Substrate EVM (#3927)

* srml-evm: init the basic structures * srml-evm: finish executor implementation * srml-evm: implement balance deposit and withdraw * srml-evm: implement the actuall call/create * srml-evm: use crates.io version of evm * srml-evm: fix no-std compile * Remove dependency patch * Update to evm 0.14 * Use double map for account storage * Add precompiles support * Add some basic docs * Use runtime_io::chain_id() * Update srml/evm/src/lib.rs Co-Authored-By: Xiliang Chen <xlchen1291@gmail.com> * Update srml/evm/src/lib.rs Co-Authored-By: Xiliang Chen <xlchen1291@gmail.com> * Fix WithdrawReason * Unique saturate balance to u128 * Unique saturate withdraw to u128 * Remove extern crate alloc * Move account code to a separate storage and use ref for convert_account_id * More match cause for error message * Fix potential interger overflow * Use decode_len for fetching code length
2026-06-13 19:51:05 +00:00 · 2019-11-03 15:57:46 +01:00
parent 77ed0dc2bc
commit 2e424f4d9f
7 changed files with 601 additions and 30 deletions
@@ -0,0 +1,40 @@
+[package]
+name = "srml-evm"
+version = "2.0.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2018"
+
+[dependencies]
+serde = { version = "1.0.101", optional = true, features = ["derive"] }
+codec = { package = "parity-scale-codec", version = "1.0.0", default-features = false }
+support = { package = "srml-support", path = "../support", default-features = false }
+system = { package = "srml-system", path = "../system", default-features = false }
+timestamp = { package = "srml-timestamp", path = "../timestamp", default-features = false }
+balances = { package = "srml-balances", path = "../balances", default-features = false }
+primitives = { package = "substrate-primitives", path = "../../core/primitives", default-features = false }
+sr-primitives = { path = "../../core/sr-primitives", default-features = false }
+rstd = { package = "sr-std", path = "../../core/sr-std", default-features = false }
+runtime-io = { package = "sr-io", path = "../../core/sr-io", default-features = false }
+primitive-types = { version = "0.6", default-features = false, features = ["rlp"] }
+rlp = { version = "0.4", default-features = false }
+evm = { version = "0.14", default-features = false }
+sha3 = { version = "0.8", default-features = false }
+
+[features]
+default = ["std"]
+std = [
+	"serde",
+	"codec/std",
+	"primitives/std",
+	"sr-primitives/std",
+	"support/std",
+	"system/std",
+	"balances/std",
+	"runtime-io/std",
+	"rstd/std",
+	"sha3/std",
+	"rlp/std",
+	"primitive-types/std",
+	"evm/std",
+	"timestamp/std",
+]
@@ -0,0 +1,187 @@
+use rstd::marker::PhantomData;
+use rstd::vec::Vec;
+#[cfg(feature = "std")]
+use serde::{Serialize, Deserialize};
+use codec::{Encode, Decode};
+use primitives::{U256, H256, H160};
+use sr_primitives::traits::UniqueSaturatedInto;
+use support::storage::{StorageMap, StorageDoubleMap};
+use sha3::{Keccak256, Digest};
+use evm::Config;
+use evm::backend::{Backend as BackendT, ApplyBackend, Apply};
+use crate::{Trait, Accounts, AccountStorages, AccountCodes, Module, Event};
+
+#[derive(Clone, Eq, PartialEq, Encode, Decode, Default)]
+#[cfg_attr(feature = "std", derive(Debug, Serialize, Deserialize))]
+/// Ethereum account nonce, balance and code. Used by storage.
+pub struct Account {
+	/// Account nonce.
+	pub nonce: U256,
+	/// Account balance.
+	pub balance: U256,
+}
+
+#[derive(Clone, Eq, PartialEq, Encode, Decode)]
+#[cfg_attr(feature = "std", derive(Debug, Serialize, Deserialize))]
+/// Ethereum log. Used for `deposit_event`.
+pub struct Log {
+	/// Source address of the log.
+	pub address: H160,
+	/// Topics of the log.
+	pub topics: Vec<H256>,
+	/// Bytearray data of the log.
+	pub data: Vec<u8>,
+}
+
+#[derive(Clone, Eq, PartialEq, Encode, Decode, Default)]
+#[cfg_attr(feature = "std", derive(Debug, Serialize, Deserialize))]
+/// External input from the transaction.
+pub struct Vicinity {
+	/// Current transaction gas price.
+	pub gas_price: U256,
+	/// Origin of the transaction.
+	pub origin: H160,
+}
+
+/// Gasometer config used for executor. Currently this is hard-coded to
+/// Istanbul hard fork.
