Auto relay exchange transactions (paritytech#227)

* auto relay exchange transactions

* docker + auto-relay-tx

* clippy

* jsonrpsee in Cargo.lock ???

* fix tests compilation

* Show sccache

* mute clippy

* move

* Update relays/ethereum/src/exchange.rs

Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com>

* finish comment

* (bool, String) -> StringifiedMaybeConnectionError

* Update deployments/rialto/docker-compose.yml

Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com>

Co-authored-by: Denis S. Soldatov aka General-Beck <general.beck@gmail.com>
Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com>

bridges/bin/node/runtime/src/lib.rs

@@ -555,6 +555,12 @@ impl_runtime_apis! {
 		}
 	}
 
+	impl sp_currency_exchange::CurrencyExchangeApi<Block, exchange::EthereumTransactionInclusionProof> for Runtime {
+		fn filter_transaction_proof(proof: exchange::EthereumTransactionInclusionProof) -> bool {
+			BridgeCurrencyExchange::filter_transaction_proof(&proof)
+		}
+	}
+
 	impl sp_transaction_pool::runtime_api::TaggedTransactionQueue<Block> for Runtime {
 		fn validate_transaction(
 			source: TransactionSource,

bridges/modules/currency-exchange/src/lib.rs

@@ -105,36 +105,21 @@ decl_module! {
 		) -> DispatchResult {
 			let submitter = frame_system::ensure_signed(origin)?;
 
-			// ensure that transaction is included in finalized block that we know of
-			let transaction = <T as Trait>::PeerBlockchain::verify_transaction_inclusion_proof(
-				&proof,
-			).ok_or_else(|| Error::<T>::UnfinalizedTransaction)?;
-
-			// parse transaction
-			let transaction = <T as Trait>::PeerMaybeLockFundsTransaction::parse(&transaction)
-				.map_err(Error::<T>::from)?;
-			let transfer_id = transaction.id;
-			ensure!(
-				!Transfers::<T>::contains_key(&transfer_id),
-				Error::<T>::AlreadyClaimed
-			);
-
-			// grant recipient
-			let recipient = T::RecipientsMap::map(transaction.recipient).map_err(Error::<T>::from)?;
-			let amount = T::CurrencyConverter::convert(transaction.amount).map_err(Error::<T>::from)?;
+			// verify and parse transaction proof
+			let deposit = prepare_deposit_details::<T>(&proof)?;
 
 			// make sure to update the mapping if we deposit successfully to avoid double spending,
 			// i.e. whenever `deposit_into` is successful we MUST update `Transfers`.
 			{
 				// if any changes were made to the storage, we can't just return error here, because
 				// otherwise the same proof may be imported again
-				let deposit_result = T::DepositInto::deposit_into(recipient, amount);
+				let deposit_result = T::DepositInto::deposit_into(deposit.recipient, deposit.amount);
 				match deposit_result {
 					Ok(_) => (),
 					Err(ExchangeError::DepositPartiallyFailed) => (),
 					Err(error) => return Err(Error::<T>::from(error).into()),
 				}
-				Transfers::<T>::insert(&transfer_id, ())
+				Transfers::<T>::insert(&deposit.transfer_id, ())
 			}
 
 			// reward submitter for providing valid message
@@ -143,7 +128,7 @@ decl_module! {
 			frame_support::debug::trace!(
 				target: "runtime",
 				"Completed currency exchange: {:?}",
-				transfer_id,
+				deposit.transfer_id,
 			);
 
 			Ok(())
@@ -158,6 +143,18 @@ decl_storage! {
 	}
 }
 
+impl<T: Trait> Module<T> {
+	/// Returns true if currency exchange module is able to import given transaction proof in
+	/// its current state.
+	pub fn filter_transaction_proof(proof: &<T::PeerBlockchain as Blockchain>::TransactionInclusionProof) -> bool {
+		if prepare_deposit_details::<T>(proof).is_err() {
+			return false;
+		}
+
+		true
+	}
+}
+
 impl<T: Trait> From<ExchangeError> for Error<T> {
 	fn from(error: ExchangeError) -> Self {
 		match error {
@@ -176,6 +173,41 @@ impl<AccountId> OnTransactionSubmitted<AccountId> for () {
 	fn on_valid_transaction_submitted(_: AccountId) {}
 }
 
+/// Exchange deposit details.
+struct DepositDetails<T: Trait> {
+	/// Transfer id.
+	pub transfer_id: <T::PeerMaybeLockFundsTransaction as MaybeLockFundsTransaction>::Id,
+	/// Transfer recipient.
+	pub recipient: <T::RecipientsMap as RecipientsMap>::Recipient,
+	/// Transfer amount.
+	pub amount: <T::CurrencyConverter as CurrencyConverter>::TargetAmount,
+}
+
+/// Verify and parse transaction proof, preparing everything required for importing
+/// this transaction proof.
+fn prepare_deposit_details<T: Trait>(
+	proof: &<<T as Trait>::PeerBlockchain as Blockchain>::TransactionInclusionProof,
+) -> Result<DepositDetails<T>, Error<T>> {
+	// ensure that transaction is included in finalized block that we know of
+	let transaction = <T as Trait>::PeerBlockchain::verify_transaction_inclusion_proof(proof)
+		.ok_or_else(|| Error::<T>::UnfinalizedTransaction)?;
+
+	// parse transaction
+	let transaction = <T as Trait>::PeerMaybeLockFundsTransaction::parse(&transaction).map_err(Error::<T>::from)?;
+	let transfer_id = transaction.id;
+	ensure!(!Transfers::<T>::contains_key(&transfer_id), Error::<T>::AlreadyClaimed);
+
+	// grant recipient
+	let recipient = T::RecipientsMap::map(transaction.recipient).map_err(Error::<T>::from)?;
+	let amount = T::CurrencyConverter::convert(transaction.amount).map_err(Error::<T>::from)?;
+
+	Ok(DepositDetails {
+		transfer_id,
+		recipient,
+		amount,
+	})
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;

