Clara van Staden
3410dfb392
## Bug Explanation Adds a check that prevents finalized headers with a gap larger than the sync committee period being imported, which could cause execution headers in the gap being unprovable. The current version of the Ethereum client checks that there is a header at least every sync committee, but it doesn't check that the headers are within a sync period of each other. For example: Header 100 (sync committee period 1) Header 9000 (sync committee period 2) (8900 blocks apart) These headers are in adjacent sync committees, but more than the sync committee period (8192 blocks) apart. The reason we need a header every 8192 slots at least, is the header is used to prove messages within the last 8192 blocks. If we import header 9000, and we receive a message to be verified at header 200, the `block_roots` field of header 9000 won't contain the header in order to do the ancestry check. ## Environment While running in Rococo, this edge case was discovered after the relayer was offline for a few days. It is unlikely, but not impossible, to happen again and so it should be backported to polkadot-sdk 1.7.0 (so that [polkadot-fellows/runtimes](https://github.com/polkadot-fellows/runtimes) can be updated with the fix). Our Ethereum client has been operational on Rococo for the past few months, and this been the only major issue discovered so far. ### Unrelated Change An unrelated nit: Removes a left over file that should have been deleted when the `parachain` directory was removed. --------- Co-authored-by: claravanstaden <Cats 4 life!>
Snowbridge ·
Snowbridge is a trustless bridge between Polkadot and Ethereum. For documentation, visit https://docs.snowbridge.network.
Components
The Snowbridge project lives in two repositories:
- Snowfork/Polkadot-sdk: The Snowbridge parachain and pallets live in a fork of the Polkadot SDK. Changes are eventually contributed back to paritytech/Polkadot-sdk
- Snowfork/snowbridge: The rest of the Snowbridge components, like contracts, off-chain relayer, end-to-end tests and test-net setup code.
Parachain
Polkadot parachain and our pallets. See README.md.
Contracts
Ethereum contracts and unit tests. See Snowfork/snowbridge/contracts/README.md
Relayer
Off-chain relayer services for relaying messages between Polkadot and Ethereum. See Snowfork/snowbridge/relayer/README.md
Local Testnet
Scripts to provision a local testnet, running the above services to bridge between local deployments of Polkadot and Ethereum. See Snowfork/snowbridge/web/packages/test/README.md.
Smoke Tests
Integration tests for our local testnet. See Snowfork/snowbridge/smoketest/README.md.
Development
We use the Nix package manager to provide a reproducible and maintainable developer environment.
After installing nix Nix, enable flakes:
mkdir -p ~/.config/nix
echo 'experimental-features = nix-command flakes' >> ~/.config/nix/nix.conf
Then activate a developer shell in the root of our repo, where
flake.nix is located:
nix develop
Also make sure to run this initialization script once:
scripts/init.sh
Support for code editors
To ensure your code editor (such as VS Code) can execute tools in the nix shell, startup your editor within the interactive shell.
Example for VS Code:
nix develop
code .
Custom shells
The developer shell is bash by default. To preserve your existing shell:
nix develop --command $SHELL
Automatic developer shells
To automatically enter the developer shell whenever you open the project, install
direnv and use the template .envrc:
cp .envrc.example .envrc
direnv allow
Upgrading the Rust toolchain
Sometimes we would like to upgrade rust toolchain. First update rust-toolchain.toml as required and then
update flake.lock running
nix flake lock --update-input rust-overlay
Troubleshooting
Check the contents of all .envrc files.
Remove untracked files:
git clean -idx
Ensure that the current Rust toolchain is the one selected in scripts/init.sh.
Ensure submodules are up-to-date:
git submodule update
Check untracked files & directories:
git clean -ndx | awk '{print $3}'
After removing node_modules directories (eg. with git clean above), clear the pnpm cache:
pnpm store prune
Check Nix config in ~/.config/nix/nix.conf.
Run a pure developer shell (note that this removes access to your local tools):
nix develop -i --pure-eval
Security
The security policy and procedures can be found in SECURITY.md.