+pub static GASOMETER_CONFIG: Config = Config::istanbul();
+
+/// Substrate backend for EVM.
+pub struct Backend<'vicinity, T> {
+	vicinity: &'vicinity Vicinity,
+	_marker: PhantomData<T>,
+}
+
+impl<'vicinity, T> Backend<'vicinity, T> {
+	/// Create a new backend with given vicinity.
+	pub fn new(vicinity: &'vicinity Vicinity) -> Self {
+		Self { vicinity, _marker: PhantomData }
+	}
+}
+
+impl<'vicinity, T: Trait> BackendT for Backend<'vicinity, T> {
+	fn gas_price(&self) -> U256 { self.vicinity.gas_price }
+	fn origin(&self) -> H160 { self.vicinity.origin }
+
+	fn block_hash(&self, number: U256) -> H256 {
+		if number > U256::from(u32::max_value()) {
+			H256::default()
+		} else {
+			let number = T::BlockNumber::from(number.as_u32());
+			H256::from_slice(system::Module::<T>::block_hash(number).as_ref())
+		}
+	}
+
+	fn block_number(&self) -> U256 {
+		let number: u128 = system::Module::<T>::block_number().unique_saturated_into();
+		U256::from(number)
+	}
+
+	fn block_coinbase(&self) -> H160 {
+		H160::default()
+	}
+
+	fn block_timestamp(&self) -> U256 {
+		let now: u128 = timestamp::Module::<T>::get().unique_saturated_into();
+		U256::from(now)
+	}
+
+	fn block_difficulty(&self) -> U256 {
+		U256::zero()
+	}
+
+	fn block_gas_limit(&self) -> U256 {
+		U256::zero()
+	}
+
+	fn chain_id(&self) -> U256 {
+		U256::from(runtime_io::chain_id())
+	}
+
+	fn exists(&self, _address: H160) -> bool {
+		true
+	}
+
+	fn basic(&self, address: H160) -> evm::backend::Basic {
+		let account = Accounts::get(&address);
+
+		evm::backend::Basic {
+			balance: account.balance,
+			nonce: account.nonce,
+		}
+	}
+
+	fn code_size(&self, address: H160) -> usize {
+		AccountCodes::decode_len(&address).unwrap_or(0)
+	}
+
+	fn code_hash(&self, address: H160) -> H256 {
+		H256::from_slice(Keccak256::digest(&AccountCodes::get(&address)).as_slice())
+	}
+
+	fn code(&self, address: H160) -> Vec<u8> {
+		AccountCodes::get(&address)
+	}
+
+	fn storage(&self, address: H160, index: H256) -> H256 {
+		AccountStorages::get(address, index)
+	}
+}
+
+impl<'vicinity, T: Trait> ApplyBackend for Backend<'vicinity, T> {
+	fn apply<A, I, L>(
+		&mut self,
+		values: A,
+		logs: L,
+		delete_empty: bool,
+	) where
+		A: IntoIterator<Item=Apply<I>>,
+		I: IntoIterator<Item=(H256, H256)>,
+		L: IntoIterator<Item=evm::backend::Log>,
+	{
+		for apply in values {
+			match apply {
+				Apply::Modify {
+					address, basic, code, storage, reset_storage,
+				} => {
+					Accounts::mutate(&address, |account| {
+						account.balance = basic.balance;
+						account.nonce = basic.nonce;
+					});
+
+					if let Some(code) = code {
+						AccountCodes::insert(address, code);
+					}
+
+					if reset_storage {
+						AccountStorages::remove_prefix(address);
+					}
+
+					for (index, value) in storage {
+						if value == H256::default() {
+							AccountStorages::remove(address, index);
+						} else {
+							AccountStorages::insert(address, index, value);
+						}
+					}
+
+					if delete_empty {
+						Module::<T>::remove_account_if_empty(&address);
+					}
+				},
+				Apply::Delete { address } => {
+					Module::<T>::remove_account(&address)
+				},
+			}
+		}
+
+		for log in logs {
+			Module::<T>::deposit_event(Event::Log(Log {
+				address: log.address,
+				topics: log.topics,
+				data: log.data,
+			}));
+		}
+	}
+}
@@ -0,0 +1,282 @@
+// Copyright 2017-2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! EVM execution module for Substrate
+
+// Ensure we're `no_std` when compiling for Wasm.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+mod backend;
+
+pub use crate::backend::{Account, Log, Vicinity, Backend};
+
+use rstd::vec::Vec;
+use support::{dispatch::Result, decl_module, decl_storage, decl_event};
+use support::traits::{Currency, WithdrawReason, ExistenceRequirement};
+use system::ensure_signed;
+use sr_primitives::weights::SimpleDispatchInfo;
+use sr_primitives::traits::UniqueSaturatedInto;
+use primitives::{U256, H256, H160};
+use evm::{ExitReason, ExitSucceed, ExitError};
+use evm::executor::StackExecutor;
+use evm::backend::ApplyBackend;
+
+/// Type alias for currency balance.
