tree 13e8a607e6e552da0f4218b4a8473dbcd738845b
parent c99f3481a598e9cadd1de96714f6b5df9ad85c4a
author Feng Lu <lu.feng@6wind.com> 1404383074 +0800
committer Nicolas Dichtel <nicolas.dichtel@6wind.com> 1433345187 +0200

lib, vtysh: support multiple VRFs by using linux netns

We realize VRFs with linux netns by default. The main job is
to associate a VRF with a netns. Currently this is done by
the configuration:

  [no] vrf N netns <netns-name>

This command is also available in vtysh and goes to only
zebra, because presently only zebra supports multiple VRF.

A file descriptor is added to "struct vrf". This is for the
associated netns file. Once the command "vrf N netns NAME"
is executed, the specified file is opened and the file
descriptor is stored in the VRF N. In this way the
association is formed.

In vrf_socket(), we first switch to the specified VRF by
using the stored file descriptor, and then can allocate
a socket which is working in the associated netns.

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>