`798647f756b4`

source

pallets/evm-coder-substrate/src/lib.rs8.4 KiBsource history
1#![cfg_attr(not(feature = "std"), no_std)]23#[cfg(not(feature = "std"))]4extern crate alloc;5// #[cfg(feature = "runtime-benchmarks")]6// pub mod benchmarking;78pub use pallet::*;910#[frame_support::pallet]11pub mod pallet {12	#[cfg(not(feature = "std"))]13	use alloc::format;1415	use evm_coder::{16		ToLog,17		abi::{AbiReader, AbiWrite, AbiWriter},18		execution::{self, Result},19		types::{Msg, value},20	};21	use frame_support::{ensure};22	use pallet_evm::{23		ExitError, ExitRevert, ExitSucceed, GasWeightMapping, PrecompileFailure, PrecompileOutput,24		PrecompileResult, runner::stack::MaybeMirroredLog,25	};26	use frame_system::ensure_signed;27	pub use frame_support::dispatch::DispatchResult;28	use pallet_ethereum::EthereumTransactionSender;29	use sp_std::cell::RefCell;30	use sp_std::vec::Vec;31	use sp_core::{H160, H256};32	use ethereum::TransactionV2;33	use frame_support::{pallet_prelude::*, traits::PalletInfo};34	use frame_system::pallet_prelude::*;3536	/// DispatchError is opaque, but we need to somehow extract correct error in case of OutOfGas failure37	/// So we have this pallet, which defines OutOfGas error, and knews its own id to check if DispatchError38	/// is thrown because of it39	///40	/// These errors shouldn't end in extrinsic results, as they only used in evm execution path41	#[pallet::error]42	pub enum Error<T> {43		OutOfGas,44		OutOfFund,45	}4647	#[pallet::config]48	pub trait Config: frame_system::Config {49		type EthereumTransactionSender: pallet_ethereum::EthereumTransactionSender;50		type GasWeightMapping: pallet_evm::GasWeightMapping;51	}5253	#[pallet::pallet]54	pub struct Pallet<T>(_);5556	#[pallet::call]57	impl<T: Config> Pallet<T> {58		#[pallet::weight(0)]59		pub fn empty_call(origin: OriginFor<T>) -> DispatchResult {60			let _sender = ensure_signed(origin)?;61			Ok(())62		}63	}6465	// From instabul hardfork configuration: https://github.com/rust-blockchain/evm/blob/fd4fd6acc0ca3208d6770fdb3ba407c94cdf97c6/runtime/src/lib.rs#L28466	pub const G_SLOAD_WORD: u64 = 800;67	pub const G_SSTORE_WORD: u64 = 20000;6869	pub fn generate_transaction() -> TransactionV2 {70		use ethereum::{TransactionV0, TransactionAction, TransactionSignature};71		TransactionV2::Legacy(TransactionV0 {72			nonce: 0.into(),73			gas_price: 0.into(),74			gas_limit: 0.into(),75			action: TransactionAction::Call(H160([0; 20])),76			value: 0.into(),77			// zero selector, this transaction always has same sender, so all data should be acquired from logs78			input: Vec::from([0, 0, 0, 0]),79			// if v is not 27 - then we need to pass some other validity checks80			signature: TransactionSignature::new(27, H256([0x88; 32]), H256([0x88; 32])).unwrap(),81		})82	}8384	#[derive(Default)]85	pub struct SubstrateRecorder<T: Config> {86		contract: H160,87		logs: RefCell<Vec<MaybeMirroredLog>>,88		initial_gas: u64,89		gas_limit: RefCell<u64>,90		_phantom: PhantomData<*const T>,91	}9293	impl<T: Config> SubstrateRecorder<T> {94		pub fn new(contract: H160, gas_limit: u64) -> Self {95			Self {96				contract,97				logs: RefCell::new(Vec::new()),98				initial_gas: gas_limit,99				gas_limit: RefCell::new(gas_limit),100				_phantom: PhantomData,101			}102		}103104		pub fn is_empty(&self) -> bool {105			self.logs.borrow().is_empty()106		}107		// Logs emitted with log_direct appear as substrate evm.Log event108		pub fn log_direct(&self, log: impl ToLog) {109			self.logs110				.borrow_mut()111				.push(MaybeMirroredLog::direct(log.to_log(self.contract)))112		}113		/// If log already has substrate equivalent - then we don't need to emit evm.Log114		pub fn log_mirrored(&self, log: impl ToLog) {115			self.logs116				.borrow_mut()117				.push(MaybeMirroredLog::mirrored(log.to_log(self.contract)))118		}119		pub fn retrieve_logs(self) -> Vec<MaybeMirroredLog> {120			self.logs.into_inner()121		}122123		pub fn gas_left(&self) -> u64 {124			*self.gas_limit.borrow()125		}126		pub fn consume_sload_sub(&self) -> DispatchResult {127			self.consume_gas_sub(G_SLOAD_WORD)128		}129		pub fn consume_sstores_sub(&self, amount: usize) -> DispatchResult {130			self.consume_gas_sub(G_SSTORE_WORD.saturating_mul(amount as u64))131		}132		pub fn consume_sstore_sub(&self) -> DispatchResult {133			self.consume_gas_sub(G_SSTORE_WORD)134		}135		pub fn consume_gas_sub(&self, gas: u64) -> DispatchResult {136			ensure!