Negative ban scores are a bit annoying since when a user bans the node
it gives a 1000 point punishment, assuming that this will make the ban
score be above the 1000 point limit which implies banned.
With the expansion of the database more agressive, checking a
larger set of items for the best one becomes more important, as
such do a 10x for finding the best sccoring item.
The observed effect is finding previously useful peers within seconds
instead of a minute.
When we didn't personally verify the services, don't judge the IP based
on them and connect anyway.
In addition to not trusting the services we receive from the net, be
more careful with the usage of the 'lastConnected' field.
Notice that we don't actually use the result of that variable in the end
if the everConnected is likewise incorrect.
this introduces a new version of the address-db, as stored in the db
file itself. Causing a one-time 'upgrade'.
Main issue solved is that the 'everSeen' bool was restored incorrectly
and from then on out saved wrong too.
This may have caused bad selection of peers to connect to as the DB
grew.
Together with the various bugs in the last months update we also reset
the punishment to not avoid connecting to possibly perfectly fine peers.
The AddressDB stores separately the ipv4 and ipv6 addresses, ensuring
that the caller only receives IP addresess compatible with what they
asked.
Until now the booleans to define this were simply private members of the
DB and ipv6 was off.
This exposes those boolean to the outside world.
When a peer sends us an 'addr' message it includes the time they report
they last connected to it. This is untrusted data and we should not act
on it for our our connectivity stats.
As we moved most of the creation of a BufferPool to be via the
Streaming::pool() method, which uses a thread-local, it makes sense
to start cleaning up the design and make it more modern C++.
The above mentioned method would return a reference and you'd see
loads of places use `auto &pool =` which is less than ideal.
As the number of places where we actually instantiate a BufferPool
goes down, the usage of some sort of smart pointer makes more sense.
This now makes all APIs use BufferPool be wrapped in a shared_ptr.
We removed the default value in order to avoid misusage of the method
and mistaking the amount with the connection-id.
From Peer we now se the faster overload of punish(), avoiding looping
through the peer list.
Also check return-code when needed.
The PeerAddressDB keeps a score for each IP/port we have about how
useful that peer is.
This change re-visits the way we use the DB where we now are more fluid
in our approach to scores. We no longer simply forever-ban a peer after
it made a mistake once.
This rewrites the select-a-peer algo to take timing into account,
preferring a peer that we connected to recently while putting a higher
score on a peer that failed a long time ago so if we start running out
of good peers we start on the not-so-great-but-maybe-improved first.
Good behavior is likewise rewarded so a peer can become higher prio
again, but generally a new IP still gets preferred. Again, the balance
is to keep not-so-great options in the running.
Based on the idea that randomly selecting a peer from our database will
prioritize based on the peers punishment score, this sets the punishment
for never connected-to peers at 10 (out of 1000) just to give a minor
benefit to speeding up the meshing.
This avoids a peer once sending acceptable headers and never
being bothered again. Instead we now check regularly and keep
track of when the peer was known to follow the same chain as us.
Avoid deleting and creating connections, which is really a rather rare
event anyway, and simply remember the connection object and reuse it
when a new one is requested.
The NetworkManager usage was mostly for low connection counts and this
made defaults selection easy.
With more usages it is important to allow the NWM-connection to be more
configurable about memory usage and leaner in general.
This changes the headers-buffers (used to create envelopes) to not be per
connection anymore but per thread using the tread_local keyword.
This changes the ring-buffers to become configurable using
NetworkConnections::setMessageQueueSizes().
Also removing some include statements where they were not really needed
in the P2PNet lib.
We reuse the NetworkManager lower level code in order to connect
to the Bitcoin P2P network.
This implements the basics for anyone wanting to be a player on
this network.
tomFlowee
TomZ