## Issue Addressed
Solves #4442
## Proposed Changes
EL clients log errors if we don't query this endpoint, but they are making releases that remove this error logging. After those are out we can stop calling it, after which point EL teams will remove the endpoint entirely.
Refer https://hackmd.io/@n0ble/deprecate-exchgTC
## Issue Addressed
This PR attempts to workaround the recent frequent eth1 simulator failures caused by missing eth logs from Anvil.
> FailedToInsertDeposit(NonConsecutive { log_index: 1, expected: 0 })
This usually occurs at the beginning of the tests, and it guarantees a timeout after a few hours if this log shows up, and this is currently causing our CIs to fail quite frequently.
Example failure here: https://github.com/sigp/lighthouse/actions/runs/5525760195/jobs/10079736914
## Proposed Changes
The quick fix applied here adds a timeout to node startup and restarts the node again.
- Add a 60 seconds timeout to beacon node startup in eth1 simulator tests. It takes ~10 seconds on my machine, but could take longer on CI runners.
- Wrap the startup code in a retry function, that allows for 3 retries before returning an error.
## Additional Info
We should probably raise an issue under the Anvil GitHub repo there so this can be further investigated.
## Proposed Changes
Replace `wget` in the EF-tests makefile with `curl`.
On macOS `curl` is pre-installed, and I found myself making this change to avoid installing `wget`.
The `-L` flag is used to follow redirects which is useful if a repo gets renamed, and more similar to `wget`'s default behaviour.
## Issue Addressed
When trying to run `eth1-sim` locally, the simulator doesn't start for me, and panicked due to duplicate arg names for `proposer-nodes` (using same arg names as `nodes`). Not sure why this isn't failing on CI but failing on mine 🤔
```
thread 'main' panicked at 'Argument short must be unique
thread 'main' panicked at 'Argument long must be unique
```
## Issue Addressed
#4118
## Proposed Changes
This PR introduces a "progressive balances" cache on the `BeaconState`, which keeps track of the accumulated target attestation balance for the current & previous epochs. The cached values are utilised by fork choice to calculate unrealized justification and finalization (instead of converting epoch participation arrays to balances for each block we receive).
This optimization will be rolled out gradually to allow for more testing. A new `--progressive-balances disabled|checked|strict|fast` flag is introduced to support this:
- `checked`: enabled with checks against participation cache, and falls back to the existing epoch processing calculation if there is a total target attester balance mismatch. There is no performance gain from this as the participation cache still needs to be computed. **This is the default mode for now.**
- `strict`: enabled with checks against participation cache, returns error if there is a mismatch. **Used for testing only**.
- `fast`: enabled with no comparative checks and without computing the participation cache. This mode gives us the performance gains from the optimization. This is still experimental and not currently recommended for production usage, but will become the default mode in a future release.
- `disabled`: disable the usage of progressive cache, and use the existing method for FFG progression calculation. This mode may be useful if we find a bug and want to stop the frequent error logs.
### Tasks
- [x] Initial cache implementation in `BeaconState`
- [x] Perform checks in fork choice to compare the progressive balances cache against results from `ParticipationCache`
- [x] Add CLI flag, and disable the optimization by default
- [x] Testing on Goerli & Benchmarking
- [x] Move caching logic from state processing to the `ProgressiveBalancesCache` (see [this comment](https://github.com/sigp/lighthouse/pull/4362#discussion_r1230877001))
- [x] Add attesting balance metrics
Co-authored-by: Jimmy Chen <jimmy@sigmaprime.io>
## Issue Addressed
- #4293
- #4264
## Proposed Changes
*Changes largely follow those suggested in the main issue*.
