With `Version::V1Lazy` and negotiation of a single protocol, a stream initiator optimistically
sends application data right after proposing its protocol. More specifically an application can
write data via `AsyncWrite::poll_write` even though the remote has not yet confirmed the stream protocol.
This saves one round-trip.
``` mermaid
sequenceDiagram
A->>B: "/multistream/1.0.0"
A->>B: "/perf/1.0.0"
A->>B: <some-perf-protocol-data>
B->>A: "/multistream/1.0.0"
B->>A: "/perf/1.0.0"
B->>A: <some-perf-protocol-data>
```
When considering stream closing, i.e. `AsyncWrite::poll_close`, and using stream closing as an
operation in ones protocol, e.g. using stream closing to signal the end of a request, this becomes tricky.
The behavior without this commit was as following:
``` mermaid
sequenceDiagram
A->>B: "/multistream/1.0.0"
A->>B: "/perf/1.0.0"
A->>B: <some-perf-protocol-data>
Note left of A: Call `AsyncWrite::poll_close` which first waits for the<br/>optimistic multistream-select negotiation to finish, before closing the stream,<br/> i.e. setting the FIN bit.
B->>A: "/multistream/1.0.0"
B->>A: "/perf/1.0.0"
Note right of B: Waiting for A to close the stream (i.e. set the `FIN` bit)<br/>before sending the response.
A->>B: FIN
B->>A: <some-perf-protocol-data>
```
The above takes 2 round trips:
1. Send the optimistic multistream-select protocol proposals as well as the initiator protocol
payload and waits for the confirmation of the protocols.
2. Close the stream, i.e. sends the `FIN` bit and waits for the responder protocol payload.
This commit proposes that the stream initiator should not wait for the multistream-select protocol
confirmation when closing the stream, but close the stream within the first round-trip.
``` mermaid
sequenceDiagram
A->>B: "/multistream/1.0.0"
A->>B: "/perf/1.0.0"
A->>B: <some-perf-protocol-data>
A->>B: FIN
B->>A: "/multistream/1.0.0"
B->>A: "/perf/1.0.0"
B->>A: <some-perf-protocol-data>
```
This takes 1 round-trip.
The downside of this commit is, that the stream initiator will no longer notice a negotiation error
when closing the stream. They will only notice it when reading from the stream. E.g. say that B does
not support "/perf/1.0.0", A will only notice on `AsyncRead::poll_read`, not on
`AsyncWrite::poll_close`. This is problematic for protocols where A only sends data, but never
receives data, i.e. never calls `AsyncRead::poll_read`. Though one can argue that such protocol is
flawed in the first place. With a response-less protocol, as even if negotiation succceeds, A
doesn't know whether B received the protocol payload.
Pull-Request: #4019.
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, the `libp2p-ping` module came with a policy to close a connection after X failed pings. This is only one of many possible policies on how users would want to do connection management.
We remove this policy without a replacement. If users wish to restore this functionality, they can easily implement such policy themselves: The default value of `max_failures` was 1. To restore the previous functionality users can simply close the connection upon the first received ping error.
In this same patch, we also simplify the API of `ping::Event` by removing the layer of `ping::Success` and instead reporting the RTT to the peer directly.
Related: #3591.
Pull-Request: #3947.
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 we would increase a counter / gauge / histogram on each received identify information. These metrics are missleading, as e.g. they depend on the identify interval and don't represent the set of currently connected peers.
With this commit, identify information is tracked for the currently connected peers only. Instead of an increase on each received identify information, metrics represent the status quo (Gauge).
Example:
```
\# HELP libp2p_libp2p_identify_remote_protocols Number of connected nodes supporting a specific protocol, with "unrecognized" for each peer supporting one or more unrecognized protocols...
\# TYPE libp2p_libp2p_identify_remote_protocols gauge
libp2p_libp2p_identify_remote_protocols_total{protocol="/ipfs/id/push/1.0.0"} 1
libp2p_libp2p_identify_remote_protocols_total{protocol="/ipfs/id/1.0.0"} 1
libp2p_libp2p_identify_remote_protocols_total{protocol="/ipfs/ping/1.0.0"} 1
libp2p_libp2p_identify_remote_protocols_total{protocol="unrecognized"} 1
\# HELP libp2p_libp2p_identify_remote_listen_addresses Number of connected nodes advertising a specific listen address...
\# TYPE libp2p_libp2p_identify_remote_listen_addresses gauge
libp2p_libp2p_identify_remote_listen_addresses_total{listen_address="/ip4/tcp"} 1
libp2p_libp2p_identify_remote_listen_addresses_total{listen_address="/ip4/udp/quic"} 1
\# HELP libp2p_libp2p_identify_local_observed_addresses Number of connected nodes observing the local node at a specific address...
\# TYPE libp2p_libp2p_identify_local_observed_addresses gauge
libp2p_libp2p_identify_local_observed_addresses_total{observed_address="/ip4/tcp"} 1
```
Pull-Request: #3325.
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 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.
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.
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.
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.
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, we reinserted the `Peer` in the "undo" function which is obviously wrong. This patch fixes the behaviour to be correct and adds two regression tests.
Pull-Request: #3789.
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.
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.
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.
