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: NDaniel 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: NGao feng <gaofeng@cn.fujitsu.com>

print debug info "container support is enabled"
when host support the user or net namespace.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

kill the "return 0;" code, it will cause memory leak.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

Introduced in commit 1f8c33b6.

* src/lxc/lxc_container.c (lxcContainerGetSubtree): Avoid TAB.

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: NGao 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: NGao feng <gaofeng@cn.fujitsu.com>

This reverts

  commit c16b4c43
  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 c529b47a
  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

we forgot to free fslist,just add VIR_FREE(fslist).
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

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: NGao feng <gaofeng@cn.fujitsu.com>

There is no code use the variable "src" in lxcContainerMountBasicFS.
so delete it and VIR_FREE.
Signed-off-by: NGao 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: NDaniel 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: NDaniel 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: NDaniel 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: NDaniel 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: NDaniel 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: NDaniel 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

Systemd has declared that all container virtualization technologies
should set 'container_uuid' to identify themselves.

http://cgit.freedesktop.org/systemd/systemd/commit/?id=09b967eaa51a39dabb7f238927f67bd682466dbc

Just a cleanup of commit 32f881c6.

Some applications expect /dev/std{in,out,err} to exist. Populate
them during container startup as symlinks to /proc/self/fd

compat{a->i}bility
erron{->e}ous
nec{c->}essary.
Either "the" or "a".
Signed-off-by: NPhilipp Hahn <hahn@univention.de>

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

* .gnulib: Update to latest, for improved syntax-check.
* src/lxc/lxc_container.c (includes): Drop unused include.
* src/network/bridge_driver.c: Likewise.
* src/node_device/node_device_linux_sysfs.c: Likewise.
* src/openvz/openvz_driver.c: Likewise.
* src/qemu/qemu_conf.c: Likewise.
* src/storage/storage_backend_iscsi.c: Likewise.
* src/storage/storage_backend_mpath.c: Likewise.
* src/uml/uml_conf.c: Likewise.
* src/uml/uml_driver.c: Likewise.

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