feat: Rebrand Polkadot/Substrate references to PezkuwiChain

This commit systematically rebrands various references from Parity Technologies'
Polkadot/Substrate ecosystem to PezkuwiChain within the kurdistan-sdk.

Key changes include:
- Updated external repository URLs (zombienet-sdk, parity-db, parity-scale-codec, wasm-instrument) to point to pezkuwichain forks.
- Modified internal documentation and code comments to reflect PezkuwiChain naming and structure.
- Replaced direct references to  with  or specific paths within the  for XCM, Pezkuwi, and other modules.
- Cleaned up deprecated  issue and PR references in various  and  files, particularly in  and  modules.
- Adjusted image and logo URLs in documentation to point to PezkuwiChain assets.
- Removed or rephrased comments related to external Polkadot/Substrate PRs and issues.

This is a significant step towards fully customizing the SDK for the PezkuwiChain ecosystem.

bizinikiwi/client/rpc-servers/src/lib.rs

@@ -0,0 +1,310 @@
+// This file is part of Bizinikiwi.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! Bizinikiwi RPC servers.
+
+#![warn(missing_docs)]
+
+pub mod middleware;
+pub mod utils;
+
+use std::{error::Error as StdError, net::SocketAddr, time::Duration};
+
+use jsonrpsee::{
+	core::BoxError,
+	server::{
+		serve_with_graceful_shutdown, stop_channel, ws, PingConfig, ServerHandle, StopHandle,
+	},
+	Methods, RpcModule,
+};
+use tower::Service;
+use utils::{
+	build_rpc_api, deny_unsafe, format_listen_addrs, get_proxy_ip, ListenAddrError, RpcSettings,
+};
+
+pub use ip_network::IpNetwork;
+pub use jsonrpsee::{
+	core::id_providers::{RandomIntegerIdProvider, RandomStringIdProvider},
+	server::{middleware::rpc::RpcServiceBuilder, BatchRequestConfig},
+};
+pub use middleware::{Metrics, MiddlewareLayer, NodeHealthProxyLayer, RpcMetrics};
+pub use utils::{RpcEndpoint, RpcMethods};
+
+const MEGABYTE: u32 = 1024 * 1024;
+
+/// Type to encapsulate the server handle and listening address.
+pub struct Server {
+	/// Handle to the rpc server
+	handle: ServerHandle,
+	/// Listening address of the server
+	listen_addrs: Vec<SocketAddr>,
+}
+
+impl Server {
+	/// Creates a new Server.
+	pub fn new(handle: ServerHandle, listen_addrs: Vec<SocketAddr>) -> Server {
+		Server { handle, listen_addrs }
+	}
+
+	/// Returns the `jsonrpsee::server::ServerHandle` for this Server. Can be used to stop the
+	/// server.
+	pub fn handle(&self) -> &ServerHandle {
+		&self.handle
+	}
+
+	/// The listen address for the running RPC service.
+	pub fn listen_addrs(&self) -> &[SocketAddr] {
+		&self.listen_addrs
+	}
+}
+
+impl Drop for Server {
+	fn drop(&mut self) {
+		// This doesn't not wait for the server to be stopped but fires the signal.
+		let _ = self.handle.stop();
+	}
+}
+
+/// Trait for providing subscription IDs that can be cloned.
+pub trait SubscriptionIdProvider:
+	jsonrpsee::core::traits::IdProvider + dyn_clone::DynClone
+{
+}
+
+dyn_clone::clone_trait_object!(SubscriptionIdProvider);
+
+/// RPC server configuration.
+#[derive(Debug)]
+pub struct Config<M: Send + Sync + 'static> {
+	/// RPC interfaces to start.
+	pub endpoints: Vec<RpcEndpoint>,
+	/// Metrics.
+	pub metrics: Option<RpcMetrics>,
+	/// RPC API.
+	pub rpc_api: RpcModule<M>,
+	/// Subscription ID provider.
+	pub id_provider: Option<Box<dyn SubscriptionIdProvider>>,
+	/// Tokio runtime handle.
+	pub tokio_handle: tokio::runtime::Handle,
+	/// RPC logger capacity (default: 1024).
+	pub request_logger_limit: u32,
+}
+
+#[derive(Debug, Clone)]
+struct PerConnection {
+	methods: Methods,
+	stop_handle: StopHandle,
+	metrics: Option<RpcMetrics>,
+	tokio_handle: tokio::runtime::Handle,
+}
+
+/// Start RPC server listening on given address.
+pub async fn start_server<M>(config: Config<M>) -> Result<Server, Box<dyn StdError + Send + Sync>>
+where
+	M: Send + Sync,
+{
+	let Config { endpoints, metrics, tokio_handle, rpc_api, id_provider, request_logger_limit } =
+		config;
+
+	let (stop_handle, server_handle) = stop_channel();
+	let cfg = PerConnection {
+		methods: build_rpc_api(rpc_api).into(),
+		metrics,
+		tokio_handle: tokio_handle.clone(),
+		stop_handle,
+	};
+
+	let mut local_addrs = Vec::new();
+
+	for endpoint in endpoints {
+		let allowed_to_fail = endpoint.is_optional;
+		let local_addr = endpoint.listen_addr;
+
+		let mut listener = match endpoint.bind().await {
+			Ok(l) => l,
+			Err(e) if allowed_to_fail => {
+				log::debug!(target: "rpc", "JSON-RPC server failed to bind optional address: {:?}, error: {:?}", local_addr, e);
+				continue;
+			},
+			Err(e) => return Err(e),
+		};
+		let local_addr = listener.local_addr();
+		local_addrs.push(local_addr);
+		let cfg = cfg.clone();
+
+		let RpcSettings {
+			batch_config,
+			max_connections,
+			max_payload_in_mb,
+			max_payload_out_mb,
+			max_buffer_capacity_per_connection,
+			max_subscriptions_per_connection,
+			rpc_methods,
+			rate_limit_trust_proxy_headers,
+			rate_limit_whitelisted_ips,
+			host_filter,
+			cors,
+			rate_limit,
+		} = listener.rpc_settings();
+
+		let http_middleware = tower::ServiceBuilder::new()
+			.option_layer(host_filter)
