## 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 <>
# Description
- What does this PR do? Allows to generate JSON schema for subset of XCM
in std builds
- Why are these changes needed? To support XCM messages in CosmWasm
contracts which require Schemars to generate contract clients
- How were these changes implemented and what do they affect? We will
use schema feature flag to build XCM pallet with JSON schema enabled
# Checklist
- [x] My PR includes a detailed description as outlined in the
"Description" section above
- [x] My PR follows the [labeling requirements](CONTRIBUTING.md#Process)
of this project (at minimum one label for `T`
required)
- [x] I have made corresponding changes to the documentation (if
applicable)
- [x] I have added tests that prove my fix is effective or that my
feature works (if applicable)
- [x] If this PR alters any external APIs or interfaces used by
Polkadot, the corresponding Polkadot PR is ready as well
as the corresponding Cumulus PR (optional)
We're going to bridge Polkadot Bridge Hub with [Polkadot Bulletin
chain](https://github.com/zdave-parity/polkadot-bulletin-chain) soon
(and Rococo Bridge Hub with 1:1 copy of Polkadot Bulletin chain even
sooner), so we need a variant for that chain in `NetworkId`. As
suggested, I'm adding a new variant for it to the `NetworkId` (we may
have used `ByGenesis(_)`, but decision was made to have a dedicated
variant for that).
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>
Adding on top of the new builder pattern for creating XCM programs, I'm
adding some more APIs:
```rust
let paying_fees: Xcm<()> = Xcm::builder() // Only allow paying for fees
.withdraw_asset() // First instruction has to load the holding register
.buy_execution() // Second instruction has to be `buy_execution`
.build();
let paying_fees_invalid: Xcm<()> = Xcm::builder()
.withdraw_asset()
.build(); // Invalid, need to pay for fees
let not_paying_fees: Xcm<()> = Xcm::builder_unpaid()
.unpaid_execution() // Needed
.withdraw_asset()
.deposit_asset()
.build();
let all_goes: Xcm<()> = Xcm::builder_unsafe() // You can do anything
.withdraw_asset()
.deposit_asset()
.build();
```
The invalid bits are because the methods don't even exist on the types
that you'd want to call them on.
---------
Co-authored-by: command-bot <>
## 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>
PalletInfo fields were private, preventing a user from actually using
the QueryPallet instruction in a meaningful way since they couldn't read
the received data.
Added a proc macro to be able to write XCMs using the builder pattern.
This means we go from having to do this:
```rust
let message: Xcm<()> = Xcm(vec![
WithdrawAsset(assets),
BuyExecution { fees: asset, weight_limit: Unlimited },
DepositAsset { assets, beneficiary },
]);
```
to this:
```rust
let message: Xcm<()> = Xcm::builder()
.withdraw_asset(assets)
.buy_execution(asset, Unlimited),
.deposit_asset(assets, beneficiary)
.build();
```
---------
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>
Co-authored-by: command-bot <>
(imported from https://github.com/paritytech/cumulus/pull/2157)
## Changes
This MR refactores the XCMP, Parachains System and DMP pallets to use
the [MessageQueue](https://github.com/paritytech/substrate/pull/12485)
for delayed execution of incoming messages. The DMP pallet is entirely
replaced by the MQ and thereby removed. This allows for PoV-bounded
execution and resolves a number of issues that stem from the current
work-around.
All System Parachains adopt this change.
The most important changes are in `primitives/core/src/lib.rs`,
`parachains/common/src/process_xcm_message.rs`,
`pallets/parachain-system/src/lib.rs`, `pallets/xcmp-queue/src/lib.rs`
and the runtime configs.
### DMP Queue Pallet
The pallet got removed and its logic refactored into parachain-system.
Overweight message management can be done directly through the MQ
pallet.
