Previously, a `ConnectionHandler` was immediately requested from the `NetworkBehaviour` as soon as a new dial was initiated or a new incoming connection accepted.
With this patch, we delay the creation of the handler until the connection is actually established and fully upgraded, i.e authenticated and multiplexed.
As a consequence, `NetworkBehaviour::new_handler` is now deprecated in favor of a new set of callbacks:
- `NetworkBehaviour::handle_pending_inbound_connection`
- `NetworkBehaviour::handle_pending_outbound_connection`
- `NetworkBehaviour::handle_established_inbound_connection`
- `NetworkBehaviour::handle_established_outbound_connection`
All callbacks are fallible, allowing the `NetworkBehaviour` to abort the connection either immediately or after it is fully established. All callbacks also receive a `ConnectionId` parameter which uniquely identifies the connection. For example, in case a `NetworkBehaviour` issues a dial via `NetworkBehaviourAction::Dial`, it can unambiguously detect this dial in these lifecycle callbacks via the `ConnectionId`.
Finally, `NetworkBehaviour::handle_pending_outbound_connection` also replaces `NetworkBehaviour::addresses_of_peer` by allowing the behaviour to return more addresses to be used for the dial.
Resolves#2824.
Pull-Request: #3254.
We create the `ConnectionId` for the new connection as part of `DialOpts`. This allows `NetworkBehaviour`s to accurately track state regarding their own dial attempts.
This patch is the main enabler of https://github.com/libp2p/rust-libp2p/pull/3254. Removing the `handler` field will allow us to deprecate the `NetworkBehaviour::new_handler` function in favor of four new ones that give more control over the connection lifecycle.
Previously, we used the full reference to the `OutEvent` of the `ConnectionHandler` in all implementations of `NetworkBehaviour`. Not only is this very verbose, it is also more brittle to changes. With the current implementation plan for #2824, we will be removing the `IntoConnectionHandler` abstraction. Using a type-alias to refer to the `OutEvent` makes the migration much easier.
Previously, inbound connections that happened to resolve to our own `PeerId` were reported as `WrongPeerId`. With this patch, we now report those in a dedicated `LocalPeerId` error.
Related: #3205.
Instead of offering a public constructor, users are now no longer able to construct `ConnectionId`s at all. They only public API exposed are the derived traits. Internally, `ConnectionId`s are monotonically incremented using a static atomic counter, thus no two connections will ever get assigned the same ID.
Currently, we only have a single channel for all established connections. This requires us to construct the channel ahead of time, before we even have a connection. As it turns out, sharing this buffer across all connections actually has downsides. In particular, this means a single, very busy connection can starve others by filling up this buffer, forcing other connections to wait until they can emit an event.
Ever since we moved `Pool` into `libp2p-swarm`, we always use it with the same `Transport`: `Boxed`. It is thus unnecessary for us to be overly generic over what kind of `Transport` we are using. This allows us to remove a few type parameters from the implementation which overall simplifies things.
This is technically a breaking change because I am removing a type parameter from two exported type aliases:
- `PendingInboundConnectionError`
- `PendingOutboundConnectionError`
Those have always only be used with `std::io::Error` in our API but it is still a breaking change.
The task for a pending connection only ever sends one event into this channel: Either a success or a failure. Cloning a sender adds one slot to the capacity of the channel. Hence, we can start this capacity at 0 and have the `cloning` of the `Sender` take care of properly increasing the capacity.
As I do frequently, I corrected for the latest clippy warnings. This will make sure the CI won't complain in the future. We could automate this btw and maybe run the nightly version of clippy.
Previously, we had one callback for each kind of message that a `ConnectionHandler` would receive from either its `NetworkBehaviour` or the connection itself.
With this patch, we combine these functions, resulting in two callbacks:
- `on_behaviour_event`
- `on_connection_event`
Resolves#3080.
Previously, the executor for connection tasks silently defaulted to a `futures::executor::ThreadPool`. This causes issues such as https://github.com/libp2p/rust-libp2p/issues/2230.
