# Note for reviewer
Most changes are just syntax changes necessary for the new version.
Most important files should be the ones under the `xcm` folder.
# Description
Added XCMv4.
## Removed `Multi` prefix
The following types have been renamed:
- MultiLocation -> Location
- MultiAsset -> Asset
- MultiAssets -> Assets
- InteriorMultiLocation -> InteriorLocation
- MultiAssetFilter -> AssetFilter
- VersionedMultiAsset -> VersionedAsset
- WildMultiAsset -> WildAsset
- VersionedMultiLocation -> VersionedLocation
In order to fix a name conflict, the `Assets` in `xcm-executor` were
renamed to `HoldingAssets`, as they represent assets in holding.
## Removed `Abstract` asset id
It was not being used anywhere and this simplifies the code.
Now assets are just constructed as follows:
```rust
let asset: Asset = (AssetId(Location::new(1, Here)), 100u128).into();
```
No need for specifying `Concrete` anymore.
## Outcome is now a named fields struct
Instead of
```rust
pub enum Outcome {
Complete(Weight),
Incomplete(Weight, Error),
Error(Error),
}
```
we now have
```rust
pub enum Outcome {
Complete { used: Weight },
Incomplete { used: Weight, error: Error },
Error { error: Error },
}
```
## Added Reanchorable trait
Now both locations and assets implement this trait, making it easier to
reanchor both.
## New syntax for building locations and junctions
Now junctions are built using the following methods:
```rust
let location = Location {
parents: 1,
interior: [Parachain(1000), PalletInstance(50), GeneralIndex(1984)].into()
};
```
or
```rust
let location = Location::new(1, [Parachain(1000), PalletInstance(50), GeneralIndex(1984)]);
```
And they are matched like so:
```rust
match location.unpack() {
(1, [Parachain(id)]) => ...
(0, Here) => ...,
(1, [_]) => ...,
}
```
This syntax is mandatory in v4, and has been also implemented for v2 and
v3 for easier migration.
This was needed to make all sizes smaller.
# TODO
- [x] Scaffold v4
- [x] Port github.com/paritytech/polkadot/pull/7236
- [x] Remove `Multi` prefix
- [x] Remove `Abstract` asset id
---------
Co-authored-by: command-bot <>
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>
In the move from the old `Currency` traits to the new `fungible/s`
family of traits, we already had the `FungiblesAdapter` and
`NonFungiblesAdapter` for multiple fungible and non fungible assets
respectively. However, for handling only one fungible asset, we were
missing a `FungibleAdapter`, and so used the old `CurrencyAdapter`
instead. This PR aims to fill in that gap, and provide the new adapter
for more updated examples.
I marked the old `CurrencyAdapter` as deprecated as part of this PR, and
I'll change it to the new `FungibleAdapter` in a following PR.
The two stages are separated so as to not bloat this PR with some name
fixes in tests.
---------
Co-authored-by: command-bot <>
We currently use a bit of a hack in `.cargo/config` to make sure that
clippy isn't too annoying by specifying the list of lints.
There is now a stable way to define lints for a workspace. The only down
side is that every crate seems to have to opt into this so there's a
*few* files modified in this PR.
Dependencies:
- [x] PR that upgrades CI to use rust 1.74 is merged.
---------
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
## Summary
This pull request proposes a solution for improved control of the
versioned XCM flow over the bridge (across different consensus chains)
and resolves the situation where the sending chain/consensus has already
migrated to a higher XCM version than the receiving chain/consensus.
## Problem/Motivation
The current flow over the bridge involves a transfer from AssetHubRococo
(AHR) to BridgeHubRococo (BHR) to BridgeHubWestend (BHW) and finally to
AssetHubWestend (AHW), beginning with a reserve-backed transfer on AHR.
In this process:
1. AHR sends XCM `ExportMessage` through `XcmpQueue`, incorporating XCM
version checks using the `WrapVersion` feature, influenced by
`pallet_xcm::SupportedVersion` (managed by
`pallet_xcm::force_xcm_version` or version discovery).
2. BHR handles the `ExportMessage` instruction, utilizing the latest XCM
version. The `HaulBlobExporter` converts the inner XCM to
[`VersionedXcm::from`](https://github.com/paritytech/polkadot-sdk/blob/63ac2471aa0210f0ac9903bdd7d8f9351f9a635f/polkadot/xcm/xcm-builder/src/universal_exports.rs#L465-L467),
also using the latest XCM version.
However, challenges arise:
- Incompatibility when BHW uses a different version than BHR. For
instance, if BHR migrates to **XCMv4** while BHW remains on **XCMv3**,
BHR's `VersionedXcm::from` uses `VersionedXcm::V4` variant, causing
encoding issues for BHW.
