git.delta.rocks / unique-network / refs/commits / cf8cdb9aa8d5

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 sp_std::{cell::RefCell, vec::Vec, rc::Rc};56	use sp_core::{H160};57	use frame_support::{pallet_prelude::*, traits::PalletInfo};58	use frame_system::pallet_prelude::*;5960	/// DispatchError is opaque, but we need to somehow extract correct error in case of OutOfGas failure61	/// So we have this pallet, which defines OutOfGas error, and knews its own id to check if DispatchError62	/// is thrown because of it63	///64	/// These errors shouldn't end in extrinsic results, as they only used in evm execution path65	#[pallet::error]66	pub enum Error<T> {67		OutOfGas,68		OutOfFund,69	}7071	#[pallet::config]72	pub trait Config: frame_system::Config {73		type GasWeightMapping: pallet_evm::GasWeightMapping;74	}7576	#[pallet::pallet]77	pub struct Pallet<T>(_);7879	#[pallet::call]80	impl<T: Config> Pallet<T> {81		#[pallet::weight(0)]82		pub fn empty_call(origin: OriginFor<T>) -> DispatchResult {83			let _sender = ensure_signed(origin)?;84			Ok(())85		}86	}87}8889// From instabul hardfork configuration: https://github.com/rust-blockchain/evm/blob/fd4fd6acc0ca3208d6770fdb3ba407c94cdf97c6/runtime/src/lib.rs#L28490pub const G_SLOAD_WORD: u64 = 800;91pub const G_SSTORE_WORD: u64 = 20000;9293pub struct GasCallsBudget<'r, T: Config> {94	recorder: &'r SubstrateRecorder<T>,95	gas_per_call: u64,96}97impl<T: Config> budget::Budget for GasCallsBudget<'_, T> {98	fn consume_custom(&self, calls: u32) -> bool {99		let (gas, overflown) = (calls as u64).overflowing_add(self.gas_per_call);100		if overflown {101			return false;102		}103		self.recorder.consume_gas(gas).is_ok()104	}105}106107#[derive(Default)]108pub struct SubstrateRecorder<T: Config> {109	initial_gas: u64,110	gas_limit: RefCell<u64>,111	_phantom: PhantomData<*const T>,112}113114impl<T: Config> SubstrateRecorder<T> {115	pub fn new(gas_limit: u64) -> Self {116		Self {117			initial_gas: gas_limit,118			gas_limit: RefCell::new(gas_limit),119			_phantom: PhantomData,120		}121	}122123	pub fn gas_left(&self) -> u64 {124		*self.gas_limit.borrow()125	}126	pub fn gas_calls_budget(&self, gas_per_call: u64) -> GasCallsBudget<T> {127		GasCallsBudget {128			recorder: self,129			gas_per_call,130		}131	}132	pub fn weight_calls_budget(&self, weight_per_call: Weight) -> GasCallsBudget<T> {133		GasCallsBudget {134			recorder: self,135			gas_per_call: T::GasWeightMapping::weight_to_gas(weight_per_call),136		}137	}138	pub fn consume_sload_sub(&self) -> DispatchResult {139		self.consume_gas_sub(G_SLOAD_WORD)140	}141	pub fn consume_sstores_sub(&self, amount: usize) -> DispatchResult {142		self.consume_gas_sub(G_SSTORE_WORD.saturating_mul(amount as u64))143	}144	pub fn consume_sstore_sub(&self) -> DispatchResult {145		self.consume_gas_sub(G_SSTORE_WORD)146	}147	pub fn consume_gas_sub(&self, gas: u64) -> DispatchResult {148		ensure!(gas != u64::MAX, Error::<T>::OutOfGas);149		let mut gas_limit = self.gas_limit.borrow_mut();150		ensure!(gas <= *gas_limit, Error::<T>::OutOfGas);151		*gas_limit -= gas;152		Ok(())153	}154155	pub fn consume_sload(&self) -> Result<()> {156		self.consume_gas(G_SLOAD_WORD)157	}158	pub fn consume_sstore(&self) -> Result<()> {159		self.consume_gas(G_SSTORE_WORD)160	}161	pub fn consume_gas(&self, gas: u64) -> Result<()> {162		if gas == u64::MAX {163			return Err(execution::Error::Error(ExitError::OutOfGas));164		}165		let mut gas_limit = self.gas_limit.borrow_mut();166		if gas > *gas_limit {167			return Err(execution::Error::Error(ExitError::OutOfGas));168		}169		*gas_limit -= gas;170		Ok(())171	}172	pub fn