With this patch, we force the user to choose, which executor they want to run the connection tasks on which results in overall simpler API with less footguns.
Closes#3068.
* Remove unreachable error case
Instead of taking the connection out of the map again, construct
the event to be returned with the data we already have available.
* Remove `Pool::get` and `PoolConnection`
These are effectively not used.
* Replace `iter_pending_info` with its only usage: `is_dialing`
* Add `is_for_same_remote_as` convenience function
* Remove `PendingConnection`
* Rename `PendingConnectionInfo` to `PendingConnection`
With the latter being gone, the name is now free.
* Merge `EstablishedConnectionInfo` and `EstablishedConnection`
This is a leftover from when `Pool` was still in `libp2p-core` and
one of them was a public API and the other one wasn't.
All of this is private to `libp2p-swarm` so we no longer need to
differentiate.
* Don't `pub use` out of `pub(crate)` modules
* Provide separate functions for injecting in- and outbound streams
* Inline `HandlerWrapper` into `Connection`
* Only poll for new inbound streams if we are below the limit
* yamux: Buffer inbound streams in `StreamMuxer::poll`
Instead of having a mix of `poll_event`, `poll_outbound` and `poll_close`, we
flatten the entire interface of `StreamMuxer` into 4 individual functions:
- `poll_inbound`
- `poll_outbound`
- `poll_address_change`
- `poll_close`
This design is closer to the design of other async traits like `AsyncRead` and
`AsyncWrite`. It also allows us to delete the `StreamMuxerEvent`.
Remove the concept of individual `Transport::Listener` streams from `Transport`.
Instead the `Transport` is polled directly via `Transport::poll`. The
`Transport` is now responsible for driving its listeners.
* core/muxing: Remove `Into<io::Error>` bound from `StreamMuxer::Error`
This allows us to preserve the type information of a muxer's concrete
error as long as possible. For `StreamMuxerBox`, we leverage `io::Error`'s
capability of wrapping any error that implements `Into<Box<dyn Error>>`.
* Use `?` in `Connection::poll`
* Use `?` in `muxing::boxed::Wrap`
* Use `futures::ready!` in `muxing::boxed::Wrap`
* Fill PR number into changelog
* Put `Error + Send + Sync` bounds directly on `StreamMuxer::Error`
* Move `Send + Sync` bounds to higher layers
* Use `map_inbound_stream` helper
* Update changelog to match new implementation
Log peer ID and stream limit as well as reference config option when limit is
exceeded. This should help folks running into this limit debug what is going on.
This limit is shared across all `ConnectionHandler`s on a single connection. It
only enforces a limit on the number of negotiating substreams. Once negotiated a
`ConnectionHandler` manages the lifecycle of the substream and has to enforce
limits themselves.
The `HandlerWrapper` polls three components:
1. `ConnectionHandler`
2. Outbound negotiating streams
3. Inbound negotiating streams
The `ConnectionHandler` itself might itself poll already negotiated streams.
By polling the three components above in the listed order one:
- Prioritizes local work and work coming from negotiated streams over
negotiating streams.
- Prioritizes outbound negotiating streams over inbound negotiating
streams, i.e. outbound requests over inbound requests.
Have the main event loop (`Swarm::poll_next_event`) prioritize:
1. Work on `NetworkBehaviour` over work on `Pool`, thus prioritizing
local work over work coming from a remote.
2. Work on `Pool` over work on `ListenersStream`, thus prioritizing work
on existing connections over upgrading new incoming connections.
Co-authored-by: Thomas Eizinger <thomas@eizinger.io>
Simplifies `PoolEvent`, no longer carrying a reference to an
`EstablishedConnection` or the `Pool`, but instead the `PeerId`,
`ConnectionId` and `ConnectedPoint` directly.
Co-authored-by: Elena Frank <elena.frank@protonmail.com>
Previously `libp2p-swarm` required a `Transport` to be `Clone`. Methods
on `Transport`, e.g. `Transport::dial` would take ownership, requiring
e.g. a `Clone::clone` before calling `Transport::dial`.