bridges/primitives/currency-exchange/Cargo.toml

@@ -11,6 +11,12 @@ codec = { package = "parity-scale-codec", version = "1.3.1", default-features =
 
 # Substrate Based Dependencies
 
+[dependencies.sp-api]
+version = "2.0.0-rc4"
+tag = 'v2.0.0-rc4'
+default-features = false
+git = "https://github.com/paritytech/substrate.git"
+
 [dependencies.sp-std]
 version = "2.0.0-rc4"
 tag = 'v2.0.0-rc4'
@@ -27,6 +33,7 @@ git = "https://github.com/paritytech/substrate.git"
 default = ["std"]
 std = [
 	"codec/std",
+	"sp-api/std",
 	"sp-std/std",
 	"frame-support/std",
 ]

bridges/primitives/currency-exchange/src/lib.rs

@@ -15,9 +15,14 @@
 // along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
 
 #![cfg_attr(not(feature = "std"), no_std)]
+// RuntimeApi generated functions
+#![allow(clippy::too_many_arguments)]
+// Generated by `DecodeLimit::decode_with_depth_limit`
+#![allow(clippy::unnecessary_mut_passed)]
 
 use codec::{Decode, Encode, EncodeLike};
-use frame_support::RuntimeDebug;
+use frame_support::{Parameter, RuntimeDebug};
+use sp_api::decl_runtime_apis;
 use sp_std::marker::PhantomData;
 
 /// All errors that may happen during exchange.
@@ -127,3 +132,12 @@ impl<Amount> CurrencyConverter for IdentityCurrencyConverter<Amount> {
 		Ok(currency)
 	}
 }
+
+decl_runtime_apis! {
+	/// API for exchange transactions submitters.
+	pub trait CurrencyExchangeApi<Proof: Parameter> {
+		/// Returns true if currency exchange module is able to import transaction proof in
+		/// its current state.
+		fn filter_transaction_proof(proof: Proof) -> bool;
+	}
+}

bridges/relays/ethereum/Cargo.toml

@@ -29,6 +29,7 @@ rustc-hex = "2.0.1"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0.57"
 sysinfo = "0.15"
+sp-currency-exchange = { path = "../../primitives/currency-exchange" }
 sp-bridge-eth-poa = { path = "../../primitives/ethereum-poa" }
 time = "0.2"
 web3 = "0.13"

bridges/relays/ethereum/src/cli.yml

@@ -111,12 +111,18 @@ subcommands:
         args:
             - eth-host: *eth-host
             - eth-port: *eth-port
+            - eth-start-with-block:
+                long: eth-start-with-block
+                value_name: ETH_START_WITH_BLOCK
+                help: Auto-relay transactions starting with given block number. If not specified, starts with best finalized Ethereum block (known to Substrate node) transactions.
+                takes_value: true
+                conflicts_with:
+                    - eth-tx-hash
             - eth-tx-hash:
                 long: eth-tx-hash
                 value_name: ETH_TX_HASH
                 help: Hash of the lock funds transaction.
                 takes_value: true
-                required: true
             - sub-host: *sub-host
             - sub-port: *sub-port
             - sub-signer: *sub-signer

bridges/relays/ethereum/src/ethereum_client.rs

@@ -129,6 +129,23 @@ impl EthereumRpc for EthereumRpcClient {
 		}
 	}
 
+	async fn header_by_number_with_transactions(&self, number: u64) -> Result<HeaderWithTransactions> {
+		let get_full_tx_objects = true;
+		let header = Ethereum::get_block_by_number_with_transactions(&self.client, number, get_full_tx_objects).await?;
+
+		let is_complete_header = header.number.is_some() && header.hash.is_some() && header.logs_bloom.is_some();
+		if !is_complete_header {
+			return Err(RpcError::Ethereum(EthereumNodeError::IncompleteHeader));
+		}
+
+		let is_complete_transactions = header.transactions.iter().all(|tx| tx.raw.is_some());
+		if !is_complete_transactions {
+			return Err(RpcError::Ethereum(EthereumNodeError::IncompleteTransaction));
+		}
+
+		Ok(header)
+	}
+
 	async fn header_by_hash_with_transactions(&self, hash: H256) -> Result<HeaderWithTransactions> {
 		let get_full_tx_objects = true;
 		let header = Ethereum::get_block_by_hash_with_transactions(&self.client, hash, get_full_tx_objects).await?;