lxc-destroy container only if it is in the STOPPED state

Currently, lxc-destory will attempt to destroy a container if it is not in
the RUNNING state, but doing so is not good when the container is FROZEN, or
in other transitional states.

Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Support MS_SHARED /

(I'll be out until Jan 2, but in the meantime, here is hopefully a
little newyears gift - this seems to allow lxc-start with / being
MS_SHARED on the host)

When / is MS_SHARED (for instance with f18 and modern arch), lxc-start
fails on pivot_root.  The kernel enforces that, when doing pivot_root,
the parent of current->fs->root (as well as the new root and the putold
location) not be MS_SHARED.

To work around this, check /proc/self/mountinfo for a 'shared:' in
the '/' line.  If it is there, then create a tiny MS_SLAVE tmpfs dir to
serve as parent of /, recursively bind mount / into /root under that dir,
make it rslave, and chroot into it.

Tested with ubuntu raring image after doing 'mount --make-rshared /'.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
configure.ac: Add code to detect bionic C library

This adds a new IS_BIONIC define that can be used to detect whether we are
building with eglibc or with bionic.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
configure.ac: Cleanup, comments, indent, ...

This commit doesn't do any functional change to configure.ac but does a fair
amount of cleaning up.

It re-orders the various blocks by type (options, checks, expands, ...).
It also consistently uses tabs for indents and moves all user visible strings
between double-quotes (makes my syntax highlighter much happier).

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Replace all reference to ushort by unsigned short

ushort appears to be a glibc specific type which doesn't exist in
bionic, this commit simply replace all occurences by the equivalent
unsigned short type.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Support both getline and fgetln

Some libc implementations don't have the getline function but instead
have an equivalent fgetln function.

Add code to detect both and use whatever is available.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
No need to link against rt and util on bionic

When building on bionic, -lrt and -lutil only cause a build failure.
Dropping those fixes the build, so it appears that the symbols are defined
in the main library.

This commit moves -lrt and -lutil under a !IS_BIONIC check.

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

get_current_dir_name appears to be specific to glibc. Replace that call
by an equivalent getcwd call.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Add/remove extra includes

While cross-building with bionic, a number of failures were triggered by some
missing includes and in a few cases by extra unused includes.

This commit updates the various headers based on those observations.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
conf.c: Define LO_FLAGS_AUTOCLEAR if it's not

LO_FLAGS_AUTOCLEAR isn't defined on bionic, so add an extra ifndef
and set it to its usual value if it's not.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
clone: Support bionic's clone() defintion

The clone() call in bionic is very slightly different.
This updates namespace.h to support both glibc and bionic.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
tty.h: Ship our own minimal openpty.h

bionic is missing an openpty() function, so ship our own and only
build it and use it on bionic.

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