+			// Proxy `GET /health, /health/readiness` requests to the internal
+			// `system_health` method.
+			.layer(NodeHealthProxyLayer::default())
+			.layer(cors);
+
+		let mut builder = jsonrpsee::server::Server::builder()
+			.max_request_body_size(max_payload_in_mb.saturating_mul(MEGABYTE))
+			.max_response_body_size(max_payload_out_mb.saturating_mul(MEGABYTE))
+			.max_connections(max_connections)
+			.max_subscriptions_per_connection(max_subscriptions_per_connection)
+			.enable_ws_ping(
+				PingConfig::new()
+					.ping_interval(Duration::from_secs(30))
+					.inactive_limit(Duration::from_secs(60))
+					.max_failures(3),
+			)
+			.set_http_middleware(http_middleware)
+			.set_message_buffer_capacity(max_buffer_capacity_per_connection)
+			.set_batch_request_config(batch_config)
+			.custom_tokio_runtime(cfg.tokio_handle.clone());
+
+		if let Some(provider) = id_provider.clone() {
+			builder = builder.set_id_provider(provider);
+		} else {
+			builder = builder.set_id_provider(RandomStringIdProvider::new(16));
+		};
+
+		let service_builder = builder.to_service_builder();
+		let deny_unsafe = deny_unsafe(&local_addr, &rpc_methods);
+
+		tokio_handle.spawn(async move {
+			loop {
+				let (sock, remote_addr) = tokio::select! {
+					res = listener.accept() => {
+						match res {
+							Ok(s) => s,
+							Err(e) => {
+								log::debug!(target: "rpc", "Failed to accept connection: {:?}", e);
+								continue;
+							}
+						}
+					}
+					_ = cfg.stop_handle.clone().shutdown() => break,
+				};
+
+				let ip = remote_addr.ip();
+				let cfg2 = cfg.clone();
+				let service_builder2 = service_builder.clone();
+				let rate_limit_whitelisted_ips2 = rate_limit_whitelisted_ips.clone();
+
+				let svc =
+					tower::service_fn(move |mut req: http::Request<hyper::body::Incoming>| {
+						req.extensions_mut().insert(deny_unsafe);
+
+						let PerConnection { methods, metrics, tokio_handle, stop_handle } =
+							cfg2.clone();
+						let service_builder = service_builder2.clone();
+
+						let proxy_ip =
+							if rate_limit_trust_proxy_headers { get_proxy_ip(&req) } else { None };
+
+						let rate_limit_cfg = if rate_limit_whitelisted_ips2
+							.iter()
+							.any(|ips| ips.contains(proxy_ip.unwrap_or(ip)))
+						{
+							log::debug!(target: "rpc", "ip={ip}, proxy_ip={:?} is trusted, disabling rate-limit", proxy_ip);
+							None
+						} else {
+							if !rate_limit_whitelisted_ips2.is_empty() {
+								log::debug!(target: "rpc", "ip={ip}, proxy_ip={:?} is not trusted, rate-limit enabled", proxy_ip);
+							}
+							rate_limit
+						};
+
+						let is_websocket = ws::is_upgrade_request(&req);
+						let transport_label = if is_websocket { "ws" } else { "http" };
+
+						let middleware_layer = match (metrics, rate_limit_cfg) {
+							(None, None) => None,
+							(Some(metrics), None) => Some(
+								MiddlewareLayer::new()
+									.with_metrics(Metrics::new(metrics, transport_label)),
+							),
+							(None, Some(rate_limit)) =>
+								Some(MiddlewareLayer::new().with_rate_limit_per_minute(rate_limit)),
+							(Some(metrics), Some(rate_limit)) => Some(
+								MiddlewareLayer::new()
+									.with_metrics(Metrics::new(metrics, transport_label))
+									.with_rate_limit_per_minute(rate_limit),
+							),
+						};
+
+						let rpc_middleware = RpcServiceBuilder::new()
+							.rpc_logger(request_logger_limit)
+							.option_layer(middleware_layer.clone());
+						let mut svc = service_builder
+							.set_rpc_middleware(rpc_middleware)
+							.build(methods, stop_handle);
+
+						async move {
+							if is_websocket {
+								let on_disconnect = svc.on_session_closed();
+
+								// Spawn a task to handle when the connection is closed.
+								tokio_handle.spawn(async move {
+									let now = std::time::Instant::now();
+									middleware_layer.as_ref().map(|m| m.ws_connect());
+									on_disconnect.await;
+									middleware_layer.as_ref().map(|m| m.ws_disconnect(now));
+								});
+							}
+
+							// https://github.com/rust-lang/rust/issues/102211 the error type can't be inferred
+							// to be `Box<dyn std::error::Error + Send + Sync>` so we need to
+							// convert it to a concrete type as workaround.
+							svc.call(req).await.map_err(|e| BoxError::from(e))
+						}
+					});
+
+				cfg.tokio_handle.spawn(serve_with_graceful_shutdown(
+					sock,
+					svc,
+					cfg.stop_handle.clone().shutdown(),
+				));
+			}
+		});
+	}
+
+	if local_addrs.is_empty() {
+		return Err(Box::new(ListenAddrError));
+	}
+
+	// The previous logging format was before
+	// `Running JSON-RPC server: addr=127.0.0.1:9944, allowed origins=["*"]`
+	//
+	// The new format is `Running JSON-RPC server: addr=<addr1, addr2, .. addr_n>`
+	// with the exception that for a single address it will be `Running JSON-RPC server: addr=addr,`
+	// with a trailing comma.
+	//
+	// This is to make it work with old scripts/utils that parse the logs.
+	log::info!("Running JSON-RPC server: addr={}", format_listen_addrs(&local_addrs));
+
+	Ok(Server::new(server_handle, local_addrs))
+}

