git.delta.rocks / unique-network / refs/commits / 281abcbf9b51

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,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 {70		type GasWeightMapping: pallet_evm::GasWeightMapping;71	}7273	#[pallet::pallet]74	pub struct Pallet<T>(_);7576	#[pallet::call]77	impl<T: Config> Pallet<T> {78		#[pallet::weight(0)]79		pub fn empty_call(origin: OriginFor<T>) -> DispatchResult {80			let _sender = ensure_signed(origin)?;81			Ok(())82		}83	}84}8586// From instabul hardfork configuration: https://github.com/rust-blockchain/evm/blob/fd4fd6acc0ca3208d6770fdb3ba407c94cdf97c6/runtime/src/lib.rs#L28487pub const G_SLOAD_WORD: u64 = 800;88pub const G_SSTORE_WORD: u64 = 20000;8990pub struct GasCallsBudget<'r, T: Config> {91	recorder: &'r SubstrateRecorder<T>,92	gas_per_call: u64,93}94impl<T: Config> budget::Budget for GasCallsBudget<'_, T> {95	fn consume_custom(&self, calls: u32) -> bool {96		let (gas, overflown) = (calls as u64).overflowing_add(self.gas_per_call);97		if overflown {98			return false;99		}100		self.recorder.consume_gas(gas).is_ok()101	}102}103104#[derive(Default)]105pub struct SubstrateRecorder<T: Config> {106	initial_gas: u64,107	gas_limit: RefCell<u64>,108	_phantom: PhantomData<*const T>,109}110111impl<T: Config> SubstrateRecorder<T> {112	pub fn new(gas_limit: u64) -> Self {113		Self {114			initial_gas: gas_limit,115			gas_limit: RefCell::new(gas_limit),116			_phantom: PhantomData,117		}118	}119120	pub fn gas_left(&self) -> u64 {121		*self.gas_limit.borrow()122	}123	pub fn gas_calls_budget(&self, gas_per_call: u64) -> GasCallsBudget<T> {124		GasCallsBudget {125			recorder: self,126			gas_per_call,127		}128	}129	pub fn weight_calls_budget(&self, weight_per_call: Weight) -> GasCallsBudget<T> {130		GasCallsBudget {131			recorder: self,132			gas_per_call: T::GasWeightMapping::weight_to_gas(weight_per_call),133		}134	}135	pub fn consume_sload_sub(&self) -> DispatchResult {136		self.consume_gas_sub(G_SLOAD_WORD)137	}138	pub fn consume_sstores_sub(&self, amount: usize) -> DispatchResult {139		self.consume_gas_sub(G_SSTORE_WORD.saturating_mul(amount as u64))140	}141	pub fn consume_sstore_sub(&self) -> DispatchResult {142		self.consume_gas_sub(G_SSTORE_WORD)143	}144	pub fn consume_gas_sub(&self, gas: u64) -> DispatchResult {145		ensure!(gas != u64::MAX, Error::<T>::OutOfGas);146		let mut gas_limit = self.gas_limit.borrow_mut();147		ensure!(gas <= *gas_limit, Error::<T>::OutOfGas);148		*gas_limit -= gas;149		Ok(())150	}151152	pub fn consume_sload(&self) -> Result<()> {153		self.consume_gas(G_SLOAD_WORD)154	}155	pub fn consume_sstore(&self) -> Result<()> {156		self.consume_gas(G_SSTORE_WORD)157	}158	pub fn consume_gas(&self, gas: u64) -> Result<()> {159		if gas == u64::MAX {160			return Err(execution::Error::Error(ExitError::OutOfGas));161		}162		let mut gas_limit = self.gas_limit.borrow_mut();163		if gas > *gas_limit {164			return Err(execution::Error::Error(ExitError::OutOfGas));165		}166		*gas_limit -= gas;167		Ok(())168	}169	pub fn return_gas(&self, gas: u64) {170		let mut gas_limit = self.gas_limit.borrow_mut();171		*gas_limit += gas;172	}173174	pub fn evm_to_precompile_output(175		self,176		result: evm_coder::execution::Result<Option<AbiWriter>>,177	) -> Option<PrecompileResult> {178		use evm_coder::execution::Error;179		Some(match result {180			Ok(Some(v)) => Ok(PrecompileOutput {181				exit_status: ExitSucceed::Returned,182				cost: self.initial_gas - self.gas_left(),183				// We don't use this interface184				logs: sp_std::vec![],185				output: v.finish(),186			}),187			Ok(None) => return None,188			Err(Error::Revert(e)) => {189				let mut writer = AbiWriter::new_call(evm_coder::fn_selector!