Polkadot <> Kusama relayers (#1122)

* relay headers between Kusama and Polkadot

* relay messages between Kusama and Polkadot

* complex Kusama <> Polkadot relayer

* expose relayer_fund_account_id from messages pallet

* create relayers fund accounts on Kusama/Polkadot + some more fixes

* fmt

* fix compilation

* compilation + clippy

* compilation

* MAXIMAL_BALANCE_DECREASE_PER_DAY for K<>P header relays

* fmt

* deduplicate tests

* Update modules/messages/src/lib.rs

Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

* extract storage_parameter_key function

* other grumbles

* fix

* fmt

Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

bridges/primitives/chain-kusama/Cargo.toml

@@ -20,6 +20,7 @@ bp-runtime = { path = "../runtime", default-features = false }
 frame-support = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-api = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-std = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-version = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 
 [features]
 default = ["std"]
@@ -30,4 +31,5 @@ std = [
 	"frame-support/std",
 	"sp-api/std",
 	"sp-std/std",
+	"sp-version/std",
 ]

bridges/primitives/chain-kusama/src/lib.rs

@@ -23,12 +23,24 @@
 use bp_messages::{LaneId, MessageDetails, MessageNonce, UnrewardedRelayersState};
 use frame_support::weights::{WeightToFeeCoefficient, WeightToFeeCoefficients, WeightToFeePolynomial};
 use sp_std::prelude::*;
+use sp_version::RuntimeVersion;
 
 pub use bp_polkadot_core::*;
 
 /// Kusama Chain
 pub type Kusama = PolkadotLike;
 
+// NOTE: This needs to be kept up to date with the Kusama runtime found in the Polkadot repo.
+pub const VERSION: RuntimeVersion = RuntimeVersion {
+	spec_name: sp_version::create_runtime_str!("kusama"),
+	impl_name: sp_version::create_runtime_str!("parity-kusama"),
+	authoring_version: 2,
+	spec_version: 9100,
+	impl_version: 0,
+	apis: sp_version::create_apis_vec![[]],
+	transaction_version: 5,
+};
+
 // NOTE: This needs to be kept up to date with the Kusama runtime found in the Polkadot repo.
 pub struct WeightToFee;
 impl WeightToFeePolynomial for WeightToFee {
@@ -57,9 +69,22 @@ pub fn derive_account_from_polkadot_id(id: bp_runtime::SourceAccount<AccountId>)
 /// Per-byte fee for Kusama transactions.
 pub const TRANSACTION_BYTE_FEE: Balance = 10 * 1_000_000_000_000 / 30_000 / 1_000;
 
+/// Existential deposit on Kusama.
+pub const EXISTENTIAL_DEPOSIT: Balance = 1_000_000_000_000 / 30_000;
+
+/// The target length of a session (how often authorities change) on Kusama measured in of number of
+/// blocks.
+///
+/// Note that since this is a target sessions may change before/after this time depending on network
+/// conditions.
+pub const SESSION_LENGTH: BlockNumber = 1 * time_units::HOURS;
+
 /// Name of the With-Polkadot messages pallet instance in the Kusama runtime.
 pub const WITH_POLKADOT_MESSAGES_PALLET_NAME: &str = "BridgePolkadotMessages";
 
+/// Name of the DOT->KSM conversion rate stored in the Kusama runtime.
+pub const POLKADOT_TO_KUSAMA_CONVERSION_RATE_PARAMETER_NAME: &str = "PolkadotToKusamaConversionRate";
+
 /// Name of the `KusamaFinalityApi::best_finalized` runtime method.
 pub const BEST_FINALIZED_KUSAMA_HEADER_METHOD: &str = "KusamaFinalityApi_best_finalized";
 /// Name of the `KusamaFinalityApi::is_known_header` runtime method.

bridges/primitives/chain-polkadot/Cargo.toml

@@ -20,6 +20,7 @@ bp-runtime = { path = "../runtime", default-features = false }
 frame-support = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-api = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-std = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-version = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 
 [features]
 default = ["std"]
@@ -30,4 +31,5 @@ std = [
 	"frame-support/std",
 	"sp-api/std",
 	"sp-std/std",
+	"sp-version/std",
 ]

bridges/primitives/chain-polkadot/src/lib.rs

@@ -23,12 +23,24 @@
 use bp_messages::{LaneId, MessageDetails, MessageNonce, UnrewardedRelayersState};
 use frame_support::weights::{WeightToFeeCoefficient, WeightToFeeCoefficients, WeightToFeePolynomial};
 use sp_std::prelude::*;
+use sp_version::RuntimeVersion;
 
 pub use bp_polkadot_core::*;
 
 /// Polkadot Chain
 pub type Polkadot = PolkadotLike;
 
+// NOTE: This needs to be kept up to date with the Polkadot runtime found in the Polkadot repo.
+pub const VERSION: RuntimeVersion = RuntimeVersion {
+	spec_name: sp_version::create_runtime_str!("polkadot"),
+	impl_name: sp_version::create_runtime_str!("parity-polkadot"),
+	authoring_version: 0,
+	spec_version: 9100,
+	impl_version: 0,
+	apis: sp_version::create_apis_vec![[]],
+	transaction_version: 7,
+};
+
 // NOTE: This needs to be kept up to date with the Polkadot runtime found in the Polkadot repo.
 pub struct WeightToFee;
 impl WeightToFeePolynomial for WeightToFee {
@@ -57,9 +69,22 @@ pub fn derive_account_from_kusama_id(id: bp_runtime::SourceAccount<AccountId>) -
 /// Per-byte fee for Polkadot transactions.
 pub const TRANSACTION_BYTE_FEE: Balance = 10 * 10_000_000_000 / 100 / 1_000;
 
+/// Existential deposit on Polkadot.
+pub const EXISTENTIAL_DEPOSIT: Balance = 10_000_000_000;
+
+/// The target length of a session (how often authorities change) on Polkadot measured in of number of
+/// blocks.
+///
+/// Note that since this is a target sessions may change before/after this time depending on network
+/// conditions.
+pub const SESSION_LENGTH: BlockNumber = 4 * time_units::HOURS;
+
 /// Name of the With-Kusama messages pallet instance in the Polkadot runtime.
 pub const WITH_KUSAMA_MESSAGES_PALLET_NAME: &str = "BridgeKusamaMessages";
 
+/// Name of the KSM->DOT conversion rate stored in the Polkadot runtime.
+pub const KUSAMA_TO_POLKADOT_CONVERSION_RATE_PARAMETER_NAME: &str = "KusamaToPolkadotConversionRate";
+
 /// Name of the `PolkadotFinalityApi::best_finalized` runtime method.
 pub const BEST_FINALIZED_POLKADOT_HEADER_METHOD: &str = "PolkadotFinalityApi_best_finalized";
 /// Name of the `PolkadotFinalityApi::is_known_header` runtime method.

bridges/primitives/polkadot-core/src/lib.rs

@@ -217,6 +217,9 @@ pub type AccountPublic = <Signature as Verify>::Signer;
 /// Id of account on Polkadot-like chains.
 pub type AccountId = <AccountPublic as IdentifyAccount>::AccountId;
 
+/// Address of account on Polkadot-like chains.
+pub type AccountAddress = MultiAddress<AccountId, ()>;
+
 /// Index of a transaction on the Polkadot-like chains.
 pub type Nonce = u32;
 
@@ -231,7 +234,7 @@ pub type Balance = u128;
 
 /// Unchecked Extrinsic type.
 pub type UncheckedExtrinsic<Call> =
-	generic::UncheckedExtrinsic<MultiAddress<AccountId, ()>, Call, Signature, SignedExtensions<Call>>;
+	generic::UncheckedExtrinsic<AccountAddress, Call, Signature, SignedExtensions<Call>>;
 
 /// Account address, used by the Polkadot-like chain.
 pub type Address = MultiAddress<AccountId, ()>;

bridges/primitives/runtime/src/lib.rs

@@ -20,9 +20,9 @@
 
 use codec::Encode;
 use frame_support::RuntimeDebug;
-use sp_core::hash::H256;
+use sp_core::{hash::H256, storage::StorageKey};
 use sp_io::hashing::blake2_256;
-use sp_std::convert::TryFrom;
+use sp_std::{convert::TryFrom, vec::Vec};
 
 pub use chain::{
 	AccountIdOf, AccountPublicOf, BalanceOf, BlockNumberOf, Chain, HashOf, HasherOf, HeaderOf, IndexOf, SignatureOf,
@@ -183,3 +183,15 @@ impl<BlockNumber: Copy + Into<u64>, BlockHash: Copy> TransactionEra<BlockNumber,
 		}
 	}
 }
+
+/// This is how a storage key of storage parameter (`parameter_types! { storage Param: bool = false; }`) is computed.
+///
+/// Copypaste from `frame_support::parameter_types` macro
+pub fn storage_parameter_key(parameter_name: &str) -> StorageKey {
+	let mut buffer = Vec::with_capacity(1 + parameter_name.len() + 1 + 1);
+	buffer.push(':' as u8);
+	buffer.extend_from_slice(parameter_name.as_bytes());
+	buffer.push(':' as u8);
+	buffer.push(0);
+	StorageKey(sp_io::hashing::twox_128(&buffer).to_vec())
+}