+pub type BalanceOf<T> = <<T as Trait>::Currency as Currency<<T as system::Trait>::AccountId>>::Balance;
+
+/// Trait that outputs the current transaction gas price.
+pub trait FeeCalculator {
+	/// Return the current gas price.
+	fn gas_price() -> U256;
+}
+
+/// Trait for converting account ids of `balances` module into
+/// `H160` for EVM module.
+///
+/// Accounts and contracts of this module are stored in its own
+/// storage, in an Ethereum-compatible format. In order to communicate
+/// with the rest of Substrate module, we require an one-to-one
+/// mapping of Substrate account to Ethereum address.
+pub trait ConvertAccountId<A> {
+	/// Given a Substrate address, return the corresponding Ethereum address.
+	fn convert_account_id(account_id: &A) -> H160;
+}
+
+/// Custom precompiles to be used by EVM engine.
+pub trait Precompiles {
+	/// Try to execute the code address as precompile. If the code address is not
+	/// a precompile or the precompile is not yet available, return `None`.
+	/// Otherwise, calculate the amount of gas needed with given `input` and
+	/// `target_gas`. Return `Some(Ok(status, output, gas_used))` if the execution
+	/// is successful. Otherwise return `Some(Err(_))`.
+	fn execute(
+		address: H160,
+		input: &[u8],
+		target_gas: Option<usize>
+	) -> Option<core::result::Result<(ExitSucceed, Vec<u8>, usize), ExitError>>;
+}
+
+impl Precompiles for () {
+	fn execute(
+		_address: H160,
+		_input: &[u8],
+		_target_gas: Option<usize>
+	) -> Option<core::result::Result<(ExitSucceed, Vec<u8>, usize), ExitError>> {
+		None
+	}
+}
+
+/// EVM module trait
+pub trait Trait: system::Trait + timestamp::Trait {
+	/// Calculator for current gas price.
+	type FeeCalculator: FeeCalculator;
+	/// Convert account ID to H160;
+	type ConvertAccountId: ConvertAccountId<Self::AccountId>;
+	/// Currency type for deposit and withdraw.
+	type Currency: Currency<Self::AccountId>;
+	/// The overarching event type.
+	type Event: From<Event> + Into<<Self as system::Trait>::Event>;
+	/// Precompiles associated with this EVM engine.
+	type Precompiles: Precompiles;
+}
+
+decl_storage! {
+	trait Store for Module<T: Trait> as Example {
+		Accounts get(fn accounts) config(): map H160 => Account;
+		AccountCodes: map H160 => Vec<u8>;
+		AccountStorages: double_map H160, blake2_256(H256) => H256;
+	}
+}
+
+decl_event!(
+	/// EVM events
+	pub enum Event {
+		/// Ethereum events from contracts.
+		Log(Log),
+	}
+);
+
+decl_module! {
+	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
+		fn deposit_event() = default;
+
+		#[weight = SimpleDispatchInfo::FixedNormal(10_000)]
+		fn deposit_balance(origin, value: BalanceOf<T>) -> Result {
+			let sender = ensure_signed(origin)?;
+
+			T::Currency::withdraw(
+				&sender,
+				value,
+				WithdrawReason::Reserve.into(),
+				ExistenceRequirement::KeepAlive,
+			)?;
+
+			let bvalue = U256::from(UniqueSaturatedInto::<u128>::unique_saturated_into(value));
+			let address = T::ConvertAccountId::convert_account_id(&sender);
+			Accounts::mutate(&address, |account| {
+				account.balance += bvalue;
+			});
+
+			Ok(())
+		}
+
+		#[weight = SimpleDispatchInfo::FixedNormal(10_000)]
+		fn withdraw_balance(origin, value: BalanceOf<T>) -> Result {
+			let sender = ensure_signed(origin)?;
+			let address = T::ConvertAccountId::convert_account_id(&sender);
+			let bvalue = U256::from(UniqueSaturatedInto::<u128>::unique_saturated_into(value));
+
+			if Accounts::get(&address).balance < bvalue {
+				return Err("Not enough balance to withdraw")
+			}
+
+			Accounts::mutate(&address, |account| {
+				account.balance -= bvalue;
+			});
+
+			T::Currency::deposit_creating(&sender, value);
+
+			Ok(())
+		}
+
+		#[weight = SimpleDispatchInfo::FixedNormal(10_000)]
+		fn call(origin, target: H160, input: Vec<u8>, value: U256, gas_limit: u32) -> Result {
+			let sender = ensure_signed(origin)?;
+			let source = T::ConvertAccountId::convert_account_id(&sender);
+			let gas_price = T::FeeCalculator::gas_price();
+
+			let vicinity = Vicinity {
+				gas_price,
+				origin: source,
+			};
+
+			let mut backend = Backend::<T>::new(&vicinity);
+			let mut executor = StackExecutor::new_with_precompile(
+				&backend,
+				gas_limit as usize,
+				&backend::GASOMETER_CONFIG,
+				T::Precompiles::execute,
+			);
+
+			let total_fee = gas_price.checked_mul(U256::from(gas_limit))
+				.ok_or("Calculating total fee overflowed")?;
+			if Accounts::get(&source).balance <
+				value.checked_add(total_fee).ok_or("Calculating total payment overflowed")?
