Adds validate_block support for runtime

Cargo.toml

@@ -1,2 +1,2 @@
 [workspace]
-members = [ "consensus" ]
+members = [ "consensus", "runtime" ]

consensus/Cargo.toml

@@ -2,7 +2,7 @@
 name = "cumulus-consensus"
 description = "Proxy Polkadot's consensus as a consensus engine for Substrate"
 version = "0.1.0"
-authors = ["Parity Technologies"]
+authors = ["Parity Technologies <[email protected]>"]
 edition = "2018"
 
 [dependencies]
@@ -20,5 +20,5 @@ polkadot-runtime = { git = "https://github.com/paritytech/polkadot" }
 # other deps
 futures = "0.1.21"
 tokio = "0.1.8"
-parity-codec = "3.0"
+parity-codec = "3.1"
 log = "0.4"

runtime/Cargo.toml

@@ -0,0 +1,28 @@
+[package]
+name = "runtime"
+version = "0.1.0"
+authors = ["Parity Technologies <[email protected]>"]
+edition = "2018"
+
+[dependencies]
+codec = { package = "parity-codec", version = "3.1", default-features = false, features = [ "derive" ] }
+rstd = { package = "sr-std", git = "https://github.com/paritytech/substrate", default-features = false, branch = "bkchr-validate_block" }
+runtime-primitives = { package = "sr-primitives", git = "https://github.com/paritytech/substrate", default-features = false, branch = "bkchr-validate_block" }
+rio = { package = "sr-io", git = "https://github.com/paritytech/substrate", default-features = false, branch = "bkchr-validate_block" }
+executive = { package = "srml-executive", git = "https://github.com/paritytech/substrate", default-features = false, branch = "bkchr-validate_block" }
+
+[dev-dependencies]
+keyring = { package = "substrate-keyring", git = "https://github.com/paritytech/substrate", branch = "bkchr-validate_block" }
+primitives = { package = "substrate-primitives", git = "https://github.com/paritytech/substrate", branch = "bkchr-validate_block" }
+executor = { package = "substrate-executor", git = "https://github.com/paritytech/substrate", branch = "bkchr-validate_block" }
+test-runtime = { package = "substrate-test-runtime", git = "https://github.com/paritytech/substrate", branch = "bkchr-validate_block" }
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"rstd/std",
+	"rio/std",
+	"runtime-primitives/std",
+	"executive/std",
+]

runtime/src/lib.rs

@@ -0,0 +1,52 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// Cumulus 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.
+
+// Cumulus 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 Cumulus.  If not, see <http://www.gnu.org/licenses/>.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use rstd::{vec::Vec, collections::btree_map::BTreeMap};
+use codec::{Encode, Decode};
+use runtime_primitives::traits::Block as BlockT;
+
+pub mod validate_block;
+
+type WitnessData = BTreeMap<Vec<u8>, Vec<u8>>;
+
+/// The parachain block that is created on a collator and validated by a validator.
+#[derive(Encode, Decode)]
+struct ParachainBlock<B: BlockT> {
+	extrinsics: Vec<<B as BlockT>::Extrinsic>,
+	/// The data that is required to emulate the storage accesses executed by all extrinsics.
+	witness_data: WitnessData,
+}
+
+impl<B: BlockT> ParachainBlock<B> {
+	#[cfg(test)]
+	fn new(extrinsics: Vec<<B as BlockT>::Extrinsic>, witness_data: WitnessData) -> Self {
+		Self {
+			extrinsics,
+			witness_data,
+		}
+	}
+}
+
+impl<B: BlockT> Default for ParachainBlock<B> {
+	fn default() -> Self {
+		Self {
+			extrinsics: Vec::default(),
+			witness_data: BTreeMap::default(),
+		}
+	}
+}

