Merge branch 'x-netns'

Nicolas Dichtel says:

====================
This series is a follow up of the previous series whcih adds this
functionality for sit tunnels.

The goal is to add x-netns support for the module ipip and ip6_tunnel,
ie. the encapsulation addresses and the network device are not owned
by the same namespace.

Note that the two first patches are cleanups.

Example to configure an ipip tunnel:

modprobe ipip
ip netns add netns1
ip link add ipip1 type ipip remote 10.16.0.121 local 10.16.0.249
ip l s ipip1 netns netns1
ip netns exec netns1 ip l s lo up
ip netns exec netns1 ip l s ipip1 up
ip netns exec netns1 ip a a dev ipip1 192.168.2.123 remote 192.168.2.121

or an ip6_tunnel:

modprobe ip6_tunnel
ip netns add netns1
ip link add ip6tnl1 type ip6tnl remote 2001:660:3008:c1c3::121 local 2001:660:3008:c1c3::123
ip l s ip6tnl1 netns netns1
ip netns exec netns1 ip l s lo up
ip netns exec netns1 ip l s ip6tnl1 up
ip netns exec netns1 ip a a dev ip6tnl1 192.168.1.123 remote 192.168.1.121
ip netns exec netns1 ip -6 a a dev ip6tnl1 2001:1235::123 remote 2001:1235::121

v2: remove the patch 1/3 of the v1 series (already included)
    use net_eq()
    add patch 1/4 and 2/4
====================-

Signed-off-by: David S. Miller <davem@davemloft.net>