docs: add documentation for gluon-ebtables-filter-{multicast,ra-dhcp}

docs/index.rst

@@ -50,6 +50,8 @@ Packages
    :maxdepth: 1
 
    package/gluon-client-bridge
+   package/gluon-ebtables-filter-multicast
+   package/gluon-ebtables-filter-ra-dhcp
 
 Releases
 --------

docs/package/gluon-ebtables-filter-multicast.rst

+gluon-ebtables-filter-multicast
+===============================
+
+The *gluon-ebtables-filter-multicast* package filters out various kinds of
+non-essential multicast traffic, as this traffic often constitutes a
+disproportionate burden on the mesh network. Unfortunately, this breaks many useful services
+(Avahi, Bonjour chat, ...), but this seems unavoidable, as the current Avahi implementation is
+optimized for small local networks and causes too much traffic in lange mesh networks.
+
+The multicast packets are filtered between the nodes' client bridge (*br-client*) and mesh
+interface (*bat0*) on output.
+
+
+The following packet types are considered essential and aren't filtered:
+
+* ARP (except requests for/replies from 0.0.0.0)
+* DHCP, DHCPv6
+* ICMPv6 (except Echo Requests (ping) and Node Information Queries (RFC4620)
+* IGMP
+
+In addition, the following packet types are allowed to allow experimentation with
+layer 3 routing protocols.
+
+* Babel
+* OSPF
+* RIPng
+
+The following packet types are also allowed:
+
+* BitTorrent Local Peer Discovery (it seems better to have local peers for BitTorrent than sending everything through the internet)

docs/package/gluon-ebtables-filter-ra-dhcp.rst

+gluon-ebtables-filter-ra-dhcp
+=============================
+
+The *gluon-ebtables-filter-ra-dhcp* package tries to prevent common
+misconfigurations (i.e. connecting the client interface of a Gluon
+node to a private network) from causing issues for either of the
+networks.
+
+The rules are the following:
+
+* DHCP requests, DHCPv6 requests and Router Solicitations may only be sent from clients to the mesh, but aren't forwarded
+  from the mesh to clients
+* DHCP replies, DHCPv6 replies and Router Advertisements from clients aren't forwarded to the mesh