bizinikiwi/client/rpc-servers/src/middleware/metrics.rs

@@ -0,0 +1,227 @@
+// This file is part of Bizinikiwi.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! RPC middleware to collect prometheus metrics on RPC calls.
+
+use std::time::Instant;
+
+use jsonrpsee::{types::Request, MethodResponse};
+use prometheus_endpoint::{
+	register, Counter, CounterVec, HistogramOpts, HistogramVec, Opts, PrometheusError, Registry,
+	U64,
+};
+
+/// Histogram time buckets in microseconds.
+const HISTOGRAM_BUCKETS: [f64; 11] = [
+	5.0,
+	25.0,
+	100.0,
+	500.0,
+	1_000.0,
+	2_500.0,
+	10_000.0,
+	25_000.0,
+	100_000.0,
+	1_000_000.0,
+	10_000_000.0,
+];
+
+/// Metrics for RPC middleware storing information about the number of requests started/completed,
+/// calls started/completed and their timings.
+#[derive(Debug, Clone)]
+pub struct RpcMetrics {
+	/// Histogram over RPC execution times.
+	calls_time: HistogramVec,
+	/// Number of calls started.
+	calls_started: CounterVec<U64>,
+	/// Number of calls completed.
+	calls_finished: CounterVec<U64>,
+	/// Number of Websocket sessions opened.
+	ws_sessions_opened: Option<Counter<U64>>,
+	/// Number of Websocket sessions closed.
+	ws_sessions_closed: Option<Counter<U64>>,
+	/// Histogram over RPC websocket sessions.
+	ws_sessions_time: HistogramVec,
+}
+
+impl RpcMetrics {
+	/// Create an instance of metrics
+	pub fn new(metrics_registry: Option<&Registry>) -> Result<Option<Self>, PrometheusError> {
+		if let Some(metrics_registry) = metrics_registry {
+			Ok(Some(Self {
+				calls_time: register(
+					HistogramVec::new(
+						HistogramOpts::new(
+							"bizinikiwi_rpc_calls_time",
+							"Total time [μs] of processed RPC calls",
+						)
+						.buckets(HISTOGRAM_BUCKETS.to_vec()),
+						&["protocol", "method", "is_rate_limited"],
+					)?,
+					metrics_registry,
+				)?,
+				calls_started: register(
+					CounterVec::new(
+						Opts::new(
+							"bizinikiwi_rpc_calls_started",
+							"Number of received RPC calls (unique un-batched requests)",
+						),
+						&["protocol", "method"],
+					)?,
+					metrics_registry,
+				)?,
+				calls_finished: register(
+					CounterVec::new(
+						Opts::new(
+							"bizinikiwi_rpc_calls_finished",
+							"Number of processed RPC calls (unique un-batched requests)",
+						),
+						&["protocol", "method", "is_error", "is_rate_limited"],
+					)?,
+					metrics_registry,
+				)?,
+				ws_sessions_opened: register(
+					Counter::new(
+						"bizinikiwi_rpc_sessions_opened",
+						"Number of persistent RPC sessions opened",
+					)?,
+					metrics_registry,
+				)?
+				.into(),
+				ws_sessions_closed: register(
+					Counter::new(
+						"bizinikiwi_rpc_sessions_closed",
+						"Number of persistent RPC sessions closed",
+					)?,
+					metrics_registry,
+				)?
+				.into(),
+				ws_sessions_time: register(
+					HistogramVec::new(
+						HistogramOpts::new(
+							"bizinikiwi_rpc_sessions_time",
+							"Total time [s] for each websocket session",
+						)
+						.buckets(HISTOGRAM_BUCKETS.to_vec()),
+						&["protocol"],
+					)?,
+					metrics_registry,
+				)?,
+			}))
+		} else {
+			Ok(None)
+		}
+	}
+
+	pub(crate) fn ws_connect(&self) {
+		self.ws_sessions_opened.as_ref().map(|counter| counter.inc());
+	}
+
+	pub(crate) fn ws_disconnect(&self, now: Instant) {
+		let micros = now.elapsed().as_secs();
+
+		self.ws_sessions_closed.as_ref().map(|counter| counter.inc());
+		self.ws_sessions_time.with_label_values(&["ws"]).observe(micros as _);
+	}
+
+	pub(crate) fn on_call(&self, req: &Request, transport_label: &'static str) {
+		log::trace!(
+			target: "rpc_metrics",
+			"[{transport_label}] on_call name={} params={:?}",
+			req.method_name(),
+			req.params(),
+		);
+
+		self.calls_started
+			.with_label_values(&[transport_label, req.method_name()])
+			.inc();
+	}
+
+	pub(crate) fn on_response(
+		&self,
+		req: &Request,
+		rp: &MethodResponse,
+		is_rate_limited: bool,
+		transport_label: &'static str,
+		now: Instant,
+	) {
+		log::trace!(target: "rpc_metrics", "[{transport_label}] on_response started_at={:?}", now);
+		log::trace!(target: "rpc_metrics::extra", "[{transport_label}] result={}", rp.as_result());
+
+		let micros = now.elapsed().as_micros();
+		log::debug!(
+			target: "rpc_metrics",
+			"[{transport_label}] {} call took {} μs",
+			req.method_name(),
+			micros,
+		);
+		self.calls_time
+			.with_label_values(&[
+				transport_label,
+				req.method_name(),
+				if is_rate_limited { "true" } else { "false" },
+			])
+			.observe(micros as _);
+		self.calls_finished
+			.with_label_values(&[
+				transport_label,
+				req.method_name(),
+				// the label "is_error", so `success` should be regarded as false
+				// and vice-versa to be registered correctly.
+				if rp.is_success() { "false" } else { "true" },
+				if is_rate_limited { "true" } else { "false" },
+			])
+			.inc();
+	}
+}
+
+/// Metrics with transport label.
+#[derive(Clone, Debug)]
+pub struct Metrics {
+	pub(crate) inner: RpcMetrics,
+	pub(crate) transport_label: &'static str,
+}
+
+impl Metrics {
+	/// Create a new [`Metrics`].
+	pub fn new(metrics: RpcMetrics, transport_label: &'static str) -> Self {
+		Self { inner: metrics, transport_label }
+	}
+
+	pub(crate) fn ws_connect(&self) {
+		self.inner.ws_connect();
+	}
+
+	pub(crate) fn ws_disconnect(&self, now: Instant) {
+		self.inner.ws_disconnect(now)
+	}
+
+	pub(crate) fn on_call(&self, req: &Request) {
+		self.inner.on_call(req, self.transport_label)
+	}
+
+	pub(crate) fn on_response(
+		&self,
+		req: &Request,
+		rp: &MethodResponse,
+		is_rate_limited: bool,
+		now: Instant,
+	) {
+		self.inner.on_response(req, rp, is_rate_limited, self.transport_label, now)
+	}
+}

