add local fee to XcmFeeParams and charge caller

porteer/src/benchmarking.rs

@@ -49,7 +49,7 @@ benchmarks! {
 		assert_eq!(LastHeartBeat::<T>::get(), now);
 	}
 	set_xcm_fee_params {
-		let fee_params = XcmFeeParams { hop1: 1u32.into(), hop2: 2u32.into(), hop3: 3u32.into() };
+		let fee_params = XcmFeeParams { local_equivalent_sum: 6u32.into(), hop1: 1u32.into(), hop2: 2u32.into(), hop3: 3u32.into() };
 	}: _(RawOrigin::Root, fee_params)
 	verify {
 		assert_eq!(XcmFeeConfig::<T>::get(), fee_params);

porteer/src/lib.rs

@@ -112,8 +112,17 @@ pub mod pallet {
 	/// or
 	/// 2. AHP -> AHK -> IK
 	pub struct XcmFeeParams<Balance> {
+		/// to be paid by the `port_tokens` caller to cover all subsequent fees
+		#[codec(compact)]
+		pub local_equivalent_sum: Balance,
+		/// fees to be paid by sovereign account for source side Asset Hub execution involving swapping to KSM/DOT [TEER]
+		#[codec(compact)]
 		pub hop1: Balance,
+		/// fees to be paid by sovereign account for destination side Asset Hub execution involving swapping to DOT/KSM [KSM/DOT]
+		#[codec(compact)]
 		pub hop2: Balance,
+		/// fees to be paid by sovereign account for destination side Integritee execution involving swapping to TEER [DOT/KSM]
+		#[codec(compact)]
 		pub hop3: Balance,
 	}
 
@@ -148,6 +157,7 @@ pub mod pallet {
 			Location = Self::Location,
 		>;
 
+		type FeeCollectorAccount: Get<AccountIdOf<Self>>;
 		/// The location representation used by this pallet.
 		type Location: Parameter + Member + MaybeSerializeDeserialize + Debug + Ord + MaxEncodedLen;
 
@@ -381,6 +391,14 @@ pub mod pallet {
 				return Err(Error::<T>::WatchdogHeartbeatIsTooOld.into());
 			};
 
+			let user_fee = Self::xcm_fee_config().local_equivalent_sum;
+			<T::Fungible as fungible::Mutate<_>>::transfer(
+				&signer,
+				&T::FeeCollectorAccount::get(),
+				user_fee,
+				Preservation::Preserve,
+			)?;
+
 			<T::Fungible as fungible::Mutate<_>>::burn_from(
 				&signer,
 				amount,

porteer/src/mock.rs

@@ -82,6 +82,7 @@ impl pallet_balances::Config for Test {
 
 ord_parameter_types! {
 	pub const Alice: AccountId = AccountId::new(hex2array!("d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d"));
+	pub const Ferdie: AccountId = AccountId::new(hex2array!("1cbd2d43530a44705ad088af313e18f80b53ef16b36177cd4b77b846f2a5f07c"));
 }
 
 parameter_types! {
@@ -106,6 +107,7 @@ impl crate::Config for Test {
 		EitherOfDiverse<EnsureSignedBy<Alice, AccountId32>, EnsureRoot<AccountId32>>;
 	type PortTokensToDestination = MockPortTokens;
 	type ForwardPortedTokensToDestinations = MockPortTokens;
+	type FeeCollectorAccount = Ferdie;
 	type Location = TestLocation;
 	type Fungible = Balances;
 	#[cfg(feature = "runtime-benchmarks")]

porteer/src/tests.rs

@@ -121,7 +121,7 @@ fn set_xcm_fee_params_works() {
 
 		assert_eq!(XcmFeeConfig::<Test>::get(), XcmFeeParams::default());
 
-		let new_fee_params = XcmFeeParams { hop1: 1, hop2: 2, hop3: 3 };
+		let new_fee_params = XcmFeeParams { local_equivalent_sum: 6, hop1: 1, hop2: 2, hop3: 3 };
 		assert_ok!(Porteer::set_xcm_fee_params(
 			RuntimeOrigin::signed(alice.clone()),
 			new_fee_params
@@ -259,6 +259,36 @@ fn port_tokens_works_at_timeout_threshold() {
 	})
 }
 
+#[test]
+fn port_tokens_charges_fees_if_port_possible() {
+	new_test_ext().execute_with(|| {
+		let alice = Keyring::Alice.to_account_id();
+		let bob = Keyring::Bob.to_account_id();
+		let ferdie = Keyring::Ferdie.to_account_id();
+		let bob_free: BalanceOf<Test> = 15_000_000_000_000u128;
+		<Test as pallet::Config>::Fungible::make_free_balance_be(&bob, bob_free);
+		<Test as pallet::Config>::Fungible::make_free_balance_be(&ferdie, 0);
+
+		assert_eq!(XcmFeeConfig::<Test>::get(), XcmFeeParams::default());
+
+		let new_fee_params =
+			XcmFeeParams { local_equivalent_sum: 600_000_000_000, hop1: 1, hop2: 2, hop3: 3 };
+		assert_ok!(Porteer::set_xcm_fee_params(
+			RuntimeOrigin::signed(alice.clone()),
+			new_fee_params
+		));
+
+		let port_amount: BalanceOf<Test> = 10_000_000_000_000u128;
+
+		assert_ok!(Porteer::port_tokens(RuntimeOrigin::signed(bob.clone()), port_amount, None));
+		assert_eq!(
+			Balances::free_balance(bob),
+			bob_free - port_amount - new_fee_params.local_equivalent_sum
+		);
+		assert_eq!(Balances::free_balance(ferdie), new_fee_params.local_equivalent_sum);
+	})
+}
+
 #[test]
 fn port_tokens_system_test_works() {
 	// This test tests the whole logic: