* Fix an incorrect assertion when the block locator is at the tip
This might have been triggered by receiving block hash gossips
from the new Zebra code.
* Add missing tests for zebra-state requests and responses
Specifically:
* `BlockLocator` (populated state only)
* `FindBlockHashes`
* `FindBlockHeaders`
* Test `FindBlock*` before and after the current block
* Add a specific test for bug #2789
* Refactor collect_best_chain_hashes to avoid manual index calculations
* Reword a comment
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>
* Use `TipAction::Reset` for initialization and out-of-order blocks
Needs tests for:
- cloning a `ChainTipChange` resets the cloned instance
- skipped updates reset the cloned instance
- changing forks resets the cloned instance
* Use `TipAction::Reset` for network upgrade activation blocks
* Use an `if` expression
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Another if expression
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Rename ChainTipReceiver to CurrentChainTip
`fastmod ChainTipReceiver CurrentChainTip zebra*`
* Update chain tip documentation and variable names
* Basic chain tip change implementation, without resets
Also includes the following name changes:
```
fastmod CurrentChainTip LatestChainTip zebra*
fastmod chain_tip_receiver latest_chain_tip zebra*
```
* Clarify the difference between `LatestChainTip` and `ChainTipChange`
* Re-use finalized blocks for chain tip updates
This avoids serializing and deserializing blocks from the finalized state.
* Optimise tip sender equality checks
* Re-use precalculated block hashes and heights for chain tip updates
* Add chain tip mined transaction IDs
* Doc comment typo
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Always prefer the non-finalized tip in ChainTipSender
This significantly simplifies the internal implementation of ChainTipSender.
Also make the methods and types a bit more generic.
* Update ChainTipSender with blocks, not heights
Also fix a bug where queued non-finalized blocks would clear the chain tip.
* Provide a best tip hash in ChainTip receivers
* Skip finalized blocks once the non-finalized state is active
* Add tip hash and NoChainTip tests
* Remove a redundant finalized tip update
* Skip `None` updates to the finalized tip
The finalized and non-finalized tips never update to `None`
once they have added at least one block.
* Stop committing finalized queued blocks if there is an error
Also return the highest committed queued block.
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Rename BestTipHeight so it can be generalised to ChainTipSender
`fastmod BestTipHeight ChainTipSender zebra*`
For senders:
`fastmod best_tip_height chain_tip_sender zebra*`
For receivers:
`fastmod best_tip_height chain_tip_receiver zebra*`
* Rename best_tip_height module to chain_tip
* Wrap the chain tip watch channel in a ChainTipReceiver type
* Create a ChainTip trait to avoid tricky crate dependencies
And add convenience impls for optional and empty chain tips.
* Use the ChainTip trait in zebra-network
* Replace `Option<ChainTip>` with `NoChainTip`
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Simplify state service initialization in test
Use the test helper function to remove redundant code.
* Create `BestTipHeight` helper type
This type abstracts away the calculation of the best tip height based on
the finalized block height and the best non-finalized chain's tip.
* Add `best_tip_height` field to `StateService`
The receiver endpoint is currently ignored.
* Return receiver endpoint from service constructor
Make it available so that the best tip height can be watched.
* Update finalized height after finalizing blocks
After blocks from the queue are finalized and committed to disk, update
the finalized block height.
* Update best non-finalized height after validation
Update the value of the best non-finalized chain tip block height after
a new block is committed to the non-finalized state.
* Update finalized height after loading from disk
When `FinalizedState` is first created, it loads the state from
persistent storage, and the finalized tip height is updated. Therefore,
the `best_tip_height` must be notified of the initial value.
* Update the finalized height on checkpoint commit
When a checkpointed block is commited, it bypasses the non-finalized
state, so there's an extra place where the finalized height has to be
updated.
* Add `best_tip_height` to `Handshake` service
It can be configured using the `Builder::with_best_tip_height`. It's
currently not used, but it will be used to determine if a connection to
a remote peer should be rejected or not based on that peer's protocol
version.
* Require best tip height to init. `zebra_network`
Without it the handshake service can't properly enforce the minimum
network protocol version from peers. Zebrad obtains the best tip height
endpoint from `zebra_state`, and the test vectors simply use a dummy
endpoint that's fixed at the genesis height.
* Pass `best_tip_height` to proto. ver. negotiation
The protocol version negotiation code will reject connections to peers
if they are using an old protocol version. An old version is determined
based on the current known best chain tip height.