bizinikiwi/client/rpc-servers/src/middleware/mod.rs

@@ -0,0 +1,150 @@
+// This file is part of Bizinikiwi.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! JSON-RPC specific middleware.
+
+use std::{
+	num::NonZeroU32,
+	time::{Duration, Instant},
+};
+
+use futures::future::{BoxFuture, FutureExt};
+use governor::{clock::Clock, Jitter};
+use jsonrpsee::{
+	server::middleware::rpc::RpcServiceT,
+	types::{ErrorObject, Id, Request},
+	MethodResponse,
+};
+
+mod metrics;
+mod node_health;
+mod rate_limit;
+
+pub use metrics::*;
+pub use node_health::*;
+pub use rate_limit::*;
+
+const MAX_JITTER: Duration = Duration::from_millis(50);
+const MAX_RETRIES: usize = 10;
+
+/// JSON-RPC middleware layer.
+#[derive(Debug, Clone, Default)]
+pub struct MiddlewareLayer {
+	rate_limit: Option<RateLimit>,
+	metrics: Option<Metrics>,
+}
+
+impl MiddlewareLayer {
+	/// Create an empty MiddlewareLayer.
+	pub fn new() -> Self {
+		Self::default()
+	}
+
+	/// Enable new rate limit middleware enforced per minute.
+	pub fn with_rate_limit_per_minute(self, n: NonZeroU32) -> Self {
+		Self { rate_limit: Some(RateLimit::per_minute(n)), metrics: self.metrics }
+	}
+
+	/// Enable metrics middleware.
+	pub fn with_metrics(self, metrics: Metrics) -> Self {
+		Self { rate_limit: self.rate_limit, metrics: Some(metrics) }
+	}
+
+	/// Register a new websocket connection.
+	pub fn ws_connect(&self) {
+		self.metrics.as_ref().map(|m| m.ws_connect());
+	}
+
+	/// Register that a websocket connection was closed.
+	pub fn ws_disconnect(&self, now: Instant) {
+		self.metrics.as_ref().map(|m| m.ws_disconnect(now));
+	}
+}
+
+impl<S> tower::Layer<S> for MiddlewareLayer {
+	type Service = Middleware<S>;
+
+	fn layer(&self, service: S) -> Self::Service {
+		Middleware { service, rate_limit: self.rate_limit.clone(), metrics: self.metrics.clone() }
+	}
+}
+
+/// JSON-RPC middleware that handles metrics
+/// and rate-limiting.
+///
+/// These are part of the same middleware
+/// because the metrics needs to know whether
+/// a call was rate-limited or not because
+/// it will impact the roundtrip for a call.
+pub struct Middleware<S> {
+	service: S,
+	rate_limit: Option<RateLimit>,
+	metrics: Option<Metrics>,
+}
+
+impl<'a, S> RpcServiceT<'a> for Middleware<S>
+where
+	S: Send + Sync + RpcServiceT<'a> + Clone + 'static,
+{
+	type Future = BoxFuture<'a, MethodResponse>;
+
+	fn call(&self, req: Request<'a>) -> Self::Future {
+		let now = Instant::now();
+
+		self.metrics.as_ref().map(|m| m.on_call(&req));
+
+		let service = self.service.clone();
+		let rate_limit = self.rate_limit.clone();
+		let metrics = self.metrics.clone();
+
+		async move {
+			let mut is_rate_limited = false;
+
+			if let Some(limit) = rate_limit.as_ref() {
+				let mut attempts = 0;
+				let jitter = Jitter::up_to(MAX_JITTER);
+
+				loop {
+					if attempts >= MAX_RETRIES {
+						return reject_too_many_calls(req.id);
+					}
+
+					if let Err(rejected) = limit.inner.check() {
+						tokio::time::sleep(jitter + rejected.wait_time_from(limit.clock.now()))
+							.await;
+					} else {
+						break;
+					}
+
+					is_rate_limited = true;
+					attempts += 1;
+				}
+			}
+
+			let rp = service.call(req.clone()).await;
+			metrics.as_ref().map(|m| m.on_response(&req, &rp, is_rate_limited, now));
+
+			rp
+		}
+		.boxed()
+	}
+}
+
+fn reject_too_many_calls(id: Id) -> MethodResponse {
+	MethodResponse::error(id, ErrorObject::owned(-32999, "RPC rate limit exceeded", None::<()>))
+}

