tree 361484e61445a5e7efc9dfab2d6c47cd4c63846c
parent ac19a449261bf69e83827f4bb0c6e5526277b41b
author Feng Lu <lu.feng@6wind.com> 1432287608 +0200
committer David Lamparter <equinox@opensourcerouting.org> 1433224114 +0200

lib/vrf: enable / disable a VRF

A new API vrf_is_enabled() is defined to check whether a VRF is ready
to use, that is, to allocate resources in that VRF. Currently there's
only one type of resource: socket.

Two new hooks VRF_ENABLE_HOOK/VRF_DISABLE_HOOK are introduced to tell
the user when a VRF gets ready or to be unavailable.

The VRF_ENABLE_HOOK callback is called in the new function vrf_enable(),
which is used to let the VRF be ready to use. Till now, only the default
VRF can be enabled, and we need do nothing to enable the default, except
calling the hook.

The VRF_DISABLE_HOOK callback is called in the new function
vrf_disable(), which is used to let the VRF be unusable. Till now,
it is called only when the VRF is to be deleted.

A new utility vrf_socket() is defined to provide a socket in a given
VRF to the user.

Till now before introducing a way of VRF realization, only the default
VRF is enabled since its birth, and vrf_socket() creates socket for
only the default VRF.

This patch defines the framework of the VRF APIs. The way they serve
the users is:
- vrf_is_enabled() is used to tell the user whether a VRF is usable;
- users are informed by the VRF_ENABLE_HOOK that a VRF gets usable;
  they can allocate resources after that;
- users are informed by the VRF_DISABLE_HOOK that a VRF is to be
  unavailable, and they must release the resources instantly;
- vrf_socket() is used to provide a socket in a given VRF.

Signed-off-by: Feng Lu <lu.feng@6wind.com>
Reviewed-by: Alain Ritoux <alain.ritoux@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Vincent JARDIN <vincent.jardin@6wind.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>