- Add new routes to HTTP API
- `post_beacon_blocks_v2`
- `post_blinded_beacon_blocks_v2`
- Add new routes to `BeaconNodeHttpClient`
- `post_beacon_blocks_v2`
- `post_blinded_beacon_blocks_v2`
- Define new Eth2 common types
- `BroadcastValidation`, enum representing the level of validation to apply to blocks prior to broadcast
- `BroadcastValidationQuery`, the corresponding HTTP query string type for the above type
- ~~Define `_checked` variants of both `publish_block` and `publish_blinded_block` that enforce a validation level at a type level~~
- Add interactive tests to the `bn_http_api_tests` test target covering each validation level (to their own test module, `broadcast_validation_tests`)
- `beacon/blocks`
- `broadcast_validation=gossip`
- Invalid (400)
- Full Pass (200)
- Partial Pass (202)
- `broadcast_validation=consensus`
- Invalid (400)
- Only gossip (400)
- Only consensus pass (i.e., equivocates) (200)
- Full pass (200)
- `broadcast_validation=consensus_and_equivocation`
- Invalid (400)
- Invalid due to early equivocation (400)
- Only gossip (400)
- Only consensus (400)
- Pass (200)
- `beacon/blinded_blocks`
- `broadcast_validation=gossip`
- Invalid (400)
- Full Pass (200)
- Partial Pass (202)
- `broadcast_validation=consensus`
- Invalid (400)
- Only gossip (400)
- ~~Only consensus pass (i.e., equivocates) (200)~~
- Full pass (200)
- `broadcast_validation=consensus_and_equivocation`
- Invalid (400)
- Invalid due to early equivocation (400)
- Only gossip (400)
- Only consensus (400)
- Pass (200)
- Add a new trait, `IntoGossipVerifiedBlock`, which allows type-level guarantees to be made as to gossip validity
- Modify the structure of the `ObservedBlockProducers` cache from a `(slot, validator_index)` mapping to a `((slot, validator_index), block_root)` mapping
- Modify `ObservedBlockProducers::proposer_has_been_observed` to return a `SeenBlock` rather than a boolean on success
- Punish gossip peer (low) for submitting equivocating blocks
- Rename `BlockError::SlashablePublish` to `BlockError::SlashableProposal`
## Additional Info
This PR contains changes that directly modify how blocks are verified within the client. For more context, consult [comments in-thread](https://github.com/sigp/lighthouse/pull/4316#discussion_r1234724202).
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
Closes#4332
## Proposed Changes
Remove the `CountUnrealized` type, defaulting unrealized justification to _on_. This fixes the #4332 issue by ensuring that importing the same block to fork choice always results in the same outcome.
Finalized sync speed may be slightly impacted by this change, but that is deemed an acceptable trade-off until the optimisation from #4118 is implemented.
TODO:
- [x] Also check that the block isn't a duplicate before importing
This PR adds the ability to read the Lighthouse logs from the HTTP API for both the BN and the VC.
This is done in such a way to as minimize any kind of performance hit by adding this feature.
The current design creates a tokio broadcast channel and mixes is into a form of slog drain that combines with our main global logger drain, only if the http api is enabled.
The drain gets the logs, checks the log level and drops them if they are below INFO. If they are INFO or higher, it sends them via a broadcast channel only if there are users subscribed to the HTTP API channel. If not, it drops the logs.
If there are more than one subscriber, the channel clones the log records and converts them to json in their independent HTTP API tasks.
Co-authored-by: Michael Sproul <micsproul@gmail.com>
## Issue Addressed
N/A
## Proposed Changes
Replace ganache-cli with anvil https://github.com/foundry-rs/foundry/blob/master/anvil/README.md
We can lose all js dependencies in CI as a consequence.
## Additional info
Also changes the ethers-rs version used in the execution layer (for the transaction reconstruction) to a newer one. This was necessary to get use the ethers utils for anvil. The fixed execution engine integration tests should catch any potential issues with the payload reconstruction after #3592
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
Addresses #4234
## Proposed Changes
- Skip withdrawals processing in an inconsistent state replay.
- Repurpose `StateRootStrategy`: rename to `StateProcessingStrategy` and always skip withdrawals if using `StateProcessingStrategy::Inconsistent`
- Add a test to reproduce the scenario
Co-authored-by: Jimmy Chen <jimmy@sigmaprime.io>
It is a well-known fact that IP addresses for beacon nodes used by specific validators can be de-anonymized. There is an assumed risk that a malicious user may attempt to DOS validators when producing blocks to prevent chain growth/liveness.
Although there are a number of ideas put forward to address this, there a few simple approaches we can take to mitigate this risk.