* Handle an optional height in `Version`
Fallback to the genesis height in `None` is specified.
* Reject connections to peers on old proto. versions
Avoid connecting to peers that are on protocol versions that don't
recognize a network update.
* Document why peers on old versions are rejected
Describe why it's a security issue above the check.
* Test if `BestTipHeight` starts with `None`
Check if initially there is no best tip height.
* Test if best tip height is max. of latest values
After applying a list of random updates where each one either sets the
finalized height or the non-finalized height, check that the best tip
height is the maximum of the most recently set finalized height and the
most recently set non-finalized height.
* Add `queue_and_commit_finalized` method
A small refactor to make testing easier. The handling of requests for
committing non-finalized and finalized blocks is now more consistent.
* Add `assert_block_can_be_validated` helper
Refactor to move into a separate method some assertions that are done
before a block is validated. This is to allow moving these assertions
more easily to simplify testing.
* Remove redundant PoW block assertion
It's also checked in
`zebra_state::service::check::block_is_contextually_valid`, and it was
getting in the way of tests that received a gossiped block before
finalizing enough blocks.
* Create a test strategy for test vector chain
Splits a chain loaded from the test vectors in two parts, containing the
blocks to finalize and the blocks to keep in the non-finalized state.
* Test committing blocks update best tip height
Create a mock blockchain state, with a chain of finalized blocks and a
chain of non-finalized blocks. Commit all the blocks appropriately, and
verify that the best tip height is updated.
Co-authored-by: teor <teor@riseup.net>
* Add ZIP-221 history tree to finalized state
* Improve error / panic handling; improve documentation
* Return error again when preparing batch, fix expect messages
* Fix bug when pushing the Heartwood actiation block to the history tree
* Re-increase database version since it was increased in main
Co-authored-by: teor <teor@riseup.net>
* Make legacy chain limit clearer
That way, it doesn't get confused with the coinbase maturity limit.
* Allow 1-5 transactions in each generated block, not always 5
* rustfmt
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>
* Validate transparent coinbase output maturity and shielding
- Add a CoinbaseSpendRestriction enum and Transaction method
- Validate transparent coinbase spends in non-finalized chains
* Don't use genesis created UTXOs for spends in generated block chains
* Refactor out a new_transaction_ordered_outputs function
* Add Transaction::outputs_mut for tests
* Generate valid transparent spends in arbitrary block chains
* When generating blocks, fixup the block contents, then the block hash
* Test that generated chains contain at least one transparent spend
* Make generated chains long enough for reliable tests
* Add transparent and shielded input and output methods to Transaction
* Split chain generation into 3 functions
* Test that unshielded and immature transparent coinbase spends fail
* Comment punctuation
* Clarify a comment
* Clarify probability calculation
* Test that shielded mature coinbase output spends succeed
* Create a `zebra_state::init_test` helper function
This function will be used as a replacement for `zebra_state::init`
inside tests. It's a simpler alternative because it can ignore any
details that aren't relevant for tests.
* Use `init_test` inside `zebra-state` tests
Update usages of `init` to use `init_test` instead, which simplifies
most cases.
* Use `zebra_state::init_test` in `zebra-consensus`
Replace usages of `zebra_state::init` with the new helper function. This
simplifies the code a bit.
* Add `proptest-impl` feature to `zebra-state`
This prepares the `zebra-state` crate to be able to export some
test-specific helper types and functions.
* Add `arbitrary` module to `zebra-state` root
A separate module to contain the `Prepare` trait, since it's required by
some prop-test strategies and therefore can't be in the `tests` module.
* Replace usages of `tests::Prepare`
Use the same trait but placed in a new module that's accessible based on
the feature flag.
* Remove old `Prepare` trait
It was obsoleted by the new copy in the `arbitrary` module.
* Make `StateService` crate-accessible
Prepare for it to be accessible in some test modules.
* Refactor strategy function import
Import the function directly, instead of just its containing module.
* Move some strategy functions to `tests::setup`
Create a new module for the strategy functions that are only used
internally.
Co-authored-by: teor <teor@riseup.net>
* Add an OrderedUtxo type for validation of spends within a block
This change allows us to check that transparent spends use outputs from
earlier in their block. (But we don't actually do that check yet.)
We need to keep the order of UTXOs when we're contextually verifying
each new block that is added to a chain. But the block order is
irrelevant for UTXOs stored in the state.
