git.delta.rocks / unique-network / refs/commits / ea9cd14d15af

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#![cfg_attr(not(feature = "std"), no_std)]1819#[cfg(not(feature = "std"))]20extern crate alloc;21#[cfg(not(feature = "std"))]22use alloc::format;23use frame_support::dispatch::Weight;2425use core::marker::PhantomData;26use sp_std::cell::RefCell;2728use codec::Decode;29use frame_support::pallet_prelude::DispatchError;30use frame_support::traits::PalletInfo;31use frame_support::{ensure, sp_runtime::ModuleError};32use up_data_structs::budget;33use pallet_evm::{34	ExitError, ExitRevert, ExitSucceed, GasWeightMapping, PrecompileFailure, PrecompileOutput,35	PrecompileResult, PrecompileHandle,36};37use sp_core::H160;38// #[cfg(feature = "runtime-benchmarks")]39// pub mod benchmarking;4041use evm_coder::{42	abi::{AbiReader, AbiWrite, AbiWriter},43	execution::{self, Result},44	types::{Msg, value},45};4647pub use pallet::*;4849#[frame_support::pallet]50pub mod pallet {51	use super::*;5253	use frame_system::ensure_signed;54	pub use frame_support::dispatch::DispatchResult;55	use frame_system::pallet_prelude::*;5657	/// DispatchError is opaque, but we need to somehow extract correct error in case of OutOfGas failure58	/// So we have this pallet, which defines OutOfGas error, and knews its own id to check if DispatchError59	/// is thrown because of it60	///61	/// These errors shouldn't end in extrinsic results, as they only used in evm execution path62	#[pallet::error]63	pub enum Error<T> {64		OutOfGas,65		OutOfFund,66	}6768	#[pallet::config]69	pub trait Config: frame_system::Config + pallet_evm::Config {}7071	#[pallet::pallet]72	pub struct Pallet<T>(_);7374	#[pallet::call]75	impl<T: Config> Pallet<T> {76		#[pallet::weight(0)]77		pub fn empty_call(origin: OriginFor<T>) -> DispatchResult {78			let _sender = ensure_signed(origin)?;79			Ok(())80		}81	}82}8384// From instabul hardfork configuration: https://github.com/rust-blockchain/evm/blob/fd4fd6acc0ca3208d6770fdb3ba407c94cdf97c6/runtime/src/lib.rs#L28485pub const G_SLOAD_WORD: u64 = 800;86pub const G_SSTORE_WORD: u64 = 20000;8788pub struct GasCallsBudget<'r, T: Config> {89	recorder: &'r SubstrateRecorder<T>,90	gas_per_call: u64,91}92impl<T: Config> budget::Budget for GasCallsBudget<'_, T> {93	fn consume_custom(&self, calls: u32) -> bool {94		let (gas, overflown) = (calls as u64).overflowing_add(self.gas_per_call);95		if overflown {96			return false;97		}98		self.recorder.consume_gas(gas).is_ok()99	}100}101102#[derive(Default)]103pub struct SubstrateRecorder<T: Config> {104	initial_gas: u64,105	gas_limit: RefCell<u64>,106	_phantom: PhantomData<*const T>,107}108109impl<T: Config> SubstrateRecorder<T> {110	pub fn new(gas_limit: u64) -> Self {111		Self {112			initial_gas: gas_limit,113			gas_limit: RefCell::new(gas_limit),114			_phantom: PhantomData,115		}116	}117118	pub fn gas_left(&self) -> u64 {119		*self.gas_limit.borrow()120	}121	pub fn gas_calls_budget(&self, gas_per_call: u64) -> GasCallsBudget<T> {122		GasCallsBudget {123			recorder: self,124			gas_per_call,125		}126	}127	pub fn weight_calls_budget(&self, weight_per_call: Weight) -> GasCallsBudget<T> {128		GasCallsBudget {129			recorder: self,130			gas_per_call: T::GasWeightMapping::weight_to_gas(weight_per_call),131		}132	}133	pub fn consume_sload_sub(&self) -> DispatchResult {134		self.consume_gas_sub(G_SLOAD_WORD)135	}136	pub fn consume_sstores_sub(&self, amount: usize) -> DispatchResult {137		self.consume_gas_sub(G_SSTORE_WORD.saturating_mul(amount as u64))138	}139	pub fn consume_sstore_sub(&self) -> DispatchResult {140		self.consume_gas_sub(G_SSTORE_WORD)141	}142	pub fn consume_gas_sub(&self, gas: u64) -> DispatchResult {143		ensure!(gas != u64::MAX, Error::<T>::OutOfGas);144		let mut gas_limit = self.gas_limit.borrow_mut();145		ensure!