```
/// Just a simulation of possible error, which could happen on BHW
/// (this code is based on actual master without XCMv4)
let encoded = hex_literal::hex!("0400");
println!("{:?}", VersionedXcm::<()>::decode(&mut &encoded[..]));
Err(Error { cause: None, desc: "Could not decode `VersionedXcm`, variant
doesn't exist" })
```
- Similar compatibility issues exist between AHR and AHW.
## Solution
This pull request introduces the following solutions:
1. **New trait `CheckVersion`** - added to the `xcm` module and exposing
`pallet_xcm::SupportedVersion`. This enhancement allows checking the
actual XCM version for desired destinations outside of the `pallet_xcm`
module.
2. **Version Check in `HaulBlobExporter`** uses `CheckVersion` to check
known/configured destination versions, ensuring compatibility. For
example, in the scenario mentioned, BHR can store the version `3` for
BHW. If BHR is on XCMv4, it will attempt to downgrade the message to
version `3` instead of using the latest version `4`.
3. **Version Check in `pallet-xcm-bridge-hub-router`** - this check
ensures compatibility with the real destination's XCM version,
preventing the unnecessary sending of messages to the local bridge hub
if versions are incompatible.
These additions aim to improve the control and compatibility of XCM
flows over the bridge and addressing issues related to version
mismatches.
## Possible alternative solution
_(More investigation is needed, and at the very least, it should extend
to XCMv4/5. If this proves to be a viable option, I can open an RFC for
XCM.)._
Add the `XcmVersion` attribute to the `ExportMessage` so that the
sending chain can determine, based on what is stored in
`pallet_xcm::SupportedVersion`, the version the destination is using.
This way, we may not need to handle the version in `HaulBlobExporter`.
```
ExportMessage {
network: NetworkId,
destination: InteriorMultiLocation,
xcm: Xcm<()>
destination_xcm_version: Version, // <- new attritbute
},
```
```
pub trait ExportXcm {
fn validate(
network: NetworkId,
channel: u32,
universal_source: &mut Option<InteriorMultiLocation>,
destination: &mut Option<InteriorMultiLocation>,
message: &mut Option<Xcm<()>>,
destination_xcm_version: Version, , // <- new attritbute
) -> SendResult<Self::Ticket>;
```
## Future Directions
This PR does not fix version discovery over bridge, further
investigation will be conducted here:
https://github.com/paritytech/polkadot-sdk/issues/2417.
## TODO
- [x] `pallet_xcm` mock for tests uses hard-coded XCM version `2` -
change to 3 or lastest?
- [x] fix `pallet-xcm-bridge-hub-router`
- [x] fix HaulBlobExporter with version determination
[here](https://github.com/paritytech/polkadot-sdk/blob/2183669d05f9b510f979a0cc3c7847707bacba2e/polkadot/xcm/xcm-builder/src/universal_exports.rs#L465)
- [x] add unit-tests to the runtimes
- [x] run benchmarks for `ExportMessage`
- [x] extend local run scripts about `force_xcm_version(dest, version)`
- [ ] when merged, prepare governance calls for Rococo/Westend
- [ ] add PRDoc
Part of: https://github.com/paritytech/parity-bridges-common/issues/2719
---------
Co-authored-by: command-bot <>
# Motivation (+testing)
### Enable easy `ForeignAssets` transfers using `pallet-xcm`
We had just previously added capabilities to teleport fees during
reserve-based transfers, but what about reserve-transferring fees when
needing to teleport some non-fee asset?
This PR aligns everything under either explicit reserve-transfer,
explicit teleport, or this new flexible `transfer_assets()` which can
mix and match as needed with fewer artificial constraints imposed to the
user.
This will enable, for example, a (non-system) parachain to teleport
their `ForeignAssets` assets to AssetHub while using DOT to pay fees.
(the assets are teleported - as foreign assets should from their owner
chain - while DOT used for fees can only be reserve-based transferred
between said parachain and AssetHub).
Added `xcm-emulator` tests for this scenario ^.
# Description
Reverts `(limited_)reserve_transfer_assets` to only allow reserve-based
transfers for all `assets` including fees.
Similarly `(limited_)teleport_assets` only allows teleports for all
`assets` including fees.
For complex combinations of asset transfers where assets and fees may
have different reserves or different reserve/teleport trust
configurations, users can use the newly added `transfer_assets()`
extrinsic which is more flexible in allowing more complex scenarios.
`assets` (excluding `fees`) must have same reserve location or otherwise
be teleportable to `dest`.
No limitations imposed on `fees`.
- for local reserve: transfer assets to sovereign account of destination
chain and forward a notification XCM to `dest` to mint and deposit
reserve-based assets to `beneficiary`.
