This commit introduces a new concept called `NotificationService` which
allows Polkadot protocols to communicate with the underlying
notification protocol implementation directly, without routing events
through `NetworkWorker`. This implies that each protocol has its own
service which it uses to communicate with remote peers and that each
`NotificationService` is unique with respect to the underlying
notification protocol, meaning `NotificationService` for the transaction
protocol can only be used to send and receive transaction-related
notifications.
The `NotificationService` concept introduces two additional benefits:
* allow protocols to start using custom handshakes
* allow protocols to accept/reject inbound peers
Previously the validation of inbound connections was solely the
responsibility of `ProtocolController`. This caused issues with light
peers and `SyncingEngine` as `ProtocolController` would accept more
peers than `SyncingEngine` could accept which caused peers to have
differing views of their own states. `SyncingEngine` would reject excess
peers but these rejections were not properly communicated to those peers
causing them to assume that they were accepted.
With `NotificationService`, the local handshake is not sent to remote
peer if peer is rejected which allows it to detect that it was rejected.
This commit also deprecates the use of `NetworkEventStream` for all
notification-related events and going forward only DHT events are
provided through `NetworkEventStream`. If protocols wish to follow each
other's events, they must introduce additional abtractions, as is done
for GRANDPA and transactions protocols by following the syncing protocol
through `SyncEventStream`.
Fixes https://github.com/paritytech/polkadot-sdk/issues/512
Fixes https://github.com/paritytech/polkadot-sdk/issues/514
Fixes https://github.com/paritytech/polkadot-sdk/issues/515
Fixes https://github.com/paritytech/polkadot-sdk/issues/554
Fixes https://github.com/paritytech/polkadot-sdk/issues/556
---
These changes are transferred from
https://github.com/paritytech/substrate/pull/14197 but there are no
functional changes compared to that PR
---------
Co-authored-by: Dmitry Markin <dmitry@markin.tech>
Co-authored-by: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>
* substrate: peer_store: log error on disconnecting because of reputation
Disconnecting and banning a peer because of negative reputation is
usually an indicative of one of two things:
1. We've got a bug that forces disconnects.
2. We've got malicious peers that try to attack us.
We both cases I don't think we should hide this behind a trace log
and we should log errors, so that things are easy to notice and
debug/mitigated.
Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>
* Move from error to warn
Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>
---------
Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>
Aaro Altonen