It is not system-definable, rather glibc sets that to bin:/usr/bin, which is
simply too restrictive.  So just always set our preferred path.

This was reported at:
https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1384327Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

Rather than try to free all the not-being-returned items at
each if clause where we assign one to return value, just NULL
the one we are returning so we can safely free all the
values.  This should fix the newly reported coverity memory
leak
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

If we are root using a user namespace and are mounting a blockdev as rootfs,
then we do this before unsharing the userns, because we are not allowed to
do it in a userns.  But after unsharing the userns, we unconditionally
retried mounting the rootfs, resulting in failure.  stop that.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

On restore, we pass criu a script to manage the network interfaces (i.e. the
full path to lxc-restore-net), which we previously installed into
/var/lib/<tuple>/lxc. However, this is also the directory that is the default
for use in mounting the rootfs locally before pivot_root()ing. So, we mounted
the rootfs and then happliy called criu, pointing it to this directory which
didn't have lxc-restore-net any more, it just had the container's rootfs.
Instead, we should put lxc-restore-net somewhere else, so that criu can still
see it after the rootfs is mounted.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

Behave well when /etc/lxc/${name} is a symlink to directory
Signed-off-by: Dark Templar <dark_templar@hotbox.ru>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

Fix return value on bind mount failure.

If we've already mounted the rootfs, exit after the bind mount
rather than re-trying the rootfs mount.  The only case where
this happens is when root is starting a container in a user
namespace and with a block device backing store.

In that case, pre-mount hooks will be executed in the initial
user namespace.  That may be worth fixing.  Or it may be what
we want.  We should think about it and fix it.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

I've found one more typo in the gentoo template, configuration in the
generated file /etc/conf.d/hostname was not valid, but it didn't impact
me due to "lxc.utsname" being set in the configuration file of container
and hostname service being not used. Anyway, I've made a patch and
sending it with this mail.
Signed-off-by: Dark Templar <dark_templar@hotbox.ru>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

When running unprivileged, lxc-create will touch a fstab file, with bind-mounts
for the ttys and other devices. Add this entry in the container config.
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

Apply the changes found in templates/lxc-download to the busybox template as
well. Change ownership of the config and fstab files to the unprivileged user,
and the ownership of the rootfs to root in the new user namespace.

Eliminate the "unsupported for userns" flag.
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

>>> On Tue, 30 Sep 2014 19:48:09 +0000
    in message   "Re: [lxc-devel] [PATCH] lxc-config can show lxc.cgroup.(use|pattern)"
                  Serge Hallyn-san wrote:

> I think it would be worth also augmenting
> lxc_global_config_value() to return a default lxc.cgroup.use
> for 'all', and a default lxc.cgroup.pattern ("/lxc/%n" for root
> or "%n" for non-root).

lxc.cgroup.pattern is like this? (^_^;)
Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

Signed-off-by: Dark Templar <dark_templar@hotbox.ru>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

Check for it when we check for apparmor being enabled, rather
than doing it during the middle of a container setup.

This avoid the need to try mounting /sys and /sys/kernel/security
in the middle of startup, which we may not be allowed to anyway.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Dwight Engen <dwight.engen@oracle.com>

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

We previously wrote a bunch of files (eth*, veth*, and bridge*) as hard coded
files which we used as the names of interfaces to restore via criu's
--veth-pair. This meant that if people, e.g. gave a different bridge on their
new host, we would use our saved bridge in bridge* and try to restore to the
wrong bridge. Instead, we can just generate a new veth id (if the user hasn't
provided one), and use whatever the user configured values for the interface
name and bridge are.

This allows people to switch the bridge that they restore onto simply by
migrating the rootfs and config, and then changing the bridge name in the
container's configuration before running lxc-checkpoint.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

Break the monolithic ->checkpoint and ->restore functions into smaller ones.
This is in preparation for the checkpoint/restore tty work, which has a similar
need to dump information outside of criu.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

The python lxc-device supported adding wlan devices, so add that
support as well.  Since the python one did not support 'del',
I didn't try adding that support, though it should be trivial to
add.

We should be able to do the wlan adding using netlink, but I
went ahead and used 'iw' as the netlink path looked more
complicated than it does for other nics.  Patches to switch that
over would be very welcome.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

because that's what it does
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

As there is a function named attach_interface to pass
a interface to container now, we do not need to relay on
python impolementation for lxc-device any more.

changelog: 10/15/2014: serge: fail immediately if run as non-root.
changelog: 10/15/2014: serge: add explicit error message on bad usage (fix build failure)
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

Changelog: 10/15/2014: serge: make ifname mandatory for detach_interface.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

Currently, we depends on ip command to attach interface to container.
It means we only implemented it by python.

