Bridges - add version guarding for standalone relaying of parachains and messages (#5952)

This PR adds the ability to start version guarding when performing
standalone relaying of messages and parachains.

## Follow-up
- decouple and simplify `fn start_relay_guards`:
https://github.com/paritytech/polkadot-sdk/issues/5923

---------

Co-authored-by: command-bot <>

bridges/relays/lib-substrate-relay/src/cli/mod.rs

@@ -20,7 +20,6 @@ use rbtag::BuildInfo;
 use sp_runtime::traits::TryConvert;
 use std::str::FromStr;
 use structopt::StructOpt;
-use strum::{EnumString, VariantNames};
 
 pub mod bridge;
 pub mod chain_schema;
@@ -139,17 +138,6 @@ where
 	}
 }
 
-#[doc = "Runtime version params."]
-#[derive(StructOpt, Debug, PartialEq, Eq, Clone, Copy, EnumString, VariantNames)]
-pub enum RuntimeVersionType {
-	/// Auto query version from chain
-	Auto,
-	/// Custom `spec_version` and `transaction_version`
-	Custom,
-	/// Read version from bundle dependencies directly.
-	Bundle,
-}
-
 #[cfg(test)]
 mod tests {
 	use super::*;

bridges/relays/lib-substrate-relay/src/cli/relay_headers.rs

@@ -96,6 +96,7 @@ pub trait HeadersRelayer: RelayToRelayHeadersCliBridge {
 			signer: target_sign,
 			mortality: target_transactions_mortality,
 		};
+
 		Self::Finality::start_relay_guards(&target_client, target_client.can_start_version_guard())
 			.await?;
 

bridges/relays/lib-substrate-relay/src/cli/relay_messages.rs

@@ -121,6 +121,8 @@ where
 			anyhow::format_err!("Invalid laneId: {:?}!", invalid_lane_id)
 		})?;
 
+		Self::start_relay_guards(&target_client, target_client.can_start_version_guard()).await?;
+
 		crate::messages::run::<Self::MessagesLane, _, _>(MessagesRelayParams {
 			source_client,
 			source_transaction_params: TransactionParams {
@@ -216,4 +218,18 @@ where
 		)
 		.await
 	}
+
+	/// Add relay guards if required.
+	async fn start_relay_guards(
+		target_client: &impl Client<Self::Target>,
+		enable_version_guard: bool,
+	) -> relay_substrate_client::Result<()> {
+		if enable_version_guard {
+			relay_substrate_client::guard::abort_on_spec_version_change(
+				target_client.clone(),
+				target_client.simple_runtime_version().await?.spec_version,
+			);
+		}
+		Ok(())
+	}
 }

bridges/relays/lib-substrate-relay/src/cli/relay_parachains.rs

@@ -32,6 +32,7 @@ use crate::{
 		chain_schema::*,
 		DefaultClient, PrometheusParams,
 	},
+	finality::SubstrateFinalitySyncPipeline,
 	parachains::{source::ParachainsSource, target::ParachainsTarget, ParachainsPipelineAdapter},
 	TransactionParams,
 };
@@ -104,6 +105,12 @@ where
 			data.prometheus_params.into_metrics_params()?;
 		GlobalMetrics::new()?.register_and_spawn(&metrics_params.registry)?;
 
+		Self::RelayFinality::start_relay_guards(
+			target_client.target_client(),
+			target_client.target_client().can_start_version_guard(),
+		)
+		.await?;
+
 		parachains_relay::parachains_loop::run(
 			source_client,
 			target_client,

bridges/relays/parachains/src/parachains_loop.rs

@@ -177,6 +177,14 @@ pub async fn run<P: ParachainsPipeline>(
 where
 	P::SourceRelayChain: Chain<BlockNumber = RelayBlockNumber>,
 {
+	log::info!(
+		target: "bridge",
+		"Starting {} -> {} finality proof relay: relaying (only_free_headers: {:?}) headers",
+		P::SourceParachain::NAME,
+		P::TargetChain::NAME,
+		only_free_headers,
+	);
+
 	let exit_signal = exit_signal.shared();
 	relay_utils::relay_loop(source_client, target_client)
 		.with_metrics(metrics_params)