git.delta.rocks / unique-network / refs/commits / bfcf3ca7e01c

1// Copyright 2019-2022 Unique Network (Gibraltar) Ltd.2// This file is part of Unique Network.34// Unique Network is free software: you can redistribute it and/or modify5// it under the terms of the GNU General Public License as published by6// the Free Software Foundation, either version 3 of the License, or7// (at your option) any later version.89// Unique Network is distributed in the hope that it will be useful,10// but WITHOUT ANY WARRANTY; without even the implied warranty of11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the12// GNU General Public License for more details.1314// You should have received a copy of the GNU General Public License15// along with Unique Network. If not, see <http://www.gnu.org/licenses/>.1617#![doc = include_str!("../README.md")]18#![cfg_attr(not(feature = "std"), no_std)]19#![deny(missing_docs)]2021use core::marker::PhantomData;22use fp_evm::WithdrawReason;23use frame_support::traits::IsSubType;24pub use pallet::*;25use pallet_evm::{account::CrossAccountId, EnsureAddressOrigin};26use sp_core::{H160, U256};27use sp_runtime::{TransactionOutcome, DispatchError};28use up_sponsorship::SponsorshipHandler;2930#[frame_support::pallet]31pub mod pallet {32	use super::*;3334	use sp_std::vec::Vec;3536	/// Contains call data37	pub struct CallContext {38		/// Max fee for transaction - gasLimit * gasPrice39		pub max_fee: U256,40	}4142	#[pallet::config]43	pub trait Config: frame_system::Config + pallet_evm::account::Config {44		/// Loosly-coupled handlers for evm call sponsoring45		type EvmSponsorshipHandler: SponsorshipHandler<46			Self::CrossAccountId,47			(H160, Vec<u8>),48			CallContext,49		>;50	}5152	#[pallet::pallet]53	#[pallet::generate_store(pub(super) trait Store)]54	pub struct Pallet<T>(_);55}5657/// Implements [`fp_evm::TransactionValidityHack`], which provides sponsor address to pallet-evm58pub struct TransactionValidityHack<T: Config>(PhantomData<*const T>);59impl<T: Config> fp_evm::TransactionValidityHack<T::CrossAccountId> for TransactionValidityHack<T> {60	fn who_pays_fee(61		origin: H160,62		max_fee: U256,63		reason: &WithdrawReason,64	) -> Option<T::CrossAccountId> {65		match reason {66			WithdrawReason::Call { target, input } => {67				let origin_sub = T::CrossAccountId::from_eth(origin);68				let call_context = CallContext { max_fee };69				T::EvmSponsorshipHandler::get_sponsor(70					&origin_sub,71					&(*target, input.clone()),72					&call_context,73				)74			}75			_ => None,76		}77	}78}7980/// Implements sponsoring for evm calls performed from pallet-evm (via api.tx.ethereum.transact/api.tx.evm.call)81pub struct BridgeSponsorshipHandler<T>(PhantomData<T>);82impl<T, C> SponsorshipHandler<T::AccountId, C, ()> for BridgeSponsorshipHandler<T>83where84	T: Config + pallet_evm::Config,85	C: IsSubType<pallet_evm::Call<T>>,86{87	fn get_sponsor(who: &T::AccountId, call: &C, _call_context: &()) -> Option<T::AccountId> {88		match call.is_sub_type()? {89			pallet_evm::Call::call {90				source,91				target,92				input,93				gas_limit,94				max_fee_per_gas,95				..96			} => {97				let _ = T::CallOrigin::ensure_address_origin(98					source,99					<frame_system::RawOrigin<T::AccountId>>::Signed(who.clone()).into(),100				)101				.ok()?;102				let who = T::CrossAccountId::from_sub(who.clone());103				let max_fee = max_fee_per_gas.saturating_mul((*gas_limit).into());104				let call_context = CallContext { max_fee };105				// Effects from EvmSponsorshipHandler are applied by pallet_evm::runner106				// TODO: Should we implement simulation mode (test, but do not apply effects) in `up-sponsorship`?107				let sponsor = frame_support::storage::with_transaction(|| {108					TransactionOutcome::Rollback(Ok::<_, DispatchError>(109						T::EvmSponsorshipHandler::get_sponsor(110							&who,111							&(*target, input.clone()),112							&call_context,113						),114					))115				})116				// FIXME: it may fail with DispatchError in case of depth limit117				.ok()??;118				Some(sponsor.as_sub().clone())119			}120			_ => None,121		}122	}123}