We do not want to allow contained applications to be able to read fusefs_t.
So we want /proc/meminfo label to match the system default proc_t.
Fix checking of error codes
The lxcContainerMountAllFS method had a 'bool skipRoot'
flag to control whether it mounts the / filesystem. Since
removal of the non-pivot root container setup codepaths,
this flag is obsolete as the only caller always passes
'true'.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Many methods accept a string parameter specifying the
old root directory prefix. Since removal of the non-pivot
root container setup codepaths, this parameter is obsolete
in many methods where the callers always pass "/.oldroot".
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The lxcContainerMountBasicFS method had a 'bool pivotRoot'
flag to control whether it mounted a private /dev. Since
removal of the non-pivot root container setup codepaths,
this flag is obsolete as the only caller always passes
'true'.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
The LXC driver currently has code to detect cgroups mounts
and then re-mount them inside the new root filesystem. Replace
this fragile code with a call to virCgroupIsolateMount.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If the user requests a mount for /run, this may hide any existing
mounts that are lower down in /run. The result is that the
container still sees the mounts in /proc/mounts, but cannot
access them
sh-4.2# df
df: '/run/user/501/gvfs': No such file or directory
df: '/run/media/berrange/LIVE': No such file or directory
df: '/run/media/berrange/SecureDiskA1': No such file or directory
df: '/run/libvirt/lxc/sandbox': No such file or directory
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/vg_t500wlan-lv_root 151476396 135390200 8384900 95% /
tmpfs 1970888 3204 1967684 1% /run
/dev/sda1 194241 155940 28061 85% /boot
devfs 64 0 64 0% /dev
tmpfs 64 0 64 0% /sys/fs/cgroup
tmpfs 1970888 1200 1969688 1% /etc/libvirt-sandbox/scratch
Before mounting any filesystem at a particular location, we
must recursively unmount anything at or below the target mount
point
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Ensure lxcContainerUnmountSubtree is at the top of the
lxc_container.c file so it is easily referenced from
any other method. No functional change
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This allows a container-type domain to have exclusive access to one of
the host's NICs.
Wire <hostdev caps=net> with the lxc_controller - when moving the newly
created veth devices into a new namespace, also look for any hostdev
devices that should be moved. Note: once the container domain has been
destroyed, there is no code that moves the interfaces back to the
original namespace. This does happen, though, probably due to default
cleanup on namespace destruction.
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
Currently the LXC container code has two codepaths, depending on
whether there is a <filesystem> element with a target path of '/'.
If we automatically add a <filesystem> device with src=/ and dst=/,
for any container which has not specified a root filesystem, then
we only need one codepath for setting up the filesystem.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
For a root filesystem with type=file or type=block, the LXC
container was forgetting to actually mount it, before doing
the pivot root step.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the lxc controller sets up the devpts instance on
$rootfsdef->src, but this only works if $rootfsdef is using
type=mount. To support type=block or type=file for the root
filesystem, we must use /var/lib/libvirt/lxc/$NAME.devpts
for the temporary devpts mount in the controller
Instead of using /var/lib/libvirt/lxc/$NAME for the FUSE
filesystem, use /var/lib/libvirt/lxc/$NAME.fuse. This allows
room for other temporary mounts in the same directory
In the LXC container startup code when switching stdio
streams, we call VIR_FORCE_CLOSE on all FDs. This triggers
a huge number of warnings, but we don't see them because
stdio is closed at this point. strace() however shows them
which can confuse people debugging the code. Switch to
VIR_MASS_CLOSE to avoid this
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
libvirt lxc will fail to start when selinux is disabled.
error: Failed to start domain noroot
error: internal error guest failed to start: PATH=/bin:/sbin TERM=linux container=lxc-libvirt container_uuid=b9873916-3516-c199-8112-1592ff694a9e LIBVIRT_LXC_UUID=b9873916-3516-c199-8112-1592ff694a9e LIBVIRT_LXC_NAME=noroot /bin/sh
2013-01-09 11:04:05.384+0000: 1: info : libvirt version: 1.0.1
2013-01-09 11:04:05.384+0000: 1: error : lxcContainerMountBasicFS:546 : Failed to mkdir /sys/fs/selinux: No such file or directory
2013-01-09 11:04:05.384+0000: 7536: info : libvirt version: 1.0.1
2013-01-09 11:04:05.384+0000: 7536: error : virLXCControllerRun:1466 : error receiving signal from container: Input/output error
2013-01-09 11:04:05.404+0000: 7536: error : virCommandWait:2287 : internal error Child process (ip link del veth1) unexpected exit status 1: Cannot find device "veth1"
fix this problem by checking if selinuxfs is mounted
in host before we try to create dir /sys/fs/selinux.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
when we has no host's src mapped to container.