Currently, a Lighthouse user is able to set a number of beacon-nodes that their validator client can connect to. If one beacon node is taken offline, it can fallback to another. Different beacon nodes can use VPNs or rotate IPs in order to mask their IPs.
This PR provides an additional setup option which further mitigates attacks of this kind.
This PR introduces a CLI flag --proposer-only to the beacon node. Setting this flag will configure the beacon node to run with minimal peers and crucially will not subscribe to subnets or sync committees. Therefore nodes of this kind should not be identified as nodes connected to validators of any kind.
It also introduces a CLI flag --proposer-nodes to the validator client. Users can then provide a number of beacon nodes (which may or may not run the --proposer-only flag) that the Validator client will use for block production and propagation only. If these nodes fail, the validator client will fallback to the default list of beacon nodes.
Users are then able to set up a number of beacon nodes dedicated to block proposals (which are unlikely to be identified as validator nodes) and point their validator clients to produce blocks on these nodes and attest on other beacon nodes. An attack attempting to prevent liveness on the eth2 network would then need to preemptively find and attack the proposer nodes which is significantly more difficult than the default setup.
This is a follow on from: #3328
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
## Issue Addressed
There was a [`VecDeque` bug](https://github.com/rust-lang/rust/issues/108453) in some recent versions of the Rust standard library (1.67.0 & 1.67.1) that could cause Lighthouse to panic (reported by `@Sea Monkey` on discord). See full logs below.
The issue was likely introduced in Rust 1.67.0 and [fixed](https://github.com/rust-lang/rust/pull/108475) in 1.68, and we were able to reproduce the panic ourselves using [@michaelsproul's fuzz tests](https://github.com/michaelsproul/lighthouse/blob/fuzz-lru-time-cache/beacon_node/lighthouse_network/src/peer_manager/fuzz.rs#L111) on both Rust 1.67.0 and 1.67.1.
Users that uses our Docker images or binaries are unlikely affected, as our Docker images were built with `1.66`, and latest binaries were built with latest stable (`1.68.2`). It likely impacts user that builds from source using Rust versions 1.67.x.
## Proposed Changes
Bump Rust version (MSRV) to latest stable `1.68.2`.
## Additional Info
From `@Sea Monkey` on Lighthouse Discord:
> Crash on goerli using `unstable` `dd124b2d6804d02e4e221f29387a56775acccd08`
```
thread 'tokio-runtime-worker' panicked at 'Key must exist', /mnt/goerli/goerli/lighthouse/common/lru_cache/src/time.rs:68:28
stack backtrace:
Apr 15 09:37:36.993 WARN Peer sent invalid block in single block lookup, peer_id: 16Uiu2HAm6ZuyJpVpR6y51X4Enbp8EhRBqGycQsDMPX7e5XfPYznG, error: WouldRevertFinalizedSlot { block_slot: Slot(5420212), finalized_slot: Slot(5420224) }, root: 0x10f6…3165, service: sync
0: rust_begin_unwind
at /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/std/src/panicking.rs:575:5
1: core::panicking::panic_fmt
at /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/core/src/panicking.rs:64:14
2: core::panicking::panic_display
at /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/core/src/panicking.rs:135:5
3: core::panicking::panic_str
at /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/core/src/panicking.rs:119:5
4: core::option::expect_failed
at /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/core/src/option.rs:1879:5
5: lru_cache::time::LRUTimeCache<Key>::raw_remove
6: lighthouse_network::peer_manager::PeerManager<TSpec>::handle_ban_operation
7: lighthouse_network::peer_manager::PeerManager<TSpec>::handle_score_action
8: lighthouse_network::peer_manager::PeerManager<TSpec>::report_peer
9: network::service::NetworkService<T>::spawn_service::{{closure}}
10: <futures_util::future::select::Select<A,B> as core::future::future::Future>::poll
11: <futures_util::future::future::map::Map<Fut,F> as core::future::future::Future>::poll
