Currently, the kademlia behaviour can only learn that the remote node supports kademlia on a particular connection if we successfully negotiate a stream to them.
Using the newly introduced abstractions from #3651, we don't have to attempt to establish a stream to the remote to learn whether they support kademlia on a connection but we can directly learn it from the `ConnectionEvent::RemoteProtocolsChange` event. This happens directly once a connection is established which should overall benefit the DHT.
Clients do not advertise the kademlia protocol and thus we will immediately learn that a given connection is not suitable for kadmelia requests. We may receive inbound messages from it but this does not affect the routing table.
Resolves: #2032.
Pull-Request: #3877.
This modification removes deprecated dependency `wasm_timer` and enables wasm compatibility on the gossibsup protocol by simply substituting the `wasm_timer::Instant` with `instant::Instant`(which supports `fn checked_add`) and `wasm_timer::Interval` with `futures_ticker::Ticker`.
Pull-Request: #3973.
Previously, a `NetworkBehaviour` could report an `AddressScore` for an external address. This score was a `u32` and addresses would be ranked amongst those.
In reality, an address is either confirmed to be publicly reachable (via a protocol such as AutoNAT) or merely represents a candidate that might be an external address. In a way, addresses are guilty (private) until proven innocent (publicly reachable).
When a `NetworkBehaviour` reports an address candidate, we perform address translation on it to potentially correct for ephemeral ports of TCP. These candidates are then injected back into the `NetworkBehaviour`. Protocols such as AutoNAT can use these addresses as a source for probing their NAT status. Once confirmed, they can emit a `ToSwarm::ExternalAddrConfirmed` event which again will be passed to all `NetworkBehaviour`s.
This simplified approach will allow us implement Kademlia's client-mode (https://github.com/libp2p/rust-libp2p/issues/2032) without additional configuration options: As soon as an address is reported as publicly reachable, we can activate server-mode for that connection.
Related: https://github.com/libp2p/rust-libp2p/pull/3877.
Related: https://github.com/libp2p/rust-libp2p/issues/3953.
Related: https://github.com/libp2p/rust-libp2p/issues/2032.
Related: https://github.com/libp2p/go-libp2p/issues/2229.
Co-authored-by: Max Inden <mail@max-inden.de>
Pull-Request: #3954.
Previously, the associated types on `NetworkBehaviour` and `ConnectionHandler` carried generic names like `InEvent` and `OutEvent`. These names are _correct_ in that `OutEvent`s are passed out and `InEvent`s are passed in but they don't help users understand how these types are used.
In theory, a `ConnectionHandler` could be used separately from `NetworkBehaviour`s but that is highly unlikely. Thus, we rename these associated types to indicate, where the message is going to be sent to:
- `NetworkBehaviour::OutEvent` is renamed to `ToSwarm`: It describes the message(s) a `NetworkBehaviour` can emit to the `Swarm`. The user is going to receive those in `SwarmEvent::Behaviour`.
- `ConnectionHandler::InEvent` is renamed to `FromBehaviour`: It describes the message(s) a `ConnectionHandler` can receive from its behaviour via `ConnectionHandler::on_swarm_event`. The `NetworkBehaviour` can send it via the `ToSwarm::NotifyHandler` command.
- `ConnectionHandler::OutEvent` is renamed to `ToBehaviour`: It describes the message(s) a `ConnectionHandler` can send back to the behaviour via the now also renamed `ConnectionHandlerEvent::NotifyBehaviour` (previously `ConnectionHandlerEvent::Custom`)
Resolves: #2854.
Pull-Request: #3848.
This patch tackles two things at once that are fairly intertwined:
1. There is no such thing as a "substream" in libp2p, the spec and other implementations only talk about "streams". We fix this by deprecating `NegotiatedSubstream`.
2. Previously, `NegotiatedSubstream` was a type alias that pointed to a type from `multistream-select`, effectively leaking the version of `multistream-select` to all dependencies of `libp2p-swarm`. We fix this by introducing a `Stream` newtype.
Resolves: #3759.
Related: #3748.
Pull-Request: #3912.
This patch removes the 3 out of 4 deprecated public modules. I've left `store` for now because we made some mistakes in declaring that. The items within `store` still need to be publicly visible but I haven't yet figured out a good way of exporting / naming them. Thus, I've left that to a follow-up PR.
Related: #3647.
Pull-Request: #3896.
With this patch, implementations of `ConnectionHandler` (which are typically composed in a tree) can exchange information about the supported protocols of a remote with each other via `ConnectionHandlerEvent::ReportRemoteProtocols`. The provided `ProtocolSupport` enum can describe either additions or removals of the remote peer's protocols.
This information is aggregated in the connection and passed down to the `ConnectionHandler` via `ConnectionEvent::RemoteProtocolsChange`.
Similarly, if the listen protocols of a connection change, all `ConnectionHandler`s on the connection will be notified via `ConnectionEvent::LocalProtocolsChange`. This will allow us to eventually remove `PollParameters` from `NetworkBehaviour`.
This pattern allows protocols on a connection to communicate with each other. For example, protocols like identify can share the list of (supposedly) supported protocols by the remote with all other handlers. A protocol like kademlia can accurately add and remove a remote from its routing table as a result.
Resolves: #2680.
Related: #3124.
Pull-Request: #3651.
Users are encouraged to use `libp2p::connection_limit::Behaviour` which is a one-to-one replacement for this functionality but built as a `NetworkBehaviour`.
Related: #3647.
Pull-Request: #3885.
The currently provided `ConnectionHandlerUpgrErr` is very hard to use. Not only does it have a long name, it also features 3 levels of nesting which results in a lot of boilerplate. Last but not least, it exposes `multistream-select` as a dependency to all protocols.
