lnst-ctl: fix description of -s option

The description of the -s option stayed wrong after I changed what it
meant. This patch fixes that.

Signed-off-by: Ondrej Lichtner <olichtne@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
NetTestSlave: redo mapping of devices that change netns

This patch adds a new slave method "unmap_if" that removes the mapping
of the specified interface id.

I also changed how interface mapping and network namespaces work -
previously the mapping was copied from the main process when the
namespace was created, now the mapping gets cleared and each interface
is mapped separately when it's moved to its target netns and unmapped
when it's returning.

Signed-off-by: Ondrej Lichtner <olichtne@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Machine: deconfiguration fixes

Interface configuration starts with mapping the interface id to a kernel
interface index. This mapping was previously only globally cleared by
the slave when new configuration started. This patch makes the
controller unmap interfaces one by one in the correct order.

One other minor change - restoring the use_nm option now happens before
calling the "bye" method and not is not called in the "finally" block
since the connection might not be functional anymore.

Signed-off-by: Ondrej Lichtner <olichtne@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
NetTestSlave: don't remove netns in the bye method

Removing network namespaces in the "bye" method removes part of the
configuration which shouldn't happen on config_only runs. This patch
fixes that. Instead we remove network namespaces in machine_cleanup
which is called by the "hello" method.

Signed-off-by: Ondrej Lichtner <olichtne@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
InterfaceManager: keep information about peered interfaces

Device object now know when they're paired with another interface (veth)
this is needed to properly deconfigure them when deconfiguration is not
coordinated by the controller.

This patch also adds the get_id_by_if_index method to the
InterfaceManager which is a helper function that implements the reverse
mapping of if_index to if_id.

Signed-off-by: Ondrej Lichtner <olichtne@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>