bizinikiwi/client/rpc-servers/src/middleware/node_health.rs

@@ -0,0 +1,207 @@
+// This file is part of Bizinikiwi.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! Middleware for handling `/health` and `/health/readiness` endpoints.
+
+use std::{
+	error::Error,
+	future::Future,
+	pin::Pin,
+	task::{Context, Poll},
+};
+
+use futures::future::FutureExt;
+use http::{HeaderValue, Method, StatusCode, Uri};
+use jsonrpsee::{
+	server::{HttpBody, HttpRequest, HttpResponse},
+	types::{Response as RpcResponse, ResponseSuccess as RpcResponseSuccess},
+};
+use tower::Service;
+
+const RPC_SYSTEM_HEALTH_CALL: &str = r#"{"jsonrpc":"2.0","method":"system_health","id":0}"#;
+const HEADER_VALUE_JSON: HeaderValue = HeaderValue::from_static("application/json; charset=utf-8");
+
+/// Layer that applies [`NodeHealthProxy`] which
+/// proxies `/health` and `/health/readiness` endpoints.
+#[derive(Debug, Clone, Default)]
+pub struct NodeHealthProxyLayer;
+
+impl<S> tower::Layer<S> for NodeHealthProxyLayer {
+	type Service = NodeHealthProxy<S>;
+
+	fn layer(&self, service: S) -> Self::Service {
+		NodeHealthProxy::new(service)
+	}
+}
+
+/// Middleware that proxies `/health` and `/health/readiness` endpoints.
+pub struct NodeHealthProxy<S>(S);
+
+impl<S> NodeHealthProxy<S> {
+	/// Creates a new [`NodeHealthProxy`].
+	pub fn new(service: S) -> Self {
+		Self(service)
+	}
+}
+
+impl<S> tower::Service<http::Request<hyper::body::Incoming>> for NodeHealthProxy<S>
+where
+	S: Service<HttpRequest, Response = HttpResponse>,
+	S::Response: 'static,
+	S::Error: Into<Box<dyn Error + Send + Sync>> + 'static,
+	S::Future: Send + 'static,
+{
+	type Response = S::Response;
+	type Error = Box<dyn Error + Send + Sync + 'static>;
+	type Future =
+		Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send + 'static>>;
+
+	fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+		self.0.poll_ready(cx).map_err(Into::into)
+	}
+
+	fn call(&mut self, req: http::Request<hyper::body::Incoming>) -> Self::Future {
+		let mut req = req.map(|body| HttpBody::new(body));
+		let maybe_intercept = InterceptRequest::from_http(&req);
+
+		// Modify the request and proxy it to `system_health`
+		if let InterceptRequest::Health | InterceptRequest::Readiness = maybe_intercept {
+			// RPC methods are accessed with `POST`.
+			*req.method_mut() = Method::POST;
+			// Precautionary remove the URI.
+			*req.uri_mut() = Uri::from_static("/");
+
+			// Requests must have the following headers:
+			req.headers_mut().insert(http::header::CONTENT_TYPE, HEADER_VALUE_JSON);
+			req.headers_mut().insert(http::header::ACCEPT, HEADER_VALUE_JSON);
+
+			// Adjust the body to reflect the method call.
+			req = req.map(|_| HttpBody::from(RPC_SYSTEM_HEALTH_CALL));
+		}
+
+		// Call the inner service and get a future that resolves to the response.
+		let fut = self.0.call(req);
+
+		async move {
+			Ok(match maybe_intercept {
+				InterceptRequest::Deny =>
+					http_response(StatusCode::METHOD_NOT_ALLOWED, HttpBody::empty()),
+				InterceptRequest::No => fut.await.map_err(|err| err.into())?,
+				InterceptRequest::Health => {
+					let res = fut.await.map_err(|err| err.into())?;
+					if let Ok(health) = parse_rpc_response(res.into_body()).await {
+						http_ok_response(serde_json::to_string(&health)?)
+					} else {
+						http_internal_error()
+					}
+				},
+				InterceptRequest::Readiness => {
+					let res = fut.await.map_err(|err| err.into())?;
+					match parse_rpc_response(res.into_body()).await {
+						Ok(health)
+							if (!health.is_syncing && health.peers > 0) ||
+								!health.should_have_peers =>
+							http_ok_response(HttpBody::empty()),
+						_ => http_internal_error(),
+					}
+				},
+			})
+		}
+		.boxed()
+	}
+}
+
+// NOTE: This is duplicated here to avoid dependency to the `RPC API`.
+#[derive(Clone, Debug, PartialEq, serde::Serialize, serde::Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct Health {
+	/// Number of connected peers
+	pub peers: usize,
+	/// Is the node syncing
+	pub is_syncing: bool,
+	/// Should this node have any peers
+	///
+	/// Might be false for local chains or when running without discovery.
+	pub should_have_peers: bool,
+}
+
+fn http_ok_response<S: Into<HttpBody>>(body: S) -> HttpResponse {
+	http_response(StatusCode::OK, body)
+}
+
+fn http_response<S: Into<HttpBody>>(status_code: StatusCode, body: S) -> HttpResponse {
+	HttpResponse::builder()
+		.status(status_code)
+		.header(http::header::CONTENT_TYPE, HEADER_VALUE_JSON)
+		.body(body.into())
+		.expect("Header is valid; qed")
+}
+
+fn http_internal_error() -> HttpResponse {
+	http_response(hyper::StatusCode::INTERNAL_SERVER_ERROR, HttpBody::empty())
+}
+
+async fn parse_rpc_response(
+	body: HttpBody,
+) -> Result<Health, Box<dyn Error + Send + Sync + 'static>> {
+	use http_body_util::BodyExt;
+
+	let bytes = body.collect().await?.to_bytes();
+
+	let raw_rp = serde_json::from_slice::<RpcResponse<Health>>(&bytes)?;
+	let rp = RpcResponseSuccess::<Health>::try_from(raw_rp)?;
+
+	Ok(rp.result)
+}
+
+/// Whether the request should be treated as ordinary RPC call or be modified.
+enum InterceptRequest {
+	/// Proxy `/health` to `system_health`.
+	Health,
+	/// Checks if node has at least one peer and is not doing major syncing.
+	///
+	/// Returns HTTP status code 200 on success otherwise HTTP status code 500 is returned.
+	Readiness,
+	/// Treat as a ordinary RPC call and don't modify the request or response.
+	No,
+	/// Deny health or readiness calls that is not HTTP GET request.
+	///
+	/// Returns HTTP status code 405.
+	Deny,
+}
+
+impl InterceptRequest {
+	fn from_http(req: &HttpRequest) -> InterceptRequest {
+		match req.uri().path() {
+			"/health" =>
+				if req.method() == http::Method::GET {
+					InterceptRequest::Health
+				} else {
+					InterceptRequest::Deny
+				},
+			"/health/readiness" =>
+				if req.method() == http::Method::GET {
+					InterceptRequest::Readiness
+				} else {
+					InterceptRequest::Deny
+				},
+			// Forward all other requests to the RPC server.
+			_ => InterceptRequest::No,
+		}
+	}
+}