(Error(string)));190				(&e as &str).abi_write(&mut writer);191192				Err(PrecompileFailure::Revert {193					exit_status: ExitRevert::Reverted,194					cost: self.initial_gas - self.gas_left(),195					output: writer.finish(),196				})197			}198			Err(Error::Fatal(f)) => Err(f.into()),199			Err(Error::Error(e)) => Err(e.into()),200		})201	}202}203204pub fn dispatch_to_evm<T: Config>(err: DispatchError) -> evm_coder::execution::Error {205	use evm_coder::execution::Error as ExError;206	match err {207		DispatchError::Module(ModuleError { index, error, .. })208			if index209				== T::PalletInfo::index::<Pallet<T>>()210					.expect("evm-coder-substrate is a pallet, which should be added to runtime")211					as u8 =>212		{213			let mut read = &error as &[u8];214			match Error::<T>::decode(&mut read) {215				Ok(Error::<T>::OutOfGas) => ExError::Error(ExitError::OutOfGas),216				Ok(Error::<T>::OutOfFund) => ExError::Error(ExitError::OutOfFund),217				_ => unreachable!("this pallet only defines two possible errors"),218			}219		}220		DispatchError::Module(ModuleError {221			message: Some(msg), ..222		}) => ExError::Revert(msg.into()),223		DispatchError::Module(ModuleError { index, error, .. }) => {224			ExError::Revert(format!("error {:?} in pallet {}", error, index))225		}226		e => ExError::Revert(format!("substrate error: {:?}", e)),227	}228}229230pub trait WithRecorder<T: Config> {231	fn recorder(&self) -> &SubstrateRecorder<T>;232	fn into_recorder(self) -> SubstrateRecorder<T>;233}234235/// Helper to simplify implementing bridge between evm-coder definitions and pallet-evm236pub fn call<237	T: Config,238	C: evm_coder::Call + evm_coder::Weighted,239	E: evm_coder::Callable<C> + WithRecorder<T>,240>(241	caller: H160,242	mut e: E,243	value: value,244	input: &[u8],245) -> Option<PrecompileResult> {246	let result = call_internal(caller, &mut e, value, input);247	e.into_recorder().evm_to_precompile_output(result)248}249250fn call_internal<251	T: Config,252	C: evm_coder::Call + evm_coder::Weighted,253	E: evm_coder::Callable<C> + WithRecorder<T>,254>(255	caller: H160,256	e: &mut E,257	value: value,258	input: &[u8],259) -> evm_coder::execution::Result<Option<AbiWriter>> {260	let (selector, mut reader) = AbiReader::new_call(input)?;261	let call = C::parse(selector, &mut reader)?;262	if call.is_none() {263		return Ok(None);264	}265	let call = call.unwrap();266267	let dispatch_info = call.weight();268	e.recorder()269		.consume_gas(T::GasWeightMapping::weight_to_gas(dispatch_info.weight))?;270271	match e.call(Msg {272		call,273		caller,274		value,275	}) {276		Ok(v) => {277			let unspent = v.post_info.calc_unspent(&dispatch_info);278			e.recorder()279				.return_gas(T::GasWeightMapping::weight_to_gas(unspent));280			Ok(Some(v.data))281		}282		Err(v) => {283			let unspent = v.post_info.calc_unspent(&dispatch_info);284			e.recorder()285				.return_gas(T::GasWeightMapping::weight_to_gas(unspent));286			Err(v.data)287		}288	}289}