there is no .oldroot dir,so libvirt lxc will fail
to start when mouting meminfo.
in this case,the parameter srcprefix of function
lxcContainerMountProcFuse should be NULL.and make
this method handle NULL correctly.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Convert the host capabilities and domain config structs to
use the virArch datatype. Update the parsers and all drivers
to take account of datatype change
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This extends support for host device passthrough with LXC to
cover misc devices. In this case all we need todo is a
mknod in the container's /dev and whitelist the device in
cgroups
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This extends support for host device passthrough with LXC to
cover storage devices. In this case all we need todo is a
mknod in the container's /dev and whitelist the device in
cgroups
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This adds support for host device passthrough with the
LXC driver. Since there is only a single kernel image,
it doesn't make sense to pass through PCI devices, but
USB devices are fine. For the latter we merely need to
make the /dev/bus/usb/NNN/MMM character device exist
in the container's /dev
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently LXC guests can be given arbitrary pre-mounted
filesystems, however, for some usecases it is more appropriate
to provide block devices which the container can mount itself.
This first impl only allows for <disk type='block'>, in other
words exposing a host disk device to a container. Since LXC
does not have device namespace virtualization, we are cheating
a little bit. If the XML specifies /dev/sdc4 to be given to
the container as /dev/sda1, when we do the mknod /dev/sda1
in the container's /dev, we actually use the major:minor
number of /dev/sdc4, not /dev/sda1.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
we already have virtualize meminfo for container through fuse filesystem,
add function lxcContainerMountProcFuse to mount this meminfo file to
the container's /proc/meminfo.
So we can isolate container's /proc/meminfo from host now.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Currently the lxcContainerSetupMounts method uses the
virSecurityManagerPtr instance to obtain the mount options
string and then only passes the string down into methods
it calls. As functionality in LXC grows though, those
methods need to have direct access to the virSecurityManagerPtr
instance. So push the code down a level.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The impls of virSecurityManagerGetMountOptions had no way to
return errors, since the code was treating 'NULL' as a success
value. This is somewhat pointless, since the calling code did
not want NULL in the first place and has to translate it into
the empty string "". So change the code so that the impls can
return "" directly, allowing use of NULL for error reporting
once again
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This needs to be done before the container starts. Turning
off the mknod capability is noticed by systemd, which will
no longer attempt to create device nodes.
This eliminates SELinux AVC messages and ugly failure messages in the journal.
Continue consolidation of process functions by moving some
helpers out of command.{c,h} into virprocess.{c,h}
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Some kernel versions (at least RHEL-6 2.6.32) do not let you over-mount
an existing selinuxfs instance with a new one. Thus we must unmount the
existing instance inside our namespace.
Signed-off-by: Daniel 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/
The introduction of /sys/fs/cgroup came in fairly recent kernels.
Prior to that time distros would pick a custom directory like
/cgroup or /dev/cgroup. We need to auto-detect where this is,
rather than hardcoding it
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Otherwise, a build may fail with:
lxc/lxc_conatiner.c: In function 'lxcContainerDropCapabilities':
lxc/lxc_container.c:1662:46: error: unused parameter 'keepReboot' [-Werror=unused-parameter]
* src/lxc/lxc_container.c (lxcContainerDropCapabilities): Mark
parameter unused.
Check whether the reboot() system call is virtualized, and if
it is, then allow the container to keep CAP_SYS_REBOOT.
Based on an original patch by Serge Hallyn
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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
Basically within a Secure Linux Container (virt-sandbox) we want all content
that the process within the container can write to be labeled the same. We
are labeling the physical disk correctly but when we create "RAM" based file
systems
libvirt is not labeling them, and they are defaulting to tmpfs_t, which will
will not allow the processes to write. This patch labels the RAM based file
systems correctly.