- for destination reserve: burn local assets and forward a notification
to `dest` chain to withdraw the reserve assets from this chain's
sovereign account and deposit them to `beneficiary`.
- for remote reserve: burn local assets, forward XCM to reserve chain to
move reserves from this chain's SA to `dest` chain's SA, and forward
another XCM to `dest` to mint and deposit reserve-based assets to
`beneficiary`.
- for teleports: burn local assets and forward XCM to `dest` chain to
mint/teleport assets and deposit them to `beneficiary`.
## Review notes
Only around 500 lines are prod code (see `pallet_xcm/src/lib.rs`), the
rest of the PR is new tests and improving existing tests.
---------
Co-authored-by: command-bot <>
Using taplo, fixes all our broken and inconsistent toml formatting and
adds CI to keep them tidy.
If people want we can customise the format rules as described here
https://taplo.tamasfe.dev/configuration/formatter-options.html
@ggwpez, I suggest zepter is used only for checking features are
propagated, and leave formatting for taplo to avoid duplicate work and
conflicts.
TODO
- [x] Use `exclude = [...]` syntax in taplo file to ignore zombienet
tests instead of deleting the dir
---------
Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Bastian Köcher <git@kchr.de>
On extrinsics/call, ensure local XCM execution is complete/successful.
Otherwise, fail the extrinsic so that state changes don't get committed
to the db.
Added regression tests that fail without the fix.
fixes#2237
---------
Co-authored-by: Adrian Catangiu <adrian@parity.io>
Disallow reserve transfers that use teleportable fees if `(origin,
fees)` matches `XcmTeleportFilter`.
Add regression tests for filtering based on `XcmTeleportFilter` for both
`(limited_)reserve_transfer_assets()` and `(limited_)teleport_assets`
extrinsics.
## 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>
We are introducing a new set of `XcmController` traits (final name yet
to be determined).
These traits are implemented by `pallet-xcm` and allows other pallets,
such as `pallet_contracts`, to rely on these traits instead of tight
coupling them to `pallet-xcm`.
Using only the existing Xcm traits would mean duplicating the logic from
`pallet-xcm` in these other pallets, which we aim to avoid. Our
objective is to ensure that when these APIs are called from
`pallet-contracts`, they produce the exact same outcomes as if called
directly from `pallet-xcm`.
The other benefits is that we can also expose return values to
`pallet-contracts` instead of just calling `pallet-xcm` dispatchable and
getting a `DispatchResult` back.
See traits integration in this PR
https://github.com/paritytech/polkadot-sdk/pull/1248, where the traits
are used as follow to define and implement `pallet-contracts` Config.
```rs
// Contracts config:
pub trait Config: frame_system::Config {
// ...
/// A type that exposes XCM APIs, allowing contracts to interact with other parachains, and
/// execute XCM programs.
type Xcm: xcm_executor::traits::Controller<
OriginFor<Self>,
<Self as frame_system::Config>::RuntimeCall,
BlockNumberFor<Self>,
>;
}
// implementation
impl pallet_contracts::Config for Runtime {
// ...
type Xcm = pallet_xcm::Pallet<Self>;
}
```
---------
Co-authored-by: Alexander Theißen <alex.theissen@me.com>
Co-authored-by: command-bot <>
Adds a config file that allows to run `zepter` without any arguments in
the workspace to address all issues.
A secondary workflow for the CI is provided as `zepter run check`. Both
the formatting and linting are now in one check for efficiancy.
The latest version also detects some more things that `featalign` was
already showing.
Error message [in the
CI](https://gitlab.parity.io/parity/mirrors/polkadot-sdk/-/jobs/3916205)
now looks like this:
```pre
...
crate 'test-parachains' (/Users/vados/Documents/work/polkadot-sdk/polkadot/parachain/test-parachains/Cargo.toml)
feature 'std'
must propagate to:
parity-scale-codec
Found 55 issues (run with --fix to fix).
Error: Command 'lint propagate-feature' failed with exit code 1
Polkadot-SDK uses the Zepter CLI to detect abnormalities in the feature configuration.
It looks like one more more checks failed; please check the console output. You can try to automatically address them by running `zepter`.
Otherwise please ask directly in the Merge Request, GitHub Discussions or on Matrix Chat, thank you.
For more information, see:
- https://github.com/paritytech/polkadot-sdk/issues/1831
- https://github.com/ggwpez/zepter
```
TODO:
- [x] Check that CI fails correctly
---------
Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
closes https://github.com/paritytech/polkadot-sdk/issues/1882
## Breaking Changes
This PR introduces a new item to `pallet_balances::Config`:
```diff
trait Config {
++ type RuntimeFreezeReasons;
}
```
This value is only used to check it against `type MaxFreeze`. A similar
check has been added for `MaxHolds` against `RuntimeHoldReasons`, which
is already given to `pallet_balances`.
