git.delta.rocks / unique-network / refs/commits / df9b2f8abb14

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)]1819extern crate self as pallet_evm_coder_substrate;2021#[cfg(not(feature = "std"))]22extern crate alloc;23#[cfg(not(feature = "std"))]24use alloc::format;25use execution::PreDispatch;26use frame_support::dispatch::Weight;2728use core::marker::PhantomData;29use sp_std::cell::RefCell;3031use codec::Decode;32use frame_support::pallet_prelude::DispatchError;33use frame_support::traits::PalletInfo;34use frame_support::{ensure, sp_runtime::ModuleError};35use up_data_structs::budget;36use pallet_evm::{37	ExitError, ExitRevert, ExitSucceed, GasWeightMapping, PrecompileFailure, PrecompileOutput,38	PrecompileResult, PrecompileHandle,39};40use sp_core::H160;41// #[cfg(feature = "runtime-benchmarks")]42// pub mod benchmarking;43pub mod execution;44pub use evm_coder::*;4546#[doc(hidden)]47pub use spez::spez;4849use evm_coder::{50	abi::{AbiReader, AbiWrite, AbiWriter},51	types::{Msg, Value},52};5354pub use pallet::*;5556#[frame_support::pallet]57pub mod pallet {58	use super::*;5960	use frame_system::ensure_signed;61	pub use frame_support::dispatch::DispatchResult;62	use frame_system::pallet_prelude::*;6364	/// DispatchError is opaque, but we need to somehow extract correct error in case of OutOfGas failure65	/// So we have this pallet, which defines OutOfGas error, and knews its own id to check if DispatchError66	/// is thrown because of it67	///68	/// These errors shouldn't end in extrinsic results, as they only used in evm execution path69	#[pallet::error]70	pub enum Error<T> {71		OutOfGas,72		OutOfFund,73	}7475	#[pallet::config]76	pub trait Config: frame_system::Config + pallet_evm::Config {}7778	#[pallet::pallet]79	pub struct Pallet<T>(_);8081	#[pallet::call]82	impl<T: Config> Pallet<T> {83		#[pallet::call_index(0)]84		#[pallet::weight(0)]85		pub fn empty_call(origin: OriginFor<T>) -> DispatchResult {86			let _sender = ensure_signed(origin)?;87			Ok(())88		}89	}90}9192// From instabul hardfork configuration: https://github.com/rust-blockchain/evm/blob/fd4fd6acc0ca3208d6770fdb3ba407c94cdf97c6/runtime/src/lib.rs#L28493pub const G_SLOAD_WORD: u64 = 800;94pub const G_SSTORE_WORD: u64 = 20000;9596pub struct GasCallsBudget<'r, T: Config> {97	recorder: &'r SubstrateRecorder<T>,98	gas_per_call: u64,99}100impl<T: Config> budget::Budget for GasCallsBudget<'_, T> {101	fn consume_custom(&self, calls: u32) -> bool {102		let (gas, overflown) = (calls as u64).overflowing_add(self.gas_per_call);103		if overflown {104			return false;105		}106		self.recorder.consume_gas(gas).is_ok()107	}108}109110#[derive(Default)]111pub struct SubstrateRecorder<T: Config> {112	initial_gas: u64,113	gas_limit: RefCell<u64>,114	_phantom: PhantomData<*const T>,115}116117impl<T: Config> SubstrateRecorder<T> {118	pub fn new(gas_limit: u64) -> Self {119		Self {120			initial_gas: gas_limit,121			gas_limit: RefCell::new(gas_limit),122			_phantom: PhantomData,123		}124	}125126	pub fn gas_left(&self) -> u64 {127		*self.gas_limit.borrow()128	}129	pub fn gas_calls_budget(&self, gas_per_call: u64) -> GasCallsBudget<T> {130		GasCallsBudget {131			recorder: self,132			gas_per_call,133		}134	}135	pub fn weight_calls_budget(&self, weight_per_call: Weight) -> GasCallsBudget<T> {136		GasCallsBudget {137			recorder: self,138			gas_per_call: T::GasWeightMapping::weight_to_gas(weight_per_call),139		}140	}141	pub fn consume_sload_sub(&self) -> DispatchResult {142		self.consume_gas_sub(G_SLOAD_WORD)143	}144	pub fn consume_sstores_sub(&self, amount: usize) -> DispatchResult {145		self.consume_gas_sub(G_SSTORE_WORD.saturating_mul(amount as u64))146	}147	pub fn consume_sstore_sub(&self) -> DispatchResult {148		self.consume_gas_sub(G_SSTORE_WORD)149	}150	pub fn consume_gas_sub(&self, gas: u64) -> DispatchResult {151		ensure!(gas != u64::MAX, Error::<T>::OutOfGas);152		let mut gas_limit = self.gas_limit.borrow_mut();153		ensure!