* Take ownership in utxos_from_ordered_utxos
* Delete a confusing comment
* Document Ord for Chain and Proof of Work
* Create a NonFinalizedState::new method
And add some debug and clone derives.
* Test that block rejection restores internal non-finalized chain states
As part of this change, add `eq_internal_state` methods,
and proptests for them.
* Check that the chain's nullifiers are not modified on error
* Clarify a test description
* Refactor loop for readability
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Fix a variable name typo
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Reject duplicate sprout nullifiers in the state
* Improve docs and error messages
* Clarify "must be present" assert logs
* Move nullifier checks to their own module
Also:
* make non-finalized nullifier checks and errors generic over
sprout, sapling, and orchard
* create and update module and function documentation
* Fix a block type name in docs
* Move state assertions or skip them during tests
These changes enable state testing, while still asserting in production.
* Add sprout duplicate nullifier tests
* Improve comments
* Set value balance to 0 to pass future chain value pool checks
* Test finalized state in sprout nullifier accept test
* Replace assert with expect
* Improve assertion messages
* Use the block verifier and non-finalized state in the cached state tests
This substantially increases test coverage.
Previously, the cached state tests were configured with
`checkpoint_sync = true`, which only uses the checkpoint
verifier and the finalized state.
* Log the source of blocks in commit_finalized_direct
This lets us check that we're actually testing the non-finalized state
and block verifier in the cached state tests.
It also improves diagnostics for state errors.
* Fail cached state tests if they're using incorrect heights or configs
This makes sure that the cached state tests actually test the transition
from checkpoint to block verification, and the non-finalized state.
* Skip invalid legacy chain check test cases
Add proptest seeds for the failing test.
And improve some unclear documentation.
* Fix the legacy chain test blocks order
Also fix unclear documentation that might have led to this bug.
* add legacy chain check and tests
* improve has_network_upgrade check
* add docs to legacy_chain_check()
* change arbitrary module structure
* change the panic message
* move legacy chain acceptance into existing tests
* use a reduced_branch_id_strategy()
* add docs to strategy function
* add argument to check for legacy chain into sync_until()
Use `ServiceExt::oneshot` to perform state requests.
Explain that `ServiceExt::call_all` calls `poll_ready` internally.
Document a state service invariant imposed by `ServiceExt::call_all`.
Zcashd will blindly request more block headers as long as it got 160
block headers in response to a previous query, EVEN IF THOSE HEADERS ARE
ALREADY KNOWN. To dodge this behavior, return slightly fewer than the
maximum, to get it to go away.
0ccc885371/src/main.cpp (L6274-L6280)
Without this change, communication between a partially-synced `zebrad`
and fully-synced `zcashd` looked like this:
1. `zebrad` connects to `zcashd`, which sends an initial `getheaders`
request;
2. `zebrad` correctly computes the intersection of the provided block
locator with the node's current chain and returns 160 following
headers;
3. `zcashd` does not check whether it already has those headers and
assumes that any provided headers are new and re-validates them;
4. `zcashd` assumes that because `zebrad` responded with 160 headers,
the `zebrad` node is ahead of it, and requests the next 160 headers.
5. Because block locators are sparse, the intersection between the
`zcashd` and `zebrad` chains is likely well behind the `zebrad` tip,
so this process continues for thousands of blocks.
To avoid this problem, we return slightly fewer than the protocol
maximum (158 rather than 160, to guard against off-by-one errors in
zcashd). This does not interfere with use of the returned headers by
peers that check the headers, but does prevent `zcashd` from trying to
download thousands of block headers it already has.
This problem does not occur in the `zcashd<->zcashd` case only because
`zcashd` does not respond to `getheaders` messages while it is syncing.
However, implementing this behavior in Zebra would be more complicated,
because we don't have a distinct "initial block sync" state (we do
poll-based syncing continuously) and we don't have shared global
variables to modify to set that state.
Relevant links (thanks @str4d):
- The PR that introduced this behavior: https://github.com/bitcoin/bitcoin/pull/4468/files#r17026905
- https://github.com/bitcoin/bitcoin/issues/6861
- https://github.com/bitcoin/bitcoin/issues/6755
- https://github.com/bitcoin/bitcoin/pull/8306#issuecomment-614916454
We modeled a Bitcoin `headers` message as being a list of block headers.
However, the actual data structure is slightly different: it's a list of (block
header, transaction count) pairs. This caused zcashd to reject our headers
messages.
To fix this, introduce a new `CountedHeader` struct with a `block::Header` and
transaction count `usize`, then thread it through the inbound service and the
state.