+			{
+				return Err("Not enough balance to pay transaction fee")
+			}
+			executor.withdraw(source, total_fee).map_err(|_| "Withdraw fee failed")?;
+
+			let reason = executor.transact_call(
+				source,
+				target,
+				value,
+				input,
+				gas_limit as usize,
+			);
+
+			let ret = match reason {
+				ExitReason::Succeed(_) => Ok(()),
+				ExitReason::Error(_) => Err("Execute message call failed"),
+				ExitReason::Revert(_) => Err("Execute message call reverted"),
+				ExitReason::Fatal(_) => Err("Execute message call returned VM fatal error"),
+			};
+			let actual_fee = executor.fee(gas_price);
+			executor.deposit(source, total_fee.saturating_sub(actual_fee));
+
+			let (values, logs) = executor.deconstruct();
+			backend.apply(values, logs, true);
+
+			ret
+		}
+
+		#[weight = SimpleDispatchInfo::FixedNormal(10_000)]
+		fn create(origin, init: Vec<u8>, value: U256, gas_limit: u32) -> Result {
+			let sender = ensure_signed(origin)?;
+			let source = T::ConvertAccountId::convert_account_id(&sender);
+			let gas_price = T::FeeCalculator::gas_price();
+
+			let vicinity = Vicinity {
+				gas_price,
+				origin: source,
+			};
+
+			let mut backend = Backend::<T>::new(&vicinity);
+			let mut executor = StackExecutor::new_with_precompile(
+				&backend,
+				gas_limit as usize,
+				&backend::GASOMETER_CONFIG,
+				T::Precompiles::execute,
+			);
+
+			let total_fee = gas_price.checked_mul(U256::from(gas_limit))
+				.ok_or("Calculating total fee overflowed")?;
+			if Accounts::get(&source).balance <
+				value.checked_add(total_fee).ok_or("Calculating total payment overflowed")?
+			{
+				return Err("Not enough balance to pay transaction fee")
+			}
+			executor.withdraw(source, total_fee).map_err(|_| "Withdraw fee failed")?;
+
+			let reason = executor.transact_create(
+				source,
+				value,
+				init,
+				gas_limit as usize,
+			);
+
+			let ret = match reason {
+				ExitReason::Succeed(_) => Ok(()),
+				ExitReason::Error(_) => Err("Execute contract creation failed"),
+				ExitReason::Revert(_) => Err("Execute contract creation reverted"),
+				ExitReason::Fatal(_) => Err("Execute contract creation returned VM fatal error"),
+			};
+			let actual_fee = executor.fee(gas_price);
+			executor.deposit(source, total_fee.saturating_sub(actual_fee));
+
+			let (values, logs) = executor.deconstruct();
+			backend.apply(values, logs, true);
+
+			ret
+		}
+	}
+}
+
+impl<T: Trait> Module<T> {
+	/// Check whether an account is empty.
+	pub fn is_account_empty(address: &H160) -> bool {
+		let account = Accounts::get(address);
+		let code_len = AccountCodes::decode_len(address).unwrap_or(0);
+
+		account.nonce == U256::zero() &&
+			account.balance == U256::zero() &&
+			code_len == 0
+	}
+
+	/// Remove an account if its empty.
+	pub fn remove_account_if_empty(address: &H160) {
+		if Self::is_account_empty(address) {
+			Self::remove_account(address)
+		}
+	}
+
+	/// Remove an account from state.
+	fn remove_account(address: &H160) {
+		Accounts::remove(address);
+		AccountCodes::remove(address);
+		AccountStorages::remove_prefix(address);
+	}
+}