file_utils: surface ENOENT when falling back to openat()

Link: https://discuss.linuxcontainers.org/t/error-failed-to-retrieve-pid-of-executing-child-processSigned-off-by: Christian Brauner <christian.brauner@ubuntu.com>

RFC: conf: userns.conf: include userns.conf.d

lxc-unshare: fixes

We were passing the wrong PID. Fix this!

Link: https://discuss.linuxcontainers.org/t/problem-with-moving-interface-new-network-namespace-in-lxc-unshareSigned-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

If an include directive ends with a trailing slash, we now
always assume it is a directory and do not treat the
non-existence as an error.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

Update Japanese lxc.container.conf(5)

Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>

Update for commit 1852be90Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>

Update for commit 320061b3Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>

Update for commit 5025f3a6Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>

cgroups: handle funky cgroup layouts

terminal: ensure newlines are turned into newlines+carriage return fo…

cmd/lxc-checkconfig: list cgroup namespaces and rename confusing ns_c…

Link: https://discuss.linuxcontainers.org/t/cgroup-namespace-required-in-lxc-checkconfig-and-config-cgroup-nsSigned-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Fixes: #3879
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Old versions of Docker emulate a cgroup namespace by bind-mounting the
container's cgroup over the corresponding controller:

/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/systemd rw,nosuid,nodev,noexec,relatime master:11 - cgroup cgroup rw,xattr,name=systemd
/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/net_cls,net_prio rw,nosuid,nodev,noexec,relatime master:15 - cgroup cgroup rw,net_cls,net_prio
/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/cpu,cpuacct rw,nosuid,nodev,noexec,relatime master:16 - cgroup cgroup rw,cpu,cpuacct
/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/memory rw,nosuid,nodev,noexec,relatime master:17 - cgroup cgroup rw,memory
/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/devices rw,nosuid,nodev,noexec,relatime master:18 - cgroup cgroup rw,devices
/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/hugetlb rw,nosuid,nodev,noexec,relatime master:19 - cgroup cgroup rw,hugetlb
/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/perf_event rw,nosuid,nodev,noexec,relatime master:20 - cgroup cgroup rw,perf_event
/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/cpuset rw,nosuid,nodev,noexec,relatime master:21 - cgroup cgroup rw,cpuset
/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/blkio rw,nosuid,nodev,noexec,relatime master:22 - cgroup cgroup rw,blkio
/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/pids rw,nosuid,nodev,noexec,relatime master:23 - cgroup cgroup rw,pids
/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod7d4424e6_bb13_42f4_a47a_45a4828bf54d.slice/docker-d0b3604b67ac7930dd34ba3a796627e3e4717d12309e90a4afe3f38b6816ac98.scope /sys/fs/cgroup/freezer rw,nosuid,nodev,noexec,relatime master:24 - cgroup cgroup rw,freezer

New versions of LXC always stash a file descriptor for the root of the
cgroup mount at /sys/fs/cgroup and then resolve the current cgroup
parsed from /proc/{1,self}/cgroup relative to that file descriptor. This
doesn't work when the caller's cgroup is mouned over the controllers.
Older versions of LXC simply counted such layouts as having no cgroups
available for delegation at all and moved on provided no cgroup limits
were requested. But mainline LXC would fail such layouts. While I would
argue that failing such layouts is the semantically clean approach we
shouldn't regress users so make mainline LXC treat such cgroup layouts
as having no cgroups available for delegation.

Fixes: #3890
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Improve read-only /sys with read-write /sys/devices/virtual/net

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Some tools require /sys/devices/virtual/net to be read-write. At the
same time we want all other parts of /sys to be read-only. To do this we
created a layout where we hade a read-only instance of sysfs mounted on
top of a read-write instance of sysfs:

`-/sys                                  sysfs                                                        sysfs      rw,nosuid,nodev,noexec,relatime
  `-/sys                                sysfs                                                        sysfs      ro,nosuid,nodev,noexec,relatime
    |-/sys/devices/virtual/net          sysfs                                                        sysfs      rw,relatime
    | `-/sys/devices/virtual/net        sysfs[/devices/virtual/net]                                  sysfs      rw,nosuid,nodev,noexec,relatime

This causes issues for systemd services that create a separate mount
namespace as they get confused to what mount options need to be
respected.

Simplify our mounting logic so we end up with a single read-only mount
of sysfs on /sys and a read-write bind-mount of /sys/devices/virtual/net:

├─/sys                                sysfs                                                                                  sysfs         ro,nosuid,nodev,noexec,relatime
│ ├─/sys/devices/virtual/net          sysfs[/devices/virtual/net]                                                            sysfs         rw,nosuid,nodev,noexec,relatime

Link: systemd/systemd#20032
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

initutils: close dirfd in error path

Signed-off-by: Simon Deziel <simon.deziel@canonical.com>

execute: don't exec init, call it

lxc_container_init() creates the container payload process as it's child
so lxc_container_init() itself never really exits and thus the parent
isn't notified about the child exec'ing since the sync file descriptor
is never closed. Make sure it's closed to notify the parent about the
child's exec.

In addition we're currently leaking all file descriptors associated with
the handler into the stub init. Make sure that all file descriptors
other than stderr are closed.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

We can let the child finish calling exec before continuing in the
parent.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Instead of having a statically linked init that we put on the host fs
somewhere via packaging, have to either bind mount in or detect fexecve()
functionality, let's just call it as a library function. This way we don't
have to do any of that.

This also fixes up a bunch of conditions from:

if (quiet)
    fprintf(stderr, "log message");

to

if (!quiet)
    fprintf(stderr, "log message");

:)

and it drops all the code for fexecve() detection and bind mounting our
init in, since we no longer need any of that.

A couple other thoughts:

* I left the lxc-init binary in since we ship it, so someone could be using
  it outside of the internal uses.
* There are lots of unused arguments to lxc-init (including presumably
  --quiet, since nobody noticed the above); those may be part of the API
  though and so we don't want to drop them.
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>

remove_from_array() causes a crash

and the item is copied (strdup()) to the array.
Thus, when an item is removed from an array, memory allocated for that item
should be freed, successive items should be left-shifted and the array
realloc()ed again (size-1).

Additional changes:
- If strdup() fails in add_to_array(), then an array should be
  realloc()ed again to original size.
- Initialize an array in list_all_containers().
Signed-off-by: Tomasz Blaszczak <tomasz.blaszczak@consult.red>

cgroups: verify that hierarchies are non-empty

Fixes: #3881
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

lxc-download: Switch GPG server

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

When an item is added to an array, then the array is realloc()ed (to size+1),
and the item is copied (strdup()) to the array.
Thus, when an item is removed from an array, allocated memory pointed by
the item (not the item itself) should be freed, successive items should
be left-shifted and the array realloc()ed again (size-1).

Additional changes:
- Initialize an array in list_all_containers().
Signed-off-by: Tomasz Blaszczak <tomasz.blaszczak@consult.red>

and the item is copied (strdup()) to the array.
Thus, when an item is removed from an array, memory allocated for that item
should be freed, successive items should be left-shifted and the array
realloc()ed again (size-1).

Additional changes:
- If strdup() fails in add_to_array(), then an array should be
  realloc()ed again to original size.
- Initialize an array in list_all_containers().
Signed-off-by: Tomasz Blaszczak <tomasz.blaszczak@consult.red>

cgroups: use stable ordering for co-mounted v1 controllers

Fixes: #3703
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

remove problematic terminology