I tested this locally by running Zebra with these changes and inspecting a
trace-level log of the span of a peer connection that requested a nontrivial
headers packet from us, and verified that it did not reject our message.
* implement inbound `FindBlocks`
* Handle inbound peer FindHeaders requests
* handle request before having any chain tip
* Split `find_chain_hashes` into smaller functions
Add a `max_len` argument to support `FindHeaders` requests.
Rewrite the hash collection code to use heights, so we can handle the
`stop` hash and "no intersection" cases correctly.
* Split state height functions into "any chain" and "best chain"
* Rename the best chain block method to `best_block`
* Move fmt utilities to zebra_chain::fmt
* Summarise Debug for some Message variants
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Jane Lusby <jlusby42@gmail.com>
This commit changes the state system and database format to track the
provenance of UTXOs, in addition to the outputs themselves.
Specifically, it tracks the following additional metadata:
- the height at which the UTXO was created;
- whether or not the UTXO was created from a coinbase transaction or
not.
This metadata will allow us to:
- check the coinbase maturity consensus rule;
- check the coinbase inputs => no transparent outputs rule;
- implement lookup of transactions by utxo (using the height to find the
block and then scanning the block) for a future RPC mechanism.
Closes#1342
This provides useful and not too noisy output at INFO level. We do an
info-level message on every block commit instead of trying to do one
message every N blocks, because this is useful both for initial block
sync as well as continuous state updates on new blocks.
This change introduces two new types:
- `PreparedBlock`, representing a block which has undergone semantic
validation and has been prepared for contextual validation;
- `FinalizedBlock`, representing a block which is ready to be finalized
immediately;
and changes the `Request::CommitBlock`,`Request::CommitFinalizedBlock`
variants to use these types instead of their previous fields.
This change solves the problem of passing data between semantic
validation and contextual validation, and cleans up the state code by
allowing it to pass around a bundle of data. Previously, the state code
just passed around an `Arc<Block>`, which forced it to needlessly
recompute block hashes and other data, and was incompatible with the
already-known but not-yet-implemented data transfer requirements, namely
passing in the Sprout and Sapling anchors computed during contextual
validation.
This commit propagates the `PreparedBlock` and `FinalizedBlock` types
through the state code but only uses their data opportunistically, e.g.,
changing .hash() computations to use the precomputed hash. In the
future, these structures can be extended to pass data through the
verification pipeline for reuse as appropriate. For instance, these
changes allow the sprout and sapling anchors to be propagated through
the state.
The behavior of a request for a UTXO from a previous block depends on
whether that block has already been submitted to the state, or not:
* if it has, the state should be able to find it and answer immediately.
* if it has not, the state should see it in a later request.
However, the previous code only checked committed blocks, not queued
blocks, so if the block containing the UTXO had already arrived but had
not been committed, it would never be scanned.
This patch fixes the problem but is a bad solution, duplicating
computation between the block verifier and the state. A better fix
follows in the next commit.
Previously, this function was instrumented with a span containing the
parent hash that was the entry to the function. But it doesn't make
sense to consider the work done by the function as happening in the
context of the supplied parent hash (as distinct from the context of the
hash of the newly arrived block, which is already contained in an outer
span), so this adds noise without conveying extra context.
Instead, use events that occur within the context of the existing spans.
Here the span is added to the body of the `Service::call`
implementation, not to the futures it returns, because the state service
does all of the work synchronously in `call` rather than in the futures
it returns.
The service is skipped as a span field. We could either include or
exclude the request itself. It would be useful, but the request body
can be very large. Instead, we make two spans, one at info level and
one at trace level, and filter that way.
This change explicitly documents cancellation contracts for our Tower services,
and tries to correct a bug in the implementation of the CheckpointVerifier,
which duplicates information from the state service but did not ensure that it
would be kept in sync.
This change has two benefits:
* reduces conflicts with the sled refactor and any replacement
* allows the function to be called independently for testing
`check_contextual_validity` mistakenly used the new block's hash to try
to get the parent block from the state. This caused a panic, because the
new block isn't in the state yet.
Use `StateService::chain` to get the parent block, because we'll be
using `chain` for difficulty adjustment contextual verification anyway.
