Instead of using a limit of three nodes per message, we can pack more nodes
into each message based on ENR size. In my testing, this halves the number
of sent NODES messages, because ENR size is usually < 300 bytes.
This also adds RLP helper functions that compute the encoded size of
[]byte and string.
Co-authored-by: Martin Holst Swende <martin@swende.se>
Noticed that lookupDistances for FINDNODE requests didn't consider 256 a valid
distance. This is actually part of the example in the comment above the
function, surprised that wasn't tested before.
When receiving PING from an IPv4 address over IPv6, the implementation sent
back a IPv4-in-IPv6 address. This change makes it reflect the IPv4 address.
This PR implements the first one of the "lespay" UDP queries which
is already useful in itself: the capacity query. The server pool is making
use of this query by doing a cheap UDP query to determine whether it is
worth starting the more expensive TCP connection process.
This adds two new methods to UDPv5, AllNodes and LocalNode.
AllNodes returns all the nodes stored in the local table; this is
useful for the purposes of metrics collection and also debugging any
potential issues with other discovery v5 implementations.
LocalNode returns the local node object. The reason for exposing this
is so that users can modify and set/delete new key-value entries in
the local record.
This adds an implementation of the current discovery v5 spec.
There is full integration with cmd/devp2p and enode.Iterator in this
version. In theory we could enable the new protocol as a replacement of
discovery v4 at any time. In practice, there will likely be a few more
changes to the spec and implementation before this can happen.