bizinikiwi/client/rpc-servers/src/middleware/rate_limit.rs

@@ -0,0 +1,47 @@
+// This file is part of Bizinikiwi.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! RPC rate limit.
+
+use governor::{
+	clock::{DefaultClock, QuantaClock},
+	middleware::NoOpMiddleware,
+	state::{InMemoryState, NotKeyed},
+	Quota,
+};
+use std::{num::NonZeroU32, sync::Arc};
+
+type RateLimitInner = governor::RateLimiter<NotKeyed, InMemoryState, DefaultClock, NoOpMiddleware>;
+
+/// Rate limit.
+#[derive(Debug, Clone)]
+pub struct RateLimit {
+	pub(crate) inner: Arc<RateLimitInner>,
+	pub(crate) clock: QuantaClock,
+}
+
+impl RateLimit {
+	/// Create a new `RateLimit` per minute.
+	pub fn per_minute(n: NonZeroU32) -> Self {
+		let clock = QuantaClock::default();
+		Self {
+			inner: Arc::new(RateLimitInner::direct_with_clock(Quota::per_minute(n), &clock)),
+			clock,
+		}
+	}
+}

bizinikiwi/client/rpc-servers/src/utils.rs

@@ -0,0 +1,369 @@
+// This file is part of Bizinikiwi.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! Bizinikiwi RPC server utils.
+
+use crate::BatchRequestConfig;
+use std::{
+	error::Error as StdError,
+	net::{IpAddr, SocketAddr},
+	num::NonZeroU32,
+	str::FromStr,
+};
+
+use forwarded_header_value::ForwardedHeaderValue;
+use http::header::{HeaderName, HeaderValue};
+use ip_network::IpNetwork;
+use jsonrpsee::{server::middleware::http::HostFilterLayer, RpcModule};
+use pezsc_rpc_api::DenyUnsafe;
+use tower_http::cors::{AllowOrigin, CorsLayer};
+
+const X_FORWARDED_FOR: HeaderName = HeaderName::from_static("x-forwarded-for");
+const X_REAL_IP: HeaderName = HeaderName::from_static("x-real-ip");
+const FORWARDED: HeaderName = HeaderName::from_static("forwarded");
+
+#[derive(Debug)]
+pub(crate) struct ListenAddrError;
+
+impl std::error::Error for ListenAddrError {}
+
+impl std::fmt::Display for ListenAddrError {
+	fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+		write!(f, "No listen address was successfully bound")
+	}
+}
+
+/// Available RPC methods.
+#[derive(Debug, Copy, Clone)]
+pub enum RpcMethods {
+	/// Allow only a safe subset of RPC methods.
+	Safe,
+	/// Expose every RPC method (even potentially unsafe ones).
+	Unsafe,
+	/// Automatically determine the RPC methods based on the connection.
+	Auto,
+}
+
+impl Default for RpcMethods {
+	fn default() -> Self {
+		RpcMethods::Auto
+	}
+}
+
+impl FromStr for RpcMethods {
+	type Err = String;
+
+	fn from_str(s: &str) -> Result<Self, Self::Err> {
+		match s {
+			"safe" => Ok(RpcMethods::Safe),
+			"unsafe" => Ok(RpcMethods::Unsafe),
+			"auto" => Ok(RpcMethods::Auto),
+			invalid => Err(format!("Invalid rpc methods {invalid}")),
+		}
+	}
+}
+
+#[derive(Debug, Clone)]
+pub(crate) struct RpcSettings {
+	pub(crate) batch_config: BatchRequestConfig,
+	pub(crate) max_connections: u32,
+	pub(crate) max_payload_in_mb: u32,
+	pub(crate) max_payload_out_mb: u32,
+	pub(crate) max_subscriptions_per_connection: u32,
+	pub(crate) max_buffer_capacity_per_connection: u32,
+	pub(crate) rpc_methods: RpcMethods,
+	pub(crate) rate_limit: Option<NonZeroU32>,
+	pub(crate) rate_limit_trust_proxy_headers: bool,
+	pub(crate) rate_limit_whitelisted_ips: Vec<IpNetwork>,
+	pub(crate) cors: CorsLayer,
+	pub(crate) host_filter: Option<HostFilterLayer>,
+}
+
+/// Represent a single RPC endpoint with its configuration.
+#[derive(Debug, Clone)]
+pub struct RpcEndpoint {
+	/// Listen address.
+	pub listen_addr: SocketAddr,
+	/// Batch request configuration.
+	pub batch_config: BatchRequestConfig,
+	/// Maximum number of connections.
+	pub max_connections: u32,
+	/// Maximum inbound payload size in MB.
+	pub max_payload_in_mb: u32,
+	/// Maximum outbound payload size in MB.
+	pub max_payload_out_mb: u32,
