Implement basic upward & downward messages (#118)

* Start by replacing branch names and set `DownwardMessage`

* Add the upward-message crate

* Add Kusama & Polkadot

* More work on getting the upward messages working

* Fix build

* Begin to integrate it into the test Parachain

* Update

* Make everything compile again

* Switch to westend and print parachain account on startup

* Use MultiSignature etc

* Fix validate block

* Some downward messages work

* Update git reference

* More downward messages integration

* Update test runtime for downward messages

* Enable downward message handler and withdraw send tokens

* Add some docs

* Begin to implement simple XCMP

* More work

* Fixes and make parachain id configurable

* Make parachain ID be part of the genesis

* Finishing the XCMP message demo

* Update and fixes tests

* Update branch

cumulus/upward-message/src/kusama.rs

@@ -0,0 +1,37 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// 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/>.
+
+//! Kusama upward message
+
+use crate::*;
+use polkadot_core_primitives::{Balance, AccountId};
+use kusama_runtime::{BalancesCall, ParachainsCall};
+use sp_std::vec::Vec;
+
+/// The Kusama upward message.
+pub type UpwardMessage = kusama_runtime::Call;
+
+impl BalancesMessage<AccountId, Balance> for UpwardMessage {
+	fn transfer(dest: AccountId, amount: Balance) -> Self {
+		BalancesCall::transfer(dest, amount).into()
+	}
+}
+
+impl XCMPMessage for UpwardMessage {
+	fn send_message(dest: ParaId, msg: Vec<u8>) -> Self {
+		ParachainsCall::send_xcmp_message(dest, msg).into()
+	}
+}

cumulus/upward-message/src/lib.rs

@@ -0,0 +1,47 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// 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/>.
+
+//! Upward messages types and traits for Polkadot, Kusama and Westend.
+//!
+//! As Cumulus needs to suits multiple Polkadot-like runtimes the upward message
+//! type is different for each of them. To support all of them, Cumulus provides
+//! traits to write upward message generic code.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use polkadot_parachain::primitives::Id as ParaId;
+use sp_std::vec::Vec;
+
+mod polkadot;
+mod kusama;
+mod westend;
+
+pub use polkadot::UpwardMessage as PolkadotUpwardMessage;
+pub use kusama::UpwardMessage as KusamaUpwardMessage;
+pub use westend::UpwardMessage as WestendUpwardMessage;
+
+/// A `Balances` related upward message.
+pub trait BalancesMessage<AccountId, Balance>: Sized {
+	/// Transfer the given `amount` from the parachain account to the given
+	/// `dest` account.
+	fn transfer(dest: AccountId, amount: Balance) -> Self;
+}
+
+/// A `XCMP` related upward message.
+pub trait XCMPMessage: Sized {
+	/// Send the given XCMP message to given parachain.
+	fn send_message(dest: ParaId, msg: Vec<u8>) -> Self;
+}

cumulus/upward-message/src/polkadot.rs

@@ -0,0 +1,37 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// 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/>.
+
+//! Polkadot upward message
+
+use crate::*;
+use polkadot_core_primitives::{Balance, AccountId};
+use polkadot_runtime::{BalancesCall, ParachainsCall};
+use sp_std::vec::Vec;
+
+/// The Polkadot upward message.
+pub type UpwardMessage = polkadot_runtime::Call;
+
+impl BalancesMessage<AccountId, Balance> for UpwardMessage {
+	fn transfer(dest: AccountId, amount: Balance) -> Self {
+		BalancesCall::transfer(dest, amount).into()
+	}
+}
+
+impl XCMPMessage for UpwardMessage {
+	fn send_message(dest: ParaId, msg: Vec<u8>) -> Self {
+		ParachainsCall::send_xcmp_message(dest, msg).into()
+	}
+}

cumulus/upward-message/src/westend.rs

@@ -0,0 +1,37 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// 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/>.
+
+//! Westend upward message
+
+use crate::*;
+use polkadot_core_primitives::{Balance, AccountId};
+use westend_runtime::{BalancesCall, ParachainsCall};
+use sp_std::vec::Vec;
+
+/// The Westend upward message.
+pub type UpwardMessage = westend_runtime::Call;
+
+impl BalancesMessage<AccountId, Balance> for UpwardMessage {
+	fn transfer(dest: AccountId, amount: Balance) -> Self {
+		BalancesCall::transfer(dest, amount).into()
+	}
+}
+
+impl XCMPMessage for UpwardMessage {
+	fn send_message(dest: ParaId, msg: Vec<u8>) -> Self {
+		ParachainsCall::send_xcmp_message(dest, msg).into()
+	}
+}