nl-link-set: Add --state option

I modified the nl-link-set.c file to be able to set the interface up or
down. I joined the patch.
With the new nl-link-set binary I can set the tap interface down.
I am working with Ubuntu 12.04 LTS 64bits and the libnl and libnl-route
packages built from libnl3-3.2.3 from ubuntu reprositories.

--
Julien BERNARD

Signed-off-by: Thomas Graf <tgraf@suug.ch>
route/link: fixup link->l_af_ops must be set for some kind of links

Lookup on IFLA_INFO_KIND information to setup the right link->l_af_ops callbacks
For example, if you setup a bridge this is avoid to trig IS_BRIDGE_LINK_ASSERT() on rtnl_link_bridge_get_flags() call.

    line=<optimized out>, function=<optimized out>) at assert.c:94
    0x7ffff5dc39a0 "rtnl_link_bridge_get_flags") at assert.c:103

Signed-off-by: Nicolas PLANEL <nicolas.planel@enovance.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
test: add bridge creation sample

New test sample file, test-create-bridge.c
Create an bridge (testbrige) and attach an already setup interface (testtap1) to it.

Signed-off-by: Nicolas PLANEL <nicolas.planel@enovance.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
python: add basic netlink protocol bridge interface support

Implements basic bridge interface support using netlink protocol

Signed-off-by: Nicolas PLANEL <nicolas.planel@enovance.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
test: add python bridge testing sample

New test sample file, test-create-bridge.py
Create an bridge (testbrige) and attach an already setup interface (testtap1) to it.

Signed-off-by: Nicolas PLANEL <nicolas.planel@enovance.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
python: add bridge flags API

Add flags set/get methods aim to change bridge flags :
 o hairpin_mode
 o bpdu_guard
 o root_block
 o fast_leave

Signed-off-by: Nicolas PLANEL <nicolas.planel@enovance.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
obj: Check for NULL pointer in nl_object_clone()

Signed-off-by: Thomas Graf <tgraf@suug.ch>
rtnl-addr: set ifa_flags when creating/updating address

Set the address flags when creating/updating an address with
rtnl_addr_add/rtnl_addr_build_add_request. Before, the flags
were not passed on.

As of now, the flags except IFA_F_NODAD|IFA_F_HOMEADDRESS are ignored by
the kernel. Still pass them on without filtering.

Signed-off-by: Thomas Haller <thaller@redhat.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>