The requirement of `Transport` to be `Clone` is no longer needed in
`libp2p-swarm`. E.g. concurrent dialing can be done without a clone per
dial.
This commit removes the requirement of `Clone` for `Transport` in
`libp2p-swarm`. As a follow-up methods on `Transport` no longer take
ownership, but instead a mutable reference (`&mut self`).
On the one hand this simplifies `libp2p-swarm`, on the other it
simplifies implementations of `Transport`.
A `ProtocolsHandler`, now `ConnectionHandler`, handels a connection, not
a protocol. Thus the name `CONNECTIONHandler` is more appropriate.
Next to the rename of `ProtocolsHandler` this commit renames the `mod
protocols_handler` to `mod handler`. Finally all combinators (e.g.
`ProtocolsHandlerSelect`) are renamed appropriately.
Previously one would wrap a `ProtocolsHandler` into a
`NodeHandlerWrapper` as early as possible, even though the functionality
of `NodeHandlerWrapper` is only needed within `mod connection`.
This commit makes `NodeHandlerWrapper` an implementation detail of `mod
connection`, thus neither `mod protocols_handler`, `mod pool` nor the
root level (`libp2p-swarm`) need to bother about the abstraction.
In addition to the above, this commit:
- Renames `NodeHandlerWrapper` to `HandlerWrapper`. The word `Node` is
outdated.
- Removes `NodeHandlerWrapperBuilder`. With this simplification it is no
longer needed.
- Folds `NodeHandlerWrapperError` into `ConnectionError`. No need for
upper layers to be aware of the fact that `ProtocolHandler`s are
wrapped.
The `ConnectionHandler` trait is not exposed to users. The only
implementor of `ConnectionHandler` is `NodeHandlerWrapper`. Thus
`ConnectionHandler` is a superfluous abstraction. This commit removes
`ConnectionHandler`.
Next to this large change, this commit removes the `Tmuxer` trait
parameter. `Swarm` enforces dynamic dispatching via `StreamMuxerBox`
anyways, thus the trait parameter is useless.
As a follow up to this commit one could rename `ProtocolsHandler` to
`ConnectionHandler` and `NodeHandlerWrapper` to
`ConnectionHandlerWrapper` or just `Wrapper`.
Disconnect pending connections with `Swarm::disconnect` and eport aborted
connections via `SwarmEvent::OutgoingConnectionError`.
Co-authored-by: Jack Maloney <git@jmmaloney4.xyz>
Co-authored-by: Marco Munizaga <git@marcopolo.io>
This commit removes the `Network` abstraction, thus managing `Listeners`
and the connection `Pool` in `Swarm` directly. This is done under the
assumption that noone uses the `Network` abstraction directly, but
instead everyone always uses it through `Swarm`. Both `Listeners` and
`Pool` are moved from `libp2p-core` into `libp2p-swarm`. Given that they
are no longer exposed via `Network`, they can be treated as an
implementation detail of `libp2p-swarm` and `Swarm`.
This change does not include any behavioural changes.
This change has the followin benefits:
- Removal of `NetworkEvent`, which was mostly an isomorphism of
`SwarmEvent`.
- Removal of the never-directly-used `Network` abstraction.
- Removal of now obsolete verbose `Peer` (`core/src/network/peer.rs`)
construct.
- Removal of `libp2p-core` `DialOpts`, which is a direct mapping of
`libp2p-swarm` `DialOpts`.
- Allowing breaking changes to the connection handling and `Swarm` API
interface without a breaking change in `libp2p-core` and thus a
without a breaking change in `/transport` protocols.
This change enables the following potential future changes:
- Removal of `NodeHandler` and `ConnectionHandler`. Thus allowing to
rename `ProtocolsHandler` into `ConnectionHandler`.
- Moving `NetworkBehaviour` and `ProtocolsHandler` into `libp2p-core`,
having `libp2p-xxx` protocol crates only depend on `libp2p-core` and
thus allowing general breaking changes to `Swarm` without breaking all
`libp2p-xxx` crates.