Final undeployment migrations are provided by
`cumulus_pallet_dmp_queue::UndeployDmpQueue` and `DeleteDmpQueue` that
can be configured with an aux config trait like:
```rust
parameter_types! {
pub const DmpQueuePalletName: &'static str = \"DmpQueue\" < CHANGE ME;
pub const RelayOrigin: AggregateMessageOrigin = AggregateMessageOrigin::Parent;
}
impl cumulus_pallet_dmp_queue::MigrationConfig for Runtime {
type PalletName = DmpQueuePalletName;
type DmpHandler = frame_support::traits::EnqueueWithOrigin<MessageQueue, RelayOrigin>;
type DbWeight = <Runtime as frame_system::Config>::DbWeight;
}
// And adding them to your Migrations tuple:
pub type Migrations = (
...
cumulus_pallet_dmp_queue::UndeployDmpQueue<Runtime>,
cumulus_pallet_dmp_queue::DeleteDmpQueue<Runtime>,
);
```
### XCMP Queue pallet
Removed all dispatch queue functionality. Incoming XCMP messages are now
either: Immediately handled if they are Signals, enqueued into the MQ
pallet otherwise.
New config items for the XCMP queue pallet:
```rust
/// The actual queue implementation that retains the messages for later processing.
type XcmpQueue: EnqueueMessage<ParaId>;
/// How a XCM over HRMP from a sibling parachain should be processed.
type XcmpProcessor: ProcessMessage<Origin = ParaId>;
/// The maximal number of suspended XCMP channels at the same time.
#[pallet::constant]
type MaxInboundSuspended: Get<u32>;
```
How to configure those:
```rust
// Use the MessageQueue pallet to store messages for later processing. The `TransformOrigin` is needed since
// the MQ pallet itself operators on `AggregateMessageOrigin` but we want to enqueue `ParaId`s.
type XcmpQueue = TransformOrigin<MessageQueue, AggregateMessageOrigin, ParaId, ParaIdToSibling>;
// Process XCMP messages from siblings. This is type-safe to only accept `ParaId`s. They will be dispatched
// with origin `Junction::Sibling(…)`.
type XcmpProcessor = ProcessFromSibling<
ProcessXcmMessage<
AggregateMessageOrigin,
xcm_executor::XcmExecutor<xcm_config::XcmConfig>,
RuntimeCall,
>,
>;
// Not really important what to choose here. Just something larger than the maximal number of channels.
type MaxInboundSuspended = sp_core::ConstU32<1_000>;
```
The `InboundXcmpStatus` storage item was replaced by
`InboundXcmpSuspended` since it now only tracks inbound queue suspension
and no message indices anymore.
Now only sends the most recent channel `Signals`, as all prio ones are
out-dated anyway.
### Parachain System pallet
For `DMP` messages instead of forwarding them to the `DMP` pallet, it
now pushes them to the configured `DmpQueue`. The message processing
which was triggered in `set_validation_data` is now being done by the MQ
pallet `on_initialize`.
XCMP messages are still handed off to the `XcmpMessageHandler`
(XCMP-Queue pallet) - no change here.
New config items for the parachain system pallet:
```rust
/// Queues inbound downward messages for delayed processing.
///
/// Analogous to the `XcmpQueue` of the XCMP queue pallet.
type DmpQueue: EnqueueMessage<AggregateMessageOrigin>;
```
How to configure:
```rust
/// Use the MQ pallet to store DMP messages for delayed processing.
type DmpQueue = MessageQueue;
```
## Message Flow
The flow of messages on the parachain side. Messages come in from the
left via the `Validation Data` and finally end up at the `Xcm Executor`
on the right.
## Further changes
- Bumped the default suspension, drop and resume thresholds in
`QueueConfigData::default()`.
- `XcmpQueue::{suspend_xcm_execution, resume_xcm_execution}` errors when
they would be a noop.
- Properly validate the `QueueConfigData` before setting it.
- Marked weight files as auto-generated so they wont auto-expand in the
MR files view.
- Move the `hypothetical` asserts to `frame_support` under the name
`experimental_hypothetically`
Questions:
- [ ] What about the ugly `#[cfg(feature = \"runtime-benchmarks\")]` in
the runtimes? Not sure how to best fix. Just having them like this makes
tests fail that rely on the real message processor when the feature is
enabled.
- [ ] Need a good weight for `MessageQueueServiceWeight`. The scheduler
already takes 80% so I put it to 10% but that is quite low.
