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  1. 01 Jul, 2021 6 commits
    • conf: improve read-only /sys with read-write /sys/devices/virtual/net · e250f278
      Christian Brauner authored 
      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: 's avatarChristian Brauner <christian.brauner@ubuntu.com>
    • initutils: close dirfd in error path · c73a2325
      Simon Deziel authored 
      Signed-off-by: 's avatarSimon Deziel <simon.deziel@canonical.com>
    • execute: ensure parent is notified about child exec and close all unneeded fds · 0a953196
      Christian Brauner authored 
      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: 's avatarChristian Brauner <christian.brauner@ubuntu.com>
    • network: log network devices while sending · 0089d717
      Christian Brauner authored 
      Signed-off-by: 's avatarChristian Brauner <christian.brauner@ubuntu.com>
    • initutils: use vfork() in lxc_container_init() · 91ee6c8b
      Christian Brauner authored 
      We can let the child finish calling exec before continuing in the
parent.
Signed-off-by: 's avatarChristian Brauner <christian.brauner@ubuntu.com>
    • execute: don't exec init, call it · a4295196
      Tycho Andersen authored 
      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: 's avatarTycho Andersen <tycho@tycho.pizza>
  3. 29 Jun, 2021 12 commits
  5. 14 Jun, 2021 5 commits
  7. 08 Jun, 2021 3 commits
  9. 28 May, 2021 14 commits