When an inbound stream upgrade fails, there isn't a whole lot we can do about that in the handler. In fact, for several errors, we wouldn't even know which specific handler to target, for example, `NegotiationFailed`. Similiarly, in case of an IO error during the upgrade, we don't know which handler the stream was eventually meant to be for.
Pull-Request: #3605.
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.
Previously, the relay server would erroneously send its own `PeerId` in the STOP message to the client upon an incoming relay connection. This is obviously wrong and results in failed connection upgrades in other implementations.
Pull-Request: #3767.
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.
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.