(gas <= *gas_limit, Error::<T>::OutOfGas);146		*gas_limit -= gas;147		Ok(())148	}149150	pub fn consume_sload(&self) -> Result<()> {151		self.consume_gas(G_SLOAD_WORD)152	}153	pub fn consume_sstore(&self) -> Result<()> {154		self.consume_gas(G_SSTORE_WORD)155	}156	pub fn consume_gas(&self, gas: u64) -> Result<()> {157		if gas == u64::MAX {158			return Err(execution::Error::Error(ExitError::OutOfGas));159		}160		let mut gas_limit = self.gas_limit.borrow_mut();161		if gas > *gas_limit {162			return Err(execution::Error::Error(ExitError::OutOfGas));163		}164		*gas_limit -= gas;165		Ok(())166	}167	pub fn return_gas(&self, gas: u64) {168		let mut gas_limit = self.gas_limit.borrow_mut();169		*gas_limit += gas;170	}171172	pub fn evm_to_precompile_output(173		self,174		handle: &mut impl PrecompileHandle,175		result: evm_coder::execution::Result<Option<AbiWriter>>,176	) -> Option<PrecompileResult> {177		use evm_coder::execution::Error;178		// We ignore error here, as it should not occur, as we have our own bookkeeping of gas179		let _ = handle.record_cost(self.initial_gas - self.gas_left());180		Some(match result {181			Ok(Some(v)) => Ok(PrecompileOutput {182				exit_status: ExitSucceed::Returned,183				output: v.finish(),184			}),185			Ok(None) => return None,186			Err(Error::Revert(e)) => {187				let mut writer = AbiWriter::new_call(evm_coder::fn_selector!(Error(string)));188				(&e as &str).abi_write(&mut writer);189190				Err(PrecompileFailure::Revert {191					exit_status: ExitRevert::Reverted,192					output: writer.finish(),193				})194			}195			Err(Error::Fatal(f)) => Err(f.into()),196			Err(Error::Error(e)) => Err(e.into()),197		})198	}199}200201pub fn dispatch_to_evm<T: Config>(err: DispatchError) -> evm_coder::execution::Error {202	use evm_coder::execution::Error as ExError;203	match err {204		DispatchError::Module(ModuleError { index, error, .. })205			if index206				== T::PalletInfo::index::<Pallet<T>>()207					.expect("evm-coder-substrate is a pallet, which should be added to runtime")208					as u8 =>209		{210			let mut read = &error as &[u8];211			match Error::<T>::decode(&mut read) {212				Ok(Error::<T>::OutOfGas) => ExError::Error(ExitError::OutOfGas),213				Ok(Error::<T>::OutOfFund) => ExError::Error(ExitError::OutOfFund),214				_ => unreachable!("this pallet only defines two possible errors"),215			}216		}217		DispatchError::Module(ModuleError {218			message: Some(msg), ..219		}) => ExError::Revert(msg.into()),220		DispatchError::Module(ModuleError { index, error, .. }) => {221			ExError::Revert(format!("error {:?} in pallet {}", error, index))222		}223		e => ExError::Revert(format!("substrate error: {:?}", e)),224	}225}226227pub trait WithRecorder<T: Config> {228	fn recorder(&self) -> &SubstrateRecorder<T>;229	fn into_recorder(self) -> SubstrateRecorder<T>;230}231232/// Helper to simplify implementing bridge between evm-coder definitions and pallet-evm233pub fn call<234	T: Config,235	C: evm_coder::Call + evm_coder::Weighted,236	E: evm_coder::Callable<C> + WithRecorder<T>,237	H: PrecompileHandle,238>(239	handle: &mut H,240	mut e: E,241) -> Option<PrecompileResult> {242	let result = call_internal(243		handle.context().caller,244		&mut e,245		handle.context().apparent_value,246		handle.input(),247	);248	e.into_recorder().evm_to_precompile_output(handle, result)249}250251fn call_internal<252	T: Config,253	C: evm_coder::Call + evm_coder::Weighted,254	E: evm_coder::Callable<C> + WithRecorder<T>,255>(256	caller: H160,257	e: &mut E,258	value: value,259	input: &[u8],260) -> evm_coder::execution::Result<Option<AbiWriter>> {261	let (selector, mut reader) = AbiReader::new_call(input)?;262	let call = C::parse(selector, &mut reader)?;263	if call.is_none() {264		let selector = u32::from_be_bytes(selector);265		return Err(format!("unrecognized selector: 0x{selector:0<8x}").into());266	}267	let call = call.unwrap();268269	let dispatch_info = call.weight();270	e.recorder()271		.consume_gas(T::GasWeightMapping::weight_to_gas(dispatch_info.weight))?;272273	match e.call(Msg {274		call,275		caller,276		value,277	}) {278		Ok(v) => {279			let unspent = v.post_info.calc_unspent(&dispatch_info);280			e.recorder()281				.return_gas(T::GasWeightMapping::weight_to_gas(unspent));282			Ok(Some(v.data))283		}284		Err(v) => {285			let unspent = v.post_info.calc_unspent(&dispatch_info);286			e.recorder()287				.return_gas(T::GasWeightMapping::weight_to_gas(unspent));288			Err(v.data)289		}290	}291}