+	/// Maximum number of subscriptions per connection.
+	pub max_subscriptions_per_connection: u32,
+	/// Maximum buffer capacity per connection.
+	pub max_buffer_capacity_per_connection: u32,
+	/// Rate limit per minute.
+	pub rate_limit: Option<NonZeroU32>,
+	/// Whether to trust proxy headers for rate limiting.
+	pub rate_limit_trust_proxy_headers: bool,
+	/// Whitelisted IPs for rate limiting.
+	pub rate_limit_whitelisted_ips: Vec<IpNetwork>,
+	/// CORS.
+	pub cors: Option<Vec<String>>,
+	/// RPC methods to expose.
+	pub rpc_methods: RpcMethods,
+	/// Whether it's an optional listening address i.e, it's ignored if it fails to bind.
+	/// For example bizinikiwi tries to bind both ipv4 and ipv6 addresses but some platforms
+	/// may not support ipv6.
+	pub is_optional: bool,
+	/// Whether to retry with a random port if the provided port is already in use.
+	pub retry_random_port: bool,
+}
+
+impl RpcEndpoint {
+	/// Binds to the listen address.
+	pub(crate) async fn bind(self) -> Result<Listener, Box<dyn StdError + Send + Sync>> {
+		let listener = match tokio::net::TcpListener::bind(self.listen_addr).await {
+			Ok(listener) => listener,
+			Err(_) if self.retry_random_port => {
+				let mut addr = self.listen_addr;
+				addr.set_port(0);
+
+				tokio::net::TcpListener::bind(addr).await?
+			},
+			Err(e) => return Err(e.into()),
+		};
+		let local_addr = listener.local_addr()?;
+		let host_filter = host_filtering(self.cors.is_some(), local_addr);
+		let cors = try_into_cors(self.cors)?;
+
+		Ok(Listener {
+			listener,
+			local_addr,
+			cfg: RpcSettings {
+				batch_config: self.batch_config,
+				max_connections: self.max_connections,
+				max_payload_in_mb: self.max_payload_in_mb,
+				max_payload_out_mb: self.max_payload_out_mb,
+				max_subscriptions_per_connection: self.max_subscriptions_per_connection,
+				max_buffer_capacity_per_connection: self.max_buffer_capacity_per_connection,
+				rpc_methods: self.rpc_methods,
+				rate_limit: self.rate_limit,
+				rate_limit_trust_proxy_headers: self.rate_limit_trust_proxy_headers,
+				rate_limit_whitelisted_ips: self.rate_limit_whitelisted_ips,
+				host_filter,
+				cors,
+			},
+		})
+	}
+}
+
+/// TCP socket server with RPC settings.
+pub(crate) struct Listener {
+	listener: tokio::net::TcpListener,
+	local_addr: SocketAddr,
+	cfg: RpcSettings,
+}
+
+impl Listener {
+	/// Accepts a new connection.
+	pub(crate) async fn accept(&mut self) -> std::io::Result<(tokio::net::TcpStream, SocketAddr)> {
+		let (sock, remote_addr) = self.listener.accept().await?;
+		Ok((sock, remote_addr))
+	}
+
+	/// Returns the local address the listener is bound to.
+	pub fn local_addr(&self) -> SocketAddr {
+		self.local_addr
+	}
+
+	pub fn rpc_settings(&self) -> RpcSettings {
+		self.cfg.clone()
+	}
+}
+
+pub(crate) fn host_filtering(enabled: bool, addr: SocketAddr) -> Option<HostFilterLayer> {
+	if enabled {
+		// NOTE: The listening addresses are whitelisted by default.
+
+		let hosts = [
+			format!("localhost:{}", addr.port()),
+			format!("127.0.0.1:{}", addr.port()),
+			format!("[::1]:{}", addr.port()),
+		];
+
+		Some(HostFilterLayer::new(hosts).expect("Valid hosts; qed"))
+	} else {
+		None
+	}
+}
+
+pub(crate) fn build_rpc_api<M: Send + Sync + 'static>(mut rpc_api: RpcModule<M>) -> RpcModule<M> {
+	let mut available_methods = rpc_api.method_names().collect::<Vec<_>>();
+	// The "rpc_methods" is defined below and we want it to be part of the reported methods.
+	available_methods.push("rpc_methods");
+	available_methods.sort();
+
+	rpc_api
+		.register_method("rpc_methods", move |_, _, _| {
+			serde_json::json!({
+				"methods": available_methods,
+			})
+		})
