Adds Snowbridge to Rococo runtime (#2522)

# Description Adds Snowbridge to the Rococo bridge hub runtime. Includes config changes required in Rococo asset hub. --------- Co-authored-by: Alistair Singh <alistair.singh7@gmail.com> Co-authored-by: ron <yrong1997@gmail.com> Co-authored-by: Vincent Geddes <vincent.geddes@hey.com> Co-authored-by: claravanstaden <Cats 4 life!>
2026-05-30 23:21:02 +00:00 · 2023-12-21 18:06:36 +02:00
parent 9f5221cc2f
commit 18d53dbf91
151 changed files with 19379 additions and 149 deletions
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2023 Snowfork <hello@snowfork.com>
+//! # Runtime Common
+//!
+//! Common traits and types shared by runtimes.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use core::marker::PhantomData;
+use frame_support::traits::Get;
+use snowbridge_core::{outbound::SendMessageFeeProvider, sibling_sovereign_account_raw};
+use sp_arithmetic::traits::{BaseArithmetic, Unsigned};
+use xcm::prelude::*;
+use xcm_builder::{deposit_or_burn_fee, HandleFee};
+use xcm_executor::traits::{FeeReason, TransactAsset};
+
+/// A `HandleFee` implementation that takes fees from `ExportMessage` XCM instructions
+/// to Snowbridge and splits off the remote fee and deposits it to the origin
+/// parachain sovereign account. The local fee is then returned back to be handled by
+/// the next fee handler in the chain. Most likely the treasury account.
+pub struct XcmExportFeeToSibling<
+	Balance,
+	AccountId,
+	FeeAssetLocation,
+	EthereumNetwork,
+	AssetTransactor,
+	FeeProvider,
+>(
+	PhantomData<(
+		Balance,
+		AccountId,
+		FeeAssetLocation,
+		EthereumNetwork,
+		AssetTransactor,
+		FeeProvider,
+	)>,
+);
+
+impl<Balance, AccountId, FeeAssetLocation, EthereumNetwork, AssetTransactor, FeeProvider> HandleFee
+	for XcmExportFeeToSibling<
+		Balance,
+		AccountId,
+		FeeAssetLocation,
+		EthereumNetwork,
+		AssetTransactor,
+		FeeProvider,
+	> where
+	Balance: BaseArithmetic + Unsigned + Copy + From<u128> + Into<u128>,
+	AccountId: Clone + Into<[u8; 32]> + From<[u8; 32]>,
+	FeeAssetLocation: Get<MultiLocation>,
+	EthereumNetwork: Get<NetworkId>,
+	AssetTransactor: TransactAsset,
+	FeeProvider: SendMessageFeeProvider<Balance = Balance>,
+{
+	fn handle_fee(
+		fees: MultiAssets,
+		context: Option<&XcmContext>,
+		reason: FeeReason,
+	) -> MultiAssets {
+		let token_location = FeeAssetLocation::get();
+
+		// Check the reason to see if this export is for snowbridge.
+		if !matches!(
+			reason,
+			FeeReason::Export { network: bridged_network, destination }
+				if bridged_network == EthereumNetwork::get() && destination == Here
+		) {
+			return fees
+		}
+
+		// Get the parachain sovereign from the `context`.
+		let para_sovereign = if let Some(XcmContext {
+			origin: Some(MultiLocation { parents: 1, interior }),
+			..
+		}) = context
+		{
+			if let Some(Parachain(sibling_para_id)) = interior.first() {
+				let account: AccountId =
+					sibling_sovereign_account_raw((*sibling_para_id).into()).into();
+				account
+			} else {
+				return fees
+			}
+		} else {
+			return fees
+		};
+
+		// Get the total fee offered by export message.
+		let maybe_total_supplied_fee: Option<(usize, Balance)> = fees
+			.inner()
+			.iter()
+			.enumerate()
+			.filter_map(|(index, asset)| {
+				if let MultiAsset { id: Concrete(location), fun: Fungible(amount) } = asset {
+					if *location == token_location {
+						return Some((index, (*amount).into()))
+					}
+				}
+				None
+			})
+			.next();
+
+		if let Some((fee_index, total_fee)) = maybe_total_supplied_fee {
+			let remote_fee = total_fee.saturating_sub(FeeProvider::local_fee());
+			if remote_fee > (0u128).into() {
+				// Refund remote component of fee to physical origin
+				deposit_or_burn_fee::<AssetTransactor, _>(
+					MultiAsset { id: Concrete(token_location), fun: Fungible(remote_fee.into()) }
+						.into(),
+					context,
+					para_sovereign,
+				);
+				// Return remaining fee to the next fee handler in the chain.
+				let mut modified_fees = fees.inner().clone();
+				modified_fees.remove(fee_index);
+				modified_fees.push(MultiAsset {
+					id: Concrete(token_location),
+					fun: Fungible((total_fee - remote_fee).into()),
+				});
+				return modified_fees.into()
+			}
+		}
+
+		log::info!(
+			target: "xcm::fees",
+			"XcmExportFeeToSibling skipped: {fees:?}, context: {context:?}, reason: {reason:?}",
+		);
+		fees
+	}
+}