runtime/src/validate_block/mod.rs

@@ -0,0 +1,105 @@
+// Copyright 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 Cumulus. If not, see <http://www.gnu.org/licenses/>.
+
+//! A module that enables a runtime to work as parachain.
+
+#[cfg(not(feature = "std"))]
+#[doc(hidden)]
+pub use rstd::slice;
+
+#[cfg(not(feature = "std"))]
+#[doc(hidden)]
+pub mod storage_functions;
+#[cfg(test)]
+mod tests;
+
+/// Register the `validate_block` function that is used by parachains to validate blocks on a validator.
+///
+/// Does *nothing* when `std` feature is enabled.
+///
+/// Expects as parameters the block and the block executor.
+///
+/// # Example
+///
+/// ```
+///     struct Block;
+///     struct BlockExecutor;
+///
+///     srml_parachain::register_validate_block!(Block, BlockExecutor);
+///
+/// # fn main() {}
+/// ```
+#[macro_export]
+macro_rules! register_validate_block {
+	($block:ty, $block_executor:ty) => {
+		$crate::register_validate_block_impl!($block, $block_executor);
+	};
+}
+
+/// The actual implementation of `register_validate_block` for `no_std`.
+#[cfg(not(feature = "std"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! register_validate_block_impl {
+	($block:ty, $block_executor:ty) => {
+		#[doc(hidden)]
+		mod parachain_validate_block {
+			use super::*;
+
+			#[no_mangle]
+			unsafe fn validate_block(block: *const u8, block_len: u64, prev_head: *const u8, prev_head_len: u64) {
+				let block = $crate::slice::from_raw_parts(block, block_len as usize);
+				let prev_head = $crate::slice::from_raw_parts(prev_head, prev_head_len as usize);
+
+				$crate::validate_block::validate_block::<$block, $block_executor>(block, prev_head);
+			}
+		}
+	};
+}
+
+/// The actual implementation of `register_validate_block` for `std`.
+#[cfg(feature = "std")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! register_validate_block_impl {
+	($block:ty, $block_executor:ty) => {};
+}
+
+/// Validate a given parachain block on a validator.
+#[cfg(not(feature = "std"))]
+#[doc(hidden)]
+pub fn validate_block<Block: BlockT, E: ExecuteBlock<Block>>(mut block: &[u8], mut prev_head: &[u8]) {
+	use codec::Decode;
+
+	let block = ParachainBlock::<Block>::decode(&mut block).expect("Could not decode parachain block.");
+	let parent_header = <<Block as BlockT>::Header as Decode>::decode(&mut prev_head).expect("Could not decode parent header.");
+
+	let _guard = unsafe {
+		use storage_functions as storage;
+		STORAGE = Some(block.witness_data);
+		(
+			// Replace storage calls with our own implementations
+			rio::ext_get_allocated_storage.replace_implementation(storage::ext_get_allocated_storage),
+			rio::ext_get_storage_into.replace_implementation(storage::ext_get_storage_into),
+			rio::ext_set_storage.replace_implementation(storage::ext_set_storage),
+			rio::ext_exists_storage.replace_implementation(storage::ext_exists_storage),
+			rio::ext_clear_storage.replace_implementation(storage::ext_clear_storage),
+		)
+	};
+
+	let block_number = *parent_header.number() + One::one();
+	E::execute_extrinsics_without_checks(block_number, block.extrinsics);
+}

runtime/src/validate_block/storage_functions.rs

@@ -0,0 +1,82 @@
+// Copyright 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 Cumulus. If not, see <http://www.gnu.org/licenses/>.
+
+//! All storage functions that are replaced by `validate_block` in the Substrate runtime.
+
+use crate::{ParachainBlock, WitnessData};
+use runtime_primitives::traits::{Block as BlockT, One, Header as HeaderT};
+use rstd::{slice, ptr, cmp};
+use codec::Decode;
+use executive::ExecuteBlock;
+
+pub static mut STORAGE: Option<WitnessData> = None;
+const STORAGE_SET_EXPECT: &str = "`STORAGE` needs to be set before calling this function.";
+
+pub unsafe fn ext_get_allocated_storage(key_data: *const u8, key_len: u32, written_out: *mut u32) -> *mut u8 {
+	let key = slice::from_raw_parts(key_data, key_len as usize);
+	match STORAGE.as_mut().expect(STORAGE_SET_EXPECT).get_mut(key) {
+		Some(value) => {
+			*written_out = value.len() as u32;
+			value.as_mut_ptr()
+		},
+		None => {
+			*written_out = u32::max_value();
+			ptr::null_mut()
+		}
+	}
+}
+
+pub unsafe fn ext_set_storage(key_data: *const u8, key_len: u32, value_data: *const u8, value_len: u32) {
+	let key = slice::from_raw_parts(key_data, key_len as usize);
+	let value = slice::from_raw_parts(value_data, value_len as usize);
+
+	STORAGE.as_mut().map(|s| {
+		s.insert(key.to_vec(), value.to_vec());
+	});
+}
+
+pub unsafe fn ext_get_storage_into(key_data: *const u8, key_len: u32, value_data: *mut u8, value_len: u32, value_offset: u32) -> u32 {
+	let key = slice::from_raw_parts(key_data, key_len as usize);
+	let out_value = slice::from_raw_parts_mut(value_data, value_len as usize);
+
+	match STORAGE.as_mut().expect(STORAGE_SET_EXPECT).get_mut(key) {
+		Some(value) => {
+			let value = &value[value_offset as usize..];
+			let len = cmp::min(value_len as usize, value.len());
+			out_value[..len].copy_from_slice(&value[..len]);
+			len as u32
+		},
+		None => {
+			u32::max_value()
+		}
+	}
+}
+
+pub unsafe fn ext_exists_storage(key_data: *const u8, key_len: u32) -> u32 {
+	let key = slice::from_raw_parts(key_data, key_len as usize);
+
+	if STORAGE.as_mut().expect(STORAGE_SET_EXPECT).contains_key(key) {
+		1
+	} else {
+		0
+	}
+}
+
+pub unsafe fn ext_clear_storage(key_data: *const u8, key_len: u32) {
+	let key = slice::from_raw_parts(key_data, key_len as usize);
+
+	STORAGE.as_mut().expect(STORAGE_SET_EXPECT).remove(key);
+}

