[Interop-dev] NetJSON: clarify what an ID is

[Bastian Bittorf]

* Nemesis <(spam-protected)> [13.08.2015 15:44]:
> Ok, I'm open for suggestions. I want to find a solution, what about we
> try to describe a NetworkGraph JSON structure as known by a babel node?
> 
> I will try to immagine a possible JSON structure, but I'm shooting in
> the dark, so please forgive me if get it wrong, help me getting it right
> by suggesting alternative (plus ignore inline comments because they are
> not valid JSON):
> 
> {
>     "type": "NetworkGraph",
>     "protocol": "babeld",
>     "version": "1.6.2",
>     "metric": "hop-count",
>     "router_id": "12:ab:34:cd:56:ef",
>     "nodes": [
>         // current node
>         { "id": "12:ab:34:cd:56:01", "interface": "wlan0" },  // wlan0
>         { "id": "12:ab:34:cd:56:01", "interface": "wlan1" },  // wlan1
>          // other linked node
>         { "id": "12:ab:34:cd:57:01", "interface": "wlan0" },  // wlan0
>         { "id": "12:ab:34:cd:57:01", "interface": "wlan1" }  // wlan0
>     ],
>     "links": [
>         {
>             "source": "12:ab:34:cd:56:01",
>             "source_interface": "wlan0",
>             "target": "12:ab:34:cd:56:02",
>             "target_interface": "wlan0",
>             "cost": 1.000
>         },
>         {
>             "source": "12:ab:34:cd:56:01",
>             "source_interface": "wlan1",
>             "target": "12:ab:34:cd:56:02",
>             "target_interface": "wlan1",
>             "cost": 1.000
>         }
>     ]
> }
> 
> I immagine this as a possible NetworkGraph object returned by a Babel node.
> Would that work? Could you propose a better example?

this is possible, but somehow 'awkward' because we have to collect all
the mac-addresses and the 'id' should be an _arbitrary_ string (e.g.
think about anonymity). some years ago ~2004 we had the same discussion
in the freifunk networks and agreed to use the SSH_PUBLIC_KEY_HASH e.g.:

(spam-protected):~ dropbearkey -y -f /etc/dropbear/dropbear_dss_host_key | grep ^'Fingerprint:' | cut -d' ' -f3
49:4a:57:e4:bc:b2:31:1d:30:f6:5f:fd:f0:de:a5:b7

hmmm, we _can_ calculate the mac-addresses
from the IPv6-fe80/linklocal addresses, but...

would'nt it be easier in the distance-vector/babel-case to let each node
just (and very simple) send to a collector only these values.

# node
{
  "id": "$SSH_PUB_KEY_HASH"
  "local_addresses": [
     $all_my_fe80-addresses, e.g.
     fe80...xyz...%wlan7
  ]
}
# links
{
  "source_ip": "fe80...",
  "target_ip": "fe80...",
  "cost": ...
}

on the collector we can have an intermediate step, which just forms a
correct netjson, where we replace 'source/target_ip' with the correct 'id'.
this has the advantage, that we dont need to suck in a lot of special
things into the specification and the client/sender side keep simple.

bye, bastian