python: Lots of fixes in C extension

Fixes a lot of issues found by a code review done by Barry Warsaw.

Those include:
 - Wrong signature for getters
 - Various memory leaks
 - Various optimizations
 - More consistent return values
 - Proper exception handling

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Reported-by: Barry Warsaw <barry@ubuntu.com>
Acked-by: Barry Warsaw <barry@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
python: Various fixes to the python scripts

This fixes a few issues uncovered by the recent C module fix.

In lxc-start-ephemeral, the hwaddr code wasn't actually working.
Replace by code that properly iterates through the network interfaces
and sets a new MAC address for each entry.

In the python overlay, catch the newly emitted KeyError when in
set_config_item (or setting any previously unset variable would fail).

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Use "uname -m" instead of "arch"

According to "arch"'s manpage, it's identical to "uname -m".

Some distros ship uname but don't ship arch, however all distros ship uname,
therefore it makes sense to use "uname -m" whenever possible.

Signed-off-by: Christian Bühler <christian@cbuehler.de>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
ubuntu: Various fixes

 - Drop disabled entries from allowed devices list
 - Improve generated config layout a bit
 - Drop redundant uname call
 - Re-generate the SSH host keys on container creation

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
python: Fix get_ips and nesting with lxcpath

When using -P (lxcpath), the parameter path needs to be forwarded
to the various commands being run but not used by the nested lxc-ls
as it's relatively unlikely that both the host and the nested containers
use a custom path.

This isn't ideal but short of having a way to provide the container path
for every single of the nesting (with potential unlimited depth), it's
the best we can do.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
make lxc_af_unix_open() safely return error on long pathnames

Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
cgpath test: don't check path len before checking if it is null

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
remove needless check for 'line' which cannot be NULl there

(found by coverity)

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
goto correct cleanup label to ensure fd is closed

Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
python: Fix convert_tuple_to_char_pointer_array

This finally fixes a few issues with the magic
convert_tuple_to_char_pointer_array function.

This now clearly copies the char* from the python object so we don't
end up keeping reference to those.

Also add the few required free calls to free the content of the array.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
python: Make the code compatibly with 3.2

The previous change used some 3.3-specific functions.
We still support 3.2 so revert to 3.2-compatible calls.

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