(gas <= *gas_limit, Error::<T>::OutOfGas);154		*gas_limit -= gas;155		Ok(())156	}157158	pub fn consume_sload(&self) -> execution::Result<()> {159		self.consume_gas(G_SLOAD_WORD)160	}161	pub fn consume_sstore(&self) -> execution::Result<()> {162		self.consume_gas(G_SSTORE_WORD)163	}164	pub fn consume_gas(&self, gas: u64) -> execution::Result<()> {165		if gas == u64::MAX {166			return Err(execution::Error::Error(ExitError::OutOfGas));167		}168		let mut gas_limit = self.gas_limit.borrow_mut();169		if gas > *gas_limit {170			return Err(execution::Error::Error(ExitError::OutOfGas));171		}172		*gas_limit -= gas;173		Ok(())174	}175	pub fn return_gas(&self, gas: u64) {176		let mut gas_limit = self.gas_limit.borrow_mut();177		*gas_limit += gas;178	}179180	pub fn evm_to_precompile_output(181		self,182		handle: &mut impl PrecompileHandle,183		result: execution::Result<Option<AbiWriter>>,184	) -> Option<PrecompileResult> {185		use execution::Error;186		// We ignore error here, as it should not occur, as we have our own bookkeeping of gas187		let _ = handle.record_cost(self.initial_gas - self.gas_left());188		Some(match result {189			Ok(Some(v)) => Ok(PrecompileOutput {190				exit_status: ExitSucceed::Returned,191				output: v.finish(),192			}),193			Ok(None) => return None,194			Err(Error::Revert(e)) => {195				let mut writer = AbiWriter::new_call(evm_coder::fn_selector!(Error(string)));196				(&e as &str).abi_write(&mut writer);197198				Err(PrecompileFailure::Revert {199					exit_status: ExitRevert::Reverted,200					output: writer.finish(),201				})202			}203			Err(Error::Fatal(f)) => Err(PrecompileFailure::Fatal { exit_status: f }),204			Err(Error::Error(e)) => Err(e.into()),205		})206	}207}208209pub fn dispatch_to_evm<T: Config>(err: DispatchError) -> execution::Error {210	use execution::Error as ExError;211	match err {212		DispatchError::Module(ModuleError { index, error, .. })213			if index214				== T::PalletInfo::index::<Pallet<T>>()215					.expect("evm-coder-substrate is a pallet, which should be added to runtime")216					as u8 =>217		{218			let mut read = &error as &[u8];219			match Error::<T>::decode(&mut read) {220				Ok(Error::<T>::OutOfGas) => ExError::Error(ExitError::OutOfGas),221				Ok(Error::<T>::OutOfFund) => ExError::Error(ExitError::OutOfFund),222				_ => unreachable!("this pallet only defines two possible errors"),223			}224		}225		DispatchError::Module(ModuleError {226			message: Some(msg), ..227		}) => ExError::Revert(msg.into()),228		DispatchError::Module(ModuleError { index, error, .. }) => {229			ExError::Revert(format!("error {:?} in pallet {}", error, index))230		}231		e => ExError::Revert(format!("substrate error: {:?}", e)),232	}233}234235pub trait WithRecorder<T: Config> {236	fn recorder(&self) -> &SubstrateRecorder<T>;237	fn into_recorder(self) -> SubstrateRecorder<T>;238}239240/// Helper to simplify implementing bridge between evm-coder definitions and pallet-evm241pub fn call<T, C, E, H>(handle: &mut H, mut e: E) -> Option<PrecompileResult>242where243	T: Config,244	C: evm_coder::Call + PreDispatch,245	E: evm_coder::Callable<C> + WithRecorder<T>,246	H: PrecompileHandle,247	execution::ResultWithPostInfo<AbiWriter>: From<ResultWithPostInfoOf<E, AbiWriter>>,248{249	let result = call_internal(250		handle.context().caller,251		&mut e,252		handle.context().apparent_value,253		handle.input(),254	);255	e.into_recorder().evm_to_precompile_output(handle, result)256}257258fn call_internal<T, C, E>(259	caller: H160,260	e: &mut E,261	value: Value,262	input: &[u8],263) -> execution::Result<Option<AbiWriter>>264where265	T: Config,266	C: evm_coder::Call + PreDispatch,267	E: Contract + evm_coder::Callable<C> + WithRecorder<T>,268	execution::ResultWithPostInfo<AbiWriter>: From<ResultWithPostInfoOf<E, AbiWriter>>,269{270	let (selector, mut reader) = AbiReader::new_call(input)?;271	let call = C::parse(selector, &mut reader)?;272	if call.is_none() {273		let selector = u32::from_be_bytes(selector);274		return Err(format!("unrecognized selector: 0x{selector:0<8x}").into());275	}276	let call = call.unwrap();277278	let dispatch_info = call.dispatch_info();279	e.recorder()280		.consume_gas(T::GasWeightMapping::weight_to_gas(dispatch_info.weight))?;281282	match execution::ResultWithPostInfo::from(e.call(Msg {283		call,284		caller,285		value,286	})) {287		Ok(v) => {288			let unspent = v.post_info.calc_unspent(&dispatch_info);289			e.recorder()290				.return_gas(T::GasWeightMapping::weight_to_gas(unspent));291			Ok(Some(v.data))292		}293		Err(v) => {294			let unspent = v.post_info.calc_unspent(&dispatch_info);295			e.recorder()296				.return_gas(T::GasWeightMapping::weight_to_gas(unspent));297			Err(v.data)298		}299	}300}301302#[cfg(test)]303#[allow(dead_code)]304mod tests {305	use core::marker::PhantomData;306307	use evm_coder::ERC165Call;308	use frame_support::weights::Weight;309310	use crate::execution::PreDispatch;311312	#[derive(PreDispatch)]313	enum ExampleCall<T: super::Config> {314		ERC165Call(ERC165Call, PhantomData<fn() -> T>),315		OtherCall(ERC165Call),316317		#[weight(Weight::from_ref_time(a + b))]318		Example {319			a: u64,320			b: u64,321		},322	}323}