Before:
- enp1s0: wan
- enp2s0: lan (with VLANs)
- enp3s0: mgt

Changes in this patch:
- wan is moved to VLAN id 5
- bond0 is created, replacing lan as lower device for VLANs
- mgt config is removed (could be reconfigured as a VLAN, and
                         made a available on a switch port)
- all 3 ports are enslaved in bond0

From the switch towards the space server load-balance algorithm
src-dst-ip* is used.

From the space server towards the switch L3+L4 is used.

Therefore a single IP pair will always use the same 1G
from the swith to the space server, a client therefore
needs to multiplex over multiple IPs in order to

*) The src-dst-ip algorithm on the switch hasn't been
   tested with IPv6 yet. Hopefully we can find a better
   switch at some point, so we can include the L4 ports in
   the hashing on the switch.

Signed-off-by: Asbjørn Sloth Tønnesen <asbjorn@labitat.dk>

New* switch for terminating 10 Gbps uplink,
with 3x1G LACP towards the space server,
and 4x1G LACP towards the space switch.

D-Link DGS-1510-28 Ethernet switch
- 24x 10/100/1000 Mbps RJ45 port
-  2x  1 Gbps SFP  ports
-  2x 10 Gbps SFP+ ports

*) it was new in 2015, but the firmware was unusable
   back then.

Signed-off-by: Asbjørn Sloth Tønnesen <asbjorn@labitat.dk>

Move the Tor exit nodes to their own VLAN, and
their own address space.

Background for move
-------------------

For the first Tor exit node, we where able to
create inet6num object 2a01:4262:1ab:20::71/128.
So we could assign a specific Tor abuse contact.

When we added the second node it was no longer
possible to create /128 inet6num objects, but
only up to /64. We therefore need to move our
Tor exit nodes to a dedicated address space.

Connection tracking
-------------------

Connection tracking is quite expensive, so
it's better to only do it for Tor traffic,
when we actually need it, which is only when
internal clients need to access the servers.

In the future conntrack could also be disabled
for labicolo in general.

Current stats
~~~~~~~~~~~~~

[root@space ~]# grep -v '185\.38\.175\.7[12] ' /proc/net/nf_conntrack |
	grep -v '2a01:4262:01ab:0020:0000:0000:0000:007[12]' | wc -l
4071

[root@space ~]# wc -l /proc/net/nf_conntrack
39138 /proc/net/nf_conntrack

Currently 4071 out of 39138 connections are not Tor related.

Also reading /proc/net/nf_conntrack is quite slow atm.:

[root@space ~]# time cat /proc/net/nf_conntrack > /dev/null

real    0m35.097s
user    0m0.010s
sys     0m28.114s

Signed-off-by: Asbjørn Sloth Tønnesen <asbjorn@labitat.dk>

Until now BGP connections have only been established
when the space server has initiated the connection to
the peer.

It's best practice for both BGP speakers to be able to
connect to one another, lowering recovery time.

This patch changes the reverse path filtering of the labicolo VLAN
to take place in the prerouting hook, using the kernel routing
table, and removes the need to maintain a static prefix list.

Labicolo routes are exported to the kernel routing table by BIRD,
hence it should be sufficient to only have prefix lists there.

This change has been tested, and it's only possible to spoof
fellow labicolo members address space (same as before).

Esmil: prerouting before input/forward makes more sense to me

Now that we use communities, we don't need this prefix filter
anymore, only the per-customer prefix filters.

We only announce a prefix, if we have recieved it from a customer
connection or if we originate it our self.

This way we avoid announcing prefixes matching the earlier used,
prefix list if we haven't recieved it via the customer connection.
This is important for multi-homed labicolo customers.

Esmil: consistent brace placement

Assign large communities on prefix import.

Later we can then use the community, to decide if we should
announce it to our peers.

This patch prepares us for adopting Large BGP Communities (RFC 8092).

Basic format of Large BGP Communities:
  <uint32_t asn>:<uint32_t function>:<uint32_t value>

We use function 1 for storing prefix type (or relation).

We then assign a value to transit, peering, customer and originated
prefixes.

Large BGP Communities
http://largebgpcommunities.net/
https://tools.ietf.org/html/rfc8092
https://tools.ietf.org/html/rfc8195

Esmil: consistent brace placement