Previous commits added code to unmount the existing /proc,
/sys and /dev hierarchies on the root filesystem of the
container. This should only have been done if the container's
root filesystem was the same as the host's root. ie if
the root source is '/'. As it is, this causes LXC containersr
to fail to start if their root source is not '/'
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Move the veth device name state into the virLXCControllerPtr
object and stop passing it around. Also use size_t instead
of unsigned int for the array length parameters.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Since we are mounting a new /dev in the container, we must
remove any sub-mounts like /dev/shm, /dev/mqueue, etc,
otherwise they'll be recorded in /proc/mounts, but not be
accessible to applications.
Currently libvirt-lxc checks to see if the destination exists and is a
directory. If it is not a directory then the mount fails. Since
libvirt-lxc can bind mount files on an inode, this patch is needed to
allow us to bind mount files on files. Currently we want to bind mount
on top of /etc/machine-id, and /etc/adjtime
If the destination of the mount point does not exists, it checks if the
src is a directory and then attempts to create a directory, otherwise it
creates an empty file for the destination. The code will then bind mount
over the destination.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently you can configure LXC to bind a host directory to
a guest directory, but not to bind a guest directory to a
guest directory. While the guest container init could do
this itself, allowing it in the libvirt XML means a stricter
SELinux policy can be written
Introduce a new syntax for filesystems to allow use of a RAM
filesystem
<filesystem type='ram'>
<source usage='10' units='MiB'/>
<target dir='/mnt'/>
</filesystem>
The usage units default to KiB to limit consumption of host memory.
* docs/formatdomain.html.in: Document new syntax
* docs/schemas/domaincommon.rng: Add new attributes
* src/conf/domain_conf.c: Parsing/formatting of RAM filesystems
* src/lxc/lxc_container.c: Mounting of RAM filesystems
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
when lxcContainerIdentifyCGroups failed, the memory it allocated
has been freed, so we should not free this memory again in
lxcContainerSetupPivortRoot and lxcContainerSetupExtraMounts.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
when libvirt_lxc trigger oom error in lxcContainerGetSubtree
we should free the alloced memory for mounts.
so when lxcContainerGetSubtree failed,we should do some
memory cleanup in lxcContainerUnmountSubtree.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
we alloc the memory for format in lxcContainerMountDetectFilesystem
but without free it in lxcContainerMountFSBlockHelper.
this patch just call VIR_FREE to free it.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
This reverts
commit c16b4c43fc
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Fri May 11 15:09:27 2012 +0100
Avoid LXC pivot root in the root source is still /
This commit broke setup of /dev, because the code which
deals with setting up a private /dev and /dev/pts only
works if you do a pivotroot.
The original intent of avoiding the pivot root was to
try and ensure the new root has a minimumal mount
tree. The better way todo this is to just unmount the
bits we don't want (ie old /proc & /sys subtrees.
So apply the logic from
commit c529b47a75
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Fri May 11 11:35:28 2012 +0100
Trim /proc & /sys subtrees before mounting new instances
to the pivot_root codepath as well
when do remount,the source and target should be the same
values specified in the initial mount() call.
So change fs->dst to src.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Normal practice is for cgroups controllers to be mounted at
/sys/fs/cgroup. When setting up a container, /sys is mounted
with a new sysfs instance, thus we must re-mount all the
cgroups controllers. The complexity is that we must mount
them in the same layout as the host OS. ie if 'cpu' and 'cpuacct'
were mounted at the same location in the host we must preserve
this in the container. Also if any controllers are co-located
we must setup symlinks from the individual controller name to
the co-located mount-point
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Both /proc and /sys may have sub-mounts in them from the host
OS. We must explicitly unmount them all before mounting the
new instance over that location. If we don't then /proc/mounts
will show the sub-mounts as existing, even though nothing will
be able to access them, due to the over-mount.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If the LXC config has a filesystem
<filesystem>
<source dir='/'/>
<target dir='/'/>
</filesystem>
then there is no need to go down the pivot root codepath.
We can simply use the existing root as needed.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently to make sysfs readonly, we remount the existing
instance and then bind it readonly. Unfortunately this means
sysfs is still showing device objects wrt the host OS namespace.
We need it to reflect the container namespace, so we must mount
a completely new instance of it. Do the same for selinuxfs since
there is no benefit to bind mounting & this lets us simplify
the code.
* src/lxc/lxc_container.c: Mount fresh sysfs instance
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Instead of hardcoding use of SELinux contexts in the LXC driver,
switch over to using the official security driver API.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Once lxcContainerSetStdio is invoked, logging will not work as
expected in libvirt_lxc. So make sure this is the last thing to
be called, in particular after setting the security process label
The code is splattered with a mix of
sizeof foo
sizeof (foo)
sizeof(foo)
Standardize on sizeof(foo) and add a syntax check rule to
enforce it
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Pass argv to the init binary of LXC, using a new <initarg> element.