This patch implement adding and removing interface by c and added
them in struct container.

Changelog: 10/15/2014 (serge): return error if ifname is NULL.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

Function of enter_to_ns() is useful but currently is static for
lxccontainer.c.

This patch split it into two parts named as switch_to_newuser()
and switch_to_newnet() into utils.c.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

When we need to know some info about a netdev, such as is_up or not,
we need to read the flag for the netdev.

This patch introduce a interface function named lxc_netdev_isup()
to check is a netdev up or down.

And introduce a network private function named netdev_get_flag()
to get flag for netdev by netlink.

Changelog: 10/15/2015: Return failure if name==NULL to avoid later strlen fun
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

In netlink, we can set the dest_name of netdev when move netdev
between namespaces in one netlink request. And moving a netdev of
a src_name to a netdev with a dest_name is a common usecase.

So this patch add a parametaer to lxc_network_move_by_index() to
indicate the dest_name for the movement. NULL means same with
the src_name.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

We should exit with a error when starting a running container.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

When we want to get index of a ifname which does not
exist, we should return a -EINVAL in this case.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

We should not modify ifname in lxc_netdev_move_by_name(),
making it as const in param list will make our code more
robust.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>

the way config_mount was structured, sending 'lxc.mount.auto = '
ended up actually clearing all lxc.mount.entrys.  Fix that by
moving the check for an empty value to after the subkey checks.
Then, actually do the clearing of auto_mounts in config_mount_auto.

The 'strlen(subkey)' check being removed was bogus - the subkey
either known to be 'lxc.mount.entry', else subkey would have been
NULL (and forced a return in the block above).

This would have been clearer if the config_mount() and helper
fns were structured like the rest of confile.c.  It's tempting
to switch it over, but there are subtleties in there so it's
not something to do without a lot of thought and testing.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

- RHEL/OL 7 doesn't have the ifconfig command by default so have the
  lxc-net script check for its existence before use, and fall back
  to using the ip command if ifconfig is not available

- When lxc-net is run from systemd on a system with selinux enabled,
  the mkdir -p ${varrun} will create /run/lxc as init_var_run_t which
  dnsmasq can't write its pid into, so we restorecon it
  after creation (to var_run_t)

- The lxc-net systemd .service file needs an [Install] section so that
  "systemctl enable lxc-net" will work
Signed-off-by: Dwight Engen <dwight.engen@oracle.com>

If we don't close these running lxc-checkpoint via:

ssh host "sudo lxc-checkpoint ..."

just hangs. We leave stderr open so that subesquent errors will print correctly
(and also because for whatever reason it doesn't break ssh :).

Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

Previously, we let criu create the cgroups for a container as it was restoring
things. In some cases (i.e. migration across hosts), if the container being
migrated was in /lxc/u1-3, it would be migrated to the target host in
/lxc/u1-3, even if there was no /lxc/u1-2 (or worse, if there was already an
alive container in u1-3).

Instead, we use lxc's cgroup_create, and then tell criu where to restore to.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

On Tue, Oct 07, 2014 at 07:33:07PM +0000, Tycho Andersen wrote:
> This commit is in preparation for the cgroups create work, since we will need
> the handler in both the parent and the child. This commit also re-works how
> errors are propagated to be less verbose.

Here is an updated version:

From 941623498a49551411ccf185146061f3f37d3a67 Mon Sep 17 00:00:00 2001
From: Tycho Andersen <tycho.andersen@canonical.com>
Date: Tue, 7 Oct 2014 19:13:51 +0000
Subject: [PATCH 1/2] restore: Hoist handler to function level

This commit is in preparation for the cgroups create work, since we will need
the handler in both the parent and the child. This commit also re-works how
errors are propagated to be less verbose.

v2: rename error to has_error, handle it correctly, and remove some diff noise
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

This is in preparation for the cgroups creation work, but also probably just a
good idea in general. The ERROR message is handy since we print line nos. it
will to give people an indication of what arg was null.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

pivot_root can't be called if / is on a ramfs. Currently chroot is
called before pivot_root. In this case the standard well-known
'chroot escape' technique allows to escape a container.

I think the best way to handle this situation is to make following actions:
* clean all mounts, which should not be visible in CT
* move CT's rootfs into /
* make chroot into /

I don't have a host, where / is on a ramfs, so I can't test this patch.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>