feat: memory based connection limits

Implements memory-based connection limits where the user can specify an absolute or a relative limit of the process' memory usage in relation to the available system memory.

Related: #4252.

Pull-Request: #4281.

Cargo.toml

@@ -18,6 +18,7 @@ members = [
     "misc/allow-block-list",
     "misc/connection-limits",
     "misc/keygen",
+    "misc/memory-connection-limits",
     "misc/metrics",
     "misc/multistream-select",
     "misc/quick-protobuf-codec",
@@ -75,6 +76,7 @@ libp2p-identify = { version = "0.43.0", path = "protocols/identify" }
 libp2p-identity = { version = "0.2.2" }
 libp2p-kad = { version = "0.44.4", path = "protocols/kad" }
 libp2p-mdns = { version = "0.44.0", path = "protocols/mdns" }
+libp2p-memory-connection-limits = { version = "0.1.0", path = "misc/memory-connection-limits" }
 libp2p-metrics = { version = "0.13.1", path = "misc/metrics" }
 libp2p-mplex = { version = "0.40.0", path = "muxers/mplex" }
 libp2p-muxer-test-harness = { path = "muxers/test-harness" }

libp2p/CHANGELOG.md

@@ -6,8 +6,12 @@
 - Add `json` feature which exposes `request_response::json`.
   See [PR 4188].
 
+- Add `libp2p-memory-connection-limits` providing memory usage based connection limit configurations.
+  See [PR 4281].
+
 [PR 4188]: https://github.com/libp2p/rust-libp2p/pull/4188
 [PR 4217]: https://github.com/libp2p/rust-libp2p/pull/4217
+[PR 4281]: https://github.com/libp2p/rust-libp2p/pull/4281
 
 ## 0.52.1
 

libp2p/Cargo.toml

@@ -27,6 +27,7 @@ full = [
     "kad",
     "macros",
     "mdns",
+    "memory-connection-limits",
     "metrics",
     "noise",
     "ping",
@@ -65,6 +66,7 @@ json = ["libp2p-request-response?/json"]
 kad = ["dep:libp2p-kad", "libp2p-metrics?/kad"]
 macros = ["libp2p-swarm/macros"]
 mdns = ["dep:libp2p-mdns"]
+memory-connection-limits = ["dep:libp2p-memory-connection-limits"]
 metrics = ["dep:libp2p-metrics"]
 noise = ["dep:libp2p-noise"]
 ping = ["dep:libp2p-ping", "libp2p-metrics?/ping"]
@@ -124,6 +126,7 @@ pin-project = "1.0.0"
 libp2p-deflate = { workspace = true, optional = true }
 libp2p-dns = { workspace = true, optional = true }
 libp2p-mdns = { workspace = true, optional = true }
+libp2p-memory-connection-limits = { workspace = true, optional = true }
 libp2p-tcp = { workspace = true, optional = true }
 libp2p-tls = { workspace = true, optional = true }
 libp2p-uds = { workspace = true, optional = true }

libp2p/src/lib.rs

@@ -78,6 +78,11 @@ pub use libp2p_kad as kad;
 #[cfg_attr(docsrs, doc(cfg(feature = "mdns")))]
 #[doc(inline)]
 pub use libp2p_mdns as mdns;
+#[cfg(feature = "memory-connection-limits")]
+#[cfg(not(target_arch = "wasm32"))]
+#[cfg_attr(docsrs, doc(cfg(feature = "memory-connection-limits")))]
+#[doc(inline)]
+pub use libp2p_memory_connection_limits as memory_connection_limits;
 #[cfg(feature = "metrics")]
 #[doc(inline)]
 pub use libp2p_metrics as metrics;

misc/memory-connection-limits/CHANGELOG.md

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

misc/memory-connection-limits/Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "libp2p-memory-connection-limits"
+edition = "2021"
+rust-version = { workspace = true }
+description = "Memory usage based 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]
+memory-stats = { version = "1", features = ["always_use_statm"] }
+libp2p-core = { workspace = true }
+libp2p-swarm = { workspace = true }
+libp2p-identity = { workspace = true, features = ["peerid"] }
+log = "0.4"
+sysinfo = "0.29"
+void = "1"
+
+[dev-dependencies]
+async-std = { version = "1.12.0", features = ["attributes"] }
+libp2p-identify = { workspace = true }
+libp2p-swarm-derive = { path = "../../swarm-derive" }
+libp2p-swarm-test = { path = "../../swarm-test" }
+rand = "0.8.5"