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https://github.com/pezkuwichain/pezkuwi-subxt.git
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Adrian Catangiu
18257373b3
## 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>
XCM Simulator Fuzzer
This project will fuzz-test the XCM simulator. It can catch reachable panics, timeouts as well as integer overflows and underflows.
Install dependencies
cargo install honggfuzz
Run the fuzzer
In this directory, run this command:
cargo hfuzz run xcm-fuzzer
Run a single input
In this directory, run this command:
cargo hfuzz run-debug xcm-fuzzer hfuzz_workspace/xcm-fuzzer/fuzzer_input_file
Generate coverage
In this directory, run these four commands:
RUSTFLAGS="-Zprofile -Ccodegen-units=1 -Copt-level=0 -Clink-dead-code -Coverflow-checks=off -Zpanic_abort_tests -Cpanic=abort" \
CARGO_INCREMENTAL=0 SKIP_WASM_BUILD=1 CARGO_HOME=./cargo cargo build
../../../target/debug/xcm-fuzzer hfuzz_workspace/xcm-fuzzer/input/
zip -0 ccov.zip `find ../../../target/ \( -name "*.gc*" -o -name "test-*.gc*" \) -print`
grcov ccov.zip -s ../../../ -t html --llvm --branch --ignore-not-existing -o ./coverage
The code coverage will be in ./coverage/index.html.