* docs/formatdomain.html.in: Document <os> usage for containers
* docs/schemas/domaincommon.rng: Add <initarg> element
* src/conf/domain_conf.c, src/conf/domain_conf.h: parsing and
formatting of <initarg>
* src/lxc/lxc_container.c: Setup LXC argv
* tests/Makefile.am, tests/lxcxml2xmldata/lxc-systemd.xml,
tests/lxcxml2xmltest.c, tests/testutilslxc.c,
tests/testutilslxc.h: Test parsing/formatting of LXC related
XML parts
The SELinux mount point moved from /selinux to /sys/fs/selinux
when systemd came along.
* configure.ac: Probe for SELinux mount point
* src/lxc/lxc_container.c: Use SELinux mount point determined
by configure.ac
If no <interface> elements are included in an LXC guest XML
description, then the LXC guest will just see the host's
network interfaces. It is desirable to be able to hide the
host interfaces, without having to define any guest interfaces.
This patch introduces a new feature flag <privnet/> to allow
forcing of a private network namespace for LXC. In the future
I also anticipate that we will add <privuser/> to force a
private user ID namespace.
* src/conf/domain_conf.c, src/conf/domain_conf.h: Add support
for <privnet/> feature. Auto-set <privnet> if any <interface>
devices are defined
* src/lxc/lxc_container.c: Honour request for private network
namespace
This patch fixes the access of variable "con" in two files where the
variable was declared only on SELinux builds and thus the build failed
without SELinux. It's a rather nasty fix but helps fix the build
quickly and without any major changes to the code.
To allow the container to access /dev and /dev/pts when under
sVirt, set an explicit mount option. Also set a max size on
the /dev mount to prevent DOS on memory usage
* src/lxc/lxc_container.c: Set /dev mount context
* src/lxc/lxc_controller.c: Set /dev/pts mount context
For the sake of backwards compat, LXC guests are *not*
confined by default. This is because it is not practical
to dynamically relabel containers using large filesystem
trees. Applications can create confined containers though,
by giving suitable XML configs
* src/Makefile.am: Link libvirt_lxc to security drivers
* src/lxc/libvirtd_lxc.aug, src/lxc/lxc_conf.h,
src/lxc/lxc_conf.c, src/lxc/lxc.conf,
src/lxc/test_libvirtd_lxc.aug: Config file handling for
security driver
* src/lxc/lxc_driver.c: Wire up security driver functions
* src/lxc/lxc_controller.c: Add a '--security' flag to
specify which security driver to activate
* src/lxc/lxc_container.c, src/lxc/lxc_container.h: Set
the process label just before exec'ing init.
Systemd detects containers based on whether they have
an environment variable starting with 'container=lxc';
using a longer name fits the expectations, while also
allowing detection of who created the container.
Requested by Lennart Poettering, in response to
https://bugs.freedesktop.org/show_bug.cgi?id=45175
* src/lxc/lxc_container.c (lxcContainerBuildInitCmd): Add another
env-var.
The current setup code for LXC is bind mounting /dev/pts/ptmx
on top of a character device /dev/ptmx. This is denied by SELinux
policy and is just wrong. The target of a bind mount should just
be a plain file
* src/lxc/lxc_container.c: Don't bind /dev/pts/ptmx onto
a char device
Given an LXC guest with a root filesystem path of
/export/lxc/roots/helloworld/root
During startup, we will pivot the root filesystem to end up
at
/.oldroot/export/lxc/roots/helloworld/root
We then try to open
/.oldroot/export/lxc/roots/helloworld/root/dev/pts
Now consider if '/export/lxc' is an absolute symlink pointing
to '/media/lxc'. The kernel will try to open
/media/lxc/roots/helloworld/root/dev/pts
whereas it should be trying to open
/.oldroot//media/lxc/roots/helloworld/root/dev/pts
To deal with the fact that the root filesystem can be moved,
we need to resolve symlinks in *any* part of the filesystem
source path.
* src/libvirt_private.syms, src/util/util.c,
src/util/util.h: Add virFileResolveAllLinks to resolve
all symlinks in a path
* src/lxc/lxc_container.c: Resolve all symlinks in filesystem
paths during startup
Move the virNetDevSetName and virNetDevSetNamespace APIs out
of LXC's veth.c and into virnetdev.c.
