a bug in the UML driver, that always returned 0
as version number.

Introduce STRSKIP to check if a string has a certain prefix and
to skip this prefix.

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>