We fix all of the above by renaming the type to `StreamUpgradeError` and flattening out its interface. Unrecoverable errors during protocol selection are hidden within the `Io` variant.
Related: #3759.
Pull-Request: #3882.
Previously, a protocol could be any sequence of bytes as long as it started with `/`. Now, we directly parse a protocol as `String` which enforces it to be valid UTF8.
To notify users of this change, we delete the `ProtocolName` trait. The new requirement is that users need to provide a type that implements `AsRef<str>`.
We also add a `StreamProtocol` newtype in `libp2p-swarm` which provides an easy way for users to ensure their protocol strings are compliant. The newtype enforces that protocol strings start with `/`. `StreamProtocol` also implements `AsRef<str>`, meaning users can directly use it in their upgrades.
`multistream-select` by itself only changes marginally with this patch. The only thing we enforce in the type-system is that protocols must implement `AsRef<str>`.
Resolves: #2831.
Pull-Request: #3746.
Previously, we would specify the version and path of our workspace dependencies in each of our crates. This is error prone as https://github.com/libp2p/rust-libp2p/pull/3658#discussion_r1153278072 for example shows. Problems like these happened in the past too.
There is no need for us to ever depend on a earlier version than the most current one in our crates. It thus makes sense that we manage this version in a single place.
Cargo supports a feature called "workspace inheritance" which allows us to share a dependency declaration across a workspace and inherit it with `{ workspace = true }`.
We do this for all our workspace dependencies and for the MSRV.
Resolves#3787.
Pull-Request: #3715.
In the libp2p specs, the only handshake pattern that is specified is the XX handshake. Support for other handshake patterns can be added through external modules. While we are at it, we rename the remaining types to following the laid out naming convention.
The tests for handshakes other than XX are removed. The handshakes still work as we don't touch them in this patch.
Related #2217.
Pull-Request: #3768.
The `unreachable_pub` lint makes us aware of uses of `pub` that are not actually reachable from the crate root. This is considered good because it means reading a `pub` somewhere means it is actually public API. Some of our crates are quite large and keeping their entire API surface in your head is difficult.
We should strive for most items being `pub(crate)`. This lint helps us enforce that.
Pull-Request: #3735.
Previous to this change if the ConnectionHandler::poll for kad was called more frequently than the connection idle timeout the timeout would continually be pushed further into the future. After this change kad now will preserve the existing idle deadline.
Pull-Request: #3801.
The `RoutingUpdate` type that `add_address` returns was not made available publicly. This type is added in this PR by `pub use`.
Resolves#3737.
Pull-Request: #3739.
With https://github.com/libp2p/rust-libp2p/pull/3658, these crates depend on the `0.42.1` release to access the new `ToSwarm` type. With the currently specified version, a user could theoretically run into a compile error if they pin `libp2p-swarm` to `0.42.0` in their lockfile but update to the latest patch release of one of these crates.
Pull-Request: #3711.
All we need from the multihash is for it to be a data structure that we pass around. We only ever use the identity "hasher" and the sha256 hasher. Those are easily implemented without depending the (fairly heavy) machinery in `multihash`.
Unfortunately, this patch by itself does not yet lighten our dependency tree because `multiaddr` activates those features unconditionally. I opened a companion PR for this: https://github.com/multiformats/rust-multiaddr/pull/77.
https://github.com/multiformats/rust-multiaddr/pull/77 is another breaking change and we are trying to delay those at the moment. However, it will (hopefully) land eventually which should then be much easier to implement.
Fixes#3276.
Pull-Request: #3514.
Currently, banning peers is a first-class feature of `Swarm`. With the new connection management capabilities of `NetworkBehaviour`, we can now implement allow and block lists as a separate module.
We introduce a new crate `libp2p-allow-block-list` and deprecate `Swarm::ban_peer_id` in favor of that.
Related #2824.
Pull-Request: #3590.
In earlier iterations of the design for generic connection management, we removed the `ConnectionId::new` constructor because it would have allowed users to create `ConnectionId`s that are already taken, thus breaking invariants that `NetworkBehaviour`s rely on. Later, we incorporated the creation of `ConnectionId` in `DialOpts` which mitigates this risk altogether.
Thus, it is reasonably safe to introduce a public, non-deprecated constructor for `ConnectionId` that can be used for tests.
Related https://github.com/libp2p/rust-libp2p/pull/3327#issuecomment-1469870307.
Pull-Request: #3652.
This patch deprecates the existing connection limits within `Swarm` and uses the new `NetworkBehaviour` APIs to implement it as a plugin instead.
Related #2824.
Pull-Request: #3386.
Mark constructors `Swarm::with_X_executor` as deprecated.
Move the deprecated functionality to `SwarmBuilder::with_X_executor`
Use `SwarmBuilder` throughout.
Resolves#3186.
Resolves#3107.
Pull-Request: #3588.
Instead of relying on `protoc` and buildscripts, we generate the bindings using `pb-rs` and version them within our codebase. This makes for a better IDE integration, a faster build and an easier use of `rust-libp2p` because we don't force the `protoc` dependency onto them.
Resolves#3024.
Pull-Request: #3312.
A large release with lots of changes I am looking forward to. Sorry for the long release cadence.
Anything folks would like to see included that is not yet in `master`? As usual I would like to only block on bug fixes.
Pull-Request: #3491.
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.
The trick with this one is to use `futures::Either` everywhere where we may wrap something that implements any of the `futures` traits. This includes the output of `EitherFuture` itself. We also need to implement `StreamMuxer` on `future::Either` because `StreamMuxer`s may be the the `Output` of `InboundUpgrade`.