Move the remaining content of the file to src/util/virnetdevveth.c
* src/lxc/veth.c: Rename to src/util/virnetdevveth.c
* src/lxc/veth.h: Rename to src/util/virnetdevveth.h
* src/util/virnetdev.c, src/util/virnetdev.h: Add
virNetDevSetName and virNetDevSetNamespace
* src/lxc/lxc_container.c, src/lxc/lxc_controller.c,
src/lxc/lxc_driver.c: Update include paths
The src/lxc/veth.c file contains APIs for managing veth devices,
but some of the APIs duplicate stuff from src/util/virnetdev.h.
Delete thed duplicate APIs and rename the remaining ones to
follow virNetDevVethXXXX
* src/lxc/veth.c, src/lxc/veth.h: Rename APIs & delete duplicates
* src/lxc/lxc_container.c, src/lxc/lxc_controller.c,
src/lxc/lxc_driver.c: Update for API renaming
Currently the LXC controller only supports setup of a single
text console. This is wired up to the container init's stdio,
as well as /dev/console and /dev/tty1. Extending support for
multiple consoles, means wiring up additional PTYs to /dev/tty2,
/dev/tty3, etc, etc. The LXC controller is passed multiple open
file handles, one for each console requested.
* src/lxc/lxc_container.c, src/lxc/lxc_container.h: Wire up
all the /dev/ttyN links required to symlink to /dev/pts/NN
* src/lxc/lxc_container.h: Open more container side /dev/pts/NN
devices, and adapt event loop to handle I/O from all consoles
* src/lxc/lxc_driver.c: Setup multiple host side PTYs
The LXC code for mounting container filesystems from block devices
tries all filesystems in /etc/filesystems and possibly those in
/proc/filesystems. The regular mount binary, however, first tries
using libblkid to detect the format. Add support for doing the same
in libvirt, since Fedora's /etc/filesystems is missing many formats,
most notably ext4 which is the default filesystem Fedora uses!
* src/Makefile.am: Link libvirt_lxc to libblkid
* src/lxc/lxc_container.c: Probe filesystem format with libblkid
If we looped through /etc/filesystems trying to mount with each
type and failed all options, we forget to actually raise an
error message.
* src/lxc/lxc_container.c: Raise error if unable to detect
the filesystems. Also fix existing error message
The kernel automounter is mostly broken wrt to containers. Most
notably if you start a new filesystem namespace and then attempt
to unmount any autofs filesystem, it will typically fail with a
weird error message like
Failed to unmount '/.oldroot/sys/kernel/security':Too many levels of symbolic links
Attempting to detach the autofs mount using umount2(MNT_DETACH)
will also fail with the same error. Therefore if we get any error on
unmount()ing a filesystem from the old root FS when starting a
container, we must immediately break out and detach the entire
old root filesystem (ignoring any mounts below it).
This has the effect of making the old root filesystem inaccessible
to anything inside the container, but at the cost that the mounts
live on in the kernel until the container exits. Given that SystemD
uses autofs by default, we need LXC to be robust this scenario and
thus this tradeoff is worthwhile.
* src/lxc/lxc_container.c: Detach root filesystem if any umount
operation fails.
The /etc/filesystems file can contain a '*' on the last line to
indicate that /proc/filessystems should be tried next. We have
a check that this '*' only occurs on the last line. Unfortunately
when we then start reading /proc/filesystems, we mistakenly think
we've seen '*' in /proc/filesystems and fail
* src/lxc/lxc_container.c: Skip '*' validation when we're reading
/proc/filesystems
Only some of the return paths of lxcContainerWaitForContinue will
have set errno. In other paths we need to set it manually to avoid
the caller getting a random stale errno value
* src/lxc/lxc_container.c: Set errno in lxcContainerWaitForContinue
Based on a report by Coverity. waitpid() can leak resources if it
fails with EINTR, so it should never be used without checking return
status. But we already have a helper function that does that, so
use it in more places.
* src/lxc/lxc_container.c (lxcContainerAvailable): Use safer
virWaitPid.
* daemon/libvirtd.c (daemonForkIntoBackground): Likewise.
* tests/testutils.c (virtTestCaptureProgramOutput, virtTestMain):
Likewise.
* src/libvirt.c (virConnectAuthGainPolkit): Simplify with virCommand.