12: <futures_util::future::future::flatten::Flatten<Fut,<Fut as core::future::future::Future>::Output> as core::future::future::Future>::poll
13: tokio::loom::std::unsafe_cell::UnsafeCell<T>::with_mut
14: tokio::runtime::task::core::Core<T,S>::poll
15: tokio::runtime::task::harness::Harness<T,S>::poll
16: tokio::runtime::scheduler::multi_thread::worker::Context::run_task
17: tokio::runtime::scheduler::multi_thread::worker::Context::run
18: tokio::macros::scoped_tls::ScopedKey<T>::set
19: tokio::runtime::scheduler::multi_thread::worker::run
20: tokio::loom::std::unsafe_cell::UnsafeCell<T>::with_mut
21: tokio::runtime::task::core::Core<T,S>::poll
22: tokio::runtime::task::harness::Harness<T,S>::poll
23: tokio::runtime::blocking::pool::Inner::run
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
Apr 15 09:37:37.069 INFO Saved DHT state service: network
Apr 15 09:37:37.070 INFO Network service shutdown service: network
Apr 15 09:37:37.132 CRIT Task panic. This is a bug! advice: Please check above for a backtrace and notify the developers, message: <none>, task_name: network
Apr 15 09:37:37.132 INFO Internal shutdown received reason: Panic (fatal error)
Apr 15 09:37:37.133 INFO Shutting down.. reason: Failure("Panic (fatal error)")
Apr 15 09:37:37.135 WARN Unable to free worker error: channel closed, msg: did not free worker, shutdown may be underway
Apr 15 09:37:39.350 INFO Saved beacon chain to disk service: beacon
Panic (fatal error)
```
## Proposed Changes
Builds on #4028 to use the new payload bodies methods in the HTTP API as well.
## Caveats
The payloads by range method only works for the finalized chain, so it can't be used in the execution engine integration tests because we try to reconstruct unfinalized payloads there.
## Issue Addressed
Attempt to fix#3812
## Proposed Changes
Move web3signer binary download script out of build script to avoid downloading unless necessary. If this works, it should also reduce the build time for all jobs that runs compilation.
## Issue Addressed
#3212
## Proposed Changes
- Introduce a new `rate_limiting_backfill_queue` - any new inbound backfill work events gets immediately sent to this FIFO queue **without any processing**
- Spawn a `backfill_scheduler` routine that pops a backfill event from the FIFO queue at specified intervals (currently halfway through a slot, or at 6s after slot start for 12s slots) and sends the event to `BeaconProcessor` via a `scheduled_backfill_work_tx` channel
- This channel gets polled last in the `InboundEvents`, and work event received is wrapped in a `InboundEvent::ScheduledBackfillWork` enum variant, which gets processed immediately or queued by the `BeaconProcessor` (existing logic applies from here)
Diagram comparing backfill processing with / without rate-limiting:
https://github.com/sigp/lighthouse/issues/3212#issuecomment-1386249922
See this comment for @paulhauner's explanation and solution: https://github.com/sigp/lighthouse/issues/3212#issuecomment-1384674956
## Additional Info
I've compared this branch (with backfill processing rate limited to to 1 and 3 batches per slot) against the latest stable version. The CPU usage during backfill sync is reduced by ~5% - 20%, more details on this page:
https://hackmd.io/@jimmygchen/SJuVpJL3j
The above testing is done on Goerli (as I don't currently have hardware for Mainnet), I'm guessing the differences are likely to be bigger on mainnet due to block size.
### TODOs
- [x] Experiment with processing multiple batches per slot. (need to think about how to do this for different slot durations)
- [x] Add option to disable rate-limiting, enabed by default.
- [x] (No longer required now we're reusing the reprocessing queue) Complete the `backfill_scheduler` task when backfill sync is completed or not required
## Issue Addressed
NA
## Proposed Changes
- Implements https://github.com/ethereum/consensus-specs/pull/3290/
- Bumps `ef-tests` to [v1.3.0-rc.4](https://github.com/ethereum/consensus-spec-tests/releases/tag/v1.3.0-rc.4).
The `CountRealizedFull` concept has been removed and the `--count-unrealized-full` and `--count-unrealized` BN flags now do nothing but log a `WARN` when used.