return_gas(&self, gas: u64) {173		let mut gas_limit = self.gas_limit.borrow_mut();174		*gas_limit += gas;175	}176177	pub fn evm_to_precompile_output(178		self,179		result: evm_coder::execution::Result<Option<AbiWriter>>,180	) -> Option<PrecompileResult> {181		use evm_coder::execution::Error;182		Some(match result {183			Ok(Some(v)) => Ok(PrecompileOutput {184				exit_status: ExitSucceed::Returned,185				cost: self.initial_gas - self.gas_left(),186				// We don't use this interface187				logs: sp_std::vec![],188				output: v.finish(),189			}),190			Ok(None) => return None,191			Err(Error::Revert(e)) => {192				let mut writer = AbiWriter::new_call(evm_coder::fn_selector!(Error(string)));193				(&e as &str).abi_write(&mut writer);194195				Err(PrecompileFailure::Revert {196					exit_status: ExitRevert::Reverted,197					cost: self.initial_gas - self.gas_left(),198					output: writer.finish(),199				})200			}201			Err(Error::Fatal(f)) => Err(f.into()),202			Err(Error::Error(e)) => Err(e.into()),203		})204	}205}206207pub fn dispatch_to_evm<T: Config>(err: DispatchError) -> evm_coder::execution::Error {208	use evm_coder::execution::Error as ExError;209	match err {210		DispatchError::Module(ModuleError { index, error, .. })211			if index212				== T::PalletInfo::index::<Pallet<T>>()213					.expect("evm-coder-substrate is a pallet, which should be added to runtime")214					as u8 =>215		{216			let mut read = &error as &[u8];217			match Error::<T>::decode(&mut read) {218				Ok(Error::<T>::OutOfGas) => ExError::Error(ExitError::OutOfGas),219				Ok(Error::<T>::OutOfFund) => ExError::Error(ExitError::OutOfFund),220				_ => unreachable!("this pallet only defines two possible errors"),221			}222		}223		DispatchError::Module(ModuleError {224			message: Some(msg), ..225		}) => ExError::Revert(msg.into()),226		DispatchError::Module(ModuleError { index, error, .. }) => {227			ExError::Revert(format!("error {:?} in pallet {}", error, index))228		}229		e => ExError::Revert(format!("substrate error: {:?}", e)),230	}231}232233pub trait WithRecorder<T: Config> {234	fn recorder(&self) -> &SubstrateRecorder<T>;235	fn into_recorder(self) -> SubstrateRecorder<T>;236}237238/// Helper to simplify implementing bridge between evm-coder definitions and pallet-evm239pub fn call<240	T: Config,241	C: evm_coder::Call + evm_coder::Weighted,242	E: evm_coder::Callable<C> + WithRecorder<T>,243>(244	caller: H160,245	mut e: E,246	value: value,247	input: &[u8],248) -> Option<PrecompileResult> {249	let result = call_internal(caller, &mut e, value, input);250	e.into_recorder().evm_to_precompile_output(result)251}252253fn call_internal<254	T: Config,255	C: evm_coder::Call + evm_coder::Weighted,256	E: evm_coder::Callable<C> + WithRecorder<T>,257>(258	caller: H160,259	e: &mut E,260	value: value,261	input: &[u8],262) -> evm_coder::execution::Result<Option<AbiWriter>> {263	let (selector, mut reader) = AbiReader::new_call(input)?;264	let call = C::parse(selector, &mut reader)?;265	if call.is_none() {266		return Ok(None);267	}268	let call = call.unwrap();269270	let dispatch_info = call.weight();271	e.recorder()272		.consume_gas(T::GasWeightMapping::weight_to_gas(dispatch_info.weight))?;273274	match e.call(Msg {275		call,276		caller,277		value,278	}) {279		Ok(v) => {280			let unspent = v.post_info.calc_unspent(&dispatch_info);281			e.recorder()282				.return_gas(T::GasWeightMapping::weight_to_gas(unspent));283			Ok(Some(v.data))284		}285		Err(v) => {286			let unspent = v.post_info.calc_unspent(&dispatch_info);287			e.recorder()288				.return_gas(T::GasWeightMapping::weight_to_gas(unspent));289			Err(v.data)290		}291	}292}