* Add internal iterator API for accessing relevant chain blocks
* get blocks from all chains in non_finalized state
* Impl FusedIterator for service::Iter
* impl ExactSizedIterator for service::Iter
* let size_hint find heights in side chains
Co-authored-by: teor <teor@riseup.net>
* Add transcript test for requests while state is empty
* Add happy path test for each query once the state is populated
* let populate logic handle out of order blocks
* make service use both finalized and non-finalized state
* Document new functions
* add documentation to sled fns
* cleanup tip fn now that errors are gone
* rename height unwrap fn
## Motivation
The zebra-state service needs to be able to handle duplicate blocks.
## Solution
This implements changes already outlined by [The State
RFC](https://zebra.zfnd.org/dev/rfcs/0005-state-updates.html). We check for
successfully committed blocks first, since interacting with the queued blocks
struct at this point just complicates the implimentation. If the block has not
already been committed we then check if the block has already been queued, if
not we handle the block normally (normally here being the bit we already had
implemented).
## Documentation Changes
- [x] Update the state RFC to match the ways this fix departs from the design
- the main thing is that I switched the order of checking for duplicates
- [x] ~~Add newly added functions to the state rfc~~ Decided not to do this because they're minor getters that don't influence the rest of the design and aren't exposed as part of the API
- [x] Document newly added functions inline
## Testing
## Related Issues
- fixes https://github.com/ZcashFoundation/zebra/issues/1182
- tracking issue https://github.com/ZcashFoundation/zebra/issues/1049
Co-authored-by: teor <teor@riseup.net>
We already use an actor model for the state service, so we get an
ordered sequence of state queries by message-passing. Instead of
performing reads in the futures we return, this commit performs them
synchronously. This means that all sled access is done from the same
task, which
(1) might reduce contention
(2) allows us to avoid using sled transactions when writing to the
state.
Co-authored-by: Jane Lusby <jane@zfnd.org>
Co-authored-by: Jane Lusby <jane@zfnd.org>
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
There's no reason to return a pre-Buffer'd service (there's no need for
internal access to the state service, as in zebra-network), but wrapping
it internally removes control of the buffer size from the caller.
This commit begins the process of integrating `zcash_script` with the rest of the system for verifying scripts while syncing the block chain. It does so by adding the necessary support for looking up UTXOs from the state service and implements the first parts of the `script::Verifier` for looking up the necessary UTXOs in the state and then generating the necessary call to `zcash_script` to verify the script itself.
Co-authored-by: teor <teor@riseup.net>
* implement most of the chain functions
* implement fork
* fix outpoint handling in Chain struct
* update expect for work
* split utxo into two sets
* update the Chain definition
* remove allow attribute in zebra-state/lib.rs
* merge ChainSet type into MemoryState
* Add error messages to asserts
* export proptest impls for use in downstream crates
* add testjob for disabled feature in zebra-chain
* try to fix github actions syntax
* add module doc comment
* update RFC for utxos
* add missing header
* working proptest for Chain
* propagate back results over channel
* Start updating RFC to match changes
* implement queued block pruning
* and now it syncs wooo!
* remove empty modules
* setup config for proptests
* re-enable missing_docs lint
* update RFC to match changes in impl
* add documentation
* use more explicit variable names
* Begin work on RFC5 implementation
* I think this is necessary
* holy shit supertrait implemented via subtrait
* implement most of the chain functions
* change to slightly better name
* implement fork
* fix outpoint handling in Chain struct
* update expect for work
* resolve review comment
* split utxo into two sets
* update the Chain definition
* just a little more
* update comment
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* apply changes from code review
* remove allow attribute in zebra-state/lib.rs
* Update zebra-state/src/memory_state.rs
Co-authored-by: teor <teor@riseup.net>
* merge ChainSet type into MemoryState
* rename state impl types
* Add error messages to asserts
* add module doc comment
* update RFC for utxos
* add missing header
Co-authored-by: teor <teor@riseup.net>
Using a Buffer with size 1 is a footgun because it allows only one
sender to call poll_ready at a time. This is usually undesirable
because it means that a task or service that calls poll_ready but only
makes a service call later (potentially much later) will block all other
callers.
The new `StateService` type wraps a `SledState` and a `MemoryState`.
This will allow the sled-related code and the in-memory code to be kept
separate, with the top-level `StateService` making method calls to one
or the other, as appropriate.
This commit removes the existing Service impl for the SledService. This
saves time in refactoring, and the code needs to be rewritten
anyways so there's no loss to deleting it now.
teor
Conrado Gouvea
Janito Vaqueiro Ferreira Filho
Alfredo Garcia
Henry de Valence
Jane Lusby
Jane Lusby