runtime/src/validate_block/tests.rs

@@ -0,0 +1,96 @@
+use crate::ParachainBlock;
+
+use rio::{twox_128, TestExternalities};
+use keyring::Keyring;
+use primitives::map;
+use runtime_primitives::traits::Block as BlockT;
+use executor::{WasmExecutor, error::Result, wasmi::RuntimeValue::{I64, I32}};
+use test_runtime::{Block, Header, Transfer};
+
+use std::collections::BTreeMap;
+
+use codec::{KeyedVec, Encode};
+
+const WASM_CODE: &'static [u8] =
+	include_bytes!("../../../core/test-runtime/wasm/target/wasm32-unknown-unknown/release/substrate_test_runtime.compact.wasm");
+
+fn create_witness_data() -> BTreeMap<Vec<u8>, Vec<u8>> {
+	map![
+		twox_128(&Keyring::Alice.to_raw_public().to_keyed_vec(b"balance:")).to_vec() => vec![111u8, 0, 0, 0, 0, 0, 0, 0]
+	]
+}
+
+fn call_validate_block(block: ParachainBlock<Block>, prev_header: <Block as BlockT>::Header) -> Result<()> {
+	let mut ext = TestExternalities::default();
+	WasmExecutor::new().call_with_custom_signature(
+		&mut ext,
+		8,
+		&WASM_CODE,
+		"validate_block",
+		|alloc| {
+			let block = block.encode();
+			let prev_header = prev_header.encode();
+			let block_offset = alloc(&block)?;
+			let prev_head_offset = alloc(&prev_header)?;
+
+			Ok(
+				vec![
+					I32(block_offset as i32),
+					I64(block.len() as i64),
+					I32(prev_head_offset as i32),
+					I64(prev_header.len() as i64),
+				]
+			)
+		},
+		|res, _| {
+			if res.is_none() {
+				Ok(Some(()))
+			} else {
+				Ok(None)
+			}
+		}
+	)
+}
+
+fn create_extrinsics() -> Vec<<Block as BlockT>::Extrinsic> {
+	vec![
+		Transfer {
+			from: Keyring::Alice.to_raw_public().into(),
+			to: Keyring::Bob.to_raw_public().into(),
+			amount: 69,
+			nonce: 0,
+		}.into_signed_tx()
+	]
+}
+
+fn create_prev_header() -> Header {
+	Header {
+		parent_hash: Default::default(),
+		number: 1,
+		state_root: Default::default(),
+		extrinsics_root: Default::default(),
+		digest: Default::default(),
+	}
+}
+
+#[test]
+fn validate_block_with_empty_block() {
+	let prev_header = create_prev_header();
+	call_validate_block(ParachainBlock::default(), prev_header).expect("Calls `validate_block`");
+}
+
+#[test]
+fn validate_block_with_empty_witness_data() {
+	let prev_header = create_prev_header();
+
+	let block = ParachainBlock::new(create_extrinsics(), Default::default());
+	assert!(call_validate_block(block, prev_header).is_err());
+}
+
+#[test]
+fn validate_block_with_witness_data() {
+	let prev_header = create_prev_header();
+
+	let block = ParachainBlock::new(create_extrinsics(), create_witness_data());
+	call_validate_block(block, prev_header).expect("`validate_block` succeeds");
+}