(gas != u64::MAX, Error::<T>::OutOfGas);137			let mut gas_limit = self.gas_limit.borrow_mut();138			ensure!(gas <= *gas_limit, Error::<T>::OutOfGas);139			*gas_limit -= gas;140			Ok(())141		}142143		pub fn consume_sload(&self) -> Result<()> {144			self.consume_gas(G_SLOAD_WORD)145		}146		pub fn consume_sstore(&self) -> Result<()> {147			self.consume_gas(G_SSTORE_WORD)148		}149		pub fn consume_gas(&self, gas: u64) -> Result<()> {150			if gas == u64::MAX {151				return Err(execution::Error::Error(ExitError::OutOfGas));152			}153			let mut gas_limit = self.gas_limit.borrow_mut();154			if gas > *gas_limit {155				return Err(execution::Error::Error(ExitError::OutOfGas));156			}157			*gas_limit -= gas;158			Ok(())159		}160		pub fn return_gas(&self, gas: u64) {161			let mut gas_limit = self.gas_limit.borrow_mut();162			*gas_limit += gas;163		}164165		pub fn evm_to_precompile_output(166			self,167			result: evm_coder::execution::Result<Option<AbiWriter>>,168		) -> Option<PrecompileResult> {169			use evm_coder::execution::Error;170			Some(match result {171				Ok(Some(v)) => Ok(PrecompileOutput {172					exit_status: ExitSucceed::Returned,173					cost: self.initial_gas - self.gas_left(),174					// TODO: preserve mirroring status175					logs: self.retrieve_logs().into_iter().map(|l| l.log).collect(),176					output: v.finish(),177				}),178				Ok(None) => return None,179				Err(Error::Revert(e)) => {180					let mut writer = AbiWriter::new_call(evm_coder::fn_selector!(Error(string)));181					(&e as &str).abi_write(&mut writer);182183					Err(PrecompileFailure::Revert {184						exit_status: ExitRevert::Reverted,185						cost: self.initial_gas - self.gas_left(),186						output: writer.finish(),187					})188				}189				Err(Error::Fatal(f)) => Err(f.into()),190				Err(Error::Error(e)) => Err(e.into()),191			})192		}193194		pub fn submit_logs(self) {195			let logs = self.retrieve_logs();196			if logs.is_empty() {197				return;198			}199			T::EthereumTransactionSender::submit_logs_transaction(200				Default::default(),201				generate_transaction(),202				logs,203			)204		}205	}206207	pub 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 { 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				match error {217					v if v == Error::<T>::OutOfGas.as_u8() => ExError::Error(ExitError::OutOfGas),218					v if v == Error::<T>::OutOfFund.as_u8() => ExError::Error(ExitError::OutOfFund),219					_ => unreachable!("this pallet only defines two possible errors"),220				}221			}222			DispatchError::Module {223				message: Some(msg), ..224			} => ExError::Revert(msg.into()),225			DispatchError::Module { index, error, .. } => {226				ExError::Revert(format!("error {} in pallet {}", error, index))227			}228			e => ExError::Revert(format!("substrate error: {:?}", e)),229		}230	}231232	pub trait WithRecorder<T: Config> {233		fn recorder(&self) -> &SubstrateRecorder<T>;234		fn into_recorder(self) -> SubstrateRecorder<T>;235	}236237	/// Helper to simplify implementing bridge between evm-coder definitions and pallet-evm238	pub fn call<239		T: Config,240		C: evm_coder::Call + evm_coder::Weighted,241		E: evm_coder::Callable<C> + WithRecorder<T>,242	>(243		caller: H160,244		mut e: E,245		value: value,246		input: &[u8],247	) -> Option<PrecompileResult> {248		let result = call_internal(caller, &mut e, value, input);249		e.into_recorder().evm_to_precompile_output(result)250	}251252	fn call_internal<253		T: Config,254		C: evm_coder::Call + evm_coder::Weighted,255		E: evm_coder::Callable<C> + WithRecorder<T>,256	>(257		caller: H160,258		e: &mut E,259		value: value,260		input: &[u8],261	) -> evm_coder::execution::Result<Option<AbiWriter>> {262		let (selector, mut reader) = AbiReader::new_call(input)?;263		let call = C::parse(selector, &mut reader)?;264		if call.is_none() {265			return Ok(None);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	}292}