In all contexts, you should pass the real `RuntimeFreezeReasons`
generated by `construct_runtime` to `type RuntimeFreezeReasons`. Passing
`()` would also work, but it would imply that the runtime uses no
freezes at all.
---------
Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
The `xcm` crate was renamed to `staging-xcm` to be able to publish it to
crates.io as someone as squatted `xcm`. The problem with this rename is
that the `TypeInfo` includes the crate name which ultimately lands in
the metadata. The metadata is consumed by downstream users like
`polkadot-js` or people building on top of `polkadot-js`. These people
are using the entire `path` to find the type in the type registry. Thus,
their code would break as the type path would now be [`staging_xcm`,
`VersionedXcm`] instead of [`xcm`, `VersionedXcm`]. This pull request
fixes this by renaming the path segment `staging_xcm` to `xcm`.
This requires: https://github.com/paritytech/scale-info/pull/197
---------
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
Combination of paritytech/polkadot#7005, its addon PR
paritytech/polkadot#7585 and its companion paritytech/cumulus#2433.
This PR introduces a new XcmFeesToAccount struct which implements the
`FeeManager` trait, and assigns this struct as the `FeeManager` in the
XCM config for all runtimes.
The struct simply deposits all fees handled by the XCM executor to a
specified account. In all runtimes, the specified account is configured
as the treasury account.
XCM __delivery__ fees are now being introduced (unless the root origin
is sending a message to a system parachain on behalf of the originating
chain).
# Note for reviewers
Most file changes are tests that had to be modified to account for the
new fees.
Main changes are in:
- cumulus/pallets/xcmp-queue/src/lib.rs <- To make it track the delivery
fees exponential factor
- polkadot/xcm/xcm-builder/src/fee_handling.rs <- Added. Has the
FeeManager implementation
- All runtime xcm_config files <- To add the FeeManager to the XCM
configuration
# Important note
After this change, instructions that create and send a new XCM (Query*,
Report*, ExportMessage, InitiateReserveWithdraw, InitiateTeleport,
DepositReserveAsset, TransferReserveAsset, LockAsset and RequestUnlock)
will require the corresponding origin account in the origin register to
pay for transport delivery fees, and the onward message will fail to be
sent if the origin account does not have the required amount. This
delivery fee is on top of what we already collect as tx fees in
pallet-xcm and XCM BuyExecution fees!
Wallet UIs that want to expose the new delivery fee can do so using the
formula:
```
delivery_fee_factor * (base_fee + encoded_msg_len * per_byte_fee)
```
where the delivery fee factor can be obtained from the corresponding
pallet based on which transport you are using (UMP, HRMP or bridges),
the base fee is a constant, the encoded message length from the message
itself and the per byte fee is the same as the configured per byte fee
for txs (i.e. `TransactionByteFee`).
---------
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Giles Cope <gilescope@gmail.com>
Co-authored-by: command-bot <>
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Two old functions should be deprecated and have their code altered in
line with capabilities of XCMv2 and above.
This means we can use the proper `Unlimited` form of weight limit rather
than guessing weight from the local chain.
`VersionedMigration` has become somewhat widely used for handling
version bumps in migrations the last few months.
It is currently behind the `experimental` feature flag, requiring every
pallet that writes a new migration with version bumps to set up the
`experimental` flag in their own Cargo.tomls, and also for every runtime
using these pallets to explicitly enable the `experimental` flag for
each pallet.
This is becoming quite verbose, and I can only see the number of pallets
requiring the experimental flag increasing for no other reason than
using what has become a commonly used feature.
Additionally, I'm writing migration docs and would like to avoid
stepping through how to use the `experimental` feature to get
`VersionedMigration` working.
Since the feature has been used in production for some time now without
any reported issues, is becoming commonly used and ready to advertise in
docs, I feel this is a good time to make it non-experimental.
* Rename `polkadot-parachain` to `polkadot-parachain-primitives`
While doing this it also fixes some last `rustdoc` issues and fixes
another Cargo warning related to `pallet-paged-list`.
* Fix compilation
* ".git/.scripts/commands/fmt/fmt.sh"
* Fix XCM docs
---------
Co-authored-by: command-bot <>
* Rename squatted crates
This commit adds the staging- prefix to squatted crates so we can go forward and publish them to crates.io.
Using the staging- prefix is a temp fix until we decide on replacement names.
https://forum.parity.io/t/renaming-squated-crates-in-substrate-polkadot-cumulus/1964/6
* Fix test after crate renames
* Update Lockfile
Francisco Aguirre