TODO:
- [x] Remove c&p code after
https://github.com/paritytech/polkadot/pull/6271
- [x] Use `HandleMessage` once it is public in Substrate
- [x] fix `runtime-benchmarks` feature
https://github.com/paritytech/polkadot/pull/6966
- [x] Benchmarks
- [x] Tests
- [ ] Migrate `InboundXcmpStatus` to `InboundXcmpSuspended`
- [x] Possibly cleanup Migrations (DMP+XCMP)
- [x] optional: create `TransformProcessMessageOrigin` in Substrate and
replace `ProcessFromSibling`
- [ ] Rerun weights on ref HW
---------
Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Co-authored-by: command-bot <>
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>
* Enforce a decoding limit in MultiAssets
* ".git/.scripts/commands/fmt/fmt.sh"
* Update polkadot/xcm/src/v3/multiasset.rs
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>
* Just use a BoundedVec
* Conflicts
---------
Co-authored-by: command-bot <>
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>
* 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 <>
* Put `GetWeight` where it belongs
* add GetWeight to v2
* Re-export unchanged trait
---------
Co-authored-by: Just van Stam <just.van.stam@gmail.com>
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>
* Add instruction limit when decoding XCMs
* Make the instruction limit a constant
* Use vec for buffer
* ".git/.scripts/commands/fmt/fmt.sh"
* Go back on std
* Use BoundedVec's Decode implementation
* ".git/.scripts/commands/fmt/fmt.sh"
* Use an actual BoundedVec to decode XCMs
* Change comment location
* ".git/.scripts/commands/fmt/fmt.sh"
* Remove unused imports
* ".git/.scripts/commands/fmt/fmt.sh"
---------
Co-authored-by: command-bot <>
* Tools for unique topic references
* Formatting
* Naming
* Repot into routing.rs.
* More things done
* Universal Exporter supports topic-as-reference
* Some tests for the topic routing
* More tests
* Paid bridge tests
* Add message ID to sending events
* Formatting
* fix and integrate into test nets
* Move DenyThenTry and friend from Cumulus
* Append SetTopic rather than prepend
* Docs
* Docs
* Work with new ProcessMessage ID API
* Formatting
* Fix build
* Fixes
* Formatting
* Update xcm/xcm-builder/src/barriers.rs
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
* Update xcm/xcm-builder/src/routing.rs
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
* Docs
* Rename message_hash
* Formatting
* ".git/.scripts/commands/fmt/fmt.sh"
* Rename
* Another Rename
* ".git/.scripts/commands/fmt/fmt.sh"
* ".git/.scripts/commands/fmt/fmt.sh"
* Update xcm/xcm-builder/src/routing.rs
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>
---------
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
Co-authored-by: command-bot <>
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>
* Reduce base proof size weight component to 1KiB
* Create TempFixedXcmWeight and set PoV weight to 0
* Set DEFAULT_PROOF_SIZE to 0
* Fix comment
* Update test expectations
* Fix comment
* Properly set the pricing for the DMP router
* Publicize price types
* Use FixedU128 instead of Percent
* Add sp-arithmetic as a dependency for rococo runtime
* Add sp-arithmetic as a dependency to all runtimes
* Remove duplicate import
* Add missing import
* Fix tests
* Create an appropriate QueueDownwardMessageError variant
* Recalculate delivery fee factor based on past queue sizes
* Remove unused error variant
* Fixes
* Fixes
* Remove unused imports
* Rewrite fee factor update mechanism
* Remove unused imports
* Fixes
* Update runtime/parachains/src/dmp.rs
Co-authored-by: Squirrel <gilescope@gmail.com>
* Make DeliveryFeeFactor be a StorageMap keyed on ParaIds
* Fixes
* introduce limit for fee increase on dmp queue
* add message_size based fee factor to increment_fee_factor
* change message_size fee rate to correct value
* fix div by 0 error
* bind limit to variable
* fix message_size_factor and add DeliveryFeeFactor test
* add test for ExponentialPrice implementation
* make test formula based
* make delivery fee factor test formula based
* add max value test for DeliveryFeeFactor and move limit to config
* change threshold back to dynamic value and fix tests
* fmt
* suggested changes and fmt
* small stylistic change
* fmt
* change to tokenlocation
* small fixes
* fmt
* remove sp_arithmetic dependency
* Update runtime/parachains/src/dmp.rs
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
---------
Co-authored-by: Squirrel <gilescope@gmail.com>
Co-authored-by: Just van Stam <just.van.stam@gmail.com>
Co-authored-by: Just van Stam <vstam1@users.noreply.github.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
* Happy New Year!
* Remove year entierly
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
* Remove years from copyright notice in the entire repo
---------
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Bastian Köcher