This function gets all the PIDs listed in /proc/PID/task. This will be
needed at least to move all qmeu-nbd tasks to the container cgroup.

Refactor the function to return the bitmap instead of an integer and the
inner workings so that they make more sense.

This patch also fixes possible segfault on old systems that was
introduced by commit:

commit f1a43a8e
Author: Hu Tao <hutao@cn.fujitsu.com>
Date:   Fri Sep 14 15:46:59 2012 +0800

    use virBitmap to store cpu affinity info

This function uses sched_setscheduler() function so it works with
processes and threads as well (even threads not created by us, which is
what we'll need in the future).
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Right now, a caller waiting for a child process either requires
the child to have status 0, or must use WIFEXITED() and friends
itself.  But in many cases, we want the middle ground of treating
fatal signals as an error, and directly accessing the normal exit
value without having to use WEXITSTATUS(), in order to easily
detect an expected non-zero exit status.  This adds the middle
ground to the low-level virProcessWait; the next patch will add
it to virCommand.

* src/util/virprocess.h (virProcessWait): Alter signature.
* src/util/virprocess.c (virProcessWait): Add parameter.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/vircommand.c (virCommandWait): Likewise.
* src/util/virfile.c (virFileAccessibleAs): Likewise.
* src/lxc/lxc_container.c (lxcContainerHasReboot)
(lxcContainerAvailable): Likewise.
* daemon/libvirtd.c (daemonForkIntoBackground): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/testutils.c (virtTestCaptureProgramOutput): Likewise.
* tests/commandtest.c (test23): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

The documentation of namespace callbacks was inconsistent on whether
it preserved positive return values.  Now that we have a dedicated
EXIT_CANCELED to flag all errors before getting to the callback,
it is possible to use positive return values (not that any of the
current callers do, but it is better to match the docs).

Also, while vircommand.c is careful to close fds that a child should
not have, it's still better to be in the practice of setting
FD_CLOEXEC up front.

* src/util/virprocess.c (virProcessRunInMountNamespace): Tweak
return value to pass back non-zero status.  Avoid leaking pipe fds
to other threads.
* src/util/virprocess.h: Fix comment.
Signed-off-by: NEric Blake <eblake@redhat.com>

Thanks to namespaces, we have a couple of places in the code
base that want to reflect a child exit status, including the
ability to detect death by a signal, back to a grandparent.
Best to make it a reusable function.

* src/util/virprocess.h (virProcessExitWithStatus): New prototype.
* src/libvirt_private.syms (util/virprocess.h): Export it.
* src/util/virprocess.c (virProcessExitWithStatus): New function.
* tests/commandtest.c (test23): Test it.
Signed-off-by: NEric Blake <eblake@redhat.com>

Implement virProcessRunInMountNamespace, which runs callback of type
virProcessNamespaceCallback in a container namespace. This uses a
child process to run the callback, since you can't change the mount
namespace of a thread. This implies that callbacks have to be careful
about what code they run due to async safety rules.

Idea by Dan Berrange, based on an initial report by Reco
<recoverym4n@gmail.com> at
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=732394Signed-off-by: NDaniel Berrange <berrange@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Since PIDs can be reused, polkit prefers to be given
a (PID,start time) pair. If given a PID on its own,
it will attempt to lookup the start time in /proc/pid/stat,
though this is subject to races.

It is safer if the client app resolves the PID start
time itself, because as long as the app has the client
socket open, the client PID won't be reused.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This patch adds two sets of functions:

1) lower level virProcessSet*() functions that will immediately set
the RLIMIT_MEMLOCK. RLIMIT_NPROC, or RLIMIT_NOFILE of either the
current process (using setrlimit()) or any other process (using
prlimit()). "current process" is indicated by passing a 0 for pid.

2) functions for virCommand* that will setup a virCommand object to
set those limits at a later time just after it has forked a new
process, but before it execs the new program.

configure.ac has prlimit and setrlimit added to the list of functions
to check for, and the low level functions log an "unsupported" error)
on platforms that don't support those functions.

