git.delta.rocks / unique-network / refs/commits / 98753eca331b

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		/// Contract address39		pub contract_address: H160,40		/// Transaction data41		pub input: Vec<u8>,42		/// Max fee for transaction - gasLimit * gasPrice43		pub max_fee: U256,44	}4546	#[pallet::config]47	pub trait Config: frame_system::Config + pallet_evm::Config {48		/// Loosly-coupled handlers for evm call sponsoring49		type EvmSponsorshipHandler: SponsorshipHandler<Self::CrossAccountId, CallContext>;50	}5152	#[pallet::pallet]53	pub struct Pallet<T>(_);54}5556/// Implements [`fp_evm::TransactionValidityHack`], which provides sponsor address to pallet-evm57pub struct TransactionValidityHack<T: Config>(PhantomData<*const T>);58impl<T: Config> fp_evm::TransactionValidityHack<T::CrossAccountId> for TransactionValidityHack<T> {59	fn who_pays_fee(60		origin: H160,61		max_fee: U256,62		reason: &WithdrawReason,63	) -> Option<T::CrossAccountId> {64		match reason {65			WithdrawReason::Call { target, input } => {66				let origin_sub = T::CrossAccountId::from_eth(origin);67				let call_context = CallContext {68					contract_address: *target,69					input: input.clone(),70					max_fee,71				};72				T::EvmSponsorshipHandler::get_sponsor(&origin_sub, &call_context)73			}74			_ => None,75		}76	}77}7879/// Implements sponsoring for evm calls performed from pallet-evm (via api.tx.ethereum.transact/api.tx.evm.call)80pub struct BridgeSponsorshipHandler<T>(PhantomData<T>);81impl<T, C> SponsorshipHandler<T::AccountId, C> for BridgeSponsorshipHandler<T>82where83	T: Config + pallet_evm::Config,84	C: IsSubType<pallet_evm::Call<T>>,85{86	fn get_sponsor(who: &T::AccountId, call: &C) -> Option<T::AccountId> {87		match call.is_sub_type()? {88			pallet_evm::Call::call {89				source,90				target,91				input,92				gas_limit,93				max_fee_per_gas,94				..95			} => {96				let _ = T::CallOrigin::ensure_address_origin(97					source,98					<frame_system::RawOrigin<T::AccountId>>::Signed(who.clone()).into(),99				)100				.ok()?;101				let who = T::CrossAccountId::from_sub(who.clone());102				let max_fee = max_fee_per_gas.saturating_mul((*gas_limit).into());103				let call_context = CallContext {104					contract_address: *target,105					input: input.clone(),106					max_fee,107				};108				// Effects from EvmSponsorshipHandler are applied by pallet_evm::runner109				// TODO: Should we implement simulation mode (test, but do not apply effects) in `up-sponsorship`?110				let sponsor = frame_support::storage::with_transaction(|| {111					TransactionOutcome::Rollback(Ok::<_, DispatchError>(112						T::EvmSponsorshipHandler::get_sponsor(&who, &call_context),113					))114				})115				// FIXME: it may fail with DispatchError in case of depth limit116				.ok()??;117				Some(sponsor.as_sub().clone())118			}119			_ => None,120		}121	}122}