feat: introduce libp2p-connection-limits connection management module

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.

Cargo.toml

@@ -11,43 +11,43 @@ members = [
     "examples/ping-example",
     "examples/rendezvous",
     "identity",
+    "interop-tests",
+    "misc/connection-limits",
+    "misc/keygen",
     "misc/metrics",
     "misc/multistream-select",
-    "misc/rw-stream-sink",
-    "misc/keygen",
     "misc/quick-protobuf-codec",
     "misc/quickcheck-ext",
+    "misc/rw-stream-sink",
     "muxers/mplex",
-    "muxers/yamux",
     "muxers/test-harness",
-    "protocols/dcutr",
+    "muxers/yamux",
     "protocols/autonat",
+    "protocols/dcutr",
     "protocols/floodsub",
     "protocols/gossipsub",
-    "protocols/rendezvous",
     "protocols/identify",
     "protocols/kad",
     "protocols/mdns",
     "protocols/perf",
     "protocols/ping",
     "protocols/relay",
+    "protocols/rendezvous",
     "protocols/request-response",
     "swarm",
     "swarm-derive",
-    "interop-tests",
     "swarm-test",
     "transports/deflate",
     "transports/dns",
     "transports/noise",
-    "transports/tls",
     "transports/plaintext",
     "transports/pnet",
     "transports/quic",
     "transports/tcp",
+    "transports/tls",
     "transports/uds",
-    "transports/websocket",
     "transports/wasm-ext",
     "transports/webrtc",
-    "interop-tests"
+    "transports/websocket",
 ]
 resolver = "2"

libp2p/CHANGELOG.md

@@ -1,3 +1,10 @@
+# 0.52.2 - unreleased
+
+- Introduce `libp2p::connection_limits` module.
+  See [PR 3386].
+
+[PR 3386]: https://github.com/libp2p/rust-libp2p/pull/3386
+
 # 0.51.1
 
 - Depend on `libp2p-tls` `v0.1.0`.

libp2p/Cargo.toml

@@ -3,7 +3,7 @@ name = "libp2p"
 edition = "2021"
 rust-version = "1.65.0"
 description = "Peer-to-peer networking library"
-version = "0.51.1"
+version = "0.51.2"
 authors = ["Parity Technologies <admin@parity.io>"]
 license = "MIT"
 repository = "https://github.com/libp2p/rust-libp2p"
@@ -97,6 +97,7 @@ getrandom = "0.2.3" # Explicit dependency to be used in `wasm-bindgen` feature
 instant = "0.1.11" # Explicit dependency to be used in `wasm-bindgen` feature
 
 libp2p-autonat = { version = "0.10.0", path = "../protocols/autonat", optional = true }
+libp2p-connection-limits = { version = "0.1.0", path = "../misc/connection-limits" }
 libp2p-core = { version = "0.39.0", path = "../core" }
 libp2p-dcutr = { version = "0.9.0", path = "../protocols/dcutr", optional = true }
 libp2p-floodsub = { version = "0.42.0", path = "../protocols/floodsub", optional = true }

libp2p/src/lib.rs

@@ -44,6 +44,8 @@ pub use multiaddr;
 #[doc(inline)]
 pub use libp2p_autonat as autonat;
 #[doc(inline)]
+pub use libp2p_connection_limits as connection_limits;
+#[doc(inline)]
 pub use libp2p_core as core;
 #[cfg(feature = "dcutr")]
 #[doc(inline)]

misc/connection-limits/CHANGELOG.md

@@ -0,0 +1,3 @@
+# 0.1.0 - unreleased
+
+- Initial release.

misc/connection-limits/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "libp2p-connection-limits"
+edition = "2021"
+rust-version = "1.62.0"
+description = "Connection limits for libp2p."
+version = "0.1.0"
+license = "MIT"
+repository = "https://github.com/libp2p/rust-libp2p"
+keywords = ["peer-to-peer", "libp2p", "networking"]
+categories = ["network-programming", "asynchronous"]
+
+[dependencies]
+libp2p-core = { version = "0.39.0", path = "../../core" }
+libp2p-swarm = { version = "0.42.0", path = "../../swarm" }
+libp2p-identity = { version = "0.1.0", path = "../../identity", features = ["peerid"] }
+void = "1"
+
+[dev-dependencies]
+async-std = { version = "1.12.0", features = ["attributes"] }
+libp2p-identify = { path = "../../protocols/identify" }
+libp2p-ping = { path = "../../protocols/ping" }
+libp2p-swarm-derive = { path = "../../swarm-derive" }
+libp2p-swarm-test = { path = "../../swarm-test" }
+quickcheck-ext = { path = "../quickcheck-ext" }
+rand = "0.8.5"