## Database Migration Debt
This PR removes the `best_justified_checkpoint` from fork choice. This field is persisted on-disk and the correct way to go about this would be to make a DB migration to remove the field. However, in this PR I've simply stubbed out the value with a junk value. I've taken this approach because if we're going to do a DB migration I'd love to remove the `Option`s around the justified and finalized checkpoints on `ProtoNode` whilst we're at it. Those options were added in #2822 which was included in Lighthouse v2.1.0. The options were only put there to handle the migration and they've been set to `Some` ever since v2.1.0. There's no reason to keep them as options anymore.
I started adding the DB migration to this branch but I started to feel like I was bloating this rather critical PR with nice-to-haves. I've kept the partially-complete migration [over in my repo](https://github.com/paulhauner/lighthouse/tree/fc-pr-18-migration) so we can pick it up after this PR is merged.
## Issue Addressed
Add support for ipv6 and dual stack in lighthouse.
## Proposed Changes
From an user perspective, now setting an ipv6 address, optionally configuring the ports should feel exactly the same as using an ipv4 address. If listening over both ipv4 and ipv6 then the user needs to:
- use the `--listen-address` two times (ipv4 and ipv6 addresses)
- `--port6` becomes then required
- `--discovery-port6` can now be used to additionally configure the ipv6 udp port
### Rough list of code changes
- Discovery:
- Table filter and ip mode set to match the listening config.
- Ipv6 address, tcp port and udp port set in the ENR builder
- Reported addresses now check which tcp port to give to libp2p
- LH Network Service:
- Can listen over Ipv6, Ipv4, or both. This uses two sockets. Using mapped addresses is disabled from libp2p and it's the most compatible option.
- NetworkGlobals:
- No longer stores udp port since was not used at all. Instead, stores the Ipv4 and Ipv6 TCP ports.
- NetworkConfig:
- Update names to make it clear that previous udp and tcp ports in ENR were Ipv4
- Add fields to configure Ipv6 udp and tcp ports in the ENR
- Include advertised enr Ipv6 address.
- Add type to model Listening address that's either Ipv4, Ipv6 or both. A listening address includes the ip, udp port and tcp port.
- UPnP:
- Kept only for ipv4
- Cli flags:
- `--listen-addresses` now can take up to two values
- `--port` will apply to ipv4 or ipv6 if only one listening address is given. If two listening addresses are given it will apply only to Ipv4.
- `--port6` New flag required when listening over ipv4 and ipv6 that applies exclusively to Ipv6.
- `--discovery-port` will now apply to ipv4 and ipv6 if only one listening address is given.
- `--discovery-port6` New flag to configure the individual udp port of ipv6 if listening over both ipv4 and ipv6.
- `--enr-udp-port` Updated docs to specify that it only applies to ipv4. This is an old behaviour.
- `--enr-udp6-port` Added to configure the enr udp6 field.
- `--enr-tcp-port` Updated docs to specify that it only applies to ipv4. This is an old behaviour.
- `--enr-tcp6-port` Added to configure the enr tcp6 field.
- `--enr-addresses` now can take two values.
- `--enr-match` updated behaviour.
- Common:
- rename `unused_port` functions to specify that they are over ipv4.
- add functions to get unused ports over ipv6.
- Testing binaries
- Updated code to reflect network config changes and unused_port changes.
## Additional Info
TODOs:
- use two sockets in discovery. I'll get back to this and it's on https://github.com/sigp/discv5/pull/160
- lcli allow listening over two sockets in generate_bootnodes_enr
- add at least one smoke flag for ipv6 (I have tested this and works for me)
- update the book
## Proposed Changes
Two tiny updates to satisfy Clippy 1.68
Plus refactoring of the `http_api` into less complex types so the compiler can chew and digest them more easily.
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
NA
## Proposed Changes
As discovered in #4034, Lighthouse is not accepting `latest_valid_hash == None` in an `INVALID` response to `newPayload`. The `null`/`None` response *was* illegal at one point, however it was added in https://github.com/ethereum/execution-apis/pull/254.
This PR brings Lighthouse in line with the standard and should fix the root cause of what #4034 patched around.
## Additional Info
NA
## Proposed Changes
Remove built-in support for Ropsten and Kiln via the `--network` flag. Both testnets are long dead and deprecated.
