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pezkuwi-subxt/polkadot/runtime/test-runtime/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

157 lines
5.1 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/>.
use frame_support::{
parameter_types,
traits::{Everything, Nothing},
weights::Weight,
};
use frame_system::EnsureRoot;
use xcm::latest::prelude::*;
use xcm_builder::{
AllowUnpaidExecutionFrom, EnsureXcmOrigin, FixedWeightBounds, SignedAccountId32AsNative,
SignedToAccountId32,
};
use xcm_executor::{
traits::{TransactAsset, WeightTrader},
Assets,
};
parameter_types! {
pub const BaseXcmWeight: xcm::latest::Weight = Weight::from_parts(1_000, 1_000);
pub const AnyNetwork: Option<NetworkId> = None;
pub const MaxInstructions: u32 = 100;
pub const MaxAssetsIntoHolding: u32 = 16;
pub const UniversalLocation: xcm::latest::InteriorMultiLocation = xcm::latest::Junctions::Here;
}
/// Type to convert an `Origin` type value into a `MultiLocation` value which represents an interior
/// location of this chain.
pub type LocalOriginToLocation = (
// And a usual Signed origin to be used in XCM as a corresponding AccountId32
SignedToAccountId32<crate::RuntimeOrigin, crate::AccountId, AnyNetwork>,
);
pub struct DoNothingRouter;
impl SendXcm for DoNothingRouter {
type Ticket = ();
fn validate(_dest: &mut Option<MultiLocation>, _msg: &mut Option<Xcm<()>>) -> SendResult<()> {
Ok(((), MultiAssets::new()))
}
fn deliver(_: ()) -> Result<XcmHash, SendError> {
Ok([0; 32])
}
}
pub type Barrier = AllowUnpaidExecutionFrom<Everything>;
pub struct DummyAssetTransactor;
impl TransactAsset for DummyAssetTransactor {
fn deposit_asset(
_what: &MultiAsset,
_who: &MultiLocation,
_context: Option<&XcmContext>,
) -> XcmResult {
Ok(())
}
fn withdraw_asset(
_what: &MultiAsset,
_who: &MultiLocation,
_maybe_context: Option<&XcmContext>,
) -> Result<Assets, XcmError> {
let asset: MultiAsset = (Parent, 100_000).into();
Ok(asset.into())
}
}
pub struct DummyWeightTrader;
impl WeightTrader for DummyWeightTrader {
fn new() -> Self {
DummyWeightTrader
}
fn buy_weight(
&mut self,
_weight: Weight,
_payment: Assets,
_context: &XcmContext,
) -> Result<Assets, XcmError> {
Ok(Assets::default())
}
}
type OriginConverter = (
pallet_xcm::XcmPassthrough<super::RuntimeOrigin>,
SignedAccountId32AsNative<AnyNetwork, super::RuntimeOrigin>,
);
pub struct XcmConfig;
impl xcm_executor::Config for XcmConfig {
type RuntimeCall = super::RuntimeCall;
type XcmSender = DoNothingRouter;
type AssetTransactor = DummyAssetTransactor;
type OriginConverter = OriginConverter;
type IsReserve = ();
type IsTeleporter = ();
type UniversalLocation = UniversalLocation;
type Barrier = Barrier;
type Weigher = FixedWeightBounds<BaseXcmWeight, super::RuntimeCall, MaxInstructions>;
type Trader = DummyWeightTrader;
type ResponseHandler = super::Xcm;
type AssetTrap = super::Xcm;
type AssetLocker = ();
type AssetExchanger = ();
type AssetClaims = super::Xcm;
type SubscriptionService = super::Xcm;
type PalletInstancesInfo = ();
type MaxAssetsIntoHolding = MaxAssetsIntoHolding;
type FeeManager = ();
type MessageExporter = ();
type UniversalAliases = Nothing;
type CallDispatcher = super::RuntimeCall;
type SafeCallFilter = Everything;
type Aliasers = Nothing;
}
impl pallet_xcm::Config for crate::Runtime {
// The config types here are entirely configurable, since the only one that is sorely needed
// is `XcmExecutor`, which will be used in unit tests located in xcm-executor.
type RuntimeEvent = crate::RuntimeEvent;
type ExecuteXcmOrigin = EnsureXcmOrigin<crate::RuntimeOrigin, LocalOriginToLocation>;
type UniversalLocation = UniversalLocation;
type SendXcmOrigin = EnsureXcmOrigin<crate::RuntimeOrigin, LocalOriginToLocation>;
type Weigher = FixedWeightBounds<BaseXcmWeight, crate::RuntimeCall, MaxInstructions>;
type XcmRouter = DoNothingRouter;
type XcmExecuteFilter = Everything;
type XcmExecutor = xcm_executor::XcmExecutor<XcmConfig>;
type XcmTeleportFilter = Everything;
type XcmReserveTransferFilter = Everything;
type RuntimeOrigin = crate::RuntimeOrigin;
type RuntimeCall = crate::RuntimeCall;
const VERSION_DISCOVERY_QUEUE_SIZE: u32 = 100;
type AdvertisedXcmVersion = pallet_xcm::CurrentXcmVersion;
type Currency = crate::Balances;
type CurrencyMatcher = ();
type TrustedLockers = ();
type SovereignAccountOf = ();
type MaxLockers = frame_support::traits::ConstU32<8>;
type MaxRemoteLockConsumers = frame_support::traits::ConstU32<0>;
type RemoteLockConsumerIdentifier = ();
type WeightInfo = pallet_xcm::TestWeightInfo;
type AdminOrigin = EnsureRoot<crate::AccountId>;
}