* protocols/kad: Do not attempt to store expired record in record store
`Kademlia::record_received` calculates the expiration time of a record
before inserting it into the record store. Instead of inserting the
record into the record store in any case, with this patch the record is
only inserted if it is not expired. If the record is expired a
`KademliaHandlerIn::Reset` for the given (sub) stream is triggered.
This would serve as a tiny defense mechanism against an attacker trying
to fill a node's record store with expired records before the record
store's clean up procedure removes the records.
* protocols/kad: Send regular ack when record discarded due to expiration
With this commit the remote receives a
[`KademliaHandlerIn::PutRecordRes`] even in the case where the record is
discarded due to being expired. Given that the remote sent the local
node a [`KademliaHandlerEvent::PutRecord`] request, the remote perceives
the local node as one node among the k closest nodes to the target.
Returning a [`KademliaHandlerIn::Reset`] instead of an
[`KademliaHandlerIn::PutRecordRes`] to have the remote try another node
would only result in the remote node to contact an even more distant
node. In addition returning [`KademliaHandlerIn::PutRecordRes`] does not
reveal any internal information to a possibly malicious remote node.
* protocols/kad/src/behaviour: Use `now` and reword expiration comment
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* protocols/kad: Add test to reproduce right shift overflow panic
* protocols/kad: Fix right shift overflow panic in record_received
Within `Behaviour::record_received` the exponentially decreasing
expiration based on the distance to the target for a record is
calculated as following:
1. Calculate the amount of nodes between us and the record key beyond
the k replication constant as `n`.
2. Shift the configured record time-to-live `n` times to the right to
calculate an exponentially decreasing expiration.
The configured record time-to-live is a u64. If `n` is larger or equal
to 64 the right shift will lead to an overflow which panics in debug
mode.
This patch uses a checked right shift instead, defaulting to 0 (`now +
0`) for the expiration on overflow.
* protocols/kad: Put attribute below comment
* protocols/kad: Extract shifting logic and rework test
Extract right shift into isolated function and replace complex
regression test with small isolated one.
* protocols/kad/src/behaviour: Refactor exp_decr_expiration
Co-authored-by: Roman Borschel <romanb@users.noreply.github.com>
* Allow multiple connections per peer in libp2p-core.
Instead of trying to enforce a single connection per peer,
which involves quite a bit of additional complexity e.g.
to prioritise simultaneously opened connections and can
have other undesirable consequences [1], we now
make multiple connections per peer a feature.
The gist of these changes is as follows:
The concept of a "node" with an implicit 1-1 correspondence
to a connection has been replaced with the "first-class"
concept of a "connection". The code from `src/nodes` has moved
(with varying degrees of modification) to `src/connection`.
A `HandledNode` has become a `Connection`, a `NodeHandler` a
`ConnectionHandler`, the `CollectionStream` was the basis for
the new `connection::Pool`, and so forth.
Conceptually, a `Network` contains a `connection::Pool` which
in turn internally employs the `connection::Manager` for
handling the background `connection::manager::Task`s, one
per connection, as before. These are all considered implementation
details. On the public API, `Peer`s are managed as before through
the `Network`, except now the API has changed with the shift of focus
to (potentially multiple) connections per peer. The `NetworkEvent`s have
accordingly also undergone changes.
The Swarm APIs remain largely unchanged, except for the fact that
`inject_replaced` is no longer called. It may now practically happen
that multiple `ProtocolsHandler`s are associated with a single
`NetworkBehaviour`, one per connection. If implementations of
`NetworkBehaviour` rely somehow on communicating with exactly
one `ProtocolsHandler`, this may cause issues, but it is unlikely.
[1]: https://github.com/paritytech/substrate/issues/4272
* Fix intra-rustdoc links.
* Update core/src/connection/pool.rs
Co-Authored-By: Max Inden <mail@max-inden.de>
* Address some review feedback and fix doc links.
* Allow responses to be sent on the same connection.
* Remove unnecessary remainders of inject_replaced.
* Update swarm/src/behaviour.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Update swarm/src/lib.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Update core/src/connection/manager.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Update core/src/connection/manager.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Update core/src/connection/pool.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Incorporate more review feedback.
* Move module declaration below imports.
* Update core/src/connection/manager.rs
Co-Authored-By: Toralf Wittner <tw@dtex.org>
* Update core/src/connection/manager.rs
Co-Authored-By: Toralf Wittner <tw@dtex.org>
* Simplify as per review.
* Fix rustoc link.
* Add try_notify_handler and simplify.
* Relocate DialingConnection and DialingAttempt.
For better visibility constraints.
* Small cleanup.
* Small cleanup. More robust EstablishedConnectionIter.
* Clarify semantics of `DialingPeer::connect`.
* Don't call inject_disconnected on InvalidPeerId.
To preserve the previous behavior and ensure calls to
`inject_disconnected` are always paired with calls to
`inject_connected`.
* Provide public ConnectionId constructor.
Mainly needed for testing purposes, e.g. in substrate.
* Move the established connection limit check to the right place.
* Clean up connection error handling.
Separate connection errors into those occuring during
connection setup or upon rejecting a newly established
connection (the `PendingConnectionError`) and those
errors occurring on previously established connections,
i.e. for which a `ConnectionEstablished` event has
been emitted by the connection pool earlier.
* Revert change in log level and clarify an invariant.
* Remove inject_replaced entirely.
* Allow notifying all connection handlers.
Thereby simplify by introducing a new enum `NotifyHandler`,
used with a single constructor `NetworkBehaviourAction::NotifyHandler`.
* Finishing touches.
Small API simplifications and code deduplication.
Some more useful debug logging.
Co-authored-by: Max Inden <mail@max-inden.de>
Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>
Co-authored-by: Toralf Wittner <tw@dtex.org>