This shaves about 30MiB off the binary size, from 135MiB to 103MiB (maxperf), or 165MiB to 135MiB (release).
## Issue Addressed
Cleans up all the remnants of 4844 in capella. This makes sure when 4844 is reviewed there is nothing we are missing because it got included here
## Proposed Changes
drop a bomb on every 4844 thing
## Additional Info
Merge process I did (locally) is as follows:
- squash merge to produce one commit
- in new branch off unstable with the squashed commit create a `git revert HEAD` commit
- merge that new branch onto 4844 with `--strategy ours`
- compare local 4844 to remote 4844 and make sure the diff is empty
- enjoy
Co-authored-by: Paul Hauner <paul@paulhauner.com>
## Issue Addressed
NA
## Proposed Changes
Updates our `ef_tests` to use: https://github.com/ethereum/consensus-specs/releases/tag/v1.3.0-rc.3
This required:
- Skipping a `merkle_proof_validity` test (see #4022)
- Account for the `eip4844` tests changing name to `deneb`
- My IDE did some Python linting during this change. It seemed simple and nice so I left it there.
## Additional Info
NA
## Proposed Changes
* Bump Go from 1.17 to 1.20. The latest Geth release v1.11.0 requires 1.18 minimum.
* Prevent a cache miss during payload building by using the right fee recipient. This prevents Geth v1.11.0 from building a block with 0 transactions. The payload building mechanism is overhauled in the new Geth to improve the payload every 2s, and the tests were failing because we were falling back on a `getPayload` call with no lookahead due to `get_payload_id` cache miss caused by the mismatched fee recipient. Alternatively we could hack the tests to send `proposer_preparation_data`, but I think the static fee recipient is simpler for now.
* Add support for optionally enabling Lighthouse logs in the integration tests. Enable using `cargo run --release --features logging/test_logger`. This was very useful for debugging.
## Proposed Changes
Decouple the stdout and logfile formats by adding the `--logfile-format` CLI flag.
This behaves identically to the existing `--log-format` flag, but instead will only affect the logs written to the logfile.
The `--log-format` flag will no longer have any effect on the contents of the logfile.
## Additional Info
This avoids being a breaking change by causing `logfile-format` to default to the value of `--log-format` if it is not provided.
This means that users who were previously relying on being able to use a JSON formatted logfile will be able to continue to use `--log-format JSON`.
Users who want to use JSON on stdout and default logs in the logfile, will need to pass the following flags: `--log-format JSON --logfile-format DEFAULT`
* add historical summaries
* fix tree hash caching, disable the sanity slots test with fake crypto
* add ssz static HistoricalSummary
* only store historical summaries after capella
* Teach `UpdatePattern` about Capella
* Tidy EF tests
* Clippy
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
Recent discussions with other client devs about optimistic sync have revealed a conceptual issue with the optimisation implemented in #3738. In designing that feature I failed to consider that the execution node checks the `blockHash` of the execution payload before responding with `SYNCING`, and that omitting this check entirely results in a degradation of the full node's validation. A node omitting the `blockHash` checks could be tricked by a supermajority of validators into following an invalid chain, something which is ordinarily impossible.
## Proposed Changes
I've added verification of the `payload.block_hash` in Lighthouse. In case of failure we log a warning and fall back to verifying the payload with the execution client.
I've used our existing dependency on `ethers_core` for RLP support, and a new dependency on Parity's `triehash` crate for the Merkle patricia trie. Although the `triehash` crate is currently unmaintained it seems like our best option at the moment (it is also used by Reth, and requires vastly less boilerplate than Parity's generic `trie-root` library).
Block hash verification is pretty quick, about 500us per block on my machine (mainnet).
The optimistic finalized sync feature can be disabled using `--disable-optimistic-finalized-sync` which forces full verification with the EL.
## Additional Info
This PR also introduces a new dependency on our [`metastruct`](https://github.com/sigp/metastruct) library, which was perfectly suited to the RLP serialization method. There will likely be changes as `metastruct` grows, but I think this is a good way to start dogfooding it.
I took inspiration from some Parity and Reth code while writing this, and have preserved the relevant license headers on the files containing code that was copied and modified.