+		.expect("infallible all other methods have their own address space; qed");
+
+	rpc_api
+}
+
+pub(crate) fn try_into_cors(
+	maybe_cors: Option<Vec<String>>,
+) -> Result<CorsLayer, Box<dyn StdError + Send + Sync>> {
+	if let Some(cors) = maybe_cors {
+		let mut list = Vec::new();
+
+		for origin in cors {
+			list.push(HeaderValue::from_str(&origin)?)
+		}
+
+		Ok(CorsLayer::new().allow_origin(AllowOrigin::list(list)))
+	} else {
+		// allow all cors
+		Ok(CorsLayer::permissive())
+	}
+}
+
+/// Extracts the IP addr from the HTTP request.
+///
+/// It is extracted in the following order:
+/// 1. `Forwarded` header.
+/// 2. `X-Forwarded-For` header.
+/// 3. `X-Real-Ip`.
+pub(crate) fn get_proxy_ip<B>(req: &http::Request<B>) -> Option<IpAddr> {
+	if let Some(ip) = req
+		.headers()
+		.get(&FORWARDED)
+		.and_then(|v| v.to_str().ok())
+		.and_then(|v| ForwardedHeaderValue::from_forwarded(v).ok())
+		.and_then(|v| v.remotest_forwarded_for_ip())
+	{
+		return Some(ip);
+	}
+
+	if let Some(ip) = req
+		.headers()
+		.get(&X_FORWARDED_FOR)
+		.and_then(|v| v.to_str().ok())
+		.and_then(|v| ForwardedHeaderValue::from_x_forwarded_for(v).ok())
+		.and_then(|v| v.remotest_forwarded_for_ip())
+	{
+		return Some(ip);
+	}
+
+	if let Some(ip) = req
+		.headers()
+		.get(&X_REAL_IP)
+		.and_then(|v| v.to_str().ok())
+		.and_then(|v| IpAddr::from_str(v).ok())
+	{
+		return Some(ip);
+	}
+
+	None
+}
+
+/// Get the `deny_unsafe` setting based on the address and the RPC methods exposed by the interface.
+pub fn deny_unsafe(addr: &SocketAddr, methods: &RpcMethods) -> DenyUnsafe {
+	match (addr.ip().is_loopback(), methods) {
+		(_, RpcMethods::Unsafe) | (true, RpcMethods::Auto) => DenyUnsafe::No,
+		_ => DenyUnsafe::Yes,
+	}
+}
+
+pub(crate) fn format_listen_addrs(addr: &[SocketAddr]) -> String {
+	let mut s = String::new();
+
+	let mut it = addr.iter().peekable();
+
+	while let Some(addr) = it.next() {
+		s.push_str(&addr.to_string());
+
+		if it.peek().is_some() {
+			s.push(',');
+		}
+	}
+
+	if addr.len() == 1 {
+		s.push(',');
+	}
+
+	s
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use hyper::header::HeaderValue;
+	use jsonrpsee::server::{HttpBody, HttpRequest};
+
+	fn request() -> http::Request<HttpBody> {
+		HttpRequest::builder().body(HttpBody::empty()).unwrap()
+	}
+
+	#[test]
+	fn empty_works() {
+		let req = request();
+		let host = get_proxy_ip(&req);
+		assert!(host.is_none())
+	}
+
+	#[test]
+	fn host_from_x_real_ip() {
+		let mut req = request();
+
+		req.headers_mut().insert(&X_REAL_IP, HeaderValue::from_static("127.0.0.1"));
+		let ip = get_proxy_ip(&req);
+		assert_eq!(Some(IpAddr::from_str("127.0.0.1").unwrap()), ip);
+	}
+
+	#[test]
+	fn ip_from_forwarded_works() {
+		let mut req = request();
+
+		req.headers_mut().insert(
+			&FORWARDED,
+			HeaderValue::from_static("for=192.0.2.60;proto=http;by=203.0.113.43;host=example.com"),
+		);
+		let ip = get_proxy_ip(&req);
+		assert_eq!(Some(IpAddr::from_str("192.0.2.60").unwrap()), ip);
+	}
+
+	#[test]
+	fn ip_from_forwarded_multiple() {
+		let mut req = request();
+
+		req.headers_mut().append(&FORWARDED, HeaderValue::from_static("for=127.0.0.1"));
+		req.headers_mut().append(&FORWARDED, HeaderValue::from_static("for=192.0.2.60"));
+		req.headers_mut().append(&FORWARDED, HeaderValue::from_static("for=192.0.2.61"));
+		let ip = get_proxy_ip(&req);
+		assert_eq!(Some(IpAddr::from_str("127.0.0.1").unwrap()), ip);
+	}
+
+	#[test]
+	fn ip_from_x_forwarded_works() {
+		let mut req = request();
+
+		req.headers_mut()
+			.insert(&X_FORWARDED_FOR, HeaderValue::from_static("127.0.0.1,192.0.2.60,0.0.0.1"));
+		let ip = get_proxy_ip(&req);
+		assert_eq!(Some(IpAddr::from_str("127.0.0.1").unwrap()), ip);
+	}
+}