Add some APIs for acquiring namespace file descriptors and
switching namespaces
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

In the cgroups APIs we have a virCgroupKillPainfully function
which does the loop sending SIGTERM, then SIGKILL and waiting
for the process to exit. There is similar functionality for
simple processes in qemuProcessKill, but it is tangled with
the QEMU code. Untangle it to provide a virProcessKillPainfuly
function
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Continue consolidation of process functions by moving some
helpers out of command.{c,h} into virprocess.{c,h}
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

There are a number of process related functions spread
across multiple files. Start to consolidate them by
creating a virprocess.{c,h} file
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c

Move the cgroup setup code out of the lxc_controller.c file
and into lxc_cgroup.{c,h}. This reduces the size of the
lxc_controller.c file and paves the way to invoke cgroup
setup from lxc_driver.c instead of lxc_controller.c in the
future
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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

* src/lxc_conf.c, src/lxc_conf.h, src/lxc_container.c,
  src/lxc_container.h, src/lxc_controller.c, src/lxc_driver.c,
  src/lxc_driver.h, src/veth.c, src/veth.h: Move to src/lxc/
* src/opennebula/one_driver.c: Remove bogus veth.h include
* src/Makefile.am: Adjust for lxc paths
* daemon/qemud.c: Adjust include for lxc

Done with these commands:
git grep -l Local.variab|xargs \
  perl -0x3b -pi -e 's,\n+/\*\n \* vim:(.|\n)*,\n,'

git grep -l Local.variab|xargs \
  perl -0x3b -pi -e 's,\n+/\*\n \* Local variables:\n(.|\n)*,\n,'

* configure.in include/libvirt/virterror.h src/Makefile.am
  src/driver.h src/lxc_conf.[ch] src/lxc_driver.[ch] src/virterror.c:
  Applied 3 patches from Dave Leskovec for intial support of
  Linux containers, configured off by default, work in progress.
* src/libvirt.c: improve virDomainCreateLinux xmlDesc description
Daniel

Use <config.h>, not "config.h", per autoconf documentation.
* Makefile.cfg (local-checks-to-skip) [sc_require_config_h]: Enable.
* .x-sc_require_config_h: New file, to list exempted files.
* Makefile.am (EXTRA_DIST): Add .x-sc_require_config_h.

	* src/bridge.c, src/bridge.h, src/qemu_conf.c, src/qemu_conf.h,
	  src/qemu_driver.c, src/qemu_driver.h, src/test.c: Disable more
	  of qemu if configured --without-qemu.

  stylesheet
* docs/*: regenerated
* src/bridge.c src/bridge.h src/buf.c src/iptables.c src/libvirt.c
  src/qemu_driver.c src/qemu_driver.h src/uuid.c src/uuid.h: cleanup,
  addd comments, made functions static and fixe a few bugs
Daniel

  src/sexpr.h src/test.c src/xm_internal.c src/xml.c src/xml.h:
  applied patch from Richard Jones adding check to printf-like
  functions and fixing the problems raised
Daniel

        * qemud/protocol.h: add the (domain/network)(Get/Set)Autostart
        requests and replies to the protocol.

        * src/qemu_internal.c: hookup the qemu driver autostart
        methods

        * qemud/dispatch.c, qemud/driver.[ch], internal.h: add
        the daemon side, but just set an in-memory autostart
        flag for now.

        * qemud/driver.[ch], qemud/dispatch.c: fix the fact that
        qemudDispatchDomainStart() doesn't report an error if the uuid
        lookup fails and also move the uuid lookup into the driver
        so that it matches the way we do Destroy().

        * include/libvirt/libvirt.h.in, src/libvirt.c: add
        virNetworkGetBridgeName() to allow finding out what
        bridge to connect to in order to join a network.

        * src/driver.h: add networkGetBridgeName() to vtable.

        * qemud/protocol.h: add the request and reply to
        the qemud protocol.

        * qemud/dispatch.c, qemud/driver.[ch]: handle them
        here.

        * src/qemu_internal.c: implement GetBridgeName()
        in the qemu driver.

        * src/libvirt_sym.version: add new symbol.

        * qemud/protocol.h: add the protocol for virtual networks

        * qemud/dispatch.c: implement the protocol

        * qemud/driver.[ch]: add stubs for the driver

        * qemud/internal.h: add struct qemud_network

        * src/qemu_internal.c: add a virtual networks driver