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pezkuwi-subxt/polkadot/runtime/westend/src/xcm_config.rs
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Adrian Catangiu 18257373b3 pallet-xcm: enhance reserve_transfer_assets to support remote reserves (#1672)
## Motivation

`pallet-xcm` is the main user-facing interface for XCM functionality,
including assets manipulation functions like `teleportAssets()` and
`reserve_transfer_assets()` calls.

While `teleportAsset()` works both ways, `reserve_transfer_assets()`
works only for sending reserve-based assets to a remote destination and
beneficiary when the reserve is the _local chain_.

## Solution

This PR enhances `pallet_xcm::(limited_)reserve_withdraw_assets` to
support transfers when reserves are other chains.
This will allow complete, **bi-directional** reserve-based asset
transfers user stories using `pallet-xcm`.

Enables following scenarios:
- transferring assets with local reserve (was previously supported iff
asset used as fee also had local reserve - now it works in all cases),
- transferring assets with reserve on destination,
- transferring assets with reserve on remote/third-party chain (iff
assets and fees have same remote reserve),
- transferring assets with reserve different than the reserve of the
asset to be used as fees - meaning can be used to transfer random asset
with local/dest reserve while using DOT for fees on all involved chains,
even if DOT local/dest reserve doesn't match asset reserve,
- transferring assets with any type of local/dest reserve while using
fees which can be teleported between involved chains.

All of the above is done by pallet inner logic without the user having
to specify which scenario/reserves/teleports/etc. The correct scenario
and corresponding XCM programs are identified, and respectively, built
automatically based on runtime configuration of trusted teleporters and
trusted reserves.

#### Current limitations:
- while `fees` and "non-fee" `assets` CAN have different reserves (or
fees CAN be teleported), the remaining "non-fee" `assets` CANNOT, among
themselves, have different reserve locations (this is also implicitly
enforced by `MAX_ASSETS_FOR_TRANSFER=2`, but this can be safely
increased in the future).
- `fees` and "non-fee" `assets` CANNOT have **different remote**
reserves (this could also be supported in the future, but adds even more
complexity while possibly not being worth it - we'll see what the future
holds).

Fixes https://github.com/paritytech/polkadot-sdk/issues/1584
Fixes https://github.com/paritytech/polkadot-sdk/issues/2055

---------

Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
2023-11-13 17:16:55 +02:00

265 lines
11 KiB
Rust

// Copyright (C) Parity Technologies (UK) Ltd.
// This file is part of Polkadot.
// Polkadot 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.
// Polkadot 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 Polkadot. If not, see <http://www.gnu.org/licenses/>.
//! XCM configurations for Westend.
use super::{
parachains_origin, AccountId, AllPalletsWithSystem, Balances, Dmp, FellowshipAdmin,
GeneralAdmin, ParaId, Runtime, RuntimeCall, RuntimeEvent, RuntimeOrigin, StakingAdmin,
TransactionByteFee, Treasury, WeightToFee, XcmPallet,
};
use frame_support::{
match_types, parameter_types,
traits::{Everything, Nothing},
};
use frame_system::EnsureRoot;
use pallet_xcm::XcmPassthrough;
use runtime_common::{
xcm_sender::{ChildParachainRouter, ExponentialPrice},
ToAuthor,
};
use sp_core::ConstU32;
use westend_runtime_constants::{
currency::CENTS, system_parachain::*, xcm::body::FELLOWSHIP_ADMIN_INDEX,
};
use xcm::latest::prelude::*;
use xcm_builder::{
AccountId32Aliases, AllowExplicitUnpaidExecutionFrom, AllowKnownQueryResponses,
AllowSubscriptionsFrom, AllowTopLevelPaidExecutionFrom, ChildParachainAsNative,
ChildParachainConvertsVia, CurrencyAdapter as XcmCurrencyAdapter, DescribeBodyTerminal,
DescribeFamily, HashedDescription, IsConcrete, MintLocation, OriginToPluralityVoice,
SignedAccountId32AsNative, SignedToAccountId32, SovereignSignedViaLocation, TakeWeightCredit,
TrailingSetTopicAsId, UsingComponents, WeightInfoBounds, WithComputedOrigin, WithUniqueTopic,
XcmFeeManagerFromComponents, XcmFeeToAccount,
};
use xcm_executor::XcmExecutor;
parameter_types! {
pub const TokenLocation: MultiLocation = Here.into_location();
pub const ThisNetwork: NetworkId = Westend;
pub const UniversalLocation: InteriorMultiLocation = X1(GlobalConsensus(ThisNetwork::get()));
pub CheckAccount: AccountId = XcmPallet::check_account();
pub LocalCheckAccount: (AccountId, MintLocation) = (CheckAccount::get(), MintLocation::Local);
pub TreasuryAccount: AccountId = Treasury::account_id();
/// The asset ID for the asset that we use to pay for message delivery fees.
pub FeeAssetId: AssetId = Concrete(TokenLocation::get());
/// The base fee for the message delivery fees.
pub const BaseDeliveryFee: u128 = CENTS.saturating_mul(3);
}
pub type LocationConverter = (
// We can convert a child parachain using the standard `AccountId` conversion.
ChildParachainConvertsVia<ParaId, AccountId>,
// We can directly alias an `AccountId32` into a local account.
AccountId32Aliases<ThisNetwork, AccountId>,
// Allow governance body to be used as a sovereign account.
HashedDescription<AccountId, DescribeFamily<DescribeBodyTerminal>>,
);
pub type LocalAssetTransactor = XcmCurrencyAdapter<
// Use this currency:
Balances,
// Use this currency when it is a fungible asset matching the given location or name:
IsConcrete<TokenLocation>,
// We can convert the MultiLocations with our converter above:
LocationConverter,
// Our chain's account ID type (we can't get away without mentioning it explicitly):
AccountId,
// It's a native asset so we keep track of the teleports to maintain total issuance.
LocalCheckAccount,
>;
type LocalOriginConverter = (
// If the origin kind is `Sovereign`, then return a `Signed` origin with the account determined
// by the `LocationConverter` converter.
SovereignSignedViaLocation<LocationConverter, RuntimeOrigin>,
// If the origin kind is `Native` and the XCM origin is a child parachain, then we can express
// it with the special `parachains_origin::Origin` origin variant.
ChildParachainAsNative<parachains_origin::Origin, RuntimeOrigin>,
// If the origin kind is `Native` and the XCM origin is the `AccountId32` location, then it can
// be expressed using the `Signed` origin variant.
SignedAccountId32AsNative<ThisNetwork, RuntimeOrigin>,
// Xcm origins can be represented natively under the Xcm pallet's Xcm origin.
XcmPassthrough<RuntimeOrigin>,
);
pub type PriceForChildParachainDelivery =
ExponentialPrice<FeeAssetId, BaseDeliveryFee, TransactionByteFee, Dmp>;
/// The XCM router. When we want to send an XCM message, we use this type. It amalgamates all of our
/// individual routers.
pub type XcmRouter = WithUniqueTopic<
// Only one router so far - use DMP to communicate with child parachains.
ChildParachainRouter<Runtime, XcmPallet, PriceForChildParachainDelivery>,
>;
parameter_types! {
pub const AssetHub: MultiLocation = Parachain(ASSET_HUB_ID).into_location();
pub const Collectives: MultiLocation = Parachain(COLLECTIVES_ID).into_location();
pub const BridgeHub: MultiLocation = Parachain(BRIDGE_HUB_ID).into_location();
pub const Wnd: MultiAssetFilter = Wild(AllOf { fun: WildFungible, id: Concrete(TokenLocation::get()) });
pub const WndForAssetHub: (MultiAssetFilter, MultiLocation) = (Wnd::get(), AssetHub::get());
pub const WndForCollectives: (MultiAssetFilter, MultiLocation) = (Wnd::get(), Collectives::get());
pub const WndForBridgeHub: (MultiAssetFilter, MultiLocation) = (Wnd::get(), BridgeHub::get());
pub const MaxInstructions: u32 = 100;
pub const MaxAssetsIntoHolding: u32 = 64;
}
pub type TrustedTeleporters = (
xcm_builder::Case<WndForAssetHub>,
xcm_builder::Case<WndForCollectives>,
xcm_builder::Case<WndForBridgeHub>,
);
match_types! {
pub type OnlyParachains: impl Contains<MultiLocation> = {
MultiLocation { parents: 0, interior: X1(Parachain(_)) }
};
pub type CollectivesOrFellows: impl Contains<MultiLocation> = {
MultiLocation { parents: 0, interior: X1(Parachain(COLLECTIVES_ID)) } |
MultiLocation { parents: 0, interior: X2(Parachain(COLLECTIVES_ID), Plurality { id: BodyId::Technical, .. }) }
};
}
/// The barriers one of which must be passed for an XCM message to be executed.
pub type Barrier = TrailingSetTopicAsId<(
// Weight that is paid for may be consumed.
TakeWeightCredit,
// Expected responses are OK.
AllowKnownQueryResponses<XcmPallet>,
WithComputedOrigin<
(
// If the message is one that immediately attempts to pay for execution, then allow it.
AllowTopLevelPaidExecutionFrom<Everything>,
// Subscriptions for version tracking are OK.
AllowSubscriptionsFrom<OnlyParachains>,
// Collectives and Fellows plurality get free execution.
AllowExplicitUnpaidExecutionFrom<CollectivesOrFellows>,
),
UniversalLocation,
ConstU32<8>,
>,
)>;
pub struct XcmConfig;
impl xcm_executor::Config for XcmConfig {
type RuntimeCall = RuntimeCall;
type XcmSender = XcmRouter;
type AssetTransactor = LocalAssetTransactor;
type OriginConverter = LocalOriginConverter;
type IsReserve = ();
type IsTeleporter = TrustedTeleporters;
type UniversalLocation = UniversalLocation;
type Barrier = Barrier;
type Weigher = WeightInfoBounds<
crate::weights::xcm::WestendXcmWeight<RuntimeCall>,
RuntimeCall,
MaxInstructions,
>;
type Trader =
UsingComponents<WeightToFee, TokenLocation, AccountId, Balances, ToAuthor<Runtime>>;
type ResponseHandler = XcmPallet;
type AssetTrap = XcmPallet;
type AssetLocker = ();
type AssetExchanger = ();
type AssetClaims = XcmPallet;
type SubscriptionService = XcmPallet;
type PalletInstancesInfo = AllPalletsWithSystem;
type MaxAssetsIntoHolding = MaxAssetsIntoHolding;
type FeeManager = XcmFeeManagerFromComponents<
SystemParachains,
XcmFeeToAccount<Self::AssetTransactor, AccountId, TreasuryAccount>,
>;
type MessageExporter = ();
type UniversalAliases = Nothing;
type CallDispatcher = RuntimeCall;
type SafeCallFilter = Everything;
type Aliasers = Nothing;
}
parameter_types! {
// `GeneralAdmin` pluralistic body.
pub const GeneralAdminBodyId: BodyId = BodyId::Administration;
// StakingAdmin pluralistic body.
pub const StakingAdminBodyId: BodyId = BodyId::Defense;
// FellowshipAdmin pluralistic body.
pub const FellowshipAdminBodyId: BodyId = BodyId::Index(FELLOWSHIP_ADMIN_INDEX);
}
/// Type to convert the `GeneralAdmin` origin to a Plurality `MultiLocation` value.
pub type GeneralAdminToPlurality =
OriginToPluralityVoice<RuntimeOrigin, GeneralAdmin, GeneralAdminBodyId>;
/// Type to convert an `Origin` type value into a `MultiLocation` value which represents an interior
/// location of this chain.
pub type LocalOriginToLocation = (
GeneralAdminToPlurality,
// And a usual Signed origin to be used in XCM as a corresponding AccountId32
SignedToAccountId32<RuntimeOrigin, AccountId, ThisNetwork>,
);
/// Type to convert the `StakingAdmin` origin to a Plurality `MultiLocation` value.
pub type StakingAdminToPlurality =
OriginToPluralityVoice<RuntimeOrigin, StakingAdmin, StakingAdminBodyId>;
/// Type to convert the `FellowshipAdmin` origin to a Plurality `MultiLocation` value.
pub type FellowshipAdminToPlurality =
OriginToPluralityVoice<RuntimeOrigin, FellowshipAdmin, FellowshipAdminBodyId>;
/// Type to convert a pallet `Origin` type value into a `MultiLocation` value which represents an
/// interior location of this chain for a destination chain.
pub type LocalPalletOriginToLocation = (
// GeneralAdmin origin to be used in XCM as a corresponding Plurality `MultiLocation` value.
GeneralAdminToPlurality,
// StakingAdmin origin to be used in XCM as a corresponding Plurality `MultiLocation` value.
StakingAdminToPlurality,
// FellowshipAdmin origin to be used in XCM as a corresponding Plurality `MultiLocation` value.
FellowshipAdminToPlurality,
);
impl pallet_xcm::Config for Runtime {
type RuntimeEvent = RuntimeEvent;
type SendXcmOrigin = xcm_builder::EnsureXcmOrigin<RuntimeOrigin, LocalPalletOriginToLocation>;
type XcmRouter = XcmRouter;
// Anyone can execute XCM messages locally...
type ExecuteXcmOrigin = xcm_builder::EnsureXcmOrigin<RuntimeOrigin, LocalOriginToLocation>;
// ...but they must match our filter, which rejects everything.
type XcmExecuteFilter = Nothing;
type XcmExecutor = XcmExecutor<XcmConfig>;
type XcmTeleportFilter = Everything;
type XcmReserveTransferFilter = Everything;
type Weigher = WeightInfoBounds<
crate::weights::xcm::WestendXcmWeight<RuntimeCall>,
RuntimeCall,
MaxInstructions,
>;
type UniversalLocation = UniversalLocation;
type RuntimeOrigin = RuntimeOrigin;
type RuntimeCall = RuntimeCall;
const VERSION_DISCOVERY_QUEUE_SIZE: u32 = 100;
type AdvertisedXcmVersion = pallet_xcm::CurrentXcmVersion;
type Currency = Balances;
type CurrencyMatcher = IsConcrete<TokenLocation>;
type TrustedLockers = ();
type SovereignAccountOf = LocationConverter;
type MaxLockers = ConstU32<8>;
type MaxRemoteLockConsumers = ConstU32<0>;
type RemoteLockConsumerIdentifier = ();
type WeightInfo = crate::weights::pallet_xcm::WeightInfo<Runtime>;
